/**
 * 统一创建 HTTPS 出站代理 Agent，兼容 https-proxy-agent 各版本的导出方式。
 */
function resolveHttpsProxyAgentClass() {
    const mod = require('https-proxy-agent')
    const AgentClass = mod.HttpsProxyAgent || mod.default || mod
    if (typeof AgentClass !== 'function') {
        throw new Error('https-proxy-agent 未正确安装或导出格式不兼容')
    }
    return AgentClass
}

function createHttpsProxyAgent(proxyUrl) {
    const HttpsProxyAgent = resolveHttpsProxyAgentClass()
    const rejectUnauthorized = process.env.NODE_TLS_REJECT_UNAUTHORIZED !== '0'
    return new HttpsProxyAgent(proxyUrl, { rejectUnauthorized })
}

/**
 * Axios 对「HTTPS 目标 + 内置 proxy」在部分 Node 版本下会报 ERR_INVALID_PROTOCOL，
 * 改用 HttpsProxyAgent 走 CONNECT 隧道，并显式 proxy: false。
 */
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}`
    return {
        proxy: false,
        httpsAgent: createHttpsProxyAgent(proxyUrl)
    }
}

module.exports = {
    createHttpsProxyAgent,
    buildAxiosOutboundConfig
}