package middleware

import (
	"strings"

	"github.com/freefire/jiang13-bbs/model"
	"github.com/freefire/jiang13-bbs/service"
	"github.com/gin-gonic/gin"
)

// VisitCapture 服务端访问捕获：只记「UA 命中爬虫库」与「响应状态 ≥ 400」两类请求，
// 普通人类浏览由客户端埋点上报（互补、不重复）。事件非阻塞入队，不影响响应。
func VisitCapture(svc *service.VisitStatsService) gin.HandlerFunc {
	return func(c *gin.Context) {
		c.Next()

		if svc == nil || !svc.Enabled() {
			return
		}
		// 静态资源与健康检查/WS 无统计意义
		path := c.Request.URL.Path
		if strings.HasPrefix(path, "/uploads") || path == "/health" || path == "/api/ws" {
			return
		}

		ua := c.Request.UserAgent()
		bot := service.ClassifyBot(ua)
		status := c.Writer.Status()
		if bot == "" && status < 400 {
			return // 正常人类请求：不记
		}

		ev := model.VisitEvent{}
		if bot != "" {
			ev.Kind = model.VisitKindBot
			ev.Bot = bot
		} else {
			ev.Kind = model.VisitKindProbe
			ev.Status = status
		}
		if q := c.Request.URL.RawQuery; q != "" {
			ev.Path = path + "?" + q
		} else {
			ev.Path = path
		}
		if len(ev.Path) > 512 {
			ev.Path = ev.Path[:512]
		}
		ev.IP = service.CanonicalIP(c.ClientIP())
		if vid, err := c.Cookie(service.VisitorCookieName); err == nil && service.ValidVisitorID(vid) {
			ev.VidHash = service.HashVisitorID(vid)
		}
		if u := CurrentUser(c); u != nil {
			ev.UserID = u.ID
		}
		p := service.ParseUserAgent(ua)
		ev.Device = p.Kind
		ev.OS = p.OS
		ev.Browser = p.Browser
		svc.Enqueue(ev)
	}
}