//! Paint through the session: the file's colour profile (convert or assign, undo, tagged exports)
//! and image adjustment presets.

use serde_json::json;

use crate::Session;
use crate::params::id_of;
use figcraft_color::{Color, ColorProfile};

fn red_rect(s: &mut Session) -> figcraft_doc::NodeId {
    let r = id_of(&s.execute("shape.rectangle", &json!({"x": 0, "y": 0, "width": 20, "height": 10})).unwrap()["id"]).unwrap();
    s.execute("fill.set", &json!({"ids": [r], "color": "#FF0000"})).unwrap();
    r
}

fn fill(s: &Session, id: figcraft_doc::NodeId) -> Color {
    s.doc().unwrap().node(id).unwrap().fills[0].solid_color().unwrap()
}

/// Whether `bytes` holds a PNG chunk of `kind` (with `data`, when given).
fn has_chunk(bytes: &[u8], kind: &[u8; 4], data: Option<&[u8]>) -> bool {
    bytes.windows(4).enumerate().any(|(i, w)| w == kind && data.is_none_or(|d| bytes.get(i + 4..i + 4 + d.len()) == Some(d)))
}

#[test]
fn color_profile_converts_or_assigns_and_undoes() {
    let mut s = Session::new();
    let r = red_rect(&mut s);
    let v = s.execute("file.colorProfile", &json!({"profile": "displayP3"})).unwrap();
    assert_eq!(v, json!({"profile": "displayP3", "changed": true}));
    assert_eq!(s.doc().unwrap().color_profile, ColorProfile::DisplayP3);
    let p3 = fill(&s, r);
    assert_eq!(p3, ColorProfile::Srgb.conversion_to(ColorProfile::DisplayP3).apply(Color::new(1.0, 0.0, 0.0, 1.0)), "kept the appearance");
    s.execute("edit.undo", &json!({})).unwrap();
    assert_eq!(s.doc().unwrap().color_profile, ColorProfile::Srgb);
    assert_eq!(fill(&s, r).to_hex(), "FF0000");
    // Keep the values: only the profile changes.
    s.execute("file.colorProfile", &json!({"profile": "Display P3", "convert": false})).unwrap();
    assert_eq!(fill(&s, r).to_hex(), "FF0000");
    assert_eq!(s.doc().unwrap().color_profile, ColorProfile::DisplayP3);
    // The same profile again changes nothing (and adds no undo step).
    let undo = s.ds().unwrap().history.undo.len();
    assert_eq!(s.execute("file.colorProfile", &json!({"profile": "p3"})).unwrap()["changed"], false);
    assert_eq!(s.ds().unwrap().history.undo.len(), undo);
    assert!(s.execute("file.colorProfile", &json!({"profile": "cmyk"})).is_err());
}

#[test]
fn color_profile_without_a_profile_asks_the_ui() {
    let mut s = Session::new();
    let v = s.execute("file.colorProfile", &json!({})).unwrap();
    assert_eq!(v["profile"], "srgb");
    assert!(s.ui_requests.iter().any(|u| u.kind == "dialog.colorProfile"));
    assert!(s.ds().unwrap().history.undo.is_empty());
}

#[test]
fn exports_are_tagged_with_the_profile() {
    let mut s = Session::new();
    let r = red_rect(&mut s);
    let png = |s: &mut Session, format: &str| {
        let v = s.execute("file.export", &json!({"ids": [r], "format": format})).unwrap();
        base64::Engine::decode(&base64::engine::general_purpose::STANDARD, v["data"].as_str().unwrap()).unwrap()
    };
    let srgb = png(&mut s, "png");
    assert!(has_chunk(&srgb, b"sRGB", None) && !has_chunk(&srgb, b"iCCP", None) && !has_chunk(&srgb, b"cICP", None));
    s.execute("file.colorProfile", &json!({"profile": "displayP3"})).unwrap();
    let p3 = png(&mut s, "png");
    assert!(has_chunk(&p3, b"iCCP", None) && has_chunk(&p3, b"cICP", Some(&[12, 13, 0, 1])) && !has_chunk(&p3, b"sRGB", None));
    for f in ["jpg", "webp"] {
        assert!(png(&mut s, f).windows(4).any(|w| w == b"mntr"), "{f} embeds the ICC profile");
    }
    // SVG colours are sRGB: the converted red goes back to #FF0000.
    let svg = String::from_utf8(png(&mut s, "svg")).unwrap().to_ascii_uppercase();
    assert!(svg.contains("#FF0000"), "{svg}");
    let pdf = png(&mut s, "pdf");
    assert!(pdf.starts_with(b"%PDF"));
}

#[test]
fn color_profile_survives_save_and_load() {
    let mut s = Session::new();
    s.execute("file.colorProfile", &json!({"profile": "displayP3", "convert": false})).unwrap();
    let bytes = crate::cmd::file::file_bytes(s.ds().unwrap()).unwrap();
    let (doc, _) = figcraft_format::load_bytes(&bytes).unwrap();
    assert_eq!(doc.color_profile, ColorProfile::DisplayP3);
}

fn image_rect(s: &mut Session) -> figcraft_doc::NodeId {
    let r = red_rect(s);
    s.execute("fill.add", &json!({"ids": [r], "paint": {"type": "image", "image": "img"}})).unwrap();
    r
}

fn filters(s: &Session, id: figcraft_doc::NodeId) -> figcraft_color::ImageFilters {
    match &s.doc().unwrap().node(id).unwrap().fills[1].kind {
        figcraft_color::PaintKind::Image(img) => img.filters,
        _ => panic!("not an image"),
    }
}

#[test]
fn image_presets_apply_combine_and_reset() {
    let mut s = Session::new();
    let r = image_rect(&mut s);
    let v = s.execute("image.adjust", &json!({"ids": [r], "preset": "Black & white"})).unwrap();
    assert_eq!(v["changed"], 1);
    assert_eq!(filters(&s, r).saturation, -1.0);
    assert_eq!(s.doc().unwrap().node(r).unwrap().fills[0].solid_color().unwrap().to_hex(), "FF0000", "solid fills untouched");
    // Values apply over a preset, or over what the paint has.
    s.execute("image.adjust", &json!({"ids": [r], "preset": "warm", "filters": {"exposure": 0.25}})).unwrap();
    let f = filters(&s, r);
    assert_eq!((f.temperature, f.exposure, f.saturation), (0.5, 0.25, 0.1));
    s.execute("image.adjust", &json!({"ids": [r], "filters": {"tint": 7}})).unwrap();
    assert_eq!(filters(&s, r).tint, 1.0, "clamped");
    s.execute("image.adjust", &json!({"ids": [r], "preset": "reset"})).unwrap();
    assert!(filters(&s, r).is_identity());
    s.execute("edit.undo", &json!({})).unwrap();
    assert_eq!(filters(&s, r).tint, 1.0, "one undo step per adjust");
}

#[test]
fn image_adjust_refuses_what_it_cannot_do() {
    let mut s = Session::new();
    let plain = red_rect(&mut s);
    let r = image_rect(&mut s);
    assert!(s.execute("image.adjust", &json!({"ids": [plain], "preset": "vivid"})).is_err(), "no image paint");
    assert!(s.execute("image.adjust", &json!({"ids": [r], "preset": "sepia"})).is_err(), "unknown preset");
    assert!(s.execute("image.adjust", &json!({"ids": [r]})).is_err(), "nothing to set");
    assert!(s.execute("image.adjust", &json!({"ids": [r], "filters": {"glow": 1}})).is_err());
    assert!(s.execute("image.adjust", &json!({"ids": [r], "index": 0, "preset": "vivid"})).is_err(), "index 0 is the solid fill");
    assert!(s.execute("image.adjust", &json!({"ids": [r], "target": "stroke", "preset": "vivid"})).is_err());
    assert!(s.execute("image.adjust", &json!({"ids": [r], "target": "glow", "preset": "vivid"})).is_err());
    // Mixed selections adjust the layers that have images.
    assert_eq!(s.execute("image.adjust", &json!({"ids": [plain, r], "index": 1, "preset": "vivid"})).unwrap()["changed"], 1);
}

#[test]
fn saved_image_presets() {
    let mut s = Session::new();
    let r = image_rect(&mut s);
    s.execute("image.adjust", &json!({"ids": [r], "filters": {"contrast": 0.4, "shadows": -0.2}})).unwrap();
    let v = s.execute("image.savePreset", &json!({"ids": [r], "name": "  Moody "})).unwrap();
    assert_eq!(v["name"], "Moody");
    s.execute("image.adjust", &json!({"ids": [r], "preset": "reset"})).unwrap();
    s.execute("image.adjust", &json!({"ids": [r], "preset": "Moody"})).unwrap();
    assert_eq!((filters(&s, r).contrast, filters(&s, r).shadows), (0.4, -0.2));
    // Same name replaces; explicit values need no selection.
    s.execute("image.savePreset", &json!({"name": "Moody", "filters": {"exposure": -0.5}})).unwrap();
    let list = s.execute("image.presets", &json!({})).unwrap();
    assert_eq!(list["saved"].as_array().unwrap().len(), 1);
    assert_eq!(list["saved"][0]["filters"]["exposure"], -0.5);
    assert_eq!(list["builtIn"].as_array().unwrap().len(), figcraft_color::ImageFilters::PRESETS.len());
    // Saved presets travel with the file.
    let bytes = crate::cmd::file::file_bytes(s.ds().unwrap()).unwrap();
    assert_eq!(figcraft_format::load_bytes(&bytes).unwrap().0.image_presets.len(), 1);
    s.execute("image.deletePreset", &json!({"name": "Moody"})).unwrap();
    assert!(s.execute("image.deletePreset", &json!({"name": "Moody"})).is_err());
    assert!(s.execute("image.savePreset", &json!({"name": " "})).is_err());
    let plain = red_rect(&mut s);
    assert!(s.execute("image.savePreset", &json!({"ids": [plain], "name": "X"})).is_err(), "no image to save from");
}