use std::sync::Arc;

use pdfcraft_cos::{Document, Object, SaveOptions, write_incremental};

use super::*;

/// One page with a form: text fields (plain, multiline, comb, password, read-only, nested),
/// a check box with appearances, one without, a radio group, a combo and a multi-select list,
/// and a push button.
fn fixture() -> Document {
    let objs: Vec<String> = vec![
        "<< /Type /Catalog /Pages 2 0 R /AcroForm 4 0 R >>".into(),                                             // 1
        "<< /Type /Pages /Kids [3 0 R] /Count 1 /MediaBox [0 0 600 800] >>".into(),                              // 2
        "<< /Type /Page /Parent 2 0 R /Annots [10 0 R 11 0 R 12 0 R 13 0 R 14 0 R 16 0 R 17 0 R 21 0 R 22 0 R 23 0 R 24 0 R 25 0 R 26 0 R] >>".into(), // 3
        "<< /Fields [10 0 R 11 0 R 12 0 R 13 0 R 14 0 R 15 0 R 17 0 R 20 0 R 23 0 R 24 0 R 25 0 R 26 0 R] /DA (/Helv 0 Tf 0 g) /DR << /Font << /Helv 5 0 R /ZaDb 6 0 R >> >> >>".into(), // 4
        "<< /Type /Font /Subtype /Type1 /BaseFont /Helvetica /Encoding /WinAnsiEncoding >>".into(),               // 5
        "<< /Type /Font /Subtype /Type1 /BaseFont /ZapfDingbats >>".into(),                                      // 6
        "<< /Length 0 >>\nstream\n\nendstream".into(),                                                            // 7 (empty appearance)
        "<< /Length 0 >>\nstream\n\nendstream".into(),                                                            // 8
        "null".into(),                                                                                            // 9
        "<< /Type /Annot /Subtype /Widget /FT /Tx /T (name) /Rect [50 700 250 720] /P 3 0 R /V (Ada) /DV (Ada) /MK << /BG [1 1 0.9] /BC [0 0 0] >> >>".into(), // 10
        "<< /Type /Annot /Subtype /Widget /FT /Tx /T (notes) /Ff 4096 /DA (/Helv 10 Tf 0 0 1 rg) /Rect [50 600 250 680] /P 3 0 R >>".into(), // 11
        "<< /Type /Annot /Subtype /Widget /FT /Tx /T (zip) /Ff 16777216 /MaxLen 5 /Rect [50 560 150 580] /P 3 0 R >>".into(), // 12
        "<< /Type /Annot /Subtype /Widget /FT /Tx /T (pin) /Ff 8192 /Rect [50 530 150 550] /P 3 0 R >>".into(), // 13
        "<< /Type /Annot /Subtype /Widget /FT /Tx /T (id) /Ff 1 /V (A-1) /Rect [50 500 150 520] /P 3 0 R >>".into(), // 14
        "<< /T (address) /Kids [16 0 R] >>".into(),                                                               // 15
        "<< /Type /Annot /Subtype /Widget /FT /Tx /T (city) /Parent 15 0 R /Q 1 /Rect [50 470 250 490] /P 3 0 R >>".into(), // 16
        "<< /Type /Annot /Subtype /Widget /FT /Btn /T (agree) /V /Off /AS /Off /Rect [300 700 315 715] /P 3 0 R /AP << /N << /Yes 7 0 R /Off 8 0 R >> >> >>".into(), // 17
        "null".into(),                                                                                            // 18
        "null".into(),                                                                                            // 19
        "<< /FT /Btn /T (size) /Ff 49152 /V /Off /DV /S /Kids [21 0 R 22 0 R] >>".into(),                        // 20 radio, NoToggleToOff
        "<< /Type /Annot /Subtype /Widget /Parent 20 0 R /AS /Off /Rect [300 650 315 665] /P 3 0 R /AP << /N << /S 7 0 R /Off 8 0 R >> >> >>".into(), // 21
        "<< /Type /Annot /Subtype /Widget /Parent 20 0 R /AS /Off /Rect [330 650 345 665] /P 3 0 R /AP << /N << /L 7 0 R /Off 8 0 R >> >> >>".into(), // 22
        "<< /Type /Annot /Subtype /Widget /FT /Ch /T (country) /Ff 131072 /Opt [[(ca) (Canada)] [(fr) (France)]] /Rect [300 600 450 620] /P 3 0 R >>".into(), // 23
        "<< /Type /Annot /Subtype /Widget /FT /Ch /T (toppings) /Ff 2097152 /Opt [(Cheese) (Ham) (Olives)] /Rect [300 500 450 580] /P 3 0 R >>".into(), // 24
        "<< /Type /Annot /Subtype /Widget /FT /Btn /T (go) /Ff 65536 /Rect [300 450 380 470] /P 3 0 R >>".into(), // 25
        "<< /Type /Annot /Subtype /Widget /FT /Btn /T (bare) /Rect [400 700 415 715] /P 3 0 R /Foo (kept) >>".into(), // 26 check box without AP
    ];
    document(&objs)
}

/// A PDF of the given objects (numbered from 1).
fn document(objs: &[String]) -> Document {
    let mut out = b"%PDF-1.7\n".to_vec();
    let mut offsets = Vec::new();
    for (i, o) in objs.iter().enumerate() {
        offsets.push(out.len());
        out.extend_from_slice(format!("{} 0 obj\n{o}\nendobj\n", i + 1).as_bytes());
    }
    let xref = out.len();
    out.extend_from_slice(format!("xref\n0 {}\n0000000000 65535 f \n", objs.len() + 1).as_bytes());
    for o in offsets {
        out.extend_from_slice(format!("{o:010} 00000 n \n").as_bytes());
    }
    out.extend_from_slice(format!("trailer\n<< /Size {} /Root 1 0 R >>\nstartxref\n{xref}\n%%EOF\n", objs.len() + 1).as_bytes());
    Document::open(Arc::new(out)).expect("opens")
}

fn reopen(doc: &Document) -> Document {
    let bytes = write_incremental(doc, &SaveOptions::default()).expect("writes");
    hayro_syntax::Pdf::new(bytes.clone()).expect("hayro-syntax parses the output");
    Document::open(Arc::new(bytes)).expect("reopens")
}

fn field<'a>(all: &'a [Field], name: &str) -> &'a Field {
    all.iter().find(|f| f.name == name).unwrap_or_else(|| panic!("no field {name}"))
}

fn ap(doc: &Document, w: &Widget) -> String {
    let wd = doc.get(w.obj).as_dict().cloned().unwrap();
    let n = wd.get(b"AP").unwrap().as_dict().unwrap().reference(b"N").expect("normal appearance stream");
    let Object::Stream(s) = &*doc.get(n) else { panic!() };
    String::from_utf8_lossy(&s.decoded().unwrap()).into_owned()
}

#[test]
fn the_field_tree_is_read_with_inheritance() {
    let doc = fixture();
    let all = fields(&doc);
    let names: Vec<&str> = all.iter().map(|f| f.name.as_str()).collect();
    assert_eq!(names, ["name", "notes", "zip", "pin", "id", "address.city", "agree", "size", "country", "toppings", "go", "bare"]);
    let name = field(&all, "name");
    assert_eq!((name.kind, name.value.as_slice(), name.da.as_str()), (FieldKind::Text, &["Ada".to_string()][..], "/Helv 0 Tf 0 g"));
    assert_eq!(name.widgets[0].page, Some(0));
    assert_eq!(field(&all, "zip").max_len, Some(5));
    assert!(field(&all, "id").read_only());
    let size = field(&all, "size");
    assert_eq!(size.kind, FieldKind::Radio);
    assert_eq!(size.widgets.iter().map(|w| w.on_state.clone().unwrap()).collect::<Vec<_>>(), ["S", "L"]);
    assert!(size.value.is_empty(), "/Off is no value");
    assert_eq!(size.default, ["S"]);
    assert_eq!(field(&all, "country").options, [("ca".into(), "Canada".into()), ("fr".into(), "France".into())]);
    assert_eq!(field(&all, "toppings").kind, FieldKind::List);
    assert_eq!(field(&all, "go").kind, FieldKind::PushButton);
    assert_eq!(field(&all, "address.city").quadding, 1);
}

/// pdf-lib and other writers give radio groups and check boxes an `/Opt` array and name the on
/// states by position (`/0`, `/1`): the export values select them, as in Acrobat.
#[test]
fn opt_export_values_select_button_states() {
    let objs: Vec<String> = vec![
        "<< /Type /Catalog /Pages 2 0 R /AcroForm 4 0 R >>".into(),                                                // 1
        "<< /Type /Pages /Kids [3 0 R] /Count 1 /MediaBox [0 0 600 800] >>".into(),                                 // 2
        "<< /Type /Page /Parent 2 0 R /Annots [6 0 R 7 0 R 8 0 R] >>".into(),                                       // 3
        "<< /Fields [5 0 R 8 0 R] /DA (/Helv 0 Tf 0 g) >>".into(),                                                 // 4
        "<< /FT /Btn /T (ship) /Ff 49152 /Opt [(Post) (Pick-up)] /V /Off /Kids [6 0 R 7 0 R] >>".into(),            // 5 radio
        "<< /Type /Annot /Subtype /Widget /Parent 5 0 R /AS /Off /Rect [100 700 115 715] /P 3 0 R /AP << /N << /0 9 0 R /Off 10 0 R >> >> >>".into(), // 6
        "<< /Type /Annot /Subtype /Widget /Parent 5 0 R /AS /Off /Rect [200 700 215 715] /P 3 0 R /AP << /N << /1 9 0 R /Off 10 0 R >> >> >>".into(), // 7
        "<< /Type /Annot /Subtype /Widget /FT /Btn /T (terms) /Opt [(Accepted)] /V /Off /AS /Off /Rect [100 650 115 665] /P 3 0 R /AP << /N << /0 9 0 R /Off 10 0 R >> >> >>".into(), // 8 check box
        "<< /Length 0 >>\nstream\n\nendstream".into(),                                                              // 9
        "<< /Length 0 >>\nstream\n\nendstream".into(),                                                              // 10
    ];
    let mut doc = document(&objs);
    let all = fields(&doc);
    let ship = field(&all, "ship");
    assert_eq!((0..2).map(|i| ship.export_of(i)).collect::<Vec<_>>(), [Some("Post"), Some("Pick-up")]);
    assert_eq!((ship.state_for("Pick-up"), ship.state_for("1"), ship.state_for("Courier")), (Some("1"), Some("1"), None));
    set_value(&mut doc, "ship", &FieldValue::Radio(Some("Pick-up".into()))).unwrap();
    set_value(&mut doc, "terms", &FieldValue::Text("Accepted".into())).unwrap();
    let mut doc = reopen(&doc);
    let all = fields(&doc);
    let ship = field(&all, "ship");
    assert_eq!(ship.value, ["1"]);
    assert_eq!(ship.export_for_state("1"), "Pick-up");
    assert_eq!(ship.widgets.iter().map(|w| w.state.as_deref()).collect::<Vec<_>>(), [Some("Off"), Some("1")]);
    assert_eq!(field(&all, "terms").value, ["0"]);
    let err = set_value(&mut doc, "ship", &FieldValue::Radio(Some("Courier".into()))).unwrap_err();
    assert!(err.to_string().contains("options: Post, Pick-up"), "{err}");
}

#[test]
fn text_fields_get_new_appearances() {
    let mut doc = fixture();
    set_value(&mut doc, "name", &FieldValue::Text("Grace (Hopper)".into())).unwrap();
    set_value(&mut doc, "notes", &FieldValue::Text("A long note that has to wrap over several lines of the box".into())).unwrap();
    set_value(&mut doc, "zip", &FieldValue::Text("12345".into())).unwrap();
    set_value(&mut doc, "pin", &FieldValue::Text("1234".into())).unwrap();
    set_value(&mut doc, "address.city", &FieldValue::Text("Zürich".into())).unwrap();
    let doc = reopen(&doc);
    let all = fields(&doc);
    assert_eq!(field(&all, "name").value, ["Grace (Hopper)"]);
    let name_ap = ap(&doc, &field(&all, "name").widgets[0]);
    assert!(name_ap.contains("/Tx BMC") && name_ap.contains("EMC"), "{name_ap}");
    assert!(name_ap.contains("(Grace \\(Hopper\\)) Tj"), "{name_ap}");
    assert!(name_ap.contains("1 1 0.9 rg"), "background from /MK: {name_ap}");
    let notes = ap(&doc, &field(&all, "notes").widgets[0]);
    assert!(notes.matches(" Tj").count() >= 2, "wrapped: {notes}");
    assert!(notes.contains("/Helv 10 Tf") && notes.contains("0 0 1 rg"));
    let zip = ap(&doc, &field(&all, "zip").widgets[0]);
    assert_eq!(zip.matches(" Tj").count(), 5, "one cell per character: {zip}");
    let pin = ap(&doc, &field(&all, "pin").widgets[0]);
    assert!(pin.contains("(****) Tj") && !pin.contains("1234"), "{pin}");
    // WinAnsi bytes for non-ASCII text.
    let w = &field(&all, "address.city").widgets[0];
    let n = doc.get(w.obj).as_dict().unwrap().get(b"AP").unwrap().as_dict().unwrap().reference(b"N").unwrap();
    let Object::Stream(s) = &*doc.get(n) else { panic!() };
    let raw = s.decoded().unwrap();
    assert!(raw.windows(8).any(|x| x == b"(Z\xfcrich)"));
}

#[test]
fn japanese_choices_use_the_unicode_cid_font() {
    // A choice field whose /DA names a non-embedded CID font with a predefined Unicode CMap
    // (UniJIS-UTF16-H). Selecting 令 must draw it in that font, not "?" in Helvetica.
    let objs: Vec<String> = vec![
        "<< /Type /Catalog /Pages 2 0 R /AcroForm 4 0 R >>".into(),
        "<< /Type /Pages /Kids [3 0 R] /Count 1 /MediaBox [0 0 600 800] >>".into(),
        "<< /Type /Page /Parent 2 0 R /Annots [8 0 R 9 0 R 10 0 R] >>".into(),
        "<< /Fields [8 0 R 9 0 R 10 0 R] /DA (/Helv 0 Tf 0 g) /DR << /Font << /Helv 5 0 R /HeiseiMin-W3 6 0 R /Emb 7 0 R >> >> >>".into(),
        "<< /Type /Font /Subtype /Type1 /BaseFont /Helvetica /Encoding /WinAnsiEncoding >>".into(),
        "<< /Type /Font /Subtype /Type0 /BaseFont /HeiseiMin-W3 /Encoding /UniJIS-UTF16-H /DescendantFonts [<< /Type /Font /Subtype /CIDFontType0 /BaseFont /HeiseiMin-W3 /CIDSystemInfo << /Registry (Adobe) /Ordering (Japan1) /Supplement 6 >> >>] >>".into(),
        "<< /Type /Font /Subtype /Type0 /BaseFont /ABCDEF+Subset /Encoding /Identity-H /DescendantFonts [] >>".into(),
        "<< /Type /Annot /Subtype /Widget /FT /Ch /T (era) /Ff 131072 /DA (/HeiseiMin-W3 10 Tf 0 g) /Q 1 /Opt [<FEFF3000> <FEFF660E> <FEFF4EE4>] /V <FEFF3000> /Rect [50 700 80 715] /P 3 0 R >>".into(),
        "<< /Type /Annot /Subtype /Widget /FT /Tx /T (address) /Ff 4096 /DA (/HeiseiMin-W3 10 Tf 0 g) /Rect [50 600 100 680] /P 3 0 R >>".into(),
        "<< /Type /Annot /Subtype /Widget /FT /Tx /T (subset) /DA (/Emb 10 Tf 0 g) /Rect [50 500 100 520] /P 3 0 R >>".into(),
    ];
    let mut doc = document(&objs);
    assert_eq!(field(&fields(&doc), "era").options.get(2), Some(&("令".to_string(), "令".to_string())));
    set_value(&mut doc, "era", &FieldValue::Text("令".into())).unwrap();
    set_value(&mut doc, "address", &FieldValue::Text("日本語のテキスト入力欄です".into())).unwrap();
    set_value(&mut doc, "subset", &FieldValue::Text("令和".into())).unwrap();
    let doc = reopen(&doc);
    let all = fields(&doc);
    assert_eq!(field(&all, "era").value, ["令"]);
    let raw = |name: &str| {
        let w = &field(&all, name).widgets[0];
        let n = doc.get(w.obj).as_dict().unwrap().get(b"AP").unwrap().as_dict().unwrap().reference(b"N").unwrap();
        let Object::Stream(s) = &*doc.get(n) else { panic!() };
        let fonts = doc.resolve(s.dict.get(b"Resources").unwrap()).as_dict().unwrap().get(b"Font").map(|f| doc.resolve(f)).unwrap();
        let fonts: Vec<String> = fonts.as_dict().unwrap().iter().map(|(k, _)| String::from_utf8_lossy(k).into_owned()).collect();
        (s.decoded().unwrap(), fonts)
    };
    let utf16 = |t: &str| t.encode_utf16().flat_map(u16::to_be_bytes).collect::<Vec<u8>>();
    let (era, era_fonts) = raw("era");
    assert!(era.windows(4).any(|x| x == b"(N\xe4)"), "令 as UTF-16BE: {}", String::from_utf8_lossy(&era));
    assert!(String::from_utf8_lossy(&era).contains("/HeiseiMin-W3 10 Tf"));
    assert!(!era.windows(3).any(|x| x == b"(?)"), "no WinAnsi fallback");
    assert_eq!(era_fonts, ["HeiseiMin-W3"]);
    // Multiline Japanese wraps by character at about one em each (50 pt wide, 10 pt type).
    let (addr, _) = raw("address");
    let addr_text = String::from_utf8_lossy(&addr);
    assert!(addr_text.matches(" Tj").count() >= 4, "{addr_text}");
    assert!(addr.windows(4).any(|x| x == utf16("日本").as_slice()));
    // An Identity-H subset can't be addressed by Unicode: Helvetica, as before.
    let (sub, sub_fonts) = raw("subset");
    assert!(String::from_utf8_lossy(&sub).contains("/Helv "), "{}", String::from_utf8_lossy(&sub));
    assert_eq!(sub_fonts, ["Helv"]);
}

#[test]
fn check_boxes_and_radios_switch_states() {
    let mut doc = fixture();
    set_value(&mut doc, "agree", &FieldValue::Check(true)).unwrap();
    set_value(&mut doc, "size", &FieldValue::Radio(Some("L".into()))).unwrap();
    set_value(&mut doc, "bare", &FieldValue::Text("yes".into())).unwrap();
    let doc2 = reopen(&doc);
    let all = fields(&doc2);
    assert_eq!(field(&all, "agree").value, ["Yes"]);
    assert_eq!(field(&all, "agree").widgets[0].state.as_deref(), Some("Yes"));
    let size = field(&all, "size");
    assert_eq!(size.value, ["L"]);
    assert_eq!(size.widgets.iter().map(|w| w.state.clone().unwrap()).collect::<Vec<_>>(), ["Off", "L"]);
    // The bare check box got PdfCraft's own appearances and kept its other keys.
    let bare = field(&all, "bare");
    assert_eq!(bare.value, ["Yes"]);
    assert_eq!(bare.widgets[0].on_state.as_deref(), Some("Yes"));
    assert!(doc2.get(bare.widgets[0].obj).as_dict().unwrap().contains(b"Foo"));
    let mut doc = doc2;
    // Radio validation and NoToggleToOff.
    assert!(matches!(set_value(&mut doc, "size", &FieldValue::Radio(Some("XL".into()))), Err(FormError::Invalid(_))));
    assert!(matches!(set_value(&mut doc, "size", &FieldValue::Radio(None)), Err(FormError::Invalid(_))));
    set_value(&mut doc, "agree", &FieldValue::Check(false)).unwrap();
    assert!(field(&fields(&doc), "agree").value.is_empty());
}

#[test]
fn check_boxes_keep_non_utf8_state_names() {
    // Japanese forms often name a check box's on state 「はい」 in Shift-JIS: ticking it has to
    // write those exact bytes to /AS and /V, or no appearance matches and no mark shows.
    let objs: Vec<String> = vec![
        "<< /Type /Catalog /Pages 2 0 R /AcroForm 4 0 R >>".into(),
        "<< /Type /Pages /Kids [3 0 R] /Count 1 /MediaBox [0 0 600 800] >>".into(),
        "<< /Type /Page /Parent 2 0 R /Annots [5 0 R] >>".into(),
        "<< /Fields [5 0 R] >>".into(),
        "<< /Type /Annot /Subtype /Widget /FT /Btn /T (agree) /AS /Off /Rect [50 700 56 706] /P 3 0 R /AP << /N << /Off 6 0 R /#82#CD#82#A2 7 0 R >> >> >>".into(),
        "<< /Length 0 >>\nstream\n\nendstream".into(),
        "<< /Length 0 >>\nstream\n\nendstream".into(),
    ];
    let sjis_hai: &[u8] = b"\x82\xcd\x82\xa2";
    let mut doc = document(&objs);
    let all = fields(&doc);
    assert_eq!(field(&all, "agree").widgets[0].on_state.as_deref(), Some("#82#CD#82#A2"));
    set_value(&mut doc, "agree", &FieldValue::Check(true)).unwrap();
    let doc = reopen(&doc);
    let f = field(&fields(&doc), "agree").clone();
    let wd = doc.get(f.widgets[0].obj).as_dict().cloned().unwrap();
    assert_eq!(wd.name(b"AS"), Some(sjis_hai));
    assert_eq!(doc.get(f.obj).as_dict().unwrap().name(b"V"), Some(sjis_hai));
    assert_eq!(f.value, ["#82#CD#82#A2"]);
    let mut doc = doc;
    set_value(&mut doc, "agree", &FieldValue::Check(false)).unwrap();
    assert_eq!(doc.get(f.widgets[0].obj).as_dict().unwrap().name(b"AS"), Some(&b"Off"[..]));
}

#[test]
fn name_text_round_trips() {
    for bytes in [&b"Yes"[..], b"\x82\xcd\x82\xa2", "はい".as_bytes(), b"A#1", b"a b", b"", b"\xff#\x00"] {
        assert_eq!(name_bytes(&name_text(bytes)), bytes, "{bytes:?}");
    }
    assert_eq!(name_text("はい".as_bytes()), "はい");
    assert_eq!(name_text(b"A#1"), "A#231");
    // Malformed escapes stay as they are.
    assert_eq!(name_bytes("#G1#4"), b"#G1#4");
}

#[test]
fn choices_accept_exports_or_display_text() {
    let mut doc = fixture();
    set_value(&mut doc, "country", &FieldValue::Text("France".into())).unwrap();
    set_value(&mut doc, "toppings", &FieldValue::Choice(vec!["Ham".into(), "Olives".into()])).unwrap();
    let doc = reopen(&doc);
    let all = fields(&doc);
    let country = field(&all, "country");
    assert_eq!(country.value, ["fr"]);
    assert_eq!(country.display_value(), "France");
    assert!(ap(&doc, &country.widgets[0]).contains("(France) Tj"));
    let toppings = field(&all, "toppings");
    assert_eq!(toppings.value, ["Ham", "Olives"]);
    let list = ap(&doc, &toppings.widgets[0]);
    assert_eq!(list.matches("0.6 0.75 0.86 rg").count(), 2, "two highlighted rows: {list}");
    assert_eq!(doc.get(toppings.obj).as_dict().unwrap().get(b"I").unwrap().as_array().unwrap().len(), 2);
    let mut doc = doc;
    assert!(matches!(set_value(&mut doc, "country", &FieldValue::Text("Spain".into())), Err(FormError::Invalid(_))));
    assert!(matches!(set_value(&mut doc, "country", &FieldValue::Choice(vec!["ca".into(), "fr".into()])), Err(FormError::Invalid(_))));
}

#[test]
fn errors_are_specific_and_change_nothing() {
    let mut doc = fixture();
    assert_eq!(set_value(&mut doc, "nope", &FieldValue::Text("x".into())), Err(FormError::NoSuchField("nope".into())));
    assert_eq!(set_value(&mut doc, "id", &FieldValue::Text("x".into())), Err(FormError::ReadOnly("id".into())));
    assert!(matches!(set_value(&mut doc, "zip", &FieldValue::Text("123456".into())), Err(FormError::Invalid(_))));
    assert!(matches!(set_value(&mut doc, "go", &FieldValue::Text("x".into())), Err(FormError::Invalid(_))));
    assert!(matches!(set_value(&mut doc, "agree", &FieldValue::Text("maybe".into())), Err(FormError::Invalid(_))));
    assert!(!doc.is_modified());
}

#[test]
fn reset_restores_defaults() {
    let mut doc = fixture();
    set_value(&mut doc, "name", &FieldValue::Text("Grace".into())).unwrap();
    set_value(&mut doc, "agree", &FieldValue::Check(true)).unwrap();
    set_value(&mut doc, "size", &FieldValue::Radio(Some("L".into()))).unwrap();
    assert_eq!(reset(&mut doc, Some(&["agree".to_string()])).unwrap(), 1);
    assert!(field(&fields(&doc), "agree").value.is_empty());
    assert_eq!(field(&fields(&doc), "name").value, ["Grace"], "only the named field");
    let n = reset(&mut doc, None).unwrap();
    assert!(n >= 2);
    let all = fields(&reopen(&doc));
    assert_eq!(field(&all, "name").value, ["Ada"]);
    assert_eq!(field(&all, "size").value, ["S"], "back to /DV");
    assert!(matches!(reset(&mut doc, Some(&["nope".to_string()])), Err(FormError::NoSuchField(_))));
}

#[test]
fn documents_without_forms_say_so() {
    let mut doc = Document::new_empty();
    assert!(fields(&doc).is_empty());
    assert_eq!(set_value(&mut doc, "x", &FieldValue::Text("y".into())), Err(FormError::NoForm));
}

#[test]
fn every_field_type_can_be_added_named_and_drawn() {
    let mut doc = Document::new_empty();
    {
        // One page.
        let pages = doc.get(doc.root().unwrap()).as_dict().unwrap().reference(b"Pages").unwrap();
        let mut p = pdfcraft_cos::Dict::new();
        p.set(b"Type".to_vec(), Object::name("Page"));
        p.set(b"Parent".to_vec(), Object::Ref(pages));
        p.set(b"MediaBox".to_vec(), Object::Array(vec![0.into(), 0.into(), 600.into(), 800.into()]));
        let r = doc.add(p);
        doc.update_dict(pages, |d| {
            d.set(b"Kids".to_vec(), Object::Array(vec![Object::Ref(r)]));
            d.set(b"Count".to_vec(), Object::Int(1));
        })
        .unwrap();
    }
    let r = |y: f64| [50.0, y, 250.0, y + 20.0];
    let names: Vec<String> = [
        (NewField::Text { multiline: false }, r(700.0)),
        (NewField::Text { multiline: true }, [50.0, 600.0, 250.0, 680.0]),
        (NewField::Date, r(560.0)),
        (NewField::CheckBox, [50.0, 520.0, 64.0, 534.0]),
        (NewField::Radio { group: None, export: "Small".into() }, [50.0, 480.0, 64.0, 494.0]),
        (NewField::Combo { options: vec!["Red".into(), "Blue".into()], editable: false }, r(440.0)),
        (NewField::List { options: vec!["A".into(), "B".into(), "C".into()], multi: true }, [50.0, 340.0, 250.0, 420.0]),
        (NewField::Button { caption: "Submit".into() }, r(300.0)),
        (NewField::Signature, [50.0, 220.0, 250.0, 270.0]),
    ]
    .iter()
    .map(|(k, rect)| add_field(&mut doc, 0, *rect, k, None).unwrap())
    .collect();
    assert_eq!(names, ["Text1", "Text2", "Date1", "Check Box1", "Group1", "Dropdown1", "List Box1", "Button1", "Signature1"]);
    // A second radio button joins the group.
    assert_eq!(
        add_field(&mut doc, 0, [80.0, 480.0, 94.0, 494.0], &NewField::Radio { group: Some("Group1".into()), export: "Large".into() }, None).unwrap(),
        "Group1"
    );
    let doc = reopen(&doc);
    let all = fields(&doc);
    assert_eq!(all.len(), 9);
    let group = field(&all, "Group1");
    assert_eq!(group.widgets.iter().filter_map(|w| w.on_state.clone()).collect::<Vec<_>>(), ["Small", "Large"]);
    assert!(field(&all, "Text2").has(flags::MULTILINE));
    assert_eq!(field(&all, "Dropdown1").options.len(), 2);
    assert!(field(&all, "List Box1").has(flags::MULTI_SELECT));
    assert_eq!(field(&all, "Button1").kind, FieldKind::PushButton);
    assert!(ap(&doc, &field(&all, "Button1").widgets[0]).contains("(Submit) Tj"));
    // Every widget is on the page and has an appearance.
    for f in &all {
        for w in &f.widgets {
            assert_eq!(w.page, Some(0), "{}", f.name);
            assert!(doc.get(w.obj).as_dict().unwrap().contains(b"AP"), "{} has an appearance", f.name);
        }
    }
    // The new fields can be filled.
    let mut doc = doc;
    set_value(&mut doc, "Text1", &FieldValue::Text("hello".into())).unwrap();
    set_value(&mut doc, "Group1", &FieldValue::Radio(Some("Large".into()))).unwrap();
    assert!(add_field(&mut doc, 0, r(100.0), &NewField::CheckBox, Some("Text1")).is_err(), "names are unique");
    assert!(add_field(&mut doc, 0, [0.0, 0.0, 2.0, 2.0], &NewField::CheckBox, None).is_err(), "too small");
}

#[test]
fn properties_rename_and_delete() {
    let mut doc = fixture();
    let renamed = set_props(
        &mut doc,
        "name",
        &FieldProps {
            name: Some("full_name".into()),
            tooltip: Some("Your name".into()),
            required: Some(true),
            max_len: Some(Some(20)),
            font_size: Some(9.0),
            ..FieldProps::default()
        },
    )
    .unwrap();
    assert_eq!(renamed, "full_name");
    let all = fields(&doc);
    let f = field(&all, "full_name");
    assert!(f.has(flags::REQUIRED) && f.max_len == Some(20) && f.tooltip.as_deref() == Some("Your name"));
    assert!(ap(&doc, &f.widgets[0]).contains("/Helv 9 Tf"), "redrawn with the new size");
    let nested = set_props(&mut doc, "address.city", &FieldProps { name: Some("town".into()), ..FieldProps::default() }).unwrap();
    assert_eq!(nested, "address.town", "only the last part changes");
    set_props(&mut doc, "country", &FieldProps { options: Some(vec!["Japan".into()]), ..FieldProps::default() }).unwrap();
    assert_eq!(field(&fields(&doc), "country").options, [("Japan".to_string(), "Japan".to_string())]);
    assert!(set_props(&mut doc, "zip", &FieldProps { name: Some("pin".into()), ..FieldProps::default() }).is_err(), "taken");
    set_props(&mut doc, "full_name", &FieldProps { rect: Some((0, [10.0, 10.0, 110.0, 30.0])), ..FieldProps::default() }).unwrap();
    let f = field(&fields(&doc), "full_name").clone();
    assert_eq!(f.widgets[0].rect, [10.0, 10.0, 110.0, 30.0]);
    assert!(ap(&doc, &f.widgets[0]).contains("100"), "the appearance takes the new size");
    assert!(set_props(&mut doc, "full_name", &FieldProps { rect: Some((0, [0.0, 0.0, 2.0, 2.0])), ..FieldProps::default() }).is_err());
    let before = fields(&doc).len();
    delete_field(&mut doc, "size").unwrap();
    delete_field(&mut doc, "address.town").unwrap();
    let doc = reopen(&doc);
    let all = fields(&doc);
    assert_eq!(all.len(), before - 2);
    assert!(!all.iter().any(|f| f.name == "size" || f.name == "address.town"));
    let p = &page_refs(&doc)[0];
    let annots = doc.resolve(doc.get(*p).as_dict().unwrap().get(b"Annots").unwrap());
    assert_eq!(annots.as_array().unwrap().len(), 13 - 3, "the deleted widgets left the page");
}

#[test]
fn deleting_works_with_a_form_dictionary_inside_the_catalog() {
    let mut doc = fixture();
    let root = doc.root().unwrap();
    let af = doc.get(pdfcraft_cos::ObjRef::new(4, 0)).as_dict().cloned().unwrap();
    doc.update_dict(root, |d| d.set(b"AcroForm".to_vec(), Object::Dict(af))).unwrap();
    let before = fields(&doc).len();
    delete_field(&mut doc, "name").unwrap();
    let all = fields(&reopen(&doc));
    assert_eq!(all.len(), before - 1);
    assert!(!all.iter().any(|f| f.name == "name"));
}

fn one_page() -> Document {
    let mut doc = Document::new_empty();
    let pages = doc.get(doc.root().unwrap()).as_dict().unwrap().reference(b"Pages").unwrap();
    let mut p = pdfcraft_cos::Dict::new();
    p.set(b"Type".to_vec(), Object::name("Page"));
    p.set(b"Parent".to_vec(), Object::Ref(pages));
    p.set(b"MediaBox".to_vec(), Object::Array(vec![0.into(), 0.into(), 600.into(), 800.into()]));
    let r = doc.add(p);
    doc.update_dict(pages, |d| {
        d.set(b"Kids".to_vec(), Object::Array(vec![Object::Ref(r)]));
        d.set(b"Count".to_vec(), Object::Int(1));
    })
    .unwrap();
    doc
}

#[test]
fn formats_validation_and_calculations_run_like_acrobat() {
    use crate::af::{CalcOp, Calculate, Format, Validate};
    let mut doc = one_page();
    let text = NewField::Text { multiline: false };
    for (name, y) in [("Price", 700.0), ("Qty", 660.0), ("Total", 620.0), ("Count", 580.0), ("Due", 540.0)] {
        add_field(&mut doc, 0, [50.0, y, 250.0, y + 20.0], &text, Some(name)).unwrap();
    }
    let money = Format::Number { decimals: 2, sep: 0, neg: 0, currency: "$".into(), prepend: true };
    set_props(
        &mut doc,
        "Price",
        &FieldProps { format: Some(money.clone()), validate: Some(Validate::Range { min: Some(0.0), max: None }), ..FieldProps::default() },
    )
    .unwrap();
    set_props(
        &mut doc,
        "Qty",
        &FieldProps {
            format: Some(Format::Number { decimals: 0, sep: 0, neg: 0, currency: String::new(), prepend: true }),
            validate: Some(Validate::Range { min: Some(1.0), max: Some(99.0) }),
            ..FieldProps::default()
        },
    )
    .unwrap();
    set_props(
        &mut doc,
        "Total",
        &FieldProps {
            format: Some(money),
            calculate: Some(Calculate::Notation("Price * Qty".into())),
            read_only: Some(true),
            ..FieldProps::default()
        },
    )
    .unwrap();
    set_props(
        &mut doc,
        "Count",
        &FieldProps { calculate: Some(Calculate::Simple { op: CalcOp::Sum, fields: vec!["Qty".into()] }), ..FieldProps::default() },
    )
    .unwrap();
    set_props(&mut doc, "Due", &FieldProps { format: Some(Format::Date("mmm d, yyyy".into())), ..FieldProps::default() }).unwrap();
    // The scripts are Acrobat's, so Acrobat (and we, after a save) read them back.
    let doc2 = reopen(&doc);
    let total = field(&fields(&doc2), "Total").clone();
    assert_eq!(total.actions.calculate, Calculate::Notation("Price * Qty".into()));
    assert!(matches!(total.actions.format, Format::Number { decimals: 2, .. }));
    let co =
        doc2.get(doc2.root().unwrap()).as_dict().unwrap().get(b"AcroForm").cloned().map(|a| doc2.resolve(&a).as_dict().cloned().unwrap()).unwrap();
    assert_eq!(doc2.resolve(co.get(b"CO").unwrap()).as_array().unwrap().len(), 2, "both calculated fields are in the calculation order");
    let mut doc = doc2;
    // Typing a formatted number stores the number and shows it formatted.
    set_value(&mut doc, "Price", &FieldValue::Text("$1,234.5".into())).unwrap();
    set_value(&mut doc, "Qty", &FieldValue::Text("2".into())).unwrap();
    let all = fields(&doc);
    assert_eq!(field(&all, "Price").value, ["1234.5"]);
    assert!(ap(&doc, &field(&all, "Price").widgets[0]).contains("($1,234.50) Tj"));
    // Calculations ran in order.
    assert_eq!(field(&all, "Total").value, ["2469"]);
    assert!(ap(&doc, &field(&all, "Total").widgets[0]).contains("($2,469.00) Tj"));
    assert_eq!(field(&all, "Count").value, ["2"]);
    // Keystroke and validation errors use Acrobat's messages and change nothing.
    assert_eq!(
        set_value(&mut doc, "Qty", &FieldValue::Text("lots".into())),
        Err(FormError::Invalid("The value entered does not match the format of the field [ Qty ]".into()))
    );
    assert_eq!(
        set_value(&mut doc, "Qty", &FieldValue::Text("120".into())),
        Err(FormError::Invalid("Invalid value: must be greater than or equal to 1 and less than or equal to 99.".into()))
    );
    assert_eq!(field(&fields(&doc), "Qty").value, ["2"]);
    // Dates: stored as typed, shown in the format; impossible dates are refused.
    set_value(&mut doc, "Due", &FieldValue::Text("10/1/2026".into())).unwrap();
    assert!(ap(&doc, &field(&fields(&doc), "Due").widgets[0]).contains("(Oct 1, 2026) Tj"));
    assert!(set_value(&mut doc, "Due", &FieldValue::Text("2/30/2026".into())).is_err());
    // Clear form recalculates.
    reset(&mut doc, None).unwrap();
    assert_eq!(field(&fields(&doc), "Total").value, ["0"]);
    // Removing a format.
    set_props(&mut doc, "Price", &FieldProps { format: Some(Format::None), ..FieldProps::default() }).unwrap();
    assert_eq!(field(&fields(&doc), "Price").actions.format, Format::None);
}

#[test]
fn appearance_properties_restyle_every_widget() {
    let mut doc = one_page();
    add_field(&mut doc, 0, [50.0, 700.0, 250.0, 720.0], &NewField::Text { multiline: false }, Some("name")).unwrap();
    set_value(&mut doc, "name", &FieldValue::Text("Ada".into())).unwrap();
    let f = field(&fields(&doc), "name").clone();
    let before = look(&doc, &f);
    assert_eq!((before.font, before.style, before.text), (FieldFont::Helvetica, BorderStyle::Solid, [0.0; 3]));
    let new = Look {
        border: Some([1.0, 0.0, 0.0]),
        fill: Some([1.0, 1.0, 0.8]),
        width: 2.0,
        style: BorderStyle::Dashed,
        text: [0.0, 0.0, 1.0],
        font: FieldFont::Times,
    };
    set_props(&mut doc, "name", &FieldProps { look: Some(new), font_size: Some(14.0), ..FieldProps::default() }).unwrap();
    let doc = reopen(&doc);
    let f = field(&fields(&doc), "name").clone();
    assert_eq!(look(&doc, &f), new);
    let a = ap(&doc, &f.widgets[0]);
    assert!(a.contains("/TiRo 14 Tf") && a.contains("0 0 1 rg") && a.contains("[3] 0 d") && a.contains("(Ada) Tj"), "{a}");
    let mut doc = doc;
    set_props(&mut doc, "name", &FieldProps { look: Some(Look { style: BorderStyle::Underline, fill: None, ..new }), ..FieldProps::default() })
        .unwrap();
    let a = ap(&doc, &field(&fields(&doc), "name").widgets[0]);
    assert!(!a.contains(" re S") && a.contains(" l S"), "underline only: {a}");
}

#[test]
fn tab_order_follows_the_page_setting() {
    let mut doc = one_page();
    let text = NewField::Text { multiline: false };
    // Added in a scrambled order: annotation order is C, A, D, B.
    // Layout:  A (50,700)  B (300,700)
    //          C (50,600)  D (300,600)
    for (name, x, y) in [("C", 50.0, 600.0), ("A", 50.0, 700.0), ("D", 300.0, 600.0), ("B", 300.0, 700.0)] {
        add_field(&mut doc, 0, [x, y, x + 200.0, y + 20.0], &text, Some(name)).unwrap();
    }
    let order = |doc: &Document| -> String {
        let mut all: Vec<(usize, String)> = fields(doc).into_iter().map(|f| (f.widgets[0].tab, f.name)).collect();
        all.sort();
        all.into_iter().map(|x| x.1).collect()
    };
    assert_eq!(order(&doc), "CADB", "unspecified: annotation order");
    set_tab_order(&mut doc, &[0], TabOrder::Row).unwrap();
    assert_eq!(order(&doc), "ABCD");
    set_tab_order(&mut doc, &[0], TabOrder::Column).unwrap();
    assert_eq!(order(&doc), "ACBD");
    let doc = reopen(&doc);
    assert_eq!(order(&doc), "ACBD", "saved as /Tabs");
    assert!(set_tab_order(&mut doc.clone(), &[3], TabOrder::Row).is_err());
}

#[test]
fn options_tab_flags_alignment_and_defaults() {
    let mut doc = one_page();
    let text = add_field(&mut doc, 0, [50.0, 700.0, 250.0, 720.0], &NewField::Text { multiline: false }, None).unwrap();
    let combo = add_field(
        &mut doc,
        0,
        [50.0, 600.0, 250.0, 620.0],
        &NewField::Combo { options: vec!["Pear".into(), "apple".into(), "Fig".into()], editable: false },
        None,
    )
    .unwrap();
    let check = add_field(&mut doc, 0, [50.0, 500.0, 64.0, 514.0], &NewField::CheckBox, None).unwrap();
    // A comb needs a limit.
    let comb = FieldProps { flags: vec![(flags::COMB, true)], ..FieldProps::default() };
    assert!(matches!(set_props(&mut doc, &text, &comb), Err(FormError::Invalid(_))));
    set_props(
        &mut doc,
        &text,
        &FieldProps {
            flags: vec![(flags::COMB, true), (flags::DO_NOT_SPELL_CHECK, true)],
            max_len: Some(Some(6)),
            quadding: Some(1),
            default_value: Some(Some("ABC123".into())),
            ..FieldProps::default()
        },
    )
    .unwrap();
    let f = fields(&doc).into_iter().find(|f| f.name == text).unwrap();
    assert!(f.has(flags::COMB) && f.has(flags::DO_NOT_SPELL_CHECK) && !f.has(flags::MULTILINE));
    assert_eq!((f.max_len, f.quadding, f.default.clone()), (Some(6), 1, vec!["ABC123".to_string()]));
    // Reset form restores the default.
    set_value(&mut doc, &text, &FieldValue::Text("XYZ".into())).unwrap();
    reset(&mut doc, None).unwrap();
    assert_eq!(fields(&doc).into_iter().find(|f| f.name == text).unwrap().value, vec!["ABC123".to_string()]);
    // Sort items orders the list; custom text allowed.
    set_props(&mut doc, &combo, &FieldProps { flags: vec![(flags::SORT, true), (flags::EDIT, true)], ..FieldProps::default() }).unwrap();
    let c = fields(&doc).into_iter().find(|f| f.name == combo).unwrap();
    assert_eq!(c.options.iter().map(|(_, d)| d.as_str()).collect::<Vec<_>>(), vec!["apple", "Fig", "Pear"]);
    assert!(c.has(flags::EDIT));
    // Checked by default: the on state is the default.
    let on = fields(&doc).into_iter().find(|f| f.name == check).unwrap().widgets[0].on_state.clone().unwrap();
    set_props(&mut doc, &check, &FieldProps { default_value: Some(Some(on.clone())), ..FieldProps::default() }).unwrap();
    reset(&mut doc, None).unwrap();
    assert_eq!(fields(&doc).into_iter().find(|f| f.name == check).unwrap().value, vec![on]);
    assert!(set_props(&mut doc, &text, &FieldProps { quadding: Some(5), ..FieldProps::default() }).is_err());
}

#[test]
fn check_box_styles_change_the_mark() {
    // #94: Field Properties ▸ Options ▸ Check Box Style (stored as /MK /CA).
    let mut doc = one_page();
    let check = add_field(&mut doc, 0, [50.0, 700.0, 70.0, 720.0], &NewField::CheckBox, None).unwrap();
    let radio = add_field(&mut doc, 0, [50.0, 600.0, 70.0, 620.0], &NewField::Radio { group: None, export: "A".into() }, None).unwrap();
    let text = add_field(&mut doc, 0, [50.0, 500.0, 250.0, 520.0], &NewField::Text { multiline: false }, None).unwrap();
    let style = |doc: &Document, name: &str| check_style(doc, field(&fields(doc), name));
    assert_eq!((style(&doc, &check), style(&doc, &radio)), (CheckStyle::Check, CheckStyle::Circle), "the defaults");
    // The "on" appearance: the widget's /AP /N entry for its on state.
    let on_ap = |doc: &Document, name: &str| {
        let all = fields(doc);
        let w = &field(&all, name).widgets[0];
        let on = w.on_state.clone().unwrap();
        let n = doc
            .get(w.obj)
            .as_dict()
            .unwrap()
            .get(b"AP")
            .unwrap()
            .as_dict()
            .unwrap()
            .get(b"N")
            .unwrap()
            .as_dict()
            .unwrap()
            .reference(on.as_bytes())
            .unwrap();
        let Object::Stream(s) = &*doc.get(n) else { panic!() };
        String::from_utf8_lossy(&s.decoded().unwrap()).into_owned()
    };
    let before = on_ap(&doc, &check);
    for (s, code) in
        [(CheckStyle::Cross, "8"), (CheckStyle::Square, "n"), (CheckStyle::Star, "H"), (CheckStyle::Diamond, "u"), (CheckStyle::Circle, "l")]
    {
        set_props(&mut doc, &check, &FieldProps { check_style: Some(s), ..FieldProps::default() }).unwrap();
        let doc2 = reopen(&doc);
        assert_eq!(style(&doc2, &check), s, "saved and read back");
        let mk = doc2.get(field(&fields(&doc2), &check).widgets[0].obj).as_dict().unwrap().get(b"MK").unwrap().as_dict().cloned().unwrap();
        assert_eq!(mk.get(b"CA").and_then(|c| c.as_string()).map(|c| c.to_text()).as_deref(), Some(code));
        assert!(mk.get(b"BC").is_some(), "the border colour is kept");
        assert_ne!(on_ap(&doc, &check), before, "{s:?} draws a different mark");
    }
    assert!(on_ap(&doc, &check).contains(" c f"), "a circle is a filled curve");
    set_props(&mut doc, &radio, &FieldProps { check_style: Some(CheckStyle::Square), ..FieldProps::default() }).unwrap();
    assert!(on_ap(&doc, &radio).contains(" re f"), "a square");
    assert!(
        set_props(&mut doc, &text, &FieldProps { check_style: Some(CheckStyle::Star), ..FieldProps::default() }).is_err(),
        "text fields have no style"
    );
}

#[test]
fn ordering_tabs_manually() {
    let mut doc = one_page();
    let text = NewField::Text { multiline: false };
    for (name, x, y) in [("A", 50.0, 700.0), ("B", 300.0, 700.0), ("C", 50.0, 600.0)] {
        add_field(&mut doc, 0, [x, y, x + 200.0, y + 20.0], &text, Some(name)).unwrap();
    }
    // A comment between the widgets keeps its place.
    let page = page_refs(&doc)[0];
    let mut note = pdfcraft_cos::Dict::new();
    note.set(b"Type".to_vec(), Object::name("Annot"));
    note.set(b"Subtype".to_vec(), Object::name("Text"));
    note.set(b"Rect".to_vec(), Object::Array(vec![0.into(), 0.into(), 10.into(), 10.into()]));
    let note = doc.add(Object::Dict(note));
    doc.update_dict(page, |d| {
        if let Some(Object::Array(a)) = d.get_mut(b"Annots") {
            a.insert(1, Object::Ref(note));
        }
    })
    .unwrap();
    set_tab_order(&mut doc, &[0], TabOrder::Row).unwrap();
    let order = |doc: &Document| -> String {
        let mut all: Vec<(usize, String)> = fields(doc).into_iter().map(|f| (f.widgets[0].tab, f.name)).collect();
        all.sort();
        all.into_iter().map(|x| x.1).collect()
    };
    assert_eq!(order(&doc), "ABC");
    move_in_tab_order(&mut doc, "C", true).unwrap();
    assert_eq!(order(&doc), "ACB", "row order became manual");
    move_in_tab_order(&mut doc, "A", false).unwrap();
    assert_eq!(order(&doc), "CAB");
    move_in_tab_order(&mut doc, "B", false).unwrap();
    assert_eq!(order(&doc), "CAB", "already last");
    let annots = doc.get(page).as_dict().unwrap().get(b"Annots").unwrap().as_array().unwrap().clone();
    assert_eq!(annots[1].as_ref(), Some(note), "the comment stays where it was");
    assert!(!doc.get(page).as_dict().unwrap().contains(b"Tabs"));
    let doc = reopen(&doc);
    assert_eq!(order(&doc), "CAB", "saved");
}

#[test]
fn duplicating_a_field_across_pages_shares_its_value() {
    let mut doc = one_page();
    // A second and third page.
    let pages = doc.get(doc.root().unwrap()).as_dict().unwrap().reference(b"Pages").unwrap();
    for _ in 0..2 {
        let mut p = pdfcraft_cos::Dict::new();
        p.set(b"Type".to_vec(), Object::name("Page"));
        p.set(b"Parent".to_vec(), Object::Ref(pages));
        p.set(b"MediaBox".to_vec(), Object::Array(vec![0.into(), 0.into(), 600.into(), 800.into()]));
        let r = doc.add(p);
        doc.update_dict(pages, |d| {
            let mut kids = d.get(b"Kids").unwrap().as_array().unwrap().clone();
            kids.push(Object::Ref(r));
            d.set(b"Count".to_vec(), Object::Int(kids.len() as i64));
            d.set(b"Kids".to_vec(), Object::Array(kids));
        })
        .unwrap();
    }
    let name = add_field(&mut doc, 0, [50.0, 750.0, 250.0, 770.0], &NewField::Text { multiline: false }, Some("Initials")).unwrap();
    assert_eq!(duplicate_field(&mut doc, &name, &[0, 1, 2]).unwrap(), 2, "page 1 already has it");
    let f = fields(&doc).into_iter().find(|f| f.name == name).unwrap();
    assert_eq!(f.widgets.iter().filter_map(|w| w.page).collect::<Vec<_>>(), vec![0, 1, 2]);
    assert!(f.widgets.iter().all(|w| w.rect == [50.0, 750.0, 250.0, 770.0]));
    set_value(&mut doc, &name, &FieldValue::Text("AL".into())).unwrap();
    let doc = reopen(&doc);
    let f = fields(&doc).into_iter().find(|f| f.name == name).unwrap();
    assert_eq!((f.value.clone(), f.widgets.len()), (vec!["AL".to_string()], 3), "one field, one value, three widgets");
    assert_eq!(fields(&doc).len(), 1);
    assert!(duplicate_field(&mut doc.clone(), &name, &[7]).is_err());
}

#[test]
fn locked_fields_only_take_unlocking() {
    let mut doc = one_page();
    let name = add_field(&mut doc, 0, [50.0, 700.0, 250.0, 720.0], &NewField::Text { multiline: false }, Some("ID")).unwrap();
    set_props(&mut doc, &name, &FieldProps { locked: Some(true), ..FieldProps::default() }).unwrap();
    assert!(fields(&doc)[0].locked());
    assert!(set_props(&mut doc, &name, &FieldProps { required: Some(true), ..FieldProps::default() }).is_err(), "locked");
    // Values can still be filled in.
    set_value(&mut doc, &name, &FieldValue::Text("42".into())).unwrap();
    set_props(&mut doc, &name, &FieldProps { locked: Some(false), required: Some(true), ..FieldProps::default() }).unwrap();
    let f = &fields(&doc)[0];
    assert!(!f.locked() && f.has(flags::REQUIRED));
}

#[test]
fn image_fields_ask_for_a_picture_and_show_it() {
    let mut doc = one_page();
    let name = add_field(&mut doc, 0, [50.0, 600.0, 250.0, 700.0], &NewField::Image, None).unwrap();
    assert_eq!(name, "Image1");
    let f = fields(&doc).into_iter().find(|f| f.name == name).unwrap();
    assert_eq!((f.kind, f.button.clone()), (FieldKind::PushButton, Some(af::ButtonAction::ImportIcon)));
    // A 4×2 image: the icon keeps its shape and is centred in the 200×100 box.
    let mut d = Dict::new();
    for (k, v) in
        [(&b"Type"[..], Object::name("XObject")), (b"Subtype", Object::name("Image")), (b"Width", Object::Int(4)), (b"Height", Object::Int(2))]
    {
        d.set(k.to_vec(), v);
    }
    let img = doc.add(Object::Stream(pdfcraft_cos::Stream::from_raw(d, vec![0; 24])));
    set_button_icon(&mut doc, &name, img, (4, 2)).unwrap();
    let w = doc.get(f.widgets[0].obj).as_dict().cloned().unwrap();
    let mk = w.get(b"MK").unwrap().as_dict().unwrap().clone();
    assert_eq!(mk.int(b"TP"), Some(1));
    let ap = w.get(b"AP").unwrap().as_dict().unwrap().reference(b"N").unwrap();
    let Object::Stream(s) = &*doc.get(ap) else { panic!("appearance") };
    let text = String::from_utf8(s.decoded().unwrap()).unwrap();
    assert!(text.contains("/Icon Do") && text.contains("49.000000 0 0 49.000000 2.000 1.000 cm"), "{text}");
    assert!(set_button_icon(&mut doc, "nope", img, (1, 1)).is_err());
}

#[test]
fn field_actions_round_trip_on_every_trigger() {
    let mut doc = fixture();
    let name = "go".to_string();
    let acts = vec![
        (Trigger::MouseUp, FieldAction::JavaScript("app.alert('hi')".into())),
        (Trigger::MouseEnter, FieldAction::ShowHide { fields: vec!["other".into()], hide: false }),
        (Trigger::OnFocus, FieldAction::Uri("https://example.org".into())),
        (Trigger::OnBlur, FieldAction::Reset(vec![])),
        (Trigger::MouseDown, FieldAction::GoTo(0)),
    ];
    set_field_actions(&mut doc, &name, &acts).unwrap();
    let mut got = field_actions(&doc, &name).unwrap();
    let mut want = acts.clone();
    let key = |x: &(Trigger, FieldAction)| Trigger::ALL.iter().position(|t| *t == x.0);
    got.sort_by_key(key);
    want.sort_by_key(key);
    assert_eq!(got, want);
    set_field_actions(&mut doc, &name, &[(Trigger::MouseExit, FieldAction::Named("NextPage".into()))]).unwrap();
    assert_eq!(field_actions(&doc, &name).unwrap(), [(Trigger::MouseExit, FieldAction::Named("NextPage".into()))]);
    // The Mouse Up script is what the button runs.
    set_field_actions(&mut doc, &name, &[(Trigger::MouseUp, FieldAction::JavaScript("this.print();".into()))]).unwrap();
    assert_eq!(fields(&doc).iter().find(|f| f.name == "go").unwrap().button, Some(af::ButtonAction::Named("Print".into())));
}

#[test]
fn push_buttons_read_hide_actions() {
    let mut doc = fixture();
    let go = field(&fields(&doc), "go").obj;
    let s = |t: &str| Object::String(PdfString::text(t));
    let city = ObjRef::new(16, 0);
    let null = ObjRef::new(9, 0);
    let button = |doc: &mut Document, t: Object, h: Option<bool>| {
        let mut a = Dict::new();
        a.set(b"S".to_vec(), Object::name("Hide"));
        a.set(b"T".to_vec(), t);
        if let Some(h) = h {
            a.set(b"H".to_vec(), Object::Bool(h));
        }
        doc.update_dict(go, |d| d.set(b"A".to_vec(), Object::Dict(a))).unwrap();
        field(&fields(doc), "go").button.clone()
    };
    let hide = |names: &[&str], hide: bool| Some(af::ButtonAction::ShowHide { fields: names.iter().map(|n| n.to_string()).collect(), hide });
    // A name; /H defaults to true (hide).
    assert_eq!(button(&mut doc, s("name"), None), hide(&["name"], true));
    // A widget reference names its field by its fully qualified name; /H false shows.
    assert_eq!(button(&mut doc, Object::Ref(city), Some(false)), hide(&["address.city"], false));
    // An array of both; a reference to something that isn't a field is skipped.
    assert_eq!(button(&mut doc, Object::Array(vec![s("name"), Object::Ref(city), Object::Ref(null)]), None), hide(&["name", "address.city"], true));
    // A /Parent cycle ends instead of looping.
    let looped = doc.add(Object::Dict(Dict::new()));
    doc.update_dict(looped, |d| {
        d.set(b"T".to_vec(), s("loop"));
        d.set(b"Parent".to_vec(), Object::Ref(looped));
    })
    .unwrap();
    assert_eq!(button(&mut doc, Object::Ref(looped), None), hide(&["loop"], true));
}

#[test]
fn push_buttons_read_set_layer_actions() {
    use af::LayerOp::{Off, On, Toggle};
    let mut doc = fixture();
    let go = field(&fields(&doc), "go").obj;
    let ocg = |n: u32| Object::Ref(ObjRef::new(n, 0));
    let button = |doc: &mut Document, state: Option<Object>, preserve_rb: Option<Object>| {
        let mut a = Dict::new();
        a.set(b"S".to_vec(), Object::name("SetOCGState"));
        if let Some(state) = state {
            a.set(b"State".to_vec(), state);
        }
        if let Some(p) = preserve_rb {
            a.set(b"PreserveRB".to_vec(), p);
        }
        doc.update_dict(go, |d| d.set(b"A".to_vec(), Object::Dict(a))).unwrap();
        field(&fields(doc), "go").button.clone()
    };
    let layers = |changes: &[(af::LayerOp, u32)], preserve_rb: bool| {
        Some(af::ButtonAction::SetLayers { changes: changes.iter().map(|&(op, n)| (op, (n, 0))).collect(), preserve_rb })
    };
    // Each name applies to the groups after it; /PreserveRB false is read.
    let state = Object::Array(vec![Object::name("ON"), ocg(30), ocg(31), Object::name("OFF"), ocg(32), Object::name("Toggle"), ocg(30)]);
    assert_eq!(button(&mut doc, Some(state), Some(Object::Bool(false))), layers(&[(On, 30), (On, 31), (Off, 32), (Toggle, 30)], false));
    // An indirect /State; groups before the first name or after an unknown one, and entries that
    // aren't groups, are skipped. /PreserveRB defaults to true, also when it isn't a boolean.
    let state = doc.add(Object::Array(vec![
        ocg(29),
        Object::name("OFF"),
        ocg(30),
        Object::Int(7),
        Object::name("Hide"),
        ocg(31),
        Object::name("Toggle"),
        ocg(32),
    ]));
    assert_eq!(button(&mut doc, Some(Object::Ref(state)), Some(Object::Int(0))), layers(&[(Off, 30), (Toggle, 32)], true));
    // No /State: an action that changes nothing (the button still has an action).
    assert_eq!(button(&mut doc, None, None), layers(&[], true));
}

#[test]
fn detection_finds_blanks_rules_boxes_and_names_them() {
    use crate::detect::*;
    let w = |t: &str, x0: f64, y0: f64, x1: f64| Word { text: t.into(), rect: [x0, y0, x1, y0 + 10.0] };
    let words = vec![
        w("Name:", 50.0, 700.0, 80.0),
        w("______________", 85.0, 699.0, 250.0),
        w("Date", 300.0, 700.0, 325.0),
        w("of", 328.0, 700.0, 338.0),
        w("birth", 341.0, 700.0, 365.0),
        w("I", 72.0, 602.0, 75.0),
        w("agree", 78.0, 602.0, 105.0),
        w("Comments", 50.0, 560.0, 100.0),
        w("Heading", 50.0, 750.0, 100.0),
    ];
    let shapes = Shapes {
        boxes: vec![[56.0, 600.0, 68.0, 612.0], [50.0, 500.0, 300.0, 540.0], [40.0, 20.0, 560.0, 780.0]],
        rules: vec![[370.0, 699.0, 500.0, 699.0], [50.0, 748.0, 100.0, 748.0]],
    };
    let found = detect(&words, &shapes, &[], &["Comments".into()]);
    let names: Vec<(&str, &Kind)> = found.iter().map(|c| (c.name.as_str(), &c.kind)).collect();
    assert_eq!(names, [("Name", &Kind::Text), ("Date of birth", &Kind::Text), ("I agree", &Kind::CheckBox), ("Comments2", &Kind::Text)], "{found:?}");
    // An existing field there: nothing new.
    let again = detect(&words, &shapes, &found.iter().map(|c| c.rect).collect::<Vec<_>>(), &[]);
    assert!(again.is_empty(), "{again:?}");
}

#[test]
fn page_shapes_reads_boxes_and_rules() {
    let mut doc = fixture();
    let page = pdfcraft_model::pages(&doc)[0].obj;
    let s = doc.add(pdfcraft_cos::Object::Stream(pdfcraft_cos::Stream::flate(
        Default::default(),
        b"q 2 0 0 2 0 0 cm 10 10 6 6 re S 20 50 m 120 50 l S 0 0 m 5 5 l S 30 300 100 0.5 re f Q",
    )));
    doc.update_dict(page, |d| d.set(b"Contents".to_vec(), pdfcraft_cos::Object::Ref(s))).unwrap();
    let sh = crate::detect::page_shapes(&doc, 0);
    assert_eq!(sh.boxes, [[20.0, 20.0, 32.0, 32.0]]);
    assert_eq!(sh.rules, [[40.0, 100.0, 240.0, 100.0], [60.0, 600.5, 260.0, 600.5]]);
}

fn close(a: f64, b: f64) -> bool {
    (a - b).abs() < 0.05
}

fn nums(o: &Object) -> Vec<f64> {
    o.as_array().unwrap().iter().filter_map(Object::as_f64).collect()
}

/// Normal appearance `/BBox` and `/Matrix` (absent when the widget is not rotated).
fn appearance_box(doc: &Document, w: &Widget) -> (Vec<f64>, Option<Vec<f64>>) {
    let n = doc.get(w.obj).as_dict().unwrap().get(b"AP").unwrap().as_dict().unwrap().reference(b"N").unwrap();
    let Object::Stream(s) = &*doc.get(n) else { panic!("appearance") };
    (nums(s.dict.get(b"BBox").unwrap()), s.dict.get(b"Matrix").map(nums))
}

#[test]
fn rotated_fields_draw_in_their_quadrant() {
    let mut doc = fixture();
    // No /R: the appearance is the widget rectangle and carries no /Matrix.
    set_value(&mut doc, "name", &FieldValue::Text("Ada".into())).unwrap();
    let (bbox, matrix) = appearance_box(&doc, &field(&fields(&doc), "name").widgets[0]);
    assert!(close(bbox[2], 200.0) && close(bbox[3], 20.0), "{bbox:?}");
    assert!(matrix.is_none(), "{matrix:?}");

    let set_r = |doc: &mut Document, degrees: i64| {
        let obj = field(&fields(doc), "name").widgets[0].obj;
        doc.update_dict(obj, |d| {
            let mut mk = d.get(b"MK").and_then(|m| m.as_dict().cloned()).unwrap_or_default();
            mk.set(b"R".to_vec(), Object::Int(degrees));
            d.set(b"MK".to_vec(), Object::Dict(mk));
        })
        .unwrap();
        set_value(doc, "name", &FieldValue::Text("Ada".into())).unwrap();
    };
    // 90 and 270 lay the text out in the swapped box. 180 keeps the box and turns it over.
    set_r(&mut doc, 90);
    let (bbox, matrix) = appearance_box(&doc, &field(&fields(&doc), "name").widgets[0]);
    assert!(close(bbox[2], 20.0) && close(bbox[3], 200.0), "{bbox:?}");
    let m = matrix.unwrap();
    assert!(close(m[0], 0.0) && close(m[1], 1.0) && close(m[2], -1.0) && close(m[4], 200.0), "{m:?}");
    set_r(&mut doc, 180);
    let (bbox, matrix) = appearance_box(&doc, &field(&fields(&doc), "name").widgets[0]);
    assert!(close(bbox[2], 200.0) && close(bbox[3], 20.0), "{bbox:?}");
    let m = matrix.unwrap();
    assert!(close(m[0], -1.0) && close(m[3], -1.0) && close(m[4], 200.0) && close(m[5], 20.0), "{m:?}");
    set_r(&mut doc, 270);
    let (bbox, matrix) = appearance_box(&doc, &field(&fields(&doc), "name").widgets[0]);
    assert!(close(bbox[2], 20.0) && close(bbox[3], 200.0), "{bbox:?}");
    let m = matrix.unwrap();
    assert!(close(m[1], -1.0) && close(m[2], 1.0) && close(m[5], 20.0), "{m:?}");
    // A non-quadrant /R is drawn upright.
    set_r(&mut doc, 45);
    let (bbox, matrix) = appearance_box(&doc, &field(&fields(&doc), "name").widgets[0]);
    assert!(matrix.is_none() && close(bbox[2], 200.0) && close(bbox[3], 20.0), "{bbox:?} {matrix:?}");
    assert_eq!(field(&fields(&doc), "name").widgets[0].rotation, 0);

    let before = field(&fields(&doc), "name").widgets[0].rect;
    assert!(set_props(&mut doc, "name", &FieldProps { rotation: Some((0, 45)), ..FieldProps::default() }).is_err());
    assert!(field(&fields(&doc), "name").widgets[0].rect.iter().zip(before).all(|(a, b)| close(*a, b)));
    set_props(&mut doc, "name", &FieldProps { rotation: Some((0, 90)), ..FieldProps::default() }).unwrap();
    let turned = field(&fields(&doc), "name").widgets[0].clone();
    assert_eq!(turned.rotation, 90);
    let r = turned.rect;
    // [50 700 250 720] around its center becomes 20 wide and 200 tall.
    assert!(close(r[0], 140.0) && close(r[1], 610.0) && close(r[2], 160.0) && close(r[3], 810.0), "{r:?}");
    let widget = doc.get(turned.obj);
    let mk = widget.as_dict().unwrap().get(b"MK").unwrap().as_dict().cloned().unwrap();
    assert!(mk.contains(b"BG") && mk.contains(b"BC") && mk.int(b"R") == Some(90));
    let (_, matrix) = appearance_box(&doc, &turned);
    assert!(matrix.is_some());
    // 270 stays on the vertical axis, so the rectangle is not swapped again.
    set_props(&mut doc, "name", &FieldProps { rotation: Some((0, 270)), ..FieldProps::default() }).unwrap();
    let r270 = field(&fields(&doc), "name").widgets[0].rect;
    assert!(r270.iter().zip(r).all(|(a, b)| close(*a, b)), "{r270:?}");

    // A check box and a push button use the same matrix.
    let mut doc = one_page();
    add_field(&mut doc, 0, [20.0, 40.0, 40.0, 60.0], &NewField::CheckBox, Some("agree")).unwrap();
    add_field(&mut doc, 0, [20.0, 80.0, 120.0, 110.0], &NewField::Button { caption: "Go".into() }, Some("go")).unwrap();
    set_props(&mut doc, "agree", &FieldProps { rotation: Some((0, 90)), ..FieldProps::default() }).unwrap();
    set_props(&mut doc, "go", &FieldProps { rotation: Some((0, 90)), ..FieldProps::default() }).unwrap();
    let agree = field(&fields(&doc), "agree").widgets[0].clone();
    let widget = doc.get(agree.obj);
    let n = widget.as_dict().unwrap().get(b"AP").unwrap().as_dict().unwrap().get(b"N").cloned().unwrap();
    let states = doc.resolve(&n);
    let yes = states.as_dict().unwrap().reference(b"Yes").unwrap();
    let Object::Stream(s) = &*doc.get(yes) else { panic!("check") };
    assert!(s.dict.contains(b"Matrix"), "the check mark is rotated");
    let go = field(&fields(&doc), "go").widgets[0].clone();
    let (text, matrix) = (ap(&doc, &go), appearance_box(&doc, &go).1);
    assert!(text.contains("(Go) Tj") && matrix.is_some(), "{text}");
}

#[test]
fn a_rotation_refused_as_too_small_changes_nothing_else() {
    let mut doc = one_page();
    add_field(&mut doc, 0, [50.0, 700.0, 250.0, 720.0], &NewField::Text { multiline: false }, Some("thin")).unwrap();
    // 200 x 3: turned a quarter it would be 3 wide, too small to use.
    let obj = field(&fields(&doc), "thin").widgets[0].obj;
    doc.update_dict(obj, |d| d.set(b"Rect".to_vec(), Object::Array([50.0, 700.0, 250.0, 703.0].iter().map(|v| Object::Real(*v)).collect()))).unwrap();
    let props = FieldProps { tooltip: Some("changed".into()), rotation: Some((0, 90)), ..FieldProps::default() };
    assert!(set_props(&mut doc, "thin", &props).is_err());
    let f = field(&fields(&doc), "thin").clone();
    assert_eq!(f.tooltip, None, "the tooltip was written before the rotation was refused");
    assert_eq!(f.widgets[0].rotation, 0);
}

#[test]
fn filling_and_authoring_keep_shared_appearances_and_drop_stale_alternates() {
    let alternates: [(&[u8], &[u8]); 2] = [(b"R", b"0 0 20 10 re f\n"), (b"D", b"1 1 18 8 re S\n")];
    let cases = [
        (NewField::Text { multiline: false }, true),
        (NewField::Text { multiline: false }, false),
        (NewField::CheckBox, false),
        (NewField::Button { caption: "Button".into() }, false),
        (NewField::Signature, false),
    ];
    for (kind, fill) in cases {
        for indirect in [false, true] {
            let mut doc = one_page();
            let first = add_field(&mut doc, 0, [50.0, 600.0, 250.0, 630.0], &kind, Some("First")).unwrap();
            let other = add_field(&mut doc, 0, [50.0, 550.0, 250.0, 580.0], &kind, Some("Other")).unwrap();
            let first_widget = field(&fields(&doc), &first).widgets[0].obj;
            let other_widget = field(&fields(&doc), &other).widgets[0].obj;
            let mut entries = doc.get(first_widget).as_dict().unwrap().get(b"AP").unwrap().as_dict().unwrap().clone();
            for (key, bytes) in alternates {
                let mut d = Dict::new();
                d.set(b"Type".to_vec(), Object::name("XObject"));
                d.set(b"Subtype".to_vec(), Object::name("Form"));
                d.set(b"BBox".to_vec(), Object::Array(vec![0.into(), 0.into(), 20.into(), 10.into()]));
                let r = doc.add(Object::Stream(pdfcraft_cos::Stream::from_raw(d, bytes.to_vec())));
                entries.set(key.to_vec(), Object::Ref(r));
            }
            entries.set(b"VendorState".to_vec(), Object::name("Retained"));
            let shared = if indirect { Object::Ref(doc.add(Object::Dict(entries))) } else { Object::Dict(entries) };
            for widget in [first_widget, other_widget] {
                doc.update_dict(widget, |d| d.set(b"AP".to_vec(), shared.clone())).unwrap();
            }
            let original = reopen(&doc);
            for full in [false, true] {
                let mut doc = original.clone();
                let other_widget = field(&fields(&doc), &other).widgets[0].obj;
                let source = doc.get(other_widget).as_dict().unwrap().get(b"AP").unwrap().clone();
                let before = doc.resolve(&source);
                if fill {
                    set_value(&mut doc, &first, &FieldValue::Text("Updated value".into())).unwrap();
                } else {
                    set_props(&mut doc, &first, &FieldProps { tooltip: Some("Updated help".into()), ..FieldProps::default() }).unwrap();
                }
                assert_eq!(doc.resolve(&source), before, "a shared AP must not change");
                let bytes = if full {
                    pdfcraft_cos::write_full(&doc, &SaveOptions::default()).unwrap()
                } else {
                    assert!(!doc.revisions().is_empty(), "incremental save needs an existing revision");
                    assert!(!doc.encryption_changed() && !doc.full_save_required(), "this edit must not require a full rewrite");
                    let original = doc.bytes();
                    let bytes = write_incremental(&doc, &SaveOptions::default()).unwrap();
                    assert!(bytes.len() > original.len(), "incremental save appends the changed appearance");
                    assert!(bytes.starts_with(original.as_slice()), "incremental save preserves the complete original prefix");
                    bytes
                };
                hayro_syntax::Pdf::new(bytes.clone()).unwrap();
                let doc = Document::open(Arc::new(bytes)).unwrap();
                let all = fields(&doc);
                let first = field(&all, &first);
                let other = field(&all, &other);
                let first_ap = doc.resolve(doc.get(first.widgets[0].obj).as_dict().unwrap().get(b"AP").unwrap());
                let other_ap = doc.resolve(doc.get(other.widgets[0].obj).as_dict().unwrap().get(b"AP").unwrap());
                let first_ap = first_ap.as_dict().unwrap();
                let other_ap = other_ap.as_dict().unwrap();
                assert_ne!(first_ap.get(b"N"), other_ap.get(b"N"), "normal appearance was regenerated");
                assert_eq!(other_ap.len(), 4);
                // The redrawn widget keeps unknown entries, but not down/rollover looks that
                // would show its old value or caption on press or hover.
                assert_eq!(
                    first_ap.len(),
                    2,
                    "{kind:?} fill={fill} indirect={indirect} full={full}: {:?}",
                    first_ap.iter().map(|(k, _)| String::from_utf8_lossy(k).into_owned()).collect::<Vec<_>>()
                );
                for (key, bytes) in alternates {
                    assert!(first_ap.get(key).is_none(), "stale /{}", String::from_utf8_lossy(key));
                    let object = doc.resolve(other_ap.get(key).unwrap());
                    let Object::Stream(stream) = &*object else { panic!("alternate appearance") };
                    assert_eq!(stream.decoded().unwrap(), bytes);
                }
                assert_eq!(first_ap.name(b"VendorState"), Some(&b"Retained"[..]));
                assert_eq!(other_ap.name(b"VendorState"), Some(&b"Retained"[..]));
                if fill {
                    assert_eq!(first.value, ["Updated value"]);
                    assert!(ap(&doc, &first.widgets[0]).contains("(Updated value) Tj"));
                    assert!(other.value.is_empty());
                } else {
                    assert_eq!(first.tooltip.as_deref(), Some("Updated help"));
                    assert_eq!(other.tooltip, None);
                }
            }
        }
    }
}

#[test]
fn pushbutton_redraw_resolves_caption_and_layout_after_save_and_reopen() {
    fn saved(doc: &Document, full: bool) -> Document {
        let bytes = if full {
            pdfcraft_cos::write_full(doc, &SaveOptions::default()).unwrap()
        } else {
            assert!(!doc.revisions().is_empty(), "incremental save needs an existing revision");
            assert!(!doc.encryption_changed() && !doc.full_save_required(), "this edit must not require a full rewrite");
            let original = doc.bytes();
            let bytes = write_incremental(doc, &SaveOptions::default()).unwrap();
            assert!(bytes.len() > original.len(), "incremental save appends the changed appearance");
            assert!(bytes.starts_with(original.as_slice()), "incremental save preserves the complete original prefix");
            bytes
        };
        hayro_syntax::Pdf::new(bytes.clone()).unwrap();
        Document::open(Arc::new(bytes)).unwrap()
    }

    for indirect_caption in [false, true] {
        for indirect_layout in [false, true] {
            for icon_only in [false, true] {
                let mut doc = one_page();
                let name =
                    add_field(&mut doc, 0, [50.0, 600.0, 250.0, 650.0], &NewField::Button { caption: "Original caption".into() }, Some("Picture"))
                        .unwrap();
                let widget = field(&fields(&doc), &name).widgets[0].obj;
                let caption = Object::String(pdfcraft_cos::PdfString::literal(b"Original caption".to_vec()));
                let caption = if indirect_caption { Object::Ref(doc.add(caption)) } else { caption };
                let layout = Object::Int(i64::from(icon_only));
                let layout = if indirect_layout { Object::Ref(doc.add(layout)) } else { layout };
                let mut icon_dict = Dict::new();
                icon_dict.set(b"Type".to_vec(), Object::name("XObject"));
                icon_dict.set(b"Subtype".to_vec(), Object::name("Form"));
                icon_dict.set(b"BBox".to_vec(), Object::Array(vec![0.into(), 0.into(), 4.into(), 2.into()]));
                let icon_bytes = b"0 0 4 2 re f\n";
                let icon = doc.add(Object::Stream(pdfcraft_cos::Stream::from_raw(icon_dict, icon_bytes.to_vec())));
                let mut mk = Dict::new();
                mk.set(b"CA".to_vec(), caption);
                mk.set(b"TP".to_vec(), layout);
                mk.set(b"I".to_vec(), Object::Ref(icon));
                mk.set(b"VendorNote".to_vec(), Object::name("Retained"));
                let mk = doc.add(Object::Dict(mk));
                doc.update_dict(widget, |d| d.set(b"MK".to_vec(), Object::Ref(mk))).unwrap();

                // Import the operands from a real saved file before an unrelated public edit.
                let original = saved(&doc, true);
                for full in [false, true] {
                    let mut doc = original.clone();
                    let widget = field(&fields(&doc), &name).widgets[0].obj;
                    let mk_before = doc.get(widget).as_dict().unwrap().get(b"MK").unwrap().clone();
                    let original_mk = doc.resolve(&mk_before);
                    set_props(&mut doc, &name, &FieldProps { tooltip: Some("Picture help".into()), ..FieldProps::default() }).unwrap();
                    assert_eq!(doc.get(widget).as_dict().unwrap().get(b"MK"), Some(&mk_before));
                    assert_eq!(doc.resolve(&mk_before), original_mk, "redraw must not rewrite the source MK");
                    let doc = saved(&doc, full);
                    let f = field(&fields(&doc), &name).clone();
                    assert_eq!(f.tooltip.as_deref(), Some("Picture help"));
                    let w = &f.widgets[0];
                    let wd = doc.get(w.obj);
                    let mk_object = doc.resolve(wd.as_dict().unwrap().get(b"MK").unwrap());
                    let mk = mk_object.as_dict().unwrap();
                    assert_eq!(mk.get(b"CA").unwrap().as_ref().is_some(), indirect_caption);
                    assert_eq!(doc.resolve(mk.get(b"CA").unwrap()).as_string().unwrap().bytes, b"Original caption");
                    assert_eq!(mk.get(b"TP").unwrap().as_ref().is_some(), indirect_layout);
                    assert_eq!(doc.resolve(mk.get(b"TP").unwrap()).as_int(), Some(i64::from(icon_only)));
                    assert_eq!(mk.name(b"VendorNote"), Some(&b"Retained"[..]));
                    let appearance = ap(&doc, w);
                    assert_eq!(appearance.contains("(Original caption) Tj"), !icon_only, "{appearance}");
                    assert_eq!(appearance.matches("/Icon Do").count(), 1, "{appearance}");
                    assert!(appearance.contains("24.000000 0 0 24.000000 52.000 1.000 cm"), "{appearance}");
                    let n = wd.as_dict().unwrap().get(b"AP").unwrap().as_dict().unwrap().reference(b"N").unwrap();
                    let appearance_object = doc.get(n);
                    let Object::Stream(stream) = &*appearance_object else { panic!("appearance") };
                    let resource_icon =
                        stream.dict.get(b"Resources").unwrap().as_dict().unwrap().get(b"XObject").unwrap().as_dict().unwrap().get(b"Icon").unwrap();
                    assert_eq!(resource_icon, mk.get(b"I").unwrap());
                    let icon_object = doc.resolve(resource_icon);
                    let Object::Stream(icon) = &*icon_object else { panic!("icon") };
                    assert_eq!(icon.decoded().unwrap(), icon_bytes);
                }
            }
        }
    }
}

/// A check box's down appearances survive a redraw for the states it still draws (same names),
/// and a down appearance for a state it no longer has is dropped rather than left stale.
#[test]
fn check_box_redraw_keeps_down_states_it_still_draws() {
    let mut doc = one_page();
    let name = add_field(&mut doc, 0, [50.0, 600.0, 70.0, 620.0], &NewField::CheckBox, Some("agree")).unwrap();
    let widget = field(&fields(&doc), &name).widgets[0].obj;
    let on = field(&fields(&doc), &name).widgets[0].on_state.clone().unwrap_or_else(|| "Yes".into());
    let mut ap = doc.get(widget).as_dict().unwrap().get(b"AP").unwrap().as_dict().unwrap().clone();
    let mut down = Dict::new();
    for state in [on.as_bytes(), b"Off".as_slice(), b"Gone".as_slice()] {
        let mut d = Dict::new();
        d.set(b"Subtype".to_vec(), Object::name("Form"));
        d.set(b"BBox".to_vec(), Object::Array(vec![0.into(), 0.into(), 20.into(), 20.into()]));
        let r = doc.add(Object::Stream(pdfcraft_cos::Stream::from_raw(d, b"0 0 20 20 re f\n".to_vec())));
        down.set(state.to_vec(), Object::Ref(r));
    }
    ap.set(b"D".to_vec(), Object::Dict(down));
    doc.update_dict(widget, |d| d.set(b"AP".to_vec(), Object::Dict(ap))).unwrap();
    set_props(&mut doc, &name, &FieldProps { tooltip: Some("Tick to agree".into()), ..FieldProps::default() }).unwrap();
    let ap = doc.get(widget).as_dict().unwrap().get(b"AP").map(|a| doc.resolve(a)).unwrap();
    let d = ap.as_dict().unwrap().get(b"D").map(|d| doc.resolve(d)).expect("down states kept");
    let d = d.as_dict().unwrap();
    assert!(d.contains(on.as_bytes()) && d.contains(b"Off"));
    assert!(!d.contains(b"Gone"), "a state the box no longer draws");
}