//! The persistent disk cache (PRV-2) through the session: settings, layer cache persistence
//! across restarts, invalidation on edits, purging.

use serde_json::json;

use crate::Session;
use crate::render::RenderOpts;

fn folder(name: &str) -> String {
    let d = std::env::temp_dir().join(format!("effectcraft-session-disk-{name}-{}", std::process::id()));
    let _ = std::fs::remove_dir_all(&d);
    d.to_string_lossy().to_string()
}

fn session(dir: &str) -> Session {
    let mut s = Session::default();
    s.execute_checked("prefs.set", json!({"values": {"disk.diskCacheFolder": dir, "disk.diskCacheEnabled": true}})).unwrap();
    // Write every layer buffer, however quick to render.
    s.disk_cache.as_ref().unwrap().set_min_layer_ms(0);
    s
}

fn project(s: &mut Session) -> effectcraft_project::ItemId {
    s.execute("comp.new", json!({"name": "D", "width": 160, "height": 90, "frameRate": 30, "duration": 1})).unwrap();
    s.execute("layer.newSolid", json!({"color": "#3080ff", "width": 80, "height": 40})).unwrap();
    s.execute("effect.apply", json!({"layer": "#1", "effect": "Gaussian Blur"})).unwrap();
    s.execute("prop.set", json!({"layer": "#1", "path": "effects/#1/blurriness", "value": 12})).unwrap();
    s.active_comp_id().unwrap()
}

#[test]
fn disk_cache_settings_persistence_and_invalidation() {
    let dir = folder("persist");
    let mut s = session(&dir);
    let st = s.execute_checked("cache.diskStats", json!({})).unwrap();
    assert_eq!(st["enabled"], json!(true));
    assert_eq!(st["maxBytes"], json!(100u64 << 30));
    let cid = project(&mut s);
    let t = s.time();
    let first = s.render(cid, t, RenderOpts::default());
    let dc = s.disk_cache.clone().unwrap();
    dc.flush();
    let written = dc.stats().entries;
    assert!(written > 0, "layer buffers written");
    // "Restart": a new session on the same folder and project renders from disk.
    let saved = s.project.clone();
    drop(s);
    let mut s2 = session(&dir);
    s2.project = saved;
    s2.bump();
    s2.open_comp(cid);
    let dc2 = s2.disk_cache.clone().unwrap();
    assert_eq!(dc2.stats().entries, written);
    let again = s2.render(cid, t, RenderOpts::default());
    assert!(dc2.stats().hits > 0, "{:?}", dc2.stats());
    assert_eq!(again.data, first.data, "disk-cached pixels are exact");
    // An edit changes the keys: a miss, and new entries.
    let hits = dc2.stats().hits;
    s2.execute("prop.set", json!({"layer": "#1", "path": "effects/#1/blurriness", "value": 20})).unwrap();
    let edited = s2.render(cid, t, RenderOpts::default());
    assert_ne!(edited.data, first.data);
    assert_eq!(dc2.stats().hits, hits);
    dc2.flush();
    assert!(dc2.stats().entries > written);
    // Purge ▸ All Disk Cache empties it; memory purge leaves the disk alone.
    let r = s2.execute_checked("edit.purge", json!({"what": "memory"})).unwrap();
    assert_eq!(r["diskEntries"], json!(0));
    assert!(dc2.stats().entries > 0);
    let r = s2.execute_checked("edit.purge", json!({"what": "disk"})).unwrap();
    assert!(r["diskEntries"].as_u64().unwrap() > 0);
    assert_eq!(dc2.stats().entries, 0);
    // Disabling detaches it.
    s2.execute_checked("prefs.set", json!({"key": "disk.diskCacheEnabled", "value": false})).unwrap();
    assert!(s2.disk_cache.is_none());
    assert!(s2.layer_cache.disk().is_none());
}

#[test]
fn footage_changes_change_the_salt() {
    let dir = folder("salt");
    let mut s = session(&dir);
    let foot = std::env::temp_dir().join(format!("effectcraft-salt-{}.png", std::process::id()));
    std::fs::write(&foot, b"one").unwrap();
    s.edit("add", None, |p, _| {
        let f = effectcraft_project::Footage {
            path: foot.to_string_lossy().to_string(),
            kind: effectcraft_project::FootageKind::Still,
            width: 1,
            height: 1,
            pixel_aspect: 1.0,
            frame_rate: effectcraft_time::FrameRate::FPS_30,
            native_rate: None,
            duration: effectcraft_time::Tick::ZERO,
            has_video: true,
            has_audio: false,
            alpha: effectcraft_project::AlphaMode::Ignore,
            premul_color: [0.0; 3],
            loop_count: 1,
            codec: "PNG".into(),
            missing: false,
            sequence: vec![],
            color_profile: None,
            layer: None,
            ..Default::default()
        };
        p.add_item("f.png", effectcraft_color::Label::Lavender, None, effectcraft_project::ItemKind::Footage(f));
        Ok(())
    })
    .unwrap();
    let a = effectcraft_render::disk_cache::footage_salt(&s.project);
    std::fs::write(&foot, b"two, longer").unwrap();
    let b = effectcraft_render::disk_cache::footage_salt(&s.project);
    assert_ne!(a, b);
    let cid = project(&mut s);
    let k1 = effectcraft_render::disk_cache::comp_content_key(&s.project, cid);
    s.execute("prop.set", json!({"layer": "#1", "path": "transform/opacity", "value": 50})).unwrap();
    let k2 = effectcraft_render::disk_cache::comp_content_key(&s.project, cid);
    assert_ne!(k1, k2);
    // Unrelated comps do not change it.
    s.execute("comp.new", json!({"name": "Other", "width": 10, "height": 10, "frameRate": 30, "duration": 1})).unwrap();
    assert_eq!(effectcraft_render::disk_cache::comp_content_key(&s.project, cid), k2);
}