import imdb
import jsonfile

ABOUT_FILE = "about.json"
MEDIA_KINDS = {
    "show": {"key": "shows", "label": "TV show", "omdb_type": "series"},
    "movie": {"key": "movies", "label": "movie", "omdb_type": "movie"}
}


def load_items(kind: str) -> tuple[dict, list[dict]]:
    data = jsonfile.load(ABOUT_FILE)
    return data, data.setdefault(MEDIA_KINDS[kind]["key"], [])


def find_index(items: list[dict], text: str) -> int | None:
    identifier = imdb.imdb_id(text)
    for index, item in enumerate(items):
        if identifier and imdb.imdb_id(item.get("url", "")) == identifier:
            return index
        if item.get("name", "").lower() == text.lower():
            return index
    return None


def valid_rating(value: str) -> int:
    rating = int(value)
    if not 0 <= rating <= 10:
        raise ValueError("Rating must be between 0 and 10")
    return rating


def list_items(arguments) -> None:
    _, items = load_items(arguments.kind)
    if not items:
        print(f"No {MEDIA_KINDS[arguments.kind]['label']}s yet.")
        return
    for item in sorted(items, key=lambda entry: -entry.get("rating", 0)):
        print(f"{item.get('rating', '?'):>3}/10  {item.get('name')}  {item.get('url')}")


def resolve_name(arguments, identifier: str) -> str | None:
    if arguments.name:
        return arguments.name
    details = imdb.lookup(identifier)
    if not details:
        print("Could not look up the title. Pass --name, or set OMDB_API_KEY in .env.")
        return None
    expected_type = MEDIA_KINDS[arguments.kind]["omdb_type"]
    if details.get("Type") != expected_type:
        print(f"Warning: OMDb lists {details.get('Title')} as a {details.get('Type')}, not a {expected_type}.")
    return details.get("Title")


def add_item(arguments) -> None:
    identifier = imdb.imdb_id(arguments.title)
    if not identifier:
        print(f"{arguments.title} is not an IMDb link or ID.")
        return
    data, items = load_items(arguments.kind)
    if find_index(items, identifier) is not None:
        print(f"{identifier} is already listed. Use rate to change its rating.")
        return
    name = resolve_name(arguments, identifier)
    if not name:
        return
    items.append({"name": name, "rating": arguments.rating, "url": imdb.title_url(identifier)})
    jsonfile.save(ABOUT_FILE, data)
    print(f"Added {name} ({arguments.rating}/10)")


def remove_item(arguments) -> None:
    data, items = load_items(arguments.kind)
    index = find_index(items, arguments.title)
    if index is None:
        print(f"{arguments.title} is not listed.")
        return
    removed = items.pop(index)
    jsonfile.save(ABOUT_FILE, data)
    print(f"Removed {removed.get('name')}")


def rate_item(arguments) -> None:
    data, items = load_items(arguments.kind)
    index = find_index(items, arguments.title)
    if index is None:
        print(f"{arguments.title} is not listed.")
        return
    items[index]["rating"] = arguments.rating
    jsonfile.save(ABOUT_FILE, data)
    print(f"Rated {items[index].get('name')} {arguments.rating}/10")


def register(subparsers) -> None:
    for kind, settings in MEDIA_KINDS.items():
        parser = subparsers.add_parser(kind, help=f"Manage the {settings['label']}s on the about page")
        parser.set_defaults(kind=kind)
        actions = parser.add_subparsers(dest="action", required=True)

        actions.add_parser("list", help=f"List {settings['label']}s").set_defaults(handler=list_items)

        add_parser = actions.add_parser("add", help=f"Add a {settings['label']} by IMDb link or ID")
        add_parser.add_argument("title", help="IMDb link or ID, like tt0816692")
        add_parser.add_argument("--rating", type=valid_rating, required=True, help="Your rating from 0 to 10")
        add_parser.add_argument("--name", help="Display name, looked up on OMDb when left out")
        add_parser.set_defaults(handler=add_item)

        remove_parser = actions.add_parser("remove", help=f"Remove a {settings['label']}")
        remove_parser.add_argument("title", help="IMDb link, ID or name")
        remove_parser.set_defaults(handler=remove_item)

        rate_parser = actions.add_parser("rate", help=f"Change a {settings['label']}'s rating")
        rate_parser.add_argument("title", help="IMDb link, ID or name")
        rate_parser.add_argument("rating", type=valid_rating, help="New rating from 0 to 10")
        rate_parser.set_defaults(handler=rate_item)