// ============================================================
// Storage — localStorage 封装
// 职责：会话配置持久化
// ============================================================

import type { SessionConfig, Theme } from "../types";

const CONFIG_KEY = "camtalk:config";
const THEME_KEY = "camtalk:theme";

const DEFAULT_CONFIG: SessionConfig = {
  ttsEnabled: true,
  detailLevel: "low",
  language: "zh-CN",
};

/** 加载配置，无存储时返回默认值 */
export function loadConfig(): SessionConfig {
  try {
    const raw = localStorage.getItem(CONFIG_KEY);
    if (!raw) return DEFAULT_CONFIG;
    const parsed = JSON.parse(raw) as Partial<SessionConfig>;
    return { ...DEFAULT_CONFIG, ...parsed };
  } catch {
    return DEFAULT_CONFIG;
  }
}

/** 保存配置到 localStorage */
export function saveConfig(config: SessionConfig): void {
  try {
    localStorage.setItem(CONFIG_KEY, JSON.stringify(config));
  } catch {
    // localStorage 不可用时静默失败
  }
}

/** 加载主题偏好 */
export function loadTheme(): Theme {
  try {
    const raw = localStorage.getItem(THEME_KEY);
    if (raw === "light" || raw === "dark") return raw;
  } catch { /* ignore */ }
  return "dark";
}

/** 保存主题偏好 */
export function saveTheme(theme: Theme): void {
  try {
    localStorage.setItem(THEME_KEY, theme);
  } catch { /* ignore */ }
}