#!/usr/bin/env python3
"""Generate lossless RLE assets; PNGs remain the editable source of truth."""
from pathlib import Path
from PIL import Image

ROOT = Path(__file__).resolve().parents[1]
LAYERS = ROOT / "components/platform/assets/lcd_layers/jichubiaoqing"
GENERATED = ROOT / "components/platform/src/generated/emote_gfx"


def pixels565(image):
    result = []
    for r, g, b, a in image.convert("RGBA").getdata():
        color = ((r >> 3) << 11) | ((g >> 2) << 5) | (b >> 3)
        result.append((color >> 8, color & 255, a))
    return result


def encode(pixels):
    out = bytearray()
    for pixel in pixels:
        if out and tuple(out[-3:]) == pixel and out[-4] < 255:
            out[-4] += 1
        else:
            out.extend((1, *pixel))
    # Round-trip validation for every generated asset.
    decoded = []
    for i in range(0, len(out), 4):
        decoded.extend([tuple(out[i + 1:i + 4])] * out[i])
    assert decoded == pixels
    return out


def generate(name, image, x, y):
    data = encode(pixels565(image))
    rows = ["    " + ", ".join(f"0x{v:02x}" for v in data[i:i + 24]) + ","
            for i in range(0, len(data), 24)]
    text = ('/* Generated by tools/compress_idle_expression.py; do not edit. */\n'
            '#include "lcd_emote_assets.h"\n\n'
            f'static const uint8_t {name}_rle[] = {{\n' + '\n'.join(rows) + '\n};\n\n'
            f'const lcd_emote_rle_asset_t {name}_rle_asset = {{\n'
            f'    .width = {image.width}, .height = {image.height}, .x = {x}, .y = {y},\n'
            f'    .compressed_size = sizeof({name}_rle), .data = {name}_rle,\n}};\n')
    GENERATED.mkdir(parents=True, exist_ok=True)
    (GENERATED / f"{name}.c").write_text(text)
    print(f"{name}: {image.width}x{image.height} at ({x},{y}), "
          f"raw={image.width * image.height * 3}B compressed={len(data)}B")


def main():
    base = Image.open(LAYERS / "idle_base.png").convert("RGBA")
    # Pure black is supplied by the display, preserving all nonblack RGB565 pixels.
    rgba = list(base.getdata())
    rgba = [(r, g, b, 255 if ((r >> 3) or (g >> 2) or (b >> 3)) else 0)
            for r, g, b, _ in rgba]
    base.putdata(rgba)
    bbox = base.getbbox()
    assert bbox is not None
    generate("idle_base", base.crop(bbox), bbox[0], bbox[1])
    eyes = Image.open(LAYERS / "idle_eyes_open.png").convert("RGBA")
    assert eyes.size == (238, 93), "eye geometry must match the mesh layout"
    generate("idle_eyes_open", eyes, 41, 65)


if __name__ == "__main__":
    main()