import { Node } from 'cc';
import { LevelConfig, SpawnConfig } from './LevelTypes';
import { LevelMapData } from './LevelMapData';

function hasKeys(rec?: Record<string, unknown>): boolean {
    return !!rec && Object.keys(rec).length > 0;
}

/** 地图是否覆盖玩家/道具/载具 spawn 格（旧预制体常残留错误横向砖块） */
function groundCoversSpawns(ground: Record<string, unknown> | undefined, spawns: SpawnConfig[]): boolean {
    if (!ground || !spawns.length) return false;
    for (const s of spawns) {
        if (s.kind !== 'player' && s.kind !== 'prop' && s.kind !== 'vehicle') continue;
        if (!ground[`${s.x},${s.y}`]) return false;
    }
    return true;
}

/** Cocos 预制体 LevelMapData 优先；DB 仅作 spawns 载体时的回退 */
function pickGround(
    fromPrefab: LevelConfig['ground'],
    fromDb: LevelConfig['ground'],
    spawns: SpawnConfig[],
): LevelConfig['ground'] {
    if (groundCoversSpawns(fromPrefab, spawns)) return fromPrefab;
    if (groundCoversSpawns(fromDb, spawns)) return fromDb;
    if (hasKeys(fromPrefab)) return fromPrefab;
    return fromDb;
}

function parseJsonRecord(json: string): Record<string, unknown> | undefined {
    try {
        const o = JSON.parse(json || '{}') as unknown;
        if (o && typeof o === 'object' && !Array.isArray(o)) {
            return o as Record<string, unknown>;
        }
    } catch {
        /* ignore */
    }
    return undefined;
}

/**
 * Cocos 预制体 LevelMapData 为地图/主题权威；levels-database 主要提供 spawns。
 */
export function mergeLevelConfigWithMapData(config: LevelConfig, levelRoot: Node): LevelConfig {
    if (!levelRoot?.isValid) return config;
    const md = levelRoot.getComponent(LevelMapData);
    if (!md) return config;

    const prefabGround = parseJsonRecord(md.groundJson) as LevelConfig['ground'];
    const prefabBorder = parseJsonRecord(md.borderJson) as LevelConfig['border'];
    const prefabTheme = md.theme?.trim();

    const border = hasKeys(prefabBorder as Record<string, unknown>)
        ? prefabBorder
        : config.border;

    return {
        ...config,
        theme: prefabTheme || config.theme?.trim() || config.theme,
        ground: pickGround(
            prefabGround as LevelConfig['ground'],
            config.ground,
            config.spawns ?? [],
        ),
        border,
    };
}