observability

type LogExporter struct {
	// contains filtered or unexported fields
}

type Metrics struct {

	// RequestsTotal counts fetch attempts by domain and outcome. `outcome` is
	// "ok", "error", or "retry" — a status code alone cannot distinguish a
	// transport failure from an HTTP error.
	RequestsTotal *prometheus.CounterVec

	// ResponsesTotal counts responses by domain and status code. The code is a
	// label rather than a metric per class, so 404-vs-410 stays visible.
	ResponsesTotal *prometheus.CounterVec

	// FetchDuration is the histogram that makes p50/p95/p99 latency answerable.
	// Buckets span 10 ms to ~60 s: the range between a warm CDN and a timeout.
	FetchDuration *prometheus.HistogramVec

	// ResponseSize tracks downloaded body sizes, which is how you notice a site
	// that has started serving an interstitial instead of content.
	ResponseSize *prometheus.HistogramVec

	// ItemsTotal counts pipeline outcomes: scraped, dropped, stored.
	ItemsTotal *prometheus.CounterVec

	// BytesDownloaded is the cumulative transfer counter.
	BytesDownloaded prometheus.Counter

	// FrontierDepth and ActiveWorkers are gauges — they go down as well as up,
	// which is exactly what the old exposition could not express.
	FrontierDepth prometheus.Gauge
	ActiveWorkers prometheus.Gauge

	// ProxyRotations and ProxyErrors track proxy pool health.
	ProxyRotations prometheus.Counter
	ProxyErrors    prometheus.Counter
	// contains filtered or unexported fields
}

type Span struct {
	TraceID   string         `json:"trace_id"`
	SpanID    string         `json:"span_id"`
	ParentID  string         `json:"parent_id,omitempty"`
	Operation string         `json:"operation"`
	Service   string         `json:"service"`
	StartTime time.Time      `json:"start_time"`
	EndTime   time.Time      `json:"end_time,omitempty"`
	Duration  time.Duration  `json:"duration,omitempty"`
	Status    SpanStatus     `json:"status"`
	Tags      map[string]any `json:"tags,omitempty"`
	Events    []SpanEvent    `json:"events,omitempty"`
	// contains filtered or unexported fields
}

type SpanEvent struct {
	Name      string         `json:"name"`
	Timestamp time.Time      `json:"timestamp"`
	Attrs     map[string]any `json:"attrs,omitempty"`
}

type SpanExporter interface {
	Export(spans []*Span) error
	Close() error
}

type SpanStatus int

type Tracer struct {
	// contains filtered or unexported fields
}

type TracerConfig struct {
	Enabled     bool
	ServiceName string
	SampleRate  float64
	MaxSpans    int
}