/**
 * 微信小程序统一请求封装
 * 参考 ruoyi-admin/src/utils/request.ts 结构
 */

// -------------------- 配置 --------------------
const BASE_URL = 'http://localhost:8080'
const TIMEOUT = 30000
const TOKEN_KEY = 'token'

// 防止 401 弹窗重复弹出
let isReloginPending = false

// -------------------- 工具 --------------------
function getToken() {
	return uni.getStorageSync(TOKEN_KEY) || ''
}

/**
 * 将对象序列化为 query string
 */
function toQueryString(params) {
	return Object.entries(params)
		.filter(([, v]) => v !== undefined && v !== null)
		.map(([k, v]) => `${encodeURIComponent(k)}=${encodeURIComponent(v)}`)
		.join('&')
}

// -------------------- 响应处理 --------------------
/**
 * 处理业务响应码，统一返回 { data, total, rows }（按实际字段存在）
 */
function handleResponse(responseData) {
	return new Promise((resolve, reject) => {
		const code = responseData.code
		const msg = responseData.msg || '系统异常'

		if (code === 200) {
			const result = {}
			if (responseData.data !== undefined)  result.data  = responseData.data
			if (responseData.total !== undefined) result.total = responseData.total
			if (responseData.rows  !== undefined) result.rows  = responseData.rows
			resolve(result)

		} else if (code === 401) {
			if (!isReloginPending) {
				isReloginPending = true
				uni.removeStorageSync(TOKEN_KEY)
				uni.showModal({
					title: '登录已过期',
					content: '登录状态已过期，请重新登录',
					showCancel: false,
					confirmText: '重新登录',
					confirmColor: '#C1001C',
					success: () => {
						isReloginPending = false
						const pages = getCurrentPages()
						const currentRoute = pages.length ? '/' + pages[pages.length - 1].route : ''
						uni.reLaunch({
							url: '/pages/login/index' + (currentRoute
								? '?redirect=' + encodeURIComponent(currentRoute)
								: '')
						})
					}
				})
			}
			reject(new Error('无效的会话，或者会话已过期，请重新登录。'))

		} else if (code === 500) {
			uni.showToast({ title: msg, icon: 'none', duration: 2500 })
			reject(new Error(msg))

		} else {
			uni.showToast({ title: msg, icon: 'none', duration: 2500 })
			reject(new Error(msg))
		}
	})
}

// -------------------- 核心请求 --------------------
/**
 * 统一请求方法
 * @param {object} options
 * @param {string}  options.url        接口路径，如 '/system/user/list'
 * @param {string}  [options.method]   请求方法，默认 'GET'
 * @param {object}  [options.data]     请求体（POST / PUT）
 * @param {object}  [options.params]   URL 查询参数（GET 也可用此字段）
 * @param {object}  [options.header]   额外请求头
 * @param {boolean} [options.isToken]  是否携带 Token，默认 true
 * @returns {Promise<{data?, total?, rows?}>}
 */
function request({ url, method = 'GET', data = {}, params = {}, header = {}, isToken = true } = {}) {
	return new Promise((resolve, reject) => {
		const upperMethod = method.toUpperCase()

		// 拼接 query string
		let finalUrl = BASE_URL + url
		if (Object.keys(params).length) {
			finalUrl += '?' + toQueryString(params)
		}

		// 组装请求头
		const requestHeader = {
			'Content-Type': 'application/json',
			...header
		}
		if (isToken) {
			const token = getToken()
			if (token) {
				requestHeader['Authorization'] = 'Bearer ' + token
			}
		}

		uni.request({
			url: finalUrl,
			method: upperMethod,
			data: upperMethod === 'GET' ? undefined : data,
			header: requestHeader,
			timeout: TIMEOUT,
			success: (res) => {
				const { statusCode, data: responseData } = res
				// HTTP 层异常
				if (statusCode !== 200) {
					const httpMsg = `系统接口 ${statusCode} 异常`
					uni.showToast({ title: httpMsg, icon: 'none' })
					return reject(new Error(httpMsg))
				}
				// 业务层处理
				handleResponse(responseData).then(resolve).catch(reject)
			},
			fail: (err) => {
				let message = '请求失败，请检查网络'
				if (err.errMsg) {
					if (err.errMsg.includes('timeout')) {
						message = '系统接口请求超时'
					} else if (err.errMsg.toLowerCase().includes('network') || err.errMsg.includes('连接')) {
						message = '后端接口连接异常'
					}
				}
				uni.showToast({ title: message, icon: 'none' })
				reject(new Error(message))
			}
		})
	})
}

// -------------------- 下载文件 --------------------
/**
 * 下载文件并自动打开
 * @param {string} url          接口路径
 * @param {object} [params]     URL 查询参数
 * @param {string} [fileName]   保存文件名（仅做备注，小程序由系统决定）
 * @returns {Promise<string>}   临时文件路径
 */
function download(url, params = {}, fileName = '') {
	return new Promise((resolve, reject) => {
		let finalUrl = BASE_URL + url
		if (Object.keys(params).length) {
			finalUrl += '?' + toQueryString(params)
		}

		const header = {}
		const token = getToken()
		if (token) {
			header['Authorization'] = 'Bearer ' + token
		}

		uni.showLoading({ title: '正在下载...', mask: true })

		uni.downloadFile({
			url: finalUrl,
			header,
			success: (res) => {
				uni.hideLoading()
				if (res.statusCode === 200) {
					uni.openDocument({
						filePath: res.tempFilePath,
						showMenu: true,
						success: () => {
							resolve(res.tempFilePath)
						},
						fail: () => {
							uni.showToast({ title: '文件打开失败', icon: 'none' })
							reject(new Error('文件打开失败'))
						}
					})
				} else {
					uni.showToast({ title: '下载失败', icon: 'none' })
					reject(new Error('下载失败'))
				}
			},
			fail: () => {
				uni.hideLoading()
				uni.showToast({ title: '下载文件出现错误，请联系管理员', icon: 'none' })
				reject(new Error('下载文件出现错误，请联系管理员'))
			}
		})
	})
}

// -------------------- 导出 --------------------
export { request, download }
export default request