//! Test: read Example3-mini.psd, then save it as hcie PSD and compare
//! layer records with the original.

fn main() {
    let input_path = "/mnt/extra/00_PROJECTS/hcie-rust-_images/_test_images/example3/Example3-mini.psd";
    let output_path = "/mnt/extra/00_PROJECTS/hcie-rust-_images/_test_images/example3/Example3-mini-hcie-v2.psd";

    println!("Reading original PSD...");
    let orig_bytes = std::fs::read(input_path).unwrap();
    
    // Import via hcie-psd
    let layers = hcie_psd::psd_import::import_psd(std::path::Path::new(input_path)).unwrap();
    println!("Imported {} layers", layers.len());
    
    for (i, l) in layers.iter().enumerate() {
        println!("  Layer {}: \"{}\" blend={:?} opacity={} visible={} type={:?} mask={:?} adj={} div={}", 
            i, l.name, l.blend_mode, l.opacity, l.visible, l.layer_type,
            l.mask_bounds.is_some(), l.adjustment_raw.is_some(), l.is_section_divider);
    }
    
    // Read canvas from PSD header
    let psd = hcie_psd::Psd::from_bytes(&orig_bytes).unwrap();
    let canvas_w = psd.width();
    let canvas_h = psd.height();
    println!("Canvas: {}x{}", canvas_w, canvas_h);
    
    // Create composited image (simple white background for now)
    let composited = vec![255u8; (canvas_w * canvas_h * 4) as usize];
    
    // Save
    println!("Saving to {}...", output_path);
    hcie_psd_saver::save_psd(&layers, canvas_w, canvas_h, &composited, std::path::Path::new(output_path)).unwrap();
    println!("Saved!");
    
    // Now compare the saved output with original
    let saved_bytes = std::fs::read(output_path).unwrap();
    
    println!("\n=== Comparison ===");
    println!("Original: {} bytes", orig_bytes.len());
    println!("Saved:    {} bytes", saved_bytes.len());
    
    // Compare layer records
    println!("\n--- Original ---");
    dump_layer_meta(&orig_bytes, "ORIG");
    println!("\n--- Saved ---");
    dump_layer_meta(&saved_bytes, "SAVE");
}

fn dump_layer_meta(data: &[u8], label: &str) {
    let mut pos = 26;
    let cm_len = u32::from_be_bytes([data[pos], data[pos+1], data[pos+2], data[pos+3]]) as usize;
    pos += 4 + cm_len;
    let ir_len = u32::from_be_bytes([data[pos], data[pos+1], data[pos+2], data[pos+3]]) as usize;
    pos += 4 + ir_len;
    let _lm_len = u32::from_be_bytes([data[pos], data[pos+1], data[pos+2], data[pos+3]]) as usize;
    pos += 4;
    let _li_len = u32::from_be_bytes([data[pos], data[pos+1], data[pos+2], data[pos+3]]) as usize;
    pos += 4;
    let layer_count = i16::from_be_bytes([data[pos], data[pos+1]]).unsigned_abs() as usize;
    pos += 2;

    for idx in 0..layer_count {
        pos += 16; // bounds
        let ch_count = u16::from_be_bytes([data[pos], data[pos+1]]) as usize;
        pos += 2;
        let mut channels = Vec::new();
        for _ in 0..ch_count {
            let id = i16::from_be_bytes([data[pos], data[pos+1]]);
            let len = u32::from_be_bytes([data[pos+2], data[pos+3], data[pos+4], data[pos+5]]) as usize;
            channels.push((id, len));
            pos += 6;
        }
        pos += 4; // sig
        let blend_key = std::str::from_utf8(&data[pos..pos+4]).unwrap_or("????");
        pos += 4;
        let opacity = data[pos]; pos += 1;
        let clipping = data[pos]; pos += 1;
        let flags = data[pos]; pos += 1;
        pos += 1; // filler

        let extra_len = u32::from_be_bytes([data[pos], data[pos+1], data[pos+2], data[pos+3]]) as usize;
        pos += 4;
        let extra_start = pos;

        let mask_len = u32::from_be_bytes([data[pos], data[pos+1], data[pos+2], data[pos+3]]) as usize;
        pos += 4;
        let mask_hex = if mask_len > 0 {
            let show = mask_len.min(30);
            let hex: Vec<String> = data[pos..pos+show].iter().map(|b| format!("{:02x}", b)).collect();
            hex.join(" ")
        } else { "none".to_string() };
        pos += mask_len;

        let br_len = u32::from_be_bytes([data[pos], data[pos+1], data[pos+2], data[pos+3]]) as usize;
        pos += 4 + br_len;

        let name_len = data[pos] as usize;
        pos += 1;
        let name = String::from_utf8_lossy(&data[pos..pos + name_len]).to_string();
        pos += name_len;
        let pascal_total = 1 + name_len;
        let pad = (4 - (pascal_total % 4)) % 4;
        pos += pad;

        let ch_str = channels.iter().map(|(id, len)| format!("{}:{}", id, len)).collect::<Vec<_>>().join(",");
        print!("[{}] L{}: \"{}\" blend={} op={} clip={} flags={:08b} ch=[{}] mask_len={}", 
            label, idx, name, blend_key, opacity, clipping, flags, ch_str, mask_len);
        
        // Check for lsct
        let mut tag_pos = pos;
        while tag_pos < extra_start + extra_len {
            let tag_sig = &data[tag_pos..tag_pos+4];
            if tag_sig != b"8BIM" && tag_sig != b"8B64" { break; }
            tag_pos += 4;
            let key = std::str::from_utf8(&data[tag_pos..tag_pos+4]).unwrap_or("????");
            tag_pos += 4;
            let block_len = u32::from_be_bytes([data[tag_pos], data[tag_pos+1], data[tag_pos+2], data[tag_pos+3]]) as usize;
            tag_pos += 4;
            
            if key == "lsct" {
                let section_type = if block_len >= 4 {
                    u32::from_be_bytes([data[tag_pos], data[tag_pos+1], data[tag_pos+2], data[tag_pos+3]])
                } else { 999 };
                let blend = if block_len >= 12 {
                    std::str::from_utf8(&data[tag_pos+8..tag_pos+12]).unwrap_or("????").to_string()
                } else { "n/a".to_string() };
                print!(" lsct:type={},blend={}", section_type, blend);
            }
            
            tag_pos += block_len;
            if block_len % 2 != 0 { tag_pos += 1; }
        }
        
        println!();
        if mask_len > 0 {
            println!("      mask: {}", mask_hex);
        }
        
        pos = extra_start + extra_len;
    }
}