import { JsonAsset, resources } from 'cc';

const META_PATH = 'theme/tile-display-meta';

export interface TileDisplayEntry {
    width: number;
    height: number;
    pivotX: number;
    pivotY: number;
    ppu?: number;
    /** 相对格子宽度的额外缩放（默认 1，snow kuai11 可略大于 1 以贴满格） */
    fitMul?: number;
}

type ThemeTileMap = Record<string, TileDisplayEntry>;

let themeTiles: Record<string, ThemeTileMap> = {};
let loadPromise: Promise<void> | null = null;

function ingest(data: { themes?: Record<string, ThemeTileMap> }) {
    themeTiles = { ...(data.themes ?? {}) };
}

export function loadTileDisplayMeta(): Promise<void> {
    if (loadPromise) return loadPromise;
    loadPromise = new Promise((resolve) => {
        resources.load(META_PATH, JsonAsset, (err, asset) => {
            if (err || !asset?.json) {
                console.warn('[TileDisplayMeta] 未找到 tile-display-meta.json', err);
                themeTiles = {};
            } else {
                ingest(asset.json as { themes?: Record<string, ThemeTileMap> });
            }
            resolve();
        });
    });
    return loadPromise;
}

export function reloadTileDisplayMeta(): Promise<void> {
    themeTiles = {};
    loadPromise = null;
    return new Promise((resolve) => {
        resources.release(META_PATH);
        loadTileDisplayMeta().then(resolve);
    });
}

function normalizeThemeKey(theme?: string): string | undefined {
    if (theme == null) return undefined;
    const t = (typeof theme === 'string' ? theme : String(theme)).trim();
    if (!t) return undefined;
    if (t === 'redArmy') return 'redarmy';
    return t;
}

export function getThemeTileDisplayEntry(theme: string | undefined, tileName: string): TileDisplayEntry | null {
    const key = normalizeThemeKey(theme);
    if (!key) return null;
    const map = themeTiles[key];
    if (!map) return null;
    return map[tileName] ?? null;
}

export function getThemeTileSize(
    theme: string | undefined,
    tileName: string,
    fallback: { width: number; height: number },
): { width: number; height: number } {
    const entry = getThemeTileDisplayEntry(theme, tileName);
    if (!entry) return fallback;
    return { width: entry.width, height: entry.height };
}

export function getThemeTilePivot(
    theme: string | undefined,
    tileName: string,
    fallback: { x: number; y: number },
): { x: number; y: number } {
    const entry = getThemeTileDisplayEntry(theme, tileName);
    if (!entry) return fallback;
    return { x: entry.pivotX, y: entry.pivotY };
}

export function getThemeTileFitMul(theme: string | undefined, tileName: string): number {
    const entry = getThemeTileDisplayEntry(theme, tileName);
    const mul = entry?.fitMul ?? 1;
    return Number.isFinite(mul) && mul > 0 ? mul : 1;
}