// ConfigStore — 应用配置 JSON 持久化（vault meta、最近库）
import nodePath from 'node:path';
import { promises as fs } from 'node:fs';
import type { VaultMeta } from '@hunter/shared';
import { RECENT_VAULT_MAX } from '@hunter/shared';

export class ConfigStore {
  private file: string;
  private cache: { vault?: VaultMeta; appearance?: { themeId: string; params: Record<string, unknown>; effect: string; bgImage: string | null }; keymaps?: { id: string; combo: string }[] } | null = null;

  constructor(userDataDir: string) {
    this.file = nodePath.join(userDataDir, 'config.json');
  }

  private async read(): Promise<{ vault?: VaultMeta; appearance?: { themeId: string; params: Record<string, unknown>; effect: string; bgImage: string | null }; keymaps?: { id: string; combo: string }[] }> {
    if (this.cache) return this.cache;
    try {
      const raw = await fs.readFile(this.file, 'utf8');
      this.cache = JSON.parse(raw);
    } catch {
      this.cache = {};
    }
    return this.cache!;
  }

  private async write(): Promise<void> {
    const dir = nodePath.dirname(this.file);
    await fs.mkdir(dir, { recursive: true });
    const tmp = this.file + '.tmp';
    await fs.writeFile(tmp, JSON.stringify(this.cache, null, 2), 'utf8');
    await fs.rename(tmp, this.file);
  }

  async getVaultMeta(): Promise<VaultMeta> {
    const c = await this.read();
    return c.vault ?? { currentRoot: '', recents: [], defaultRoot: '' };
  }

  async setCurrentRoot(root: string): Promise<VaultMeta> {
    const meta = await this.getVaultMeta();
    meta.currentRoot = root;
    // 加入最近库（去重置顶，截断到上限）
    meta.recents = [root, ...meta.recents.filter(r => r !== root)].slice(0, RECENT_VAULT_MAX);
    (await this.read()).vault = meta;
    await this.write();
    return meta;
  }

  async getAppearance(): Promise<{ themeId: string; params: Record<string, unknown>; effect: string; bgImage: string | null } | null> {
    const c = await this.read();
    return c.appearance ?? null;
  }
  async saveAppearance(data: { themeId: string; params: Record<string, unknown>; effect: string; bgImage: string | null }): Promise<void> {
    (await this.read()).appearance = data;
    await this.write();
  }

  async getKeymaps(): Promise<{ id: string; combo: string }[] | null> {
    const c = await this.read();
    return c.keymaps ?? null;
  }
  async saveKeymaps(data: { id: string; combo: string }[]): Promise<void> {
    (await this.read()).keymaps = data;
    await this.write();
  }

  async setDefaultRoot(root: string): Promise<VaultMeta> {
    const meta = await this.getVaultMeta();
    meta.defaultRoot = root;
    (await this.read()).vault = meta;
    await this.write();
    return meta;
  }
}