import {
    OnitamaGame,
    OnitamaState,
    PlayerType,
    prompts
} from "./types";
import {createGameCommandRegistry} from "@/core/game";
import {moveToRegion} from "@/core/region";

export const registry = createGameCommandRegistry<OnitamaState>();

/**
 * 检查位置是否在棋盘范围内
 */
function isInBounds(x: number, y: number): boolean {
    return x >= 0 && x < 5 && y >= 0 && y < 5;
}

/**
 * 检查位置是否有棋子
 */
function getPawnAtPosition(state: OnitamaState, x: number, y: number) {
    const key = `${x},${y}`;
    const pawnId = state.regions.board.partMap[key];
    return pawnId ? state.pawns[pawnId] : null;
}

/**
 * 检查玩家是否拥有某张卡牌
 */
function playerHasCard(state: OnitamaState, player: PlayerType, cardName: string): boolean {
    const cardList = player === 'red' ? state.redCards : state.blackCards;
    return cardList.includes(cardName);
}

/**
 * 检查移动是否合法
 */
function isValidMove(state: OnitamaState, cardName: string, fromX: number, fromY: number, toX: number, toY: number, player: PlayerType): string | null {
    // 检查玩家是否拥有该卡牌
    if (!playerHasCard(state, player, cardName)) {
        return `玩家 ${player} 不拥有卡牌 ${cardName}`;
    }
    
    // 检查起始位置是否有玩家的棋子
    const fromPawn = getPawnAtPosition(state, fromX, fromY);
    if (!fromPawn) {
        return `位置 (${fromX}, ${fromY}) 没有棋子`;
    }
    if (fromPawn.owner !== player) {
        return `位置 (${fromX}, ${fromY}) 的棋子不属于玩家 ${player}`;
    }
    
    // 检查卡牌是否存在
    const card = state.cards[cardName];
    if (!card) {
        return `卡牌 ${cardName} 不存在`;
    }
    
    // 计算移动偏移量
    const dx = toX - fromX;
    const dy = toY - fromY;
    
    // 检查移动是否在卡牌的移动候选项中
    const isValid = card.moveCandidates.some(m => m.dx === dx && m.dy === dy);
    if (!isValid) {
        return `卡牌 ${cardName} 不支持移动 (${dx}, ${dy})`;
    }
    
    // 检查目标位置是否在棋盘内
    if (!isInBounds(toX, toY)) {
        return `目标位置 (${toX}, ${toY}) 超出棋盘范围`;
    }
    
    // 检查目标位置是否有己方棋子
    const toPawn = getPawnAtPosition(state, toX, toY);
    if (toPawn && toPawn.owner === player) {
        return `目标位置 (${toX}, ${toY}) 已有己方棋子`;
    }
    
    return null;
}

/**
 * 执行移动
 */
async function handleMove(game: OnitamaGame, player: PlayerType, cardName: string, fromX: number, fromY: number, toX: number, toY: number) {
    const state = game.value;
    
    // 验证移动
    const error = isValidMove(state, cardName, fromX, fromY, toX, toY, player);
    if (error) {
        throw new Error(error);
    }
    
    const capturedPawnId = getPawnAtPosition(state, toX, toY)?.id || null;
    
    await game.produceAsync(state => {
        const pawn = state.pawns[getPawnAtPosition(state, fromX, fromY)!.id];
        
        // 如果目标位置有敌方棋子，将其移除（吃掉）
        if (capturedPawnId) {
            const capturedPawn = state.pawns[capturedPawnId];
            moveToRegion(capturedPawn, state.regions.board, null);
        }
        
        // 移动棋子到目标位置
        moveToRegion(pawn, state.regions.board, state.regions.board, [toX, toY]);
    });
    
    // 交换卡牌
    await handleSwapCard(game, player, cardName);
    
    return { 
        from: { x: fromX, y: fromY }, 
        to: { x: toX, y: toY }, 
        card: cardName,
        captured: capturedPawnId 
    };
}

const move = registry.register({
    schema: 'move <player> <card:string> <fromX:number> <fromY:number> <toX:number> <toY:number>',
    run: handleMove
});

/**
 * 交换卡牌：将使用的卡牌与备用卡牌交换
 */
async function handleSwapCard(game: OnitamaGame, player: PlayerType, usedCard: string) {
    await game.produceAsync(state => {
        const spareCard = state.spareCard;
        const usedCardData = state.cards[usedCard];
        const spareCardData = state.cards[spareCard];
        
        // 从玩家手牌中移除使用的卡牌
        if (player === 'red') {
            state.redCards = state.redCards.filter(c => c !== usedCard);
            state.redCards.push(spareCard);
        } else {
            state.blackCards = state.blackCards.filter(c => c !== usedCard);
            state.blackCards.push(spareCard);
        }
        
        // 更新卡牌区域
        usedCardData.regionId = 'spare';
        spareCardData.regionId = player;
        
        // 更新备用卡牌
        state.spareCard = usedCard;
    });
}

const swapCard = registry.register({
    schema: 'swap-card <player> <card:string>',
    run: handleSwapCard
});

/**
 * 检查占领胜利条件：玩家的师父棋子到达对手的初始位置
 */
async function handleCheckConquestWin(game: OnitamaGame): Promise<PlayerType | null> {
    const state = game.value;
    
    // 红色师父到达 y=4（黑色初始位置）
    const redMaster = state.pawns['red-master'];
    if (redMaster && redMaster.regionId === 'board' && redMaster.position[1] === 4) {
        return 'red';
    }
    
    // 黑色师父到达 y=0（红色初始位置）
    const blackMaster = state.pawns['black-master'];
    if (blackMaster && blackMaster.regionId === 'board' && blackMaster.position[1] === 0) {
        return 'black';
    }
    
    return null;
}

const checkConquestWin = registry.register({
    schema: 'check-conquest-win',
    run: handleCheckConquestWin
});

/**
 * 检查吃掉胜利条件：对手的师父棋子被吃掉（不在棋盘上）
 */
async function handleCheckCaptureWin(game: OnitamaGame): Promise<PlayerType | null> {
    const state = game.value;
    
    // 红色师父不在棋盘上，黑色获胜
    const redMaster = state.pawns['red-master'];
    if (!redMaster || redMaster.regionId !== 'board') {
        return 'black';
    }
    
    // 黑色师父不在棋盘上，红色获胜
    const blackMaster = state.pawns['black-master'];
    if (!blackMaster || blackMaster.regionId !== 'board') {
        return 'red';
    }
    
    return null;
}

const checkCaptureWin = registry.register({
    schema: 'check-capture-win',
    run: handleCheckCaptureWin
});

/**
 * 综合胜利检测
 */
async function handleCheckWin(game: OnitamaGame): Promise<PlayerType | null> {
    const conquestWinner = await handleCheckConquestWin(game);
    if (conquestWinner) {
        return conquestWinner;
    }
    
    const captureWinner = await handleCheckCaptureWin(game);
    if (captureWinner) {
        return captureWinner;
    }
    
    return null;
}

const checkWin = registry.register({
    schema: 'check-win',
    run: handleCheckWin
});

/**
 * 获取玩家可用的移动
 */
function getAvailableMoves(state: OnitamaState, player: PlayerType): Array<{card: string, fromX: number, fromY: number, toX: number, toY: number}> {
    const moves: Array<{card: string, fromX: number, fromY: number, toX: number, toY: number}> = [];
    
    // 获取玩家的所有卡牌
    const cardNames = player === 'red' ? state.redCards : state.blackCards;
    
    // 获取玩家的所有棋子
    const playerPawns = Object.values(state.pawns).filter(p => p.owner === player && p.regionId === 'board');
    
    // 对于每张卡牌
    for (const cardName of cardNames) {
        const card = state.cards[cardName];
        
        // 对于每个棋子
        for (const pawn of playerPawns) {
            const [fromX, fromY] = pawn.position;
            
            // 对于卡牌的每个移动
            for (const move of card.moveCandidates) {
                const toX = fromX + move.dx;
                const toY = fromY + move.dy;
                
                // 检查移动是否合法
                if (isInBounds(toX, toY)) {
                    const targetPawn = getPawnAtPosition(state, toX, toY);
                    // 目标位置为空或有敌方棋子
                    if (!targetPawn || targetPawn.owner !== player) {
                        moves.push({ card: cardName, fromX, fromY, toX, toY });
                    }
                }
            }
        }
    }
    
    return moves;
}

/**
 * 处理回合
 */
async function handleTurn(game: OnitamaGame, turnPlayer: PlayerType) {
    const state = game.value;
    const availableMoves = getAvailableMoves(state, turnPlayer);
    
    let moveOutput;
    
    if (availableMoves.length === 0) {
        // 没有可用移动，玩家必须交换一张卡牌
        const cardToSwap = await game.prompt(
            prompts.move,
            (player, card, _fromX, _fromY, _toX, _toY) => {
                if (player !== turnPlayer) {
                    throw `Invalid player: ${player}. Expected ${turnPlayer}.`;
                }
                if (!playerHasCard(state, player, card)) {
                    throw `Player ${player} does not have card ${card}.`;
                }
                return card;
            },
            turnPlayer
        );
        
        await swapCard(game, turnPlayer, cardToSwap);
        moveOutput = { swappedCard: cardToSwap, noMoves: true };
    } else {
        // 有可用移动，提示玩家选择
        moveOutput = await game.prompt(
            prompts.move,
            (player, card, fromX, fromY, toX, toY) => {
                if (player !== turnPlayer) {
                    throw `Invalid player: ${player}. Expected ${turnPlayer}.`;
                }
                
                const error = isValidMove(state, card, fromX, fromY, toX, toY, player);
                if (error) {
                    throw error;
                }
                
                return { player, card, fromX, fromY, toX, toY };
            },
            turnPlayer
        );
        
        await move(game, moveOutput.player, moveOutput.card, moveOutput.fromX, moveOutput.fromY, moveOutput.toX, moveOutput.toY);
    }
    
    // 检查胜利
    const winner = await checkWin(game);
    
    await game.produceAsync(state => {
        state.winner = winner;
        if (!winner) {
            state.currentPlayer = state.currentPlayer === 'red' ? 'black' : 'red';
            state.turn++;
        }
    });
    
    return { winner, move: moveOutput };
}

const turn = registry.register({
    schema: 'turn <player>',
    run: handleTurn
});

/**
 * 开始游戏主循环
 */
export async function start(game: OnitamaGame) {
    while (true) {
        const currentPlayer = game.value.currentPlayer;
        const turnOutput = await turn(game, currentPlayer);
        
        if (turnOutput.winner) {
            break;
        }
    }
    
    return game.value;
}