const axios = require('axios')
const HttpsProxyAgent = require('https-proxy-agent')
const config = require('../../config.json')
const API = require('../../lib/API')
const { BaseStdResponse } = require('../../BaseStdResponse')
const QgProxyManager = require('../../lib/Lepao/QgProxyManager')

function buildAxiosOutboundConfig(fragment) {
    if (!fragment || fragment.proxy === false || !fragment.proxy) {
        return { proxy: false }
    }
    const { host, port, auth } = fragment.proxy
    let userPart = ''
    if (auth && String(auth.username || '').length > 0) {
        const u = encodeURIComponent(auth.username)
        const p = encodeURIComponent(auth.password != null ? String(auth.password) : '')
        userPart = `${u}:${p}@`
    }
    const proxyUrl = `http://${userPart}${host}:${port}`
    const rejectUnauthorized = process.env.NODE_TLS_REJECT_UNAUTHORIZED !== '0'
    return {
        proxy: false,
        httpsAgent: new HttpsProxyAgent(proxyUrl, { rejectUnauthorized })
    }
}

function resolveSelfEchoUrl() {
    const base = String(config.url || '').trim()
    if (!base) return `http://127.0.0.1:${config.port}/Corn/ProxySelfIpEcho`
    return `${base.replace(/\/+$/, '')}/Corn/ProxySelfIpEcho`
}

class ProxySelfCheck extends API {
    constructor() {
        super()
        this.noEncrypt()
        this.setPath('/Corn/ProxySelfCheck')
        this.setMethod('GET')
    }

    async onRequest(req, res) {
        try {
            const qgOn = await QgProxyManager.isOutboundProxyEnabled()
            if (!qgOn) {
                await QgProxyManager.recordLog({
                    event: 'proxy_self_check_skip',
                    detail: { reason: 'proxy_disabled' }
                })
                return res.json({
                    ...BaseStdResponse.OK,
                    data: { skipped: true, reason: 'proxy_disabled' }
                })
            }

            const frag = await QgProxyManager.getOutboundAxiosFragment({ forceRefresh: false })
            if (frag.proxy === false) {
                await QgProxyManager.recordLog({
                    event: 'proxy_self_check_skip',
                    detail: { reason: 'no_proxy_available' }
                })
                return res.json({
                    ...BaseStdResponse.OK,
                    data: { skipped: true, reason: 'no_proxy_available' }
                })
            }

            const outbound = buildAxiosOutboundConfig(frag)
            const echoUrl = resolveSelfEchoUrl()
            const rsp = await axios.get(echoUrl, {
                timeout: 15000,
                validateStatus: () => true,
                ...outbound
            })

            const body = rsp.data || {}
            const now = Date.now()
            const cached = await QgProxyManager.getCachedParsed()
            const proxyIp = body?.data?.ip || null

            await QgProxyManager.recordLog({
                event: 'proxy_self_check',
                server: cached?.server || `${frag.proxy.host}:${frag.proxy.port}`,
                deadline: cached?.deadline || null,
                detail: {
                    code: body?.code,
                    http_status: rsp.status,
                    target: echoUrl,
                    proxy_ip: proxyIp,
                    x_forwarded_for: body?.data?.x_forwarded_for || '',
                    checked_at: now
                }
            })

            return res.json({
                ...BaseStdResponse.OK,
                data: {
                    proxy_ip: proxyIp,
                    http_status: rsp.status,
                    target: echoUrl
                }
            })
        } catch (e) {
            const msg = e?.message || String(e)
            await QgProxyManager.recordLog({
                event: 'proxy_self_check_fail',
                detail: {
                    message: msg,
                    code: e?.code,
                    status: e?.response?.status
                }
            })
            this.logger?.error?.(`[ProxySelfCheck] ${e?.stack || e}`)
            return res.json({
                ...BaseStdResponse.ERR,
                msg: `代理自检失败: ${msg}`
            })
        }
    }
}

module.exports.ProxySelfCheck = ProxySelfCheck