package middleware

import (
	"strings"
	"time"

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

// 成功且延迟低于该阈值的热路径请求不再写访问日志（错误/慢请求仍全量记录）。
const slowRequestThresholdMs = 200

func RequestLogger(logger *zap.Logger) gin.HandlerFunc {
	return func(c *gin.Context) {
		start := time.Now()
		c.Next()

		latencyMs := float64(time.Since(start).Microseconds()) / 1000
		status := c.Writer.Status()
		path := c.Request.URL.Path
		route := c.FullPath()

		if shouldSkipHTTPLog(path, route, status, latencyMs) {
			return
		}

		fields := []zap.Field{
			zap.String("request_id", GetRequestID(c)),
			zap.String("method", c.Request.Method),
			zap.String("path", path),
			zap.String("route", route),
			zap.Int("status", status),
			zap.Float64("latency_ms", latencyMs),
			zap.String("client_ip", c.ClientIP()),
			zap.Int("response_size", c.Writer.Size()),
		}
		// 成功响应省略 UA/referer，错误与 4xx/5xx 保留完整现场
		if status >= 400 {
			fields = append(fields,
				zap.String("user_agent", c.GetHeader("User-Agent")),
				zap.String("referer", c.GetHeader("Referer")),
			)
		}
		if userID, ok := c.Get(ContextUserID); ok {
			fields = append(fields, zap.Any("user_id", userID))
		}
		if adminID, ok := c.Get(ContextAdminID); ok {
			fields = append(fields, zap.Any("admin_id", adminID))
		}
		if reason, ok := c.Get(ContextAuthFailureReason); ok {
			fields = append(fields, zap.Any("auth_failure_reason", reason))
		}
		if source, ok := c.Get(ContextAuthTokenSource); ok {
			fields = append(fields, zap.Any("auth_token_source", source))
		}
		if detail, ok := c.Get(ContextAuthFailureDetail); ok {
			fields = append(fields, zap.Any("auth_failure_detail", detail))
		}
		if tokenVersion, ok := c.Get(ContextAuthTokenVersion); ok {
			fields = append(fields, zap.Any("auth_token_version", tokenVersion))
		}
		if currentVersion, ok := c.Get(ContextAuthCurrentVersion); ok {
			fields = append(fields, zap.Any("auth_current_token_version", currentVersion))
		}
		if len(c.Errors) > 0 {
			fields = append(fields, zap.String("errors", strings.TrimSpace(c.Errors.String())))
		}

		switch {
		case status >= 500:
			logger.Error("http request", fields...)
		case status >= 400:
			logger.Warn("http request", fields...)
		default:
			logger.Info("http request", fields...)
		}
	}
}

// shouldSkipHTTPLog 判断是否跳过写入：仅跳过「成功 + 非慢请求」的高频热路径。
func shouldSkipHTTPLog(path, route string, status int, latencyMs float64) bool {
	if status >= 400 {
		return false
	}
	if latencyMs >= slowRequestThresholdMs {
		return false
	}
	return isHotPath(path, route)
}

func isHotPath(path, route string) bool {
	if strings.HasSuffix(path, "/unread-count") {
		return true
	}
	if path == "/api/wallet/balance" {
		return true
	}
	if path == "/api/mobile-home-config" {
		return true
	}
	if strings.HasSuffix(path, "/cover") || route == "/api/listings/:id/cover" {
		return true
	}
	if path == "/api/files/object" || path == "/api/admin/files/object" ||
		route == "/api/files/object" || route == "/api/admin/files/object" {
		return true
	}
	return false
}