Genarrative/src/components/game-distribution/gameGalleryViewState.ts

import type {
  GameCategory,
  GameDistributionGame,
} from '../../services/gameDistributionClient';

export const GAME_GALLERY_CATEGORIES: Array<GameCategory | '全部'> = [
  '全部',
  '动作',
  '益智',
  '冒险',
  '休闲',
  '模拟',
  '策略',
  '其他',
];

export type GameDeviceFilter = '全部' | '桌面' | '移动';

export const GAME_GALLERY_DEVICE_FILTERS: GameDeviceFilter[] = [
  '全部',
  '桌面',
  '移动',
];

/** 目录筛选写入地址栏，分享和刷新都能回到同一份上下文。 */
const GALLERY_QUERY_KEYS = {
  keyword: 'keyword',
  category: 'category',
  device: 'device',
} as const;

const GALLERY_STORAGE_KEYS = {
  filters: 'game-gallery-filters',
  scroll: 'game-gallery-scroll',
} as const;

/** 画廊挂在平台页签的滚动容器里，返回时按同一容器恢复位置。 */
export const GAME_GALLERY_SCROLL_CONTAINER_SELECTOR = '.platform-tab-panel';

export type GameGalleryFilters = {
  keyword: string;
  category: GameCategory | '全部';
  device: GameDeviceFilter;
};

function readGalleryStorage() {
  try {
    return globalThis.sessionStorage ?? null;
  } catch {
    return null;
  }
}

function normalizeCategory(value: string | null | undefined) {
  const normalized = value?.trim() ?? '';
  return (
    GAME_GALLERY_CATEGORIES.find(
      (item) => item !== '全部' && item === normalized,
    ) ?? '全部'
  );
}

function normalizeDevice(value: string | null | undefined) {
  const normalized = value?.trim() ?? '';
  return (
    GAME_GALLERY_DEVICE_FILTERS.find((item) => item === normalized) ?? '全部'
  );
}

export function gameGalleryScrollKey(filters: GameGalleryFilters) {
  return `${GALLERY_STORAGE_KEYS.scroll}:${filters.keyword.trim()}|${filters.category}|${filters.device}`;
}

/**
 * 只有地址栏里明确出现的筛选项才覆盖返回上下文，避免把用户分享的
 * `?category=动作` 当成“其他筛选项已被清空”。
 */
export function readGameGalleryQueryFilters(
  search: string,
): Partial<GameGalleryFilters> {
  const params = new URLSearchParams(search);
  const filters: Partial<GameGalleryFilters> = {};
  const keyword = params.get(GALLERY_QUERY_KEYS.keyword);
  if (keyword !== null) filters.keyword = keyword;
  const category = params.get(GALLERY_QUERY_KEYS.category);
  if (category !== null) filters.category = normalizeCategory(category);
  const device = params.get(GALLERY_QUERY_KEYS.device);
  if (device !== null) filters.device = normalizeDevice(device);
  return filters;
}

export function readStoredGameGalleryFilters(): Partial<GameGalleryFilters> {
  const storage = readGalleryStorage();
  if (!storage) return {};
  try {
    const raw = storage.getItem(GALLERY_STORAGE_KEYS.filters);
    if (!raw) return {};
    const parsed = JSON.parse(raw) as Partial<GameGalleryFilters> | null;
    if (!parsed || typeof parsed !== 'object') return {};
    const filters: Partial<GameGalleryFilters> = {};
    if (typeof parsed.keyword === 'string') filters.keyword = parsed.keyword;
    if (typeof parsed.category === 'string') {
      filters.category = normalizeCategory(parsed.category);
    }
    if (typeof parsed.device === 'string') {
      filters.device = normalizeDevice(parsed.device);
    }
    return filters;
  } catch {
    return {};
  }
}

export function writeStoredGameGalleryFilters(filters: GameGalleryFilters) {
  const storage = readGalleryStorage();
  if (!storage) return;
  try {
    storage.setItem(GALLERY_STORAGE_KEYS.filters, JSON.stringify(filters));
  } catch {
    // 存储被禁用时筛选仍在本页生效，只是刷新后不再恢复。
  }
}

export function readStoredGameGalleryScrollTop(key: string) {
  const storage = readGalleryStorage();
  if (!storage) return 0;
  try {
    const value = Number(storage.getItem(key));
    return Number.isFinite(value) && value > 0 ? value : 0;
  } catch {
    return 0;
  }
}

export function writeStoredGameGalleryScrollTop(
  key: string,
  scrollTop: number,
) {
  const storage = readGalleryStorage();
  if (!storage) return;
  try {
    if (scrollTop > 0) storage.setItem(key, String(Math.round(scrollTop)));
    else storage.removeItem(key);
  } catch {
    // 忽略存储失败，滚动位置不是业务状态。
  }
}

export function syncGameGalleryQuery(filters: GameGalleryFilters) {
  if (typeof window === 'undefined' || !window.history?.replaceState) return;
  try {
    const url = new URL(window.location.href);
    const assign = (key: string, value: string) => {
      if (value) url.searchParams.set(key, value);
      else url.searchParams.delete(key);
    };
    assign(GALLERY_QUERY_KEYS.keyword, filters.keyword.trim());
    assign(
      GALLERY_QUERY_KEYS.category,
      filters.category === '全部' ? '' : filters.category,
    );
    assign(
      GALLERY_QUERY_KEYS.device,
      filters.device === '全部' ? '' : filters.device,
    );
    window.history.replaceState(
      window.history.state,
      '',
      `${url.pathname}${url.search}${url.hash}`,
    );
  } catch {
    // 地址栏同步失败不影响筛选本身。
  }
}

export function matchesGameDeviceFilter(
  game: GameDistributionGame,
  device: GameDeviceFilter,
) {
  if (device === '桌面') return game.deviceSupport.desktop;
  if (device === '移动') return game.deviceSupport.mobile;
  return true;
}