"""Reproducible synthetic fixtures and CPU-only codec oracle, never browser QA."""
import sys, json, hashlib
from pathlib import Path
from PIL import Image, ImageOps
import numpy as np

if sys.argv[1] == 'generate':
    root = Path(sys.argv[2]); root.mkdir(parents=True, exist_ok=True)
    rng = np.random.default_rng(20261007)
    width, height = 4032, 3024
    pixels = rng.integers(0, 256, (height, width, 3), dtype=np.uint8)
    rgb = Image.fromarray(pixels)
    alpha = Image.new('L', (width, height), 0)
    alpha.paste(64, (width//2, 0, width, height//2))
    alpha.paste(192, (0, height//2, width//2, height))
    alpha.paste(255, (width//2, height//2, width, height))
    rgba = rgb.copy(); rgba.putalpha(alpha)
    for name, image, orientation, options in [
        ('phone-12mp-rotated.jpg', rgb, 6, {'quality':95}),
        ('phone-12mp-alpha-rotated.png', rgba, 8, {}),
        ('phone-12mp-alpha-mirrored.webp', rgba, 2, {'lossless':True}),
    ]:
        exif = Image.Exif(); exif[274] = orientation
        image.save(root / name, exif=exif, **options)
    # Large pixel count with tiny encoded size exercises the pixel resource guard.
    Image.new('RGBA', (8000,6000), (19,101,224,128)).save(root/'phone-48mp-alpha.png')
    print(json.dumps({'directory':str(root),'files':[p.name for p in sorted(root.iterdir())]}))
else:
    path = Path(sys.argv[2])
    with Image.open(path) as source:
        source_width, source_height = source.size
        orientation = source.getexif().get(274, 1)
        oriented = ImageOps.exif_transpose(source).convert('RGBA')
    if len(sys.argv) > 3:
        oriented = oriented.resize((int(sys.argv[3]), int(sys.argv[4])), Image.Resampling.LANCZOS)
    corners = [oriented.getpixel(point) for point in [(0,0),(oriented.width-1,0),(0,oriented.height-1),(oriented.width-1,oriented.height-1)]]
    # Verify transparent/partial-alpha values survive a local lossless PNG adapter.
    import io
    encoded = io.BytesIO(); oriented.save(encoded, format='PNG')
    decoded = Image.open(io.BytesIO(encoded.getvalue())).convert('RGBA')
    assert decoded.tobytes() == oriented.tobytes()
    print(json.dumps({'width':oriented.width,'height':oriented.height,'sourceWidth':source_width,'sourceHeight':source_height,'orientation':orientation,'corners':corners,'alphaExtrema':oriented.getchannel('A').getextrema(),'sourceBytes':path.stat().st_size,'workingPngBytes':len(encoded.getvalue()),'sourceRGBABytes':source_width*source_height*4,'workingRGBABytes':oriented.width*oriented.height*4,'sha256':hashlib.sha256(path.read_bytes()).hexdigest(),'pngRoundTripExact':True}))