// 请求日志中间件：记录请求ID、路由、客户端IP等关键信息
package middleware

import (
	"context"
	"fmt"
	"simple-memo/global"
	"simple-memo/utils"
	"strconv"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/sony/sonyflake"
	"go.uber.org/zap"
)

// requestIDSF 用于生成全局唯一的请求ID
var requestIDSF *sonyflake.Sonyflake

func init() {
	requestIDSF = sonyflake.NewSonyflake(sonyflake.Settings{})
}

// genRequestID 基于 sonyflake 生成请求ID（base36 紧凑字符串）
func genRequestID() string {
	if requestIDSF == nil {
		return fmt.Sprintf("%x", time.Now().UnixNano())
	}
	id, err := requestIDSF.NextID()
	if err != nil {
		return fmt.Sprintf("%x", time.Now().UnixNano())
	}
	// base36 编码：紧凑且只含 [0-9a-z]
	return strconv.FormatUint(id, 36)
}

// RequestLog 请求日志中间件
func RequestLog() gin.HandlerFunc {
	return func(c *gin.Context) {
		start := time.Now()

		// 优先从请求头获取 request-id，否则自动生成
		requestID := c.GetHeader("X-Request-ID")
		if requestID == "" {
			requestID = genRequestID()
		}

		// 客户端IP
		clientIP := c.ClientIP()

		// 路由路径
		route := c.Request.URL.Path

		// 请求方法
		method := c.Request.Method

		// 写入标准 context，供整条链路使用
		ctx := context.WithValue(c.Request.Context(), utils.RequestIdKey, requestID)
		ctx = context.WithValue(ctx, utils.RequestRouteKey, route)
		ctx = context.WithValue(ctx, utils.ClientIPKey, clientIP)
		c.Request = c.Request.WithContext(ctx)

		// 同时记录到 gin context，兼容老代码
		c.Set("request_id", requestID)
		c.Set("client_ip", clientIP)
		c.Set("route", route)

		// 打印请求进入日志
		global.Logger.Info("【请求进入】",
			zap.String("request_id", requestID),
			zap.String("route", route),
			zap.String("method", method),
			zap.String("client_ip", clientIP),
			zap.String("user_agent", c.Request.UserAgent()),
		)

		c.Next()

		// 请求结束后打印耗时日志
		duration := time.Since(start)
		global.Logger.Info("【请求结束】",
			zap.String("request_id", requestID),
			zap.String("route", route),
			zap.Int("status", c.Writer.Status()),
			zap.Duration("duration", duration),
		)
	}
}