sing-box/service/ccm/service_status.go

package ccm

import (
	"bytes"
	"encoding/json"
	"net/http"
	"strconv"
	"strings"

	"github.com/sagernet/sing-box/option"
)

type statusPayload struct {
	FiveHourUtilization float64 `json:"five_hour_utilization"`
	WeeklyUtilization   float64 `json:"weekly_utilization"`
	PlanWeight          float64 `json:"plan_weight"`
}

func (s *Service) handleStatusEndpoint(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		writeJSONError(w, r, http.StatusMethodNotAllowed, "invalid_request_error", "method not allowed")
		return
	}

	var provider credentialProvider
	var userConfig *option.CCMUser
	if len(s.options.Users) > 0 {
		if r.Header.Get("X-Api-Key") != "" || r.Header.Get("Api-Key") != "" {
			writeJSONError(w, r, http.StatusBadRequest, "invalid_request_error",
				"API key authentication is not supported; use Authorization: Bearer with a CCM user token")
			return
		}

		authHeader := r.Header.Get("Authorization")
		if authHeader == "" {
			writeJSONError(w, r, http.StatusUnauthorized, "authentication_error", "missing api key")
			return
		}
		clientToken := strings.TrimPrefix(authHeader, "Bearer ")
		if clientToken == authHeader {
			writeJSONError(w, r, http.StatusUnauthorized, "authentication_error", "invalid api key format")
			return
		}
		username, ok := s.userManager.Authenticate(clientToken)
		if !ok {
			writeJSONError(w, r, http.StatusUnauthorized, "authentication_error", "invalid api key")
			return
		}

		userConfig = s.userConfigMap[username]
		var err error
		provider, err = credentialForUser(s.userConfigMap, s.providers, username)
		if err != nil {
			writeJSONError(w, r, http.StatusInternalServerError, "api_error", err.Error())
			return
		}
	} else {
		provider = s.providers[s.options.Credentials[0].Tag]
	}
	if provider == nil {
		writeJSONError(w, r, http.StatusInternalServerError, "api_error", "no credential available")
		return
	}

	if r.URL.Query().Get("watch") == "true" {
		s.handleStatusStream(w, r, provider, userConfig)
		return
	}

	provider.pollIfStale(r.Context())
	avgFiveHour, avgWeekly, totalWeight := s.computeAggregatedUtilization(provider, userConfig)

	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusOK)
	json.NewEncoder(w).Encode(statusPayload{
		FiveHourUtilization: avgFiveHour,
		WeeklyUtilization:   avgWeekly,
		PlanWeight:          totalWeight,
	})
}

func (s *Service) handleStatusStream(w http.ResponseWriter, r *http.Request, provider credentialProvider, userConfig *option.CCMUser) {
	flusher, ok := w.(http.Flusher)
	if !ok {
		writeJSONError(w, r, http.StatusInternalServerError, "api_error", "streaming not supported")
		return
	}

	subscription, done, err := s.statusObserver.Subscribe()
	if err != nil {
		writeJSONError(w, r, http.StatusInternalServerError, "api_error", "service closing")
		return
	}
	defer s.statusObserver.UnSubscribe(subscription)

	provider.pollIfStale(r.Context())

	w.Header().Set("Content-Type", "application/json")
	w.Header().Set(statusStreamHeader, "true")
	w.WriteHeader(http.StatusOK)

	lastFiveHour, lastWeekly, lastWeight := s.computeAggregatedUtilization(provider, userConfig)
	buf := &bytes.Buffer{}
	json.NewEncoder(buf).Encode(statusPayload{
		FiveHourUtilization: lastFiveHour,
		WeeklyUtilization:   lastWeekly,
		PlanWeight:          lastWeight,
	})
	_, writeErr := w.Write(buf.Bytes())
	if writeErr != nil {
		return
	}
	flusher.Flush()

	for {
		select {
		case <-r.Context().Done():
			return
		case <-done:
			return
		case <-subscription:
			for {
				select {
				case <-subscription:
				default:
					goto drained
				}
			}
		drained:
			fiveHour, weekly, weight := s.computeAggregatedUtilization(provider, userConfig)
			if fiveHour == lastFiveHour && weekly == lastWeekly && weight == lastWeight {
				continue
			}
			lastFiveHour = fiveHour
			lastWeekly = weekly
			lastWeight = weight
			buf.Reset()
			json.NewEncoder(buf).Encode(statusPayload{
				FiveHourUtilization: fiveHour,
				WeeklyUtilization:   weekly,
				PlanWeight:          weight,
			})
			_, writeErr = w.Write(buf.Bytes())
			if writeErr != nil {
				return
			}
			flusher.Flush()
		}
	}
}

func (s *Service) computeAggregatedUtilization(provider credentialProvider, userConfig *option.CCMUser) (float64, float64, float64) {
	var totalWeightedRemaining5h, totalWeightedRemainingWeekly, totalWeight float64
	for _, credential := range provider.allCredentials() {
		if !credential.isAvailable() {
			continue
		}
		if userConfig != nil && userConfig.ExternalCredential != "" && credential.tagName() == userConfig.ExternalCredential {
			continue
		}
		if userConfig != nil && !userConfig.AllowExternalUsage && credential.isExternal() {
			continue
		}
		weight := credential.planWeight()
		remaining5h := credential.fiveHourCap() - credential.fiveHourUtilization()
		if remaining5h < 0 {
			remaining5h = 0
		}
		remainingWeekly := credential.weeklyCap() - credential.weeklyUtilization()
		if remainingWeekly < 0 {
			remainingWeekly = 0
		}
		totalWeightedRemaining5h += remaining5h * weight
		totalWeightedRemainingWeekly += remainingWeekly * weight
		totalWeight += weight
	}
	if totalWeight == 0 {
		return 100, 100, 0
	}
	return 100 - totalWeightedRemaining5h/totalWeight,
		100 - totalWeightedRemainingWeekly/totalWeight,
		totalWeight
}

func (s *Service) rewriteResponseHeadersForExternalUser(headers http.Header, provider credentialProvider, userConfig *option.CCMUser) {
	avgFiveHour, avgWeekly, totalWeight := s.computeAggregatedUtilization(provider, userConfig)

	headers.Set("anthropic-ratelimit-unified-5h-utilization", strconv.FormatFloat(avgFiveHour/100, 'f', 6, 64))
	headers.Set("anthropic-ratelimit-unified-7d-utilization", strconv.FormatFloat(avgWeekly/100, 'f', 6, 64))
	if totalWeight > 0 {
		headers.Set("X-CCM-Plan-Weight", strconv.FormatFloat(totalWeight, 'f', -1, 64))
	}
}