/** Shared request, configuration and session infrastructure. */
import { API_BASE_URL, APP_ENVIRONMENT } from './config.uts'
export { API_BASE_URL, API_DEMO_ENABLED } from './config.uts'
const REQUEST_TIMEOUT = 10000
const SESSION_KEY = 'aiFinanceSession'

const wait = (duration: number) => new Promise<void>((resolve) => { setTimeout(() => resolve(), duration) })

export function saveSession(token: string, phone: string, userId: string, expiresAt: string): void {
    if (token.length == 0 || userId.length == 0 || expiresAt.length == 0) throw new Error('登录响应不完整')
    const expiry = Date.parse(expiresAt)
    if (isNaN(expiry) || expiry <= Date.now()) throw new Error('登录凭证已过期')
    uni.setStorageSync(SESSION_KEY, { token, phone, userId, expiresAt, loggedInAt: Date.now() })
}

export function getSession(): UTSJSONObject | null {
    const value = uni.getStorageSync(SESSION_KEY)
    if (value == null || typeof value != 'object') return null
    const session = value as UTSJSONObject
    const token = session['token'] as string | null
    const userId = session['userId'] as string | null
    const expiresAt = session['expiresAt'] as string | null
    if (token == null || userId == null || expiresAt == null || token.length == 0 || userId.length == 0 || token.startsWith('demo-')) {
        uni.removeStorageSync(SESSION_KEY)
        return null
    }
    const expiry = Date.parse(expiresAt)
    if (isNaN(expiry) || expiry <= Date.now()) { uni.removeStorageSync(SESSION_KEY); return null }
    return session
}

export function isLoggedIn(): boolean { return getSession() != null }
export function clearSession(): void { uni.removeStorageSync(SESSION_KEY) }
const currentToken = (): string => { const session = getSession(); return session == null ? '' : session['token'] as string }

const apiMessage = (error: any | null, fallback: string): string => {
    if (error == null) return fallback
    if (error instanceof Error) return error.message
    const text = error.toString()
    return text.length > 0 ? text : fallback
}

const requestJson = (path: string, method: RequestMethod, payload: UTSJSONObject): Promise<UTSJSONObject> => {
    return new Promise<UTSJSONObject>((resolve, reject) => {
        if (API_BASE_URL.length == 0 || (APP_ENVIRONMENT == 'production' && !API_BASE_URL.startsWith('https://'))) {
            reject(new Error('服务地址尚未配置')); return
        }
        const sentToken = currentToken()
        const header: UTSJSONObject = { 'Content-Type': 'application/json', 'X-Requested-With': 'XMLHttpRequest' }
        if (sentToken.length > 0) header['Authorization'] = 'Bearer ' + sentToken
        uni.request({
            url: API_BASE_URL + path, method, data: payload, header, timeout: REQUEST_TIMEOUT,
            success: (response) => {
                // 旧请求不得覆盖刚登录的另一账户，也不能因旧401清除新会话。
                if (currentToken() != sentToken) { reject(new Error('登录状态已变化，请重新操作')); return }
                if (response.statusCode == 401 && sentToken.length > 0) clearSession()
                if (response.data == null || typeof response.data != 'object') {
                    reject(new Error('服务响应格式错误')); return
                }
                const body = response.data as UTSJSONObject
                const code = body['code'] as number | null
                const message = body['msg'] as string | null
                if (response.statusCode < 200 || response.statusCode >= 300 || code != 1) {
                    if (code == 401 && sentToken.length > 0) clearSession()
                    reject(new Error(message != null && message.length > 0 ? message : '请求失败，请稍后重试')); return
                }
                const data = body['data']
                if (data == null) resolve(new UTSJSONObject())
                else if (typeof data == 'object') resolve(data as UTSJSONObject)
                else reject(new Error('服务响应数据格式错误'))
            },
            fail: () => { reject(new Error('网络连接失败，请稍后重试')) }
        })
    })
}

export { apiMessage, requestJson, wait }