//! File → Print as a print-ready PDF or a PostScript file (`file.print`), what it would print
//! (`print.preview`) and the print settings saved with the document (`print.setup`,
//! [`vectorcraft_doc::Document::print_setup`]).

use serde::Deserialize;
use serde_json::{Value, json};
use vectorcraft_doc::Document;
use vectorcraft_eps::{Level, PrintJob, PrintPage};
use vectorcraft_pdf::{PrintOptions, PrintSettings};

use super::fileio::pdf::{merge, pdf_error};
use super::fileio::{extension, write_or_return};
use super::flatten::{FlattenOptions, flatten_document};
use super::*;

const SETUP: &str = "print.setup";

pub fn specs() -> Vec<CommandSpec> {
    vec![
        cmd!(
            "print.setup",
            "Print Setup",
            [],
            None,
            "{settings?: {copies: 1 (1–999), collate: true, reverse, artboards: all|range|ignore (all the art as one page), range: \"1-3, 5\" (1-based, with artboards: range), skipBlank (leave out artboards with no art that prints), media: letter|legal|tabloid|a3|a4|a5|b4|b5|custom, width, height (custom paper, 72–14400 pt), orientation: portrait|landscape|portraitFlipped|landscapeFlipped, autoRotate: true (turn the paper to each artboard; orientation ignored), transverse (the page a quarter turn on the paper), printLayers: visiblePrintable|visible|all (template layers never print), placement: {origin: topLeft|top|topRight|left|center|right|bottomLeft|bottom|bottomRight (the point of the printed area, the artboard with its bleed and marks, on the same point of the imageable area), x, y (pt, right and down)}, scaling: none|fit|custom|tileFull|tileImageable, scale: {width: 100, height: 100} (% with custom and tiling), overlap: 0 (pt between tiles), tileRange: \"\" (1-based tiles across then down; empty: all), margin: 0 (pt the device can't print around the paper: the imageable area is inside it), marks: {trim, registration, colorBars, pageInfo, kind: roman|japanese, weight: 0.25, offset: 6} (as document.exportPdf, at the paper's scale; page information adds the tile and the ink), bleed: {useDocument: true (the document's bleed, document.setup), top, bottom, left, right} (pt), output: {mode: composite|separations (one grey page per ink that prints), emulsion: up|down (down mirrors), image: positive|negative, spotsToProcess, inks: [{name: \"Cyan\"|…|a spot swatch, print: true, frequency (lpi, default 60), angle (default C 15, M 75, Y 0, K 45, spots 45)}]}, graphics: {autoFlatness: true, flatness: 1 (0.2–100), fonts: none|subset|complete}, color: {intent: perceptual|relativeColorimetric|saturation|absoluteColorimetric, preserveNumbers: true (CMYK colours keep their values in separations)}}} store the print settings with the document, over the ones it has (null keeps a value), as one undo step; no settings → {settings} (the current ones, defaults if never set up)",
            has_doc,
            setup
        ),
        cmd!(
            query "print.preview",
            "Print Preview",
            [],
            None,
            "{settings?: {…print.setup settings} (over the document's)} → {pages (copies included), sheets: [{artboard (0-based; null with artboards ignored), tile? (1-based), ink? (separations), width, height (pt, the page), orientation, scale: [width %, height %], transform: [a, b, c, d, e, f] (document space → the page, pt, y down), area: [x0, y0, x1, y1] (the document region the page prints), trim: [x0, y0, x1, y1] (the artboard on the page)}] (one copy, in order), tiles: [{artboard, columns, rows, printed: [1-based tiles], tiles: [[x0, y0, x1, y1]…] (document space)}], inks: [{name, spot, print, frequency, angle}] (separations), warnings (art larger than the imageable area, options not applied yet…), settings} without printing",
            has_doc,
            preview
        ),
        cmd!(
            "file.print",
            "Print",
            [],
            Some("Cmd+P"),
            "{settings?: {…print.setup settings} (over the document's), path?, format?: pdf (default: a print-ready PDF) | postscript (the default for a .ps path: a PostScript file with DSC comments, %%Pages, a page per sheet with its paper size, marks, separations with their ink and halftone screen, the fixed flatness, negatives), level?: 3|2 (the PostScript language level), flattenerPreset?: \"medium\" (PostScript: the preset transparency is flattened with — high, low or a saved one, see flattener.presets.list)} print the document, one page per sheet of paper (per tile, per ink, per copy) → {pages, format, path, bytes, warnings}; no path → {dataBase64, bytes, pages, format, warnings}. Raster effects print at the document's raster effects resolution; a PDF leaves halftone screens and flatness to the output device",
            has_doc,
            print
        ),
    ]
}

/// The print settings saved with `doc` (defaults if never set up) as JSON.
fn saved(doc: &Document) -> Value {
    doc.print_setup.clone().unwrap_or_else(|| serde_json::to_value(PrintSettings::default()).unwrap_or_default())
}

/// The settings of `doc` with `p.settings` over them, checked.
fn settings(cmd: &str, doc: &Document, p: &Value) -> Result<PrintSettings> {
    settings_over(cmd, saved(doc), p)
}

/// The settings `v` (JSON) with `p.settings` over them, checked.
pub(crate) fn settings_over(cmd: &str, mut v: Value, p: &Value) -> Result<PrintSettings> {
    match p.get("settings") {
        None | Some(Value::Null) => {}
        Some(over @ Value::Object(_)) => merge(&mut v, over),
        Some(_) => return Err(bad(cmd, "settings must be an object")),
    }
    let set = PrintSettings::deserialize(&v).map_err(|e| bad(cmd, format!("print settings: {e}")))?;
    set.check().map_err(|e| pdf_error(cmd, e))?;
    Ok(set)
}

fn to_json(set: &PrintSettings) -> Result<Value> {
    serde_json::to_value(set).map_err(|e| EngineError::Other(e.to_string()))
}

fn setup(s: &mut Session, p: &Value) -> Result<Value> {
    let doc = &s.doc()?.doc;
    let set = to_json(&settings(SETUP, doc, p)?)?;
    if p.get("settings").is_some_and(|v| !v.is_null()) && doc.print_setup.as_ref() != Some(&set) {
        let stored = set.clone();
        s.edit("Print Setup", |d, _| {
            d.print_setup = Some(stored);
            Ok(())
        })?;
    }
    Ok(json!({ "settings": set }))
}

fn preview(s: &mut Session, p: &Value) -> Result<Value> {
    const C: &str = "print.preview";
    let doc = &s.doc()?.doc;
    let set = settings(C, doc, p)?;
    let pv = vectorcraft_pdf::preview(doc, &set).map_err(|e| pdf_error(C, e))?;
    let mut v = serde_json::to_value(pv).map_err(|e| EngineError::Other(e.to_string()))?;
    v["settings"] = to_json(&set)?;
    Ok(v)
}

const PRINT: &str = "file.print";

/// Whether `file.print` writes PostScript: `format`, else a `.ps` path.
fn to_postscript(p: &Value) -> Result<bool> {
    match str_param(p, "format") {
        None => Ok(str_param(p, "path").is_some_and(|path| extension(path) == "ps")),
        Some("postscript") => Ok(true),
        Some("pdf") => Ok(false),
        Some(f) => Err(bad(PRINT, format!("format `{f}`: pdf or postscript"))),
    }
}

fn print(s: &mut Session, p: &Value) -> Result<Value> {
    let postscript = to_postscript(p)?;
    let flattener = if postscript {
        let preset = str_param(p, "flattenerPreset").unwrap_or("medium");
        Some(
            FlattenOptions::find_preset(preset, &s.prefs.flattener_presets)
                .ok_or_else(|| bad(PRINT, format!("flattenerPreset `{preset}`: high, medium, low or a saved one (see flattener.presets.list)")))?,
        )
    } else {
        None
    };
    let doc = &s.doc()?.doc;
    let set = settings(PRINT, doc, p)?;
    // Raster effects print as images at the document's raster effects resolution.
    let flat = super::rasterfx::flatten_raster_effects(doc);
    let doc = flat.as_ref().unwrap_or(doc);
    let path = str_param(p, "path");
    let Some(flattener) = flattener else {
        let r = vectorcraft_pdf::print(doc, &PrintOptions { settings: set, ..Default::default() }).map_err(|e| pdf_error(PRINT, e))?;
        return write_or_return(path, &r.bytes, json!({ "pages": r.pages, "format": "pdf", "warnings": r.warnings }));
    };
    let level = match p.get("level").filter(|v| !v.is_null()) {
        Some(v) => {
            let t = super::fileio::dxf::text(v);
            Level::from_id(&t).ok_or_else(|| bad(PRINT, format!("level `{t}`: 2 or 3")))?
        }
        None => Level::default(),
    };
    // PostScript has no transparency.
    let flat = flatten_document(doc, &flattener)?;
    let mut warnings = vec![];
    if flat.is_some() && doc.layers.iter().any(|l| l.shows_transparency()) {
        warnings.push("transparency is flattened into opaque art and images (PostScript has none): see flattenerPreset".to_string());
    }
    let flatness = (!set.graphics.auto_flatness).then_some(set.graphics.flatness);
    let plan = vectorcraft_pdf::plan(flat.as_ref().unwrap_or(doc), &PrintOptions { settings: set, postscript: true, ..Default::default() })
        .map_err(|e| pdf_error(PRINT, e))?;
    let pages: Vec<PrintPage> = plan
        .sheets
        .iter()
        .map(|sh| PrintPage {
            doc: sh.plate.and_then(|i| plan.plates.get(i)).unwrap_or(&plan.doc),
            size: sh.size,
            view: sh.view,
            window: sh.window,
            place: sh.place,
            area: sh.area,
            marks: sh.marks.as_ref(),
            negative: sh.negative,
            ink: sh.ink.as_ref().map(|i| (i.name.as_str(), i.frequency, i.angle)),
        })
        .collect();
    let job = PrintJob { level, title: plan.title.clone(), created: plan.created, flatness };
    let out = vectorcraft_eps::print(&pages, &plan.order, &job).map_err(|e| bad(PRINT, e))?;
    for w in plan.warnings.iter().chain(&out.warnings) {
        if !warnings.contains(w) {
            warnings.push(w.clone());
        }
    }
    write_or_return(path, &out.bytes, json!({ "pages": plan.order.len(), "format": "postscript", "warnings": warnings }))
}