from pathlib import Path

from .assets import load_json, load_rgb
from .settings import BOARD_DECK, DECKS_DIR, BuildConfig

ORIGINAL_BOARD_MM = (88.9, 139.7)
TRIMMED_BOARD_ASPECT_RATIO = ORIGINAL_BOARD_MM[0] / ORIGINAL_BOARD_MM[1]
BOARD_SIZE_OPTIONS_MM = {
    "original": ORIGINAL_BOARD_MM,
    "a6": (105.0, 148.0),
    "a5": (148.0, 210.0),
    "a4": (210.0, 297.0),
    "half-letter": (139.7, 215.9),
    "letter": (215.9, 279.4),
}
BOARD_MODE_CHOICES = tuple(
    [name for name in BOARD_SIZE_OPTIONS_MM]
    + [f"{name}-fit" for name in BOARD_SIZE_OPTIONS_MM]
    + ["custom", "custom-fit"]
)
VISIBLE_BOARD_MODE_CHOICES = ("original", "a6", "a6-fit", "a5", "a5-fit", "half-letter", "half-letter-fit", "custom")


def fit_size_inside(box_mm: tuple[float, float], ratio: float = TRIMMED_BOARD_ASPECT_RATIO) -> tuple[float, float]:
    max_w, max_h = box_mm
    if ratio > max_w / max_h:
        return max_w, max_w / ratio
    return max_h * ratio, max_h


def board_target_mm_for_mode(
    board_path: Path,
    board_mode: str,
    board_custom_mm: tuple[float, float] | None = None,
) -> tuple[float, float]:
    if board_custom_mm is not None:
        if board_mode == "custom-fit":
            return fit_size_inside(board_custom_mm)
        return board_custom_mm

    if board_mode.endswith("-fit"):
        base_mode = board_mode.removesuffix("-fit")
        if base_mode in BOARD_SIZE_OPTIONS_MM and base_mode != "original":
            return fit_size_inside(BOARD_SIZE_OPTIONS_MM[base_mode])

    return BOARD_SIZE_OPTIONS_MM.get(board_mode, ORIGINAL_BOARD_MM)


def board_aspect_ratio(board_path: Path) -> float:
    deck_json = board_path.parent / "deck.json"
    if deck_json.exists():
        meta = load_json(deck_json)
        if meta.get("cardWidth") and meta.get("cardHeight"):
            return float(meta["cardWidth"]) / float(meta["cardHeight"])
    with load_rgb(board_path) as img:
        return img.width / img.height


def board_target_mm(board_path: Path, config: BuildConfig) -> tuple[float, float]:
    return board_target_mm_for_mode(board_path, config.board_mode, config.board_custom_mm)


def board_size_fits_paper(
    board_mode: str,
    board_custom_mm: tuple[float, float] | None,
    paper_mm: tuple[float, float],
    margin_mm: float,
) -> bool:
    usable_w = paper_mm[0] - 2 * margin_mm
    usable_h = paper_mm[1] - 2 * margin_mm
    board_paths = sorted((DECKS_DIR / BOARD_DECK).glob("*-jumbo-front.png"))
    if not board_paths:
        return True
    for board_path in board_paths:
        board_w, board_h = board_target_mm_for_mode(board_path, board_mode, board_custom_mm)
        fits_upright = board_w <= usable_w and board_h <= usable_h
        fits_rotated = board_h <= usable_w and board_w <= usable_h
        if not (fits_upright or fits_rotated):
            return False
    return True


def board_mode_fits_paper(board_mode: str, paper_mm: tuple[float, float], margin_mm: float) -> bool:
    return board_size_fits_paper(board_mode, None, paper_mm, margin_mm)


def crop_board_bleed(img):
    target_w = round(img.width * (3.5 / 3.75))
    target_h = round(img.height * (5.5 / 5.75))
    left = max(0, (img.width - target_w) // 2)
    top = max(0, (img.height - target_h) // 2)
    return img.crop((left, top, left + target_w, top + target_h))