metrics

var (
	// Request metrics
	RequestsTotal = prometheus.NewCounterVec(
		prometheus.CounterOpts{
			Name: "proxy_requests_total",
			Help: "Total number of requests by ecosystem and status",
		},
		[]string{"ecosystem", "status"},
	)

	RequestDuration = prometheus.NewHistogramVec(
		prometheus.HistogramOpts{
			Name:    "proxy_request_duration_seconds",
			Help:    "Request duration in seconds",
			Buckets: prometheus.DefBuckets,
		},
		[]string{"ecosystem", "status"},
	)

	// Cache metrics
	CacheHits = prometheus.NewCounterVec(
		prometheus.CounterOpts{
			Name: "proxy_cache_hits_total",
			Help: "Total number of cache hits by ecosystem",
		},
		[]string{"ecosystem"},
	)

	CacheMisses = prometheus.NewCounterVec(
		prometheus.CounterOpts{
			Name: "proxy_cache_misses_total",
			Help: "Total number of cache misses by ecosystem",
		},
		[]string{"ecosystem"},
	)

	CacheSize = prometheus.NewGauge(
		prometheus.GaugeOpts{
			Name: "proxy_cache_size_bytes",
			Help: "Total size of cached artifacts in bytes",
		},
	)

	CachedArtifacts = prometheus.NewGauge(
		prometheus.GaugeOpts{
			Name: "proxy_cached_artifacts_total",
			Help: "Total number of cached artifacts",
		},
	)

	// Upstream metrics
	UpstreamFetchDuration = prometheus.NewHistogramVec(
		prometheus.HistogramOpts{
			Name:    "proxy_upstream_fetch_duration_seconds",
			Help:    "Upstream fetch duration in seconds",
			Buckets: []float64{.1, .25, .5, 1, 2.5, 5, 10, 30},
		},
		[]string{"ecosystem"},
	)

	UpstreamErrors = prometheus.NewCounterVec(
		prometheus.CounterOpts{
			Name: "proxy_upstream_errors_total",
			Help: "Total number of upstream fetch errors by type",
		},
		[]string{"ecosystem", "error_type"},
	)

	// Circuit breaker metrics
	CircuitBreakerState = prometheus.NewGaugeVec(
		prometheus.GaugeOpts{
			Name: "proxy_circuit_breaker_state",
			Help: "Circuit breaker state (0=closed, 1=half-open, 2=open)",
		},
		[]string{"registry"},
	)

	CircuitBreakerTrips = prometheus.NewCounterVec(
		prometheus.CounterOpts{
			Name: "proxy_circuit_breaker_trips_total",
			Help: "Total number of circuit breaker trips",
		},
		[]string{"registry"},
	)

	// Storage metrics
	StorageOperationDuration = prometheus.NewHistogramVec(
		prometheus.HistogramOpts{
			Name:    "proxy_storage_operation_duration_seconds",
			Help:    "Storage operation duration in seconds",
			Buckets: []float64{.001, .005, .01, .025, .05, .1, .25, .5, 1},
		},
		[]string{"operation"},
	)

	StorageErrors = prometheus.NewCounterVec(
		prometheus.CounterOpts{
			Name: "proxy_storage_errors_total",
			Help: "Total number of storage errors by operation",
		},
		[]string{"operation"},
	)

	// Active requests
	ActiveRequests = prometheus.NewGauge(
		prometheus.GaugeOpts{
			Name: "proxy_active_requests",
			Help: "Number of currently active requests",
		},
	)
)