#!/usr/bin/env python3
"""Deterministically package imagegen artwork and synthesize mission PCM cues.

Source artwork is generated by the built-in image tool. This packaging step
only resizes/quantizes it and slices a shared terrain canvas; it paints no art.
"""
import argparse
import hashlib
import json
import math
import random
import struct
import wave
from pathlib import Path
from PIL import Image, ImageOps

ROOT = Path(__file__).resolve().parent


def palette_image(path):
    raw = path.read_bytes()
    if len(raw) != 768:
        raise ValueError("expected 768-byte original VGA palette")
    colors = [(min(v, 63) << 2) | (min(v, 63) >> 4) for v in raw]
    palette = Image.new("P", (1, 1))
    palette.putpalette(colors)
    return palette, colors


def sd(source, size, palette):
    resized = source.convert("RGB").resize(size, Image.Resampling.LANCZOS)
    return resized.quantize(palette=palette, dither=Image.Dither.NONE).convert("RGBA")


def synth(name, duration, notes, alarm=False):
    rate = 22050
    rng = random.Random(70404 + sum(map(ord, name)))
    samples = bytearray()
    for i in range(int(rate * duration)):
        t = i / rate
        segment = min(len(notes) - 1, int(t / duration * len(notes)))
        local = t / duration * len(notes) - segment
        freq = notes[segment]
        envelope = min(1.0, local * 30) * (1 - local) ** 1.3
        tone = math.sin(2 * math.pi * freq * t)
        tone += 0.23 * math.sin(2 * math.pi * freq * 2 * t)
        if alarm:
            tone += 0.14 * math.sin(2 * math.pi * freq * 0.5 * t)
            tone += 0.07 * rng.uniform(-1, 1) * math.exp(-local * 8)
        value = int(tone * envelope * 7800)
        samples.extend(struct.pack("<h", max(-32767, min(32767, value))))
    path = ROOT / "audio" / f"{name}.wav"
    with wave.open(str(path), "wb") as output:
        output.setnchannels(1)
        output.setsampwidth(2)
        output.setframerate(rate)
        output.writeframes(samples)
    return {"file": str(path.relative_to(ROOT)), "seconds": duration,
            "sample_rate": rate, "samples": len(samples) // 2,
            "sha256": hashlib.sha256(path.read_bytes()).hexdigest()}


def main():
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--palette", type=Path,
                        default=ROOT.parents[2] / "data/misc/PALETTE_DAT")
    args = parser.parse_args()
    art = ROOT / "art"
    (ROOT / "audio").mkdir(exist_ok=True)
    palette, colors = palette_image(args.palette)
    source = Image.open(art / "terrain-source-hd.png")
    hd = source.convert("RGBA").resize((1152, 1536), Image.Resampling.LANCZOS)
    standard = sd(source, (288, 384), palette)
    # One full-map palette conversion precedes slicing. Forward/reflected rows
    # form a continuous 24-row period without independently filtered tile edges.
    tile = 0
    for reflected in [False, True]:
        h = ImageOps.flip(hd) if reflected else hd
        s = ImageOps.flip(standard) if reflected else standard
        for row in range(12):
            for column in range(9):
                h.crop((column*128, row*128, (column+1)*128, (row+1)*128)).save(
                    art / f"tile_{tile:03}_hd.png")
                s.crop((column*32, row*32, (column+1)*32, (row+1)*32)).save(
                    art / f"tile_{tile:03}_sd.png")
                tile += 1
    for image in [hd, standard]:
        width, height = image.size
        reflected = ImageOps.flip(image)
        assert image.crop((0,height-1,width,height)).tobytes() == reflected.crop((0,0,width,1)).tobytes()
        assert reflected.crop((0,height-1,width,height)).tobytes() == image.crop((0,0,width,1)).tobytes()
    for scale, master, suffix in [(128,hd,"hd"),(32,standard,"sd")]:
        joined = Image.new("RGBA",(9*scale,24*scale))
        for number in range(216):
            joined.paste(Image.open(art/f"tile_{number:03}_{suffix}.png"),
                         ((number%9)*scale,(number//9)*scale))
        assert joined.crop((0,0,9*scale,12*scale)).tobytes() == master.tobytes()
        assert joined.crop((0,12*scale,9*scale,24*scale)).tobytes() == ImageOps.flip(master).tobytes()
    hd.save(art / "terrain-preview-hd.png")
    standard.save(art / "terrain-preview-sd.png")
    briefing = Image.open(art / "briefing-source-hd.png")
    briefing.convert("RGBA").resize((1280,800), Image.Resampling.LANCZOS).save(art / "briefing_hd.png")
    briefing.convert("RGBA").resize((1280,800), Image.Resampling.LANCZOS).convert("RGB").resize((320,200), Image.Resampling.LANCZOS).save(art / "briefing_sd.png")
    palette_colors = {tuple(colors[i:i+3]) for i in range(0,768,3)}
    rgb_pixels = standard.convert("RGB").tobytes()
    sd_colors = {tuple(rgb_pixels[i:i+3]) for i in range(0,len(rgb_pixels),3)}
    assert sd_colors <= palette_colors
    audio = {
        "approach": synth("approach", 0.9, [130.81, 196.0, 146.83]),
        "battery_alarm": synth("battery_alarm", 0.8, [369.99, 246.94, 369.99, 246.94], True),
        "cruiser_alarm": synth("cruiser_alarm", 1.1, [164.81, 130.81, 98.0], True),
        "victory": synth("victory", 1.15, [293.66, 369.99, 440.0, 587.33]),
    }
    report = {
        "tile_count": tile, "logical_tile_size": [32,32], "hd_tile_size": [128,128],
        "terrain_period_rows": 24, "mission_rows": 96,
        "vertical_repeat": "12 forward rows followed by 12 reflected rows",
        "seam_checks_passed": True, "joined_tile_canvas_checks_passed": True,
        "sd_pixels_match_original_palette": True,
        "actual_sd_unique_colors": len(sd_colors),
        "palette_sha256": hashlib.sha256(args.palette.read_bytes()).hexdigest(),
        "sources": {p.name: {"size": list(Image.open(p).size),
                    "sha256": hashlib.sha256(p.read_bytes()).hexdigest()}
                    for p in art.glob("*-source-hd.png")}, "audio": audio,
    }
    (ROOT / "asset-report.json").write_text(json.dumps(report,indent=2)+"\n")
    print(f"Packaged {tile} SD/HD terrain pairs, briefing pair and {len(audio)} synthesized WAVs")


if __name__ == "__main__":
    main()