//! Scratch: confirm the `.rat` layout record offsets against a real screen pak.
//! Run: cargo run -p sylpheed-formats --example rat_inspect -- <GP_SCREEN.pak>
use sylpheed_formats::{pak::PakArchive, ratc, t8ad};

fn be32(b: &[u8], o: usize) -> u32 {
    u32::from_be_bytes([b[o], b[o + 1], b[o + 2], b[o + 3]])
}

fn main() {
    let path = std::env::args().nth(1).expect("pak path");
    let ar = PakArchive::open(&path).expect("open pak");
    println!("entries: {}", ar.len());

    let mut decoded: Vec<Vec<u8>> = Vec::new();
    for (i, e) in ar.entries().iter().enumerate() {
        let d = ar.read(e).unwrap_or_default();
        let magic = String::from_utf8_lossy(&d[..4.min(d.len())]).to_string();
        let (nt, nr) = if ratc::is_ratc(&d) {
            let k = ratc::parse(&d).unwrap_or_default();
            (
                k.iter().filter(|c| c.kind == "T8aD").count(),
                k.iter()
                    .filter(|c| c.name.to_lowercase().ends_with(".rat"))
                    .count(),
            )
        } else {
            (0, 0)
        };
        println!(
            "  entry[{:2}] {:>8} B  magic={:4}  t32={:2} rat={:2}",
            i,
            d.len(),
            magic,
            nt,
            nr
        );
        decoded.push(d);
    }
    // Pick the entry with the most children as "build0".
    let bi = (0..decoded.len())
        .filter(|&i| ratc::is_ratc(&decoded[i]))
        .max_by_key(|&i| ratc::parse(&decoded[i]).map(|k| k.len()).unwrap_or(0))
        .unwrap();
    println!("=> inspecting richest build: entry[{}]", bi);
    let bundle = &decoded[bi];
    let kids = ratc::parse(bundle).unwrap_or_default();
    let t32: Vec<_> = kids.iter().filter(|c| c.kind == "T8aD").collect();
    let rat: Vec<_> = kids
        .iter()
        .filter(|c| c.name.to_lowercase().ends_with(".rat"))
        .collect();
    println!(
        "build0: {} children, {} t32 sprites, {} rat records",
        kids.len(),
        t32.len(),
        rat.len()
    );
    for c in t32.iter().take(5) {
        let b = &bundle[c.offset..(c.offset + c.size).min(bundle.len())];
        if let Some(img) = t8ad::parse(b) {
            println!("  T8aD  {:28} {}x{}", c.name, img.width, img.height);
        }
    }
    println!("  -- .rat records --");
    for c in rat.iter().take(10) {
        let r = &bundle[c.offset..(c.offset + c.size).min(bundle.len())];
        if r.len() < 0x60 {
            println!("  .rat {:20} (len {}, too short)", c.name, r.len());
            continue;
        }
        let (dw, dh) = (be32(r, 0x18), be32(r, 0x1c));
        let sprite = {
            let s = &r[0x20..0x30.min(r.len())];
            let end = s.iter().position(|&b| b == 0).unwrap_or(s.len());
            String::from_utf8_lossy(&s[..end]).to_string()
        };
        let (pvx, pvy) = (be32(r, 0x50), be32(r, 0x54));
        // scan for placement block [scaleX=100, scaleY=100, tint, X<dw, Y<dh]
        let mut placement = None;
        let mut o = 0x58;
        while o + 20 <= r.len() {
            if be32(r, o) == 100 && be32(r, o + 4) == 100 {
                let (tint, x, y) = (be32(r, o + 8), be32(r, o + 12), be32(r, o + 16));
                if x < dw && y < dh {
                    placement = Some((o, tint, x, y));
                    break;
                }
            }
            o += 4;
        }
        println!(
            "  .rat {:22} {}x{} sprite={:16} pivot=({},{}) place={:x?}",
            c.name, dw, dh, sprite, pvx, pvy, placement
        );
    }

    // End-to-end: composite the build and write it out as a PNG.
    if let Some(screen) = sylpheed_formats::ui_layout::compose_build(bundle, false) {
        println!(
            "compose: {}x{}, drew {} records: {:?}",
            screen.width,
            screen.height,
            screen.drawn.len(),
            screen.drawn
        );
        if let Some(out) = std::env::args().nth(2) {
            // Dependency-free PPM (P6, RGB — alpha already composited over the backdrop).
            let mut buf = format!("P6\n{} {}\n255\n", screen.width, screen.height).into_bytes();
            for px in screen.rgba.chunks_exact(4) {
                buf.extend_from_slice(&px[..3]);
            }
            std::fs::write(&out, buf).unwrap();
            println!("wrote {out}");
        }
    } else {
        println!("compose: build produced no image");
    }
}