"""五子棋游戏逻辑模块"""
from typing import Optional, Tuple, List, Dict, Any


def create_empty_board() -> List[List[int]]:
    """创建空棋盘
    
    Returns:
        15x15的二维列表，0表示空位
    """
    return [[0] * 15 for _ in range(15)]


def parse_coord(coord_str: str) -> Optional[Tuple[int, int]]:
    """解析坐标字符串
    
    Args:
        coord_str: 如 "A1", "O15", "h8"
        
    Returns:
        (row, col) 或 None
    """
    coord_str = coord_str.strip().upper()
    
    if len(coord_str) < 2:
        return None
    
    # 解析列（A-O）
    col_char = coord_str[0]
    if not ('A' <= col_char <= 'O'):
        return None
    col = ord(col_char) - ord('A')
    
    # 解析行（1-15）
    try:
        row = int(coord_str[1:]) - 1
        if not (0 <= row <= 14):
            return None
    except ValueError:
        return None
    
    return (row, col)


def format_coord(row: int, col: int) -> str:
    """格式化坐标
    
    Args:
        row: 0-14
        col: 0-14
        
    Returns:
        如 "A1", "O15"
    """
    col_char = chr(ord('A') + col)
    row_num = row + 1
    return f"{col_char}{row_num}"


def is_valid_position(row: int, col: int) -> bool:
    """检查坐标是否在棋盘范围内
    
    Args:
        row: 行号
        col: 列号
        
    Returns:
        是否有效
    """
    return 0 <= row <= 14 and 0 <= col <= 14


def count_consecutive(board: List[List[int]], row: int, col: int,
                     direction: Tuple[int, int], player: int) -> int:
    """统计某方向连续同色棋子数（包括当前位置）
    
    Args:
        board: 棋盘状态
        row, col: 起始位置
        direction: 方向向量 (dr, dc)
        player: 玩家 (1:黑, 2:白)
        
    Returns:
        连续棋子数
    """
    dr, dc = direction
    count = 1  # 包括当前位置
    
    # 正方向
    r, c = row + dr, col + dc
    while is_valid_position(r, c) and board[r][c] == player:
        count += 1
        r += dr
        c += dc
    
    # 反方向
    r, c = row - dr, col - dc
    while is_valid_position(r, c) and board[r][c] == player:
        count += 1
        r -= dr
        c -= dc
    
    return count


def check_win(board: List[List[int]], row: int, col: int, player: int) -> bool:
    """检查是否获胜（恰好五连珠）
    
    Args:
        board: 棋盘状态
        row, col: 最后落子位置
        player: 玩家 (1:黑, 2:白)
        
    Returns:
        是否五连珠获胜
    """
    # 四个方向：横、竖、左斜、右斜
    directions = [(0, 1), (1, 0), (1, 1), (1, -1)]
    
    for direction in directions:
        count = count_consecutive(board, row, col, direction, player)
        if count == 5:
            return True
    
    return False


def analyze_line(board: List[List[int]], row: int, col: int,
                direction: Tuple[int, int], player: int) -> Dict[str, Any]:
    """分析某方向的棋型
    
    Args:
        board: 棋盘状态
        row, col: 待分析位置（假设已落子）
        direction: 方向向量
        player: 玩家
        
    Returns:
        {
            "consecutive": int,      # 连续数
            "left_open": bool,       # 左侧是否开放
            "right_open": bool,      # 右侧是否开放
            "pattern": str          # 棋型类型
        }
    """
    dr, dc = direction
    
    # 统计正方向连续数
    right_count = 0
    r, c = row + dr, col + dc
    while is_valid_position(r, c) and board[r][c] == player:
        right_count += 1
        r += dr
        c += dc
    right_open = is_valid_position(r, c) and board[r][c] == 0
    
    # 统计反方向连续数
    left_count = 0
    r, c = row - dr, col - dc
    while is_valid_position(r, c) and board[r][c] == player:
        left_count += 1
        r -= dr
        c -= dc
    left_open = is_valid_position(r, c) and board[r][c] == 0
    
    # 总连续数（包括当前位置）
    consecutive = left_count + 1 + right_count
    
    # 判定棋型
    pattern = "none"
    
    if consecutive >= 6:
        pattern = "overline"
    elif consecutive == 5:
        pattern = "five"
    elif consecutive == 4:
        if left_open and right_open:
            pattern = "live_four"
        elif left_open or right_open:
            pattern = "rush_four"
    elif consecutive == 3:
        if left_open and right_open:
            pattern = "live_three"
        elif left_open or right_open:
            pattern = "sleep_three"
    
    return {
        "consecutive": consecutive,
        "left_open": left_open,
        "right_open": right_open,
        "pattern": pattern
    }


def check_forbidden(board: List[List[int]], row: int, col: int) -> Tuple[bool, str]:
    """检查黑方禁手
    
    Args:
        board: 棋盘状态（不包含待落子）
        row, col: 待落子位置
        
    Returns:
        (是否禁手, 禁手类型)
    """
    # 只有黑方（玩家1）有禁手
    player = 1
    
    # 临时落子
    original_value = board[row][col]
    board[row][col] = player
    
    # 四个方向
    directions = [(0, 1), (1, 0), (1, 1), (1, -1)]
    
    live_threes = 0
    fours = 0
    has_overline = False
    
    for direction in directions:
        analysis = analyze_line(board, row, col, direction, player)
        
        if analysis["pattern"] == "overline":
            has_overline = True
        elif analysis["pattern"] == "live_three":
            live_threes += 1
        elif analysis["pattern"] in ["live_four", "rush_four"]:
            fours += 1
    
    # 恢复棋盘
    board[row][col] = original_value
    
    # 判定禁手
    if has_overline:
        return True, "长连禁手"
    if live_threes >= 2:
        return True, "三三禁手"
    if fours >= 2:
        return True, "四四禁手"
    
    return False, ""


def render_board(board: List[List[int]], last_move: Optional[Tuple[int, int]] = None) -> str:
    """渲染棋盘为字符串
    
    Args:
        board: 棋盘状态
        last_move: 最后落子位置（可选，用于标记）
        
    Returns:
        棋盘的字符串表示
    """
    lines = []
    
    # 列标题
    col_labels = "    " + " ".join([chr(ord('A') + i) for i in range(15)])
    lines.append(col_labels)
    
    # 绘制棋盘
    for row in range(15):
        row_num = f"{row + 1:2d}"  # 右对齐行号
        row_cells = []
        
        for col in range(15):
            cell = board[row][col]
            
            # 标记最后落子
            if last_move and last_move == (row, col):
                if cell == 1:
                    row_cells.append("⚫")
                elif cell == 2:
                    row_cells.append("⚪")
                else:
                    row_cells.append("➕")
            else:
                if cell == 0:
                    row_cells.append("➕")
                elif cell == 1:
                    row_cells.append("⚫")
                elif cell == 2:
                    row_cells.append("⚪")
        
        lines.append(f" {row_num} {' '.join(row_cells)}")
    
    return "\n".join(lines)