/**
 * 支付封装工具
 * 统一支付接口，内部根据平台自动选择Google Pay或Apple Pay
 */

/**
 * 获取当前设备平台
 * @returns {string} 'android' | 'ios' | 'unknown'
 */
export function getPlatform() {
  try {
    const systemInfo = uni.getSystemInfoSync()
    const platform = (systemInfo.platform || '').toLowerCase()
    if (platform === 'android') return 'android'
    if (platform === 'ios') return 'ios'
    return 'unknown'
  } catch (e) {
    return 'unknown'
  }
}

/**
 * 根据平台选择支付渠道
 * @param {string} platform - 设备平台
 * @returns {string} 'google_pay' | 'apple_pay' | 'unsupported'
 */
export function resolvePaymentChannel(platform) {
  if (platform === 'android') return 'google_pay'
  if (platform === 'ios') return 'apple_pay'
  return 'unsupported'
}

/**
 * 调用Google Pay支付
 * @param {object} params - 支付参数
 * @returns {Promise<{success: boolean, receipt: string}>}
 */
async function callGooglePay(params) {
  return new Promise((resolve, reject) => {
    // 通过UniApp原生插件调用Google Pay
    // #ifdef APP-PLUS
    const googlePay = uni.requireNativePlugin('GooglePay')
    googlePay.pay({
      productId: params.productId,
      price: params.price,
      type: params.type
    }, (res) => {
      if (res.code === 0) {
        resolve({ success: true, receipt: res.receipt })
      } else if (res.code === -1) {
        // 用户取消支付
        reject(new Error('cancelled'))
      } else {
        reject(new Error(res.message || '支付失败'))
      }
    })
    // #endif
  })
}

/**
 * 调用Apple Pay支付
 * @param {object} params - 支付参数
 * @returns {Promise<{success: boolean, receipt: string}>}
 */
async function callApplePay(params) {
  return new Promise((resolve, reject) => {
    // 通过UniApp原生插件调用Apple Pay
    // #ifdef APP-PLUS
    const applePay = uni.requireNativePlugin('ApplePay')
    applePay.pay({
      productId: params.productId,
      price: params.price,
      type: params.type
    }, (res) => {
      if (res.code === 0) {
        resolve({ success: true, receipt: res.receipt })
      } else if (res.code === -1) {
        // 用户取消支付
        reject(new Error('cancelled'))
      } else {
        reject(new Error(res.message || '支付失败'))
      }
    })
    // #endif
  })
}

/**
 * 统一支付接口，内部根据平台选择Google Pay或Apple Pay
 * @param {object} params
 * @param {string} params.productId - 商品ID
 * @param {number} params.price - 价格
 * @param {string} params.type - 'purchase' | 'subscribe'
 * @returns {Promise<{success: boolean, receipt: string}>}
 */
export async function pay(params) {
  const platform = getPlatform()
  const channel = resolvePaymentChannel(platform)

  if (channel === 'unsupported') {
    uni.showToast({ title: '当前设备不支持该支付方式', icon: 'none' })
    throw new Error('当前设备不支持该支付方式')
  }

  try {
    if (channel === 'google_pay') {
      return await callGooglePay(params)
    } else {
      return await callApplePay(params)
    }
  } catch (e) {
    if (e.message === 'cancelled') {
      // 用户取消，不做额外提示
      throw e
    }
    uni.showToast({ title: '支付失败，请重试', icon: 'none' })
    throw e
  }
}

/**
 * 检查支付环境是否可用
 * @returns {Promise<boolean>}
 */
export async function isPaymentAvailable() {
  const platform = getPlatform()
  const channel = resolvePaymentChannel(platform)
  return channel !== 'unsupported'
}