const API = require("../../lib/API.js")
const db = require("../../plugin/DataBase/db.js")
const Redis = require('../../plugin/DataBase/Redis')
const { BaseStdResponse } = require("../../BaseStdResponse.js")
const AccessControl = require("../../lib/AccessControl.js")
const crypto = require('crypto')
const config = require('../../config.json')
const mq = require('../../plugin/mq')
const { mq: mqName } = require('../../plugin/mq/mqPrefix')
const { insertLedgerRecord } = require('../../lib/Lepao/CountLedger')
const { validateCoupon, recordUsage, releaseUsageForOrder, roundMoney } = require('../../lib/CouponService')
const { normalizePayBaseUrl, queryPaymentOrder } = require('../../lib/PaymentClient')

const ORDER_PAYMENT_QUEUE = mqName('order_payment_check')
let orderPaymentWorkerStarted = false

async function writePurchaseLedger(orderId, userUuid, addCount, logger) {
    const delta = Number(addCount || 0)
    if (!orderId || !userUuid || delta === 0) return
    try {
        const userRows = await db.query(
            'SELECT lepao_count FROM users WHERE uuid = ?',
            [userUuid]
        )
        if (!userRows || userRows.length !== 1) return
        const afterCount = Number(userRows[0].lepao_count || 0)
        const beforeCount = afterCount - delta
        await insertLedgerRecord({
            userUuid,
            delta,
            balanceBefore: beforeCount,
            balanceAfter: afterCount,
            bizType: 'purchase',
            bizId: orderId,
            remark: `订单号：${orderId}`
        })
    } catch (error) {
        logger?.error?.(`写入购买次数流水失败 ${orderId}: ${error.stack || error}`)
    }
}

async function startOrderPaymentWorker(logger) {
    if (orderPaymentWorkerStarted) {
        return
    }

    try {
        const ch = await mq.getChannel('order_payment')
        await ch.assertQueue(ORDER_PAYMENT_QUEUE, {
            durable: true
        })
        await ch.prefetch(1)

        logger.info(`订单支付结果轮询消费者已启动，队列：${ORDER_PAYMENT_QUEUE}`)

        orderPaymentWorkerStarted = true

        ch.consume(ORDER_PAYMENT_QUEUE, async (msg) => {
            if (!msg) return

            const content = JSON.parse(msg.content.toString() || '{}')
            const { orderId } = content

            if (!orderId) {
                logger.warn('收到无效的订单支付检查消息（缺少 orderId）')
                ch.ack(msg)
                return
            }

            try {
                await pollOrderPaymentStatus(orderId, logger)
                ch.ack(msg)
            } catch (err) {
                logger.error(`订单支付轮询处理失败，订单号：${orderId}，错误：${err.stack || err}`)
                // 简单重试策略：出现异常时，Nack 并重新入队
                ch.nack(msg, false, true)
            }
        })
    } catch (e) {
        logger.error(`启动订单支付 MQ 消费者失败：${e.stack || e}`)
    }
}

async function pollOrderPaymentStatus(orderId, logger) {
    const paymentConfig = config.pay || {}

    if (!paymentConfig.pid || !paymentConfig.url || !paymentConfig.key) {
        logger.error('支付配置错误，无法轮询易支付状态')
        return
    }

    const MAX_RETRIES = 120 // 5分钟 / 5秒
    const DELAY = 2500 // 5秒

    const pollOrderStatus = async (retry = 0) => {
        if (retry >= MAX_RETRIES) {
            const closeRes = await db.query(
                'UPDATE orders SET state = 3 WHERE orderId = ? AND state = 0',
                [orderId]
            )
            if (closeRes?.affectedRows > 0) {
                await releaseUsageForOrder(orderId)
                logger.info(`订单超时未支付，自动取消，订单号：${orderId}`)
            }
            return
        }

        try {
            const existing = await db.query('SELECT state FROM orders WHERE orderId = ?', [orderId])
            if (!existing?.length) {
                logger.warn(`订单不存在，停止轮询：${orderId}`)
                return
            }
            if (Number(existing[0].state) !== 0) {
                logger.info(`订单已处理（state=${existing[0].state}），停止轮询：${orderId}`)
                return
            }

            const queryData = await queryPaymentOrder(orderId, logger)
            logger.info(`轮询订单支付状态，订单号：${orderId}，尝试次数：${retry + 1}，查询结果：${JSON.stringify(queryData)}`)

            if (queryData.code == 1 && queryData.status == 1) {
                const { trade_no, out_trade_no, type } = queryData
                const time = Date.now()

                let sql = 'UPDATE orders SET state = 1, pay_type = ?, pay_id = ?, pay_time = ? WHERE orderId = ? AND state = 0'
                const result = await db.query(sql, [type, trade_no, time, out_trade_no])

                if (result.affectedRows > 0) {
                    sql = `
                                    SELECT 
                                        g.lepao_count,
                                        g.ic_count,
                                        g.vip,
                                        a.create_user
                                    FROM 
                                        orders a
                                    LEFT JOIN 
                                        goods g 
                                    ON 
                                        a.goods_id = g.id
                                    WHERE 
                                        a.orderId = ?
                                `
                    const rows = await db.query(sql, [out_trade_no])
                    if (!rows || rows.length !== 1) {
                        logger.error(`订单商品信息异常，订单号：${out_trade_no}`)
                        await db.query('UPDATE orders SET state = 4 WHERE orderId = ?', [out_trade_no])
                        return
                    }

                    const { lepao_count, ic_count, vip, create_user } = rows[0]
                    sql = 'UPDATE users SET lepao_count = lepao_count + ?, ic_count = ic_count + ?, vip = ? WHERE uuid = ?'
                    const updateUser = await db.query(sql, [lepao_count, ic_count, vip, create_user])

                    if (!updateUser || updateUser.affectedRows !== 1) {
                        logger.error(`更新用户失败，UUID: ${create_user}`)
                        await db.query('UPDATE orders SET state = 4 WHERE orderId = ?', [out_trade_no])
                    }

                    sql = 'UPDATE orders SET state = 2 WHERE orderId = ?'
                    await db.query(sql, [out_trade_no])
                    await writePurchaseLedger(out_trade_no, create_user, lepao_count, logger)

                    logger.info(`订单处理成功：${out_trade_no}`)
                    return
                }

                logger.info(`支付网关已确认付款，订单已由其他进程/回调处理，停止轮询：${out_trade_no}`)
                return
            }

            // 未支付，继续轮询
            setTimeout(() => pollOrderStatus(retry + 1), DELAY)
        } catch (error) {
            logger.warn(`轮询支付状态失败，订单号：${orderId}，原因：${error.message || error}`)
            setTimeout(() => pollOrderStatus(retry + 1), DELAY)
        }
    }

    logger.info(`开始轮询订单支付状态，订单号：${orderId}`)
    pollOrderStatus()
}

function generateOrderId() {
    const now = new Date()
    const pad = (n, w = 2) => n.toString().padStart(w, '0')
    return `${now.getFullYear()}${pad(now.getMonth() + 1)}${pad(now.getDate())}` +
        `${pad(now.getHours())}${pad(now.getMinutes())}${pad(now.getSeconds())}` +
        `${pad(now.getMilliseconds(), 3)}`
}

function generatePaymentSign(params, key) {
    const sorted = Object.keys(params).sort()
    const query = sorted.map(k => `${k}=${params[k]}`).join('&') + key

    return crypto.createHash('md5').update(query, 'utf8').digest('hex')
}

async function acquireCouponUsageLock(couponId) {
    const lockKey = `coupon:usage:${couponId}`
    const rows = await db.query('SELECT GET_LOCK(?, 5) AS ok', [lockKey])
    return { lockKey, ok: Number(rows?.[0]?.ok || 0) === 1 }
}

async function releaseCouponUsageLock(lockKey) {
    if (!lockKey) return
    try {
        await db.query('SELECT RELEASE_LOCK(?)', [lockKey])
    } catch (e) {
        // 释放失败仅记录，不影响主流程
    }
}

class CreateOrder extends API {
    constructor() {
        super()
        this.setPath('/Order/CreateOrder')
        this.setMethod('POST')
    }

    async onRequest(req, res) {
        const { uuid, session, goods_id, pay_type, coupon_code } = req.body

        if ([uuid, session, goods_id, pay_type].some(v => v === '' || v === null || v === undefined)) {
            return res.json({
                ...BaseStdResponse.MISSING_PARAMETER
            })
        }

        const sessionValid = await AccessControl.checkSession(uuid, session)
        if (!sessionValid) {
            return res.status(401).json({
                ...BaseStdResponse.ACCESS_DENIED
            })
        }

        let couponLockKey = null
        try {
            const goodsSql = 'SELECT name, price, num, state FROM goods WHERE id = ?'
            const goodsRows = await db.query(goodsSql, [goods_id])

            if (!goodsRows || goodsRows.length !== 1) {
                return res.json({
                    ...BaseStdResponse.ERR,
                    msg: '商品不存在'
                })
            }

            const goods = goodsRows[0]
            if (goods.num < 1 || goods.state !== 1) {
                return res.json({
                    ...BaseStdResponse.ERR,
                    msg: '商品已下架或库存不足'
                })
            }

            const createTime = Date.now()
            const orderId = generateOrderId()

            const originalPrice = roundMoney(goods.price)
            let finalPrice = originalPrice
            let discountAmount = 0
            let couponId = null
            let appliedCouponCode = null

            if (coupon_code && String(coupon_code).trim()) {
                let couponResult = await validateCoupon({
                    code: coupon_code,
                    userUuid: uuid,
                    goodsId: goods_id,
                    goodsPrice: goods.price
                })
                if (!couponResult.ok) {
                    return res.json({ ...BaseStdResponse.ERR, msg: couponResult.msg })
                }
                finalPrice = couponResult.finalPrice
                discountAmount = couponResult.discountAmount
                couponId = couponResult.couponId
                appliedCouponCode = couponResult.code

                const lockRet = await acquireCouponUsageLock(couponId)
                if (!lockRet.ok) {
                    return res.json({
                        ...BaseStdResponse.ERR,
                        msg: '优惠码校验繁忙，请稍后重试'
                    })
                }
                couponLockKey = lockRet.lockKey

                // 拿到锁后重查一次，避免并发下单绕过“每人限用次数”
                couponResult = await validateCoupon({
                    code: coupon_code,
                    userUuid: uuid,
                    goodsId: goods_id,
                    goodsPrice: goods.price
                })
                if (!couponResult.ok) {
                    return res.json({ ...BaseStdResponse.ERR, msg: couponResult.msg })
                }

                finalPrice = couponResult.finalPrice
                discountAmount = couponResult.discountAmount
                couponId = couponResult.couponId
                appliedCouponCode = couponResult.code
            }

            const insertSql = `
                INSERT INTO orders (
                    orderId, create_user, create_time, goods_id, price, pay_type,
                    original_price, discount_amount, coupon_id, coupon_code
                )
                VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
            `
            const result = await db.query(insertSql, [
                orderId,
                uuid,
                createTime,
                goods_id,
                finalPrice,
                pay_type,
                originalPrice,
                discountAmount,
                couponId,
                appliedCouponCode
            ])

            const updateSql = 'UPDATE goods SET num = num - 1 WHERE id = ?'
            await db.query(updateSql, [goods_id])

            if (result && result.affectedRows > 0) {
                if (couponId) {
                    await recordUsage(couponId, orderId, uuid, discountAmount)
                }

                const paymentConfig = config.pay || {}

                if (!paymentConfig.pid || !paymentConfig.url || !paymentConfig.key || !paymentConfig.return_url) {
                    return res.json({
                        ...BaseStdResponse.ERR,
                        msg: '支付配置错误，请联系管理员'
                    })
                }

                const payBaseUrl = normalizePayBaseUrl(paymentConfig.url)

                const deviceType = req.headers['device-type'] ?? '浏览器'
                let return_url
                if(deviceType === 'RunForge Uniapp Client') 
                    return_url = paymentConfig.uni_return_url + orderId
                else
                    return_url = paymentConfig.return_url + orderId

                const payParams = {
                    pid: paymentConfig.pid,
                    type: pay_type,
                    out_trade_no: orderId,
                    notify_url: `${config.url}/Order/CallBack`,
                    return_url,
                    name: goods.name,
                    money: String(finalPrice)
                }

                const sign = generatePaymentSign(payParams, paymentConfig.key)
                payParams.sign = sign
                payParams.sign_type = 'MD5'

                await Redis.set(`payData:${orderId}`, JSON.stringify(payParams), {
                    EX: 300
                })

                // 下单成功后推送到订单支付检查队列，由当前模块的消费者进行轮询及超时取消
                try {
                    const ch = await mq.getChannel('order_payment')
                    await ch.assertQueue(ORDER_PAYMENT_QUEUE, {
                        durable: true
                    })
                    const msg = {
                        orderId,
                        enqueueTime: Date.now()
                    }
                    ch.sendToQueue(ORDER_PAYMENT_QUEUE, Buffer.from(JSON.stringify(msg)), {
                        persistent: true
                    })
                } catch (error) {
                    this.logger.error(`推送订单支付检查消息到 MQ 失败，订单号：${orderId}，错误：${error.stack || error}`)
                }

                res.json({
                    ...BaseStdResponse.OK,
                    id: orderId,
                    pay: {
                        payUrl: `${payBaseUrl}/submit.php`,
                        payData: payParams
                    }
                })

            } else {
                return res.json({
                    ...BaseStdResponse.ERR,
                    msg: '创建订单失败'
                })
            }
        } catch (err) {
            this.logger.error(`创建订单失败！${err.stack}`)
            return res.json({
                ...BaseStdResponse.ERR,
                msg: "创建订单异常，请联系管理员"
            })
        } finally {
            await releaseCouponUsageLock(couponLockKey)
        }
    }
}

module.exports.CreateOrder = CreateOrder
module.exports.startOrderPaymentWorker = startOrderPaymentWorker