"""
Shared coverage calculation utilities for digit templates.

This module provides utilities for calculating template coverage status,
shared between DigitTemplateBuilder and DigitTemplateLibrary.
"""

from typing import Any, Dict, Iterable, Set, Tuple


# Standard digit sets for play clock displays
ONES_DIGITS = set(range(10))  # 0-9
TENS_DIGITS = {1, 2, 3, 4}  # 10, 20, 30, 40


def categorize_template_keys(keys: Iterable[Tuple[bool, int, str]]) -> Tuple[Set[int], Set[int], Set[int], bool]:
    """
    Categorize template keys into digit sets.

    Args:
        keys: Iterable of (is_tens, digit, position) tuples

    Returns:
        Tuple of (ones_center_have, ones_right_have, tens_have, has_blank)
    """
    ones_center_have: Set[int] = set()
    ones_right_have: Set[int] = set()
    tens_have: Set[int] = set()
    has_blank = False

    for is_tens, digit, position in keys:
        if is_tens:
            if digit == -1:
                has_blank = True
            else:
                tens_have.add(digit)
        else:
            if position == "center":
                ones_center_have.add(digit)
            elif position == "right":
                ones_right_have.add(digit)

    return ones_center_have, ones_right_have, tens_have, has_blank


def calculate_coverage_status(
    ones_center_have: Set[int],
    ones_right_have: Set[int],
    tens_have: Set[int],
    has_blank: bool,
    total_items: int = 0,
) -> Dict[str, Any]:
    """
    Calculate coverage status from digit sets.

    Args:
        ones_center_have: Set of ones digits that have center templates
        ones_right_have: Set of ones digits that have right templates
        tens_have: Set of tens digits that have templates
        has_blank: Whether blank template exists
        total_items: Total number of items (templates or samples)

    Returns:
        Dictionary with coverage information
    """
    ones_center_missing = ONES_DIGITS - ones_center_have
    ones_right_missing = ONES_DIGITS - ones_right_have
    tens_missing = TENS_DIGITS - tens_have

    # Total needed: 10 ones_center + 10 ones_right + 4 tens + 1 blank = 25
    total_needed = 25

    return {
        "total_needed": total_needed,
        "total_have": total_items,
        "is_complete": total_items >= total_needed,
        "ones_center_have": sorted(ones_center_have),
        "ones_center_missing": sorted(ones_center_missing),
        "ones_right_have": sorted(ones_right_have),
        "ones_right_missing": sorted(ones_right_missing),
        "tens_have": sorted(tens_have),
        "tens_missing": sorted(tens_missing),
        "has_blank": has_blank,
    }