import argparse
import shutil
import sys
from pathlib import Path

from PIL import Image, ImageOps
from pillow_heif import register_heif_opener

from jsonfile import PROJECT_ROOT

FILES_DIR = PROJECT_ROOT / "static" / "files"
ORIGINALS_DIR = PROJECT_ROOT / "tools" / "content" / ".cache" / "heic-originals"
HEIC_EXTENSIONS = {".heic", ".heif"}
PHOTO_EXTENSIONS = {".jpg", ".jpeg", ".png", ".webp"}
JPEG_QUALITY = 90
GPS_TAG = 0x8825

register_heif_opener()


def visible_files(folder: Path, extensions: set[str]) -> list[Path]:
    return sorted(
        path
        for path in folder.rglob("*")
        if path.is_file() and path.suffix.lower() in extensions and not any(part.startswith(".") for part in path.relative_to(folder).parts)
    )


def save_without_metadata(image: Image.Image, target: Path) -> None:
    upright = ImageOps.exif_transpose(image)
    if target.suffix.lower() in {".jpg", ".jpeg"}:
        upright.convert("RGB").save(target, "JPEG", quality=JPEG_QUALITY, optimize=True)
    else:
        upright.save(target)


def keep_original(source: Path) -> Path:
    backup = ORIGINALS_DIR / source.relative_to(FILES_DIR)
    backup.parent.mkdir(parents=True, exist_ok=True)
    shutil.move(source, backup)
    return backup


def convert_heic(source: Path, delete_originals: bool) -> str:
    target = source.with_suffix(".jpg")
    if target.exists():
        return f"skipped {source.relative_to(FILES_DIR)}, {target.name} already exists"
    with Image.open(source) as image:
        save_without_metadata(image, target)
    if delete_originals:
        source.unlink()
        return f"converted {target.relative_to(FILES_DIR)}"
    return f"converted {target.relative_to(FILES_DIR)}, original kept in {keep_original(source).relative_to(PROJECT_ROOT)}"


def has_location(path: Path) -> bool:
    try:
        with Image.open(path) as image:
            return bool(image.getexif().get_ifd(GPS_TAG))
    except OSError:
        return False


def strip_location(path: Path) -> str:
    with Image.open(path) as image:
        image.load()
        save_without_metadata(image, path)
    return f"removed location from {path.relative_to(FILES_DIR)}"


def report(action) -> int:
    try:
        print(action())
        return 0
    except (OSError, ValueError) as error:
        print(f"Error: {error}", file=sys.stderr)
        return 1


def main() -> int:
    parser = argparse.ArgumentParser(description="Convert HEIC photos in static/files to JPEG and remove location data from photos")
    parser.add_argument("--delete-originals", action="store_true", help="delete converted HEIC files instead of moving them to tools/content/.cache")
    parser.add_argument("--keep-location", action="store_true", help="leave GPS data in existing photos")
    arguments = parser.parse_args()

    if not FILES_DIR.exists():
        print(f"{FILES_DIR.relative_to(PROJECT_ROOT)} does not exist", file=sys.stderr)
        return 1

    heic_files = visible_files(FILES_DIR, HEIC_EXTENSIONS)
    located_photos = [] if arguments.keep_location else [photo for photo in visible_files(FILES_DIR, PHOTO_EXTENSIONS) if has_location(photo)]
    if not heic_files and not located_photos:
        print("Nothing to do: no HEIC files and no photos with location data")
        return 0

    failed = 0
    for source in heic_files:
        failed += report(lambda: convert_heic(source, arguments.delete_originals))
    for photo in located_photos:
        failed += report(lambda: strip_location(photo))
    print(f"Done: {len(heic_files) + len(located_photos) - failed} changed, {failed} failed")
    return 1 if failed else 0


if __name__ == "__main__":
    sys.exit(main())