package s3api

import (
	"net/http"
	"strconv"
	"time"

	"github.com/seaweedfs/seaweedfs/weed/util/version"

	"github.com/seaweedfs/seaweedfs/weed/glog"
	"github.com/seaweedfs/seaweedfs/weed/s3api/s3_constants"
	"github.com/seaweedfs/seaweedfs/weed/s3api/s3err"
	stats_collect "github.com/seaweedfs/seaweedfs/weed/stats"
)

func track(f http.HandlerFunc, action string) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		inFlightGauge := stats_collect.S3InFlightRequestsGauge.WithLabelValues(action)
		inFlightGauge.Inc()
		defer inFlightGauge.Dec()

		bucket, _ := s3_constants.GetBucketAndObject(r)
		w.Header().Set("Server", "SeaweedFS "+version.VERSION)
		recorder := stats_collect.NewStatusResponseWriter(w)
		// Attach an audit-tracking flag to the request so handlers that call
		// PostLog directly mark it; we emit a fallback entry afterward for
		// handlers (e.g. successful GET/HEAD object) that don't.
		r = s3err.EnsureAuditTracking(r)
		// Attach a mutable identity holder before authentication so the fallback
		// entry can report the requester even though auth records it on a
		// request copy this middleware never sees.
		r = s3_constants.EnsureIdentityHolder(r)
		start := time.Now()
		f(recorder, r)
		elapsed := time.Since(start)
		if glog.V(2) {
			requester := s3_constants.GetIdentityNameFromContext(r)
			if requester == "" {
				requester = "-"
			}
			// %q keeps requester- and key-supplied bytes (e.g. newlines) on one line
			glog.Infof("%q %s %q %d %s", requester, r.Method, r.URL.Path, recorder.Status, elapsed)
		}
		if recorder.Status == http.StatusForbidden {
			bucket = ""
		}
		stats_collect.S3RequestHistogram.WithLabelValues(action, bucket).Observe(elapsed.Seconds())
		stats_collect.S3RequestCounter.WithLabelValues(action, strconv.Itoa(recorder.Status), bucket).Inc()
		stats_collect.RecordBucketActiveTime(bucket)
		if !s3err.AuditAlreadyLogged(r) {
			s3err.PostLog(r, recorder.Status, s3err.ErrNone)
		}
	}
}

func TimeToFirstByte(action string, start time.Time, r *http.Request) {
	bucket, _ := s3_constants.GetBucketAndObject(r)
	stats_collect.S3TimeToFirstByteHistogram.WithLabelValues(action, bucket).Observe(float64(time.Since(start).Milliseconds()))
	stats_collect.RecordBucketActiveTime(bucket)
}

func BucketTrafficReceived(bytesReceived int64, r *http.Request) {
	bucket, _ := s3_constants.GetBucketAndObject(r)
	stats_collect.RecordBucketActiveTime(bucket)
	stats_collect.S3BucketTrafficReceivedBytesCounter.WithLabelValues(bucket).Add(float64(bytesReceived))
}

func BucketTrafficSent(bytesTransferred int64, r *http.Request) {
	bucket, _ := s3_constants.GetBucketAndObject(r)
	stats_collect.RecordBucketActiveTime(bucket)
	stats_collect.S3BucketTrafficSentBytesCounter.WithLabelValues(bucket).Add(float64(bytesTransferred))
}