import {
    BOARD_SIZE,
    BoopGame,
    BoopPart,
    BoopState,
    PieceType,
    PlayerType,
    RegionType,
    WIN_LENGTH
} from "@/samples/boop/data";

const DIRS = [
    [0, 1],
    [1, 0],
    [1, 1],
    [-1, 1]
]
type PT = [number, number];
type Line = PT[];
export function* getLineCandidates(){
    for(const [dx, dy] of DIRS){
        for(let x = 0; x < BOARD_SIZE; x ++)
            for(let y = 0; y < BOARD_SIZE; y ++){
                if(!isInBounds(x + dx * (WIN_LENGTH-1), y + dy * (WIN_LENGTH-1))) continue;
                const line = [];
                for(let i = 0; i < WIN_LENGTH; i ++){
                    line.push([x + i * dx, y + i * dy]);
                }
                yield line as Line;
            }
    }
}

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

export function isCellOccupied(game: BoopGame | BoopState, x: number, y: number): boolean {
    const id = `${x},${y}`;
    return getState(game).regions.board.partMap[id] !== undefined;
}

export function* getNeighborPositions(x: number = 0, y: number = 0){
    for(let dx = -1; dx <= 1; dx ++)
        for(let dy = -1; dy <= 1; dy ++)
            if(dx !== 0 || dy !== 0)
                yield [x + dx, y + dy] as PT;
}

export function findPartInRegion(ctx: BoopGame | BoopState, regionId: keyof BoopGame['value']['regions'], type: PieceType, player?: PlayerType): BoopPart | null {
    const state = getState(ctx);
    if(!regionId){
        return Object.values(state.pieces).find(part => match(regionId, part, type, player)) || null;
    }
    const id = state.regions[regionId].childIds.find(id => match(regionId, state.pieces[id], type, player));
    return id ? state.pieces[id] || null : null;
}
function match(regionId: RegionType, part: BoopPart, type: PieceType, player?: PlayerType){
    return regionId === part.regionId && part.type === type && (!player || part.player === player);
}

export function findPartAtPosition(ctx: BoopGame | BoopState, row: number, col: number): BoopPart | null {
    const state = getState(ctx);
    const id = state.regions.board.partMap[`${row},${col}`];
    return id ? state.pieces[id] || null : null;
}

function getState(ctx: BoopGame | BoopState): BoopState {
    if('value' in ctx){
        return ctx.value;
    }
    return ctx;
}