"""Inspect actual PDF raster pixels at both sidebar edges on every exported page."""
import argparse
import json
import re
from pathlib import Path

from PIL import Image, ImageDraw


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument("directory", type=Path)
    args = parser.parse_args()
    source = json.loads((args.directory / "measurements.json").read_text(encoding="utf-8"))
    results = []
    for fixture in source["fixtures"]:
        if not fixture["fixture"].endswith(("-technical", "-creative", "-nordic")):
            continue
        html = (args.directory / fixture["fixture"] / "render.html").read_text(encoding="utf-8")
        color = re.search(r"--cv-sidebar-bg:(#[0-9a-fA-F]{6})", html)
        if not color:
            continue
        expected = tuple(int(color[1][index:index + 2], 16) for index in (1, 3, 5))
        for number in range(1, fixture["previewPages"] + 1):
            with Image.open(args.directory / fixture["fixture"] / f"pdf-{number}.png") as image:
                image = image.convert("RGB")
                # 2px and 8px lie inside the bleed and outside the 8mm text padding.
                columns = [image.width - 3, image.width - 9] if fixture["fixture"].endswith("-nordic") else [2, 8]
                samples = []
                for x in columns:
                    mismatched = [y for y in range(image.height) if max(abs(a - b) for a, b in zip(image.getpixel((x, y)), expected)) > 2]
                    samples.append({"x": x, "expectedRgb": expected, "height": image.height,
                                    "mismatchedRows": len(mismatched), "firstMismatchRows": mismatched[:8],
                                    "topPixel": image.getpixel((x, 0)), "bottomPixel": image.getpixel((x, image.height - 1))})
                results.append({"fixture": fixture["fixture"], "page": number, "pass": all(sample["mismatchedRows"] == 0 for sample in samples), "samples": samples})
    report = {"rasterizer": "pypdfium2 via unchanged verify-cv-fidelity.py, actual exported PDF bytes",
              "colorTolerancePerChannel": 2, "passedPages": sum(item["pass"] for item in results), "pages": len(results), "results": results}
    (args.directory / "sidebar-pixels.json").write_text(json.dumps(report, indent=2), encoding="utf-8")
    print(f"Full-height sidebar raster coverage: {report['passedPages']}/{report['pages']} pages")

    # Contact sheets use independent Poppler first/last rasterizations.
    for sample in ("short-en", "medium-nb", "long-en", "dense-nb"):
        fixtures = [item for item in source["fixtures"] if item["fixture"].startswith(sample + "-")]
        for edge in ("first", "last"):
            sheet = Image.new("RGB", (900, 1365), "#e5e7eb")
            draw = ImageDraw.Draw(sheet)
            for index, fixture in enumerate(fixtures):
                page = 1 if edge == "first" else fixture["previewPages"]
                filename = args.directory / fixture["fixture"] / f"poppler-{page}.png"
                if not filename.exists():
                    raise FileNotFoundError(filename)
                with Image.open(filename) as image:
                    image = image.convert("RGB")
                    image.thumbnail((286, 414))
                    x, y = (index % 3) * 300 + 7, (index // 3) * 455 + 32
                    sheet.paste(image, (x, y))
                    draw.text((x, y - 25), f"{fixture['fixture']} p{page}/{fixture['previewPages']}", fill="#111827")
            sheet.save(args.directory / f"contact-{sample}-{edge}.png")
    raise SystemExit(0 if report["passedPages"] == report["pages"] and report["pages"] > 0 else 1)


if __name__ == "__main__":
    main()