import { describe, expect, it } from 'vitest';
import {
  CHAT_VIEW_PREFERENCES_STORAGE_KEY,
  deleteChatViewPreferences,
  loadChatViewPreferences,
  saveChatViewPreferences,
} from '@/stores/chat-view-preferences';

function memoryStorage(): Storage {
  const values = new Map<string, string>();
  return {
    get length() { return values.size; },
    clear: () => values.clear(),
    getItem: (key) => values.get(key) ?? null,
    key: (index) => [...values.keys()][index] ?? null,
    removeItem: (key) => { values.delete(key); },
    setItem: (key, value) => { values.set(key, value); },
  };
}

describe('chat view preferences', () => {
  it('defaults to the current visible thinking and timestamp behavior', () => {
    expect(loadChatViewPreferences('session-1', memoryStorage())).toEqual({
      showThinking: true,
      showTimestamps: true,
      includeExecution: false,
    });
  });

  it('persists independent per-session values and ignores malformed storage', () => {
    const storage = memoryStorage();
    saveChatViewPreferences('session-1', { showThinking: false }, storage);
    saveChatViewPreferences('session-2', { showTimestamps: false }, storage);

    expect(loadChatViewPreferences('session-1', storage)).toEqual({
      showThinking: false,
      showTimestamps: true,
      includeExecution: false,
    });
    expect(loadChatViewPreferences('session-2', storage)).toEqual({
      showThinking: true,
      showTimestamps: false,
      includeExecution: false,
    });

    storage.setItem(CHAT_VIEW_PREFERENCES_STORAGE_KEY, '{not-json');
    expect(loadChatViewPreferences('session-1', storage)).toEqual({
      showThinking: true,
      showTimestamps: true,
      includeExecution: false,
    });
  });

  it('deletes only the removed session entry', () => {
    const storage = memoryStorage();
    saveChatViewPreferences('session-1', { showThinking: false }, storage);
    saveChatViewPreferences('session-2', { showTimestamps: false }, storage);

    deleteChatViewPreferences('session-1', storage);

    expect(loadChatViewPreferences('session-1', storage).showThinking).toBe(true);
    expect(loadChatViewPreferences('session-2', storage).showTimestamps).toBe(false);
  });

  it('treats unavailable storage as best-effort and never throws', () => {
    const unavailableStorage = {
      get length() { throw new Error('storage denied'); },
      clear: () => { throw new Error('storage denied'); },
      getItem: () => { throw new Error('storage denied'); },
      key: () => { throw new Error('storage denied'); },
      removeItem: () => { throw new Error('storage denied'); },
      setItem: () => { throw new Error('storage denied'); },
    } as Storage;

    expect(loadChatViewPreferences('session-1', unavailableStorage)).toEqual({
      showThinking: true,
      showTimestamps: true,
      includeExecution: false,
    });
    expect(saveChatViewPreferences(
      'session-1',
      { showThinking: false },
      unavailableStorage,
    )).toEqual({
      showThinking: false,
      showTimestamps: true,
      includeExecution: false,
    });
    expect(() => deleteChatViewPreferences('session-1', unavailableStorage)).not.toThrow();
  });
});