package middleware

import (
	"strings"

	"github.com/gin-gonic/gin"
	"github.com/google/uuid"

	"laic-backend/logger"
)

// TraceMiddleware 为每个请求生成/透传 traceID，便于链路日志追踪
func TraceMiddleware() gin.HandlerFunc {
	return func(c *gin.Context) {
		traceID := c.GetHeader("X-Trace-Id")
		if traceID == "" {
			traceID = strings.ReplaceAll(uuid.New().String(), "-", "")[:16]
		}
		logger.SetTraceID(traceID)
		defer logger.CleanTraceID()

		c.Header("X-Trace-Id", traceID)
		c.Set("trace_id", traceID)
		c.Next()
	}
}