import { describe, it, expect, beforeEach } from 'vitest'
import * as fc from 'fast-check'
import { createI18n } from 'vue-i18n'
import zhCN from '../i18n/zh-CN.js'
import zhTW from '../i18n/zh-TW.js'
import en from '../i18n/en.js'
import { SUPPORTED_LOCALES } from '../i18n/index.js'
import { setStorage, getStorage, LOCALE_KEY } from '../utils/storage.js'

// 所有语言包
const messages = { 'zh-CN': zhCN, 'zh-TW': zhTW, 'en': en }

/**
 * 递归收集所有翻译键（扁平化为 "a.b.c" 格式）
 */
function collectKeys(obj, prefix = '') {
  let keys = []
  for (const key of Object.keys(obj)) {
    const fullKey = prefix ? `${prefix}.${key}` : key
    if (typeof obj[key] === 'object' && obj[key] !== null) {
      keys = keys.concat(collectKeys(obj[key], fullKey))
    } else {
      keys.push(fullKey)
    }
  }
  return keys
}

/**
 * 根据扁平键从对象中取值
 */
function getNestedValue(obj, path) {
  return path.split('.').reduce((acc, part) => acc && acc[part], obj)
}

// 收集所有翻译键（以zh-CN为基准）
const allKeys = collectKeys(zhCN)

describe('Property 1: 语言切换翻译正确性', () => {
  /**
   * **Feature: mobile-app, Property 1: 语言切换翻译正确性**
   * **Validates: Requirements 1.2**
   *
   * 对于任意支持的语言locale和任意翻译键key，切换到该locale后，
   * 翻译函数t(key)应返回该语言对应的非空文本。
   */
  it('切换到任意支持语言后，翻译函数返回对应的非空文本', () => {
    const localeArb = fc.constantFrom(...SUPPORTED_LOCALES)
    const keyArb = fc.constantFrom(...allKeys)

    fc.assert(
      fc.property(localeArb, keyArb, (locale, key) => {
        const i18n = createI18n({
          legacy: false,
          locale,
          messages
        })

        const result = i18n.global.t(key)

        // 翻译结果应为非空字符串
        expect(typeof result).toBe('string')
        expect(result.length).toBeGreaterThan(0)

        // 翻译结果应等于该语言包中的原始值（不含插值参数的情况下）
        const expected = getNestedValue(messages[locale], key)
        if (expected !== undefined && !String(expected).includes('{')) {
          expect(result).toBe(String(expected))
        }
      }),
      { numRuns: 200 }
    )
  })
})

describe('Property 2: 语言设置持久化Round-Trip', () => {
  /**
   * **Feature: mobile-app, Property 2: 语言设置持久化Round-Trip**
   * **Validates: Requirements 1.4, 1.5**
   *
   * 对于任意支持的语言locale，设置语言后持久化到本地存储，
   * 再从本地存储读取并初始化，最终的locale应等于最初设置的值。
   */

  let mockStorage = {}

  beforeEach(() => {
    mockStorage = {}
    globalThis.uni = {
      setStorageSync: (key, value) => { mockStorage[key] = value },
      getStorageSync: (key) => mockStorage[key] || '',
      removeStorageSync: (key) => { delete mockStorage[key] },
      getSystemInfoSync: () => ({ language: 'zh-CN' })
    }
  })

  it('设置语言后持久化再读取，locale保持一致', () => {
    const localeArb = fc.constantFrom(...SUPPORTED_LOCALES)

    fc.assert(
      fc.property(localeArb, (targetLocale) => {
        // 步骤1：持久化语言设置
        setStorage(LOCALE_KEY, targetLocale)

        // 步骤2：从存储中读取
        const restored = getStorage(LOCALE_KEY)

        // 验证：读取的值应等于设置的值
        expect(restored).toBe(targetLocale)
      }),
      { numRuns: 100 }
    )
  })
})