feat: add summary and timeseries stats queries

internal/store/postgres/stats.go

@@ -0,0 +1,184 @@
+package postgres
+
+import (
+	"context"
+	"time"
+)
+
+type FrameworkStats struct {
+	Runs   int `json:"runs"`
+	Tools  int `json:"tools"`
+	Errors int `json:"errors"`
+}
+
+type Summary struct {
+	ActiveSessions int                        `json:"active_sessions"`
+	RunsToday      int                        `json:"runs_today"`
+	ToolCallsToday int                        `json:"tool_calls_today"`
+	ErrorsToday    int                        `json:"errors_today"`
+	ByFramework    map[string]FrameworkStats  `json:"by_framework"`
+}
+
+type TimeseriesBucket struct {
+	TS     time.Time `json:"ts"`
+	Runs   int       `json:"runs"`
+	Tools  int       `json:"tools"`
+	Errors int       `json:"errors"`
+}
+
+type TimeseriesResult struct {
+	Window string             `json:"window"`
+	Bucket string             `json:"bucket"`
+	Series []TimeseriesBucket `json:"series"`
+}
+
+func (d *DB) GetSummary(ctx context.Context) (*Summary, error) {
+	now := time.Now()
+	midnight := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location())
+
+	// Active sessions: sessions that started today but have not ended today
+	activeQ := `
+		SELECT COUNT(DISTINCT session_id)
+		FROM events
+		WHERE type = 'session.start'
+		  AND ts >= $1
+		  AND session_id IS NOT NULL
+		  AND session_id NOT IN (
+		      SELECT DISTINCT session_id
+		      FROM events
+		      WHERE type = 'session.end'
+		        AND ts >= $1
+		        AND session_id IS NOT NULL
+		  )
+	`
+	var activeSessions int
+	if err := d.sql.QueryRowContext(ctx, activeQ, midnight).Scan(&activeSessions); err != nil {
+		return nil, err
+	}
+
+	// Per-framework aggregates for today
+	fwQ := `
+		SELECT
+			COALESCE(source_framework, ''),
+			COUNT(*) FILTER (WHERE type = 'run.start')        AS runs,
+			COUNT(*) FILTER (WHERE type = 'span.end'
+			                   AND payload->'attributes'->>'span_kind' = 'tool') AS tools,
+			COUNT(*) FILTER (WHERE type = 'error')            AS errors
+		FROM events
+		WHERE ts >= $1
+		GROUP BY source_framework
+	`
+	rows, err := d.sql.QueryContext(ctx, fwQ, midnight)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	byFramework := make(map[string]FrameworkStats)
+	var totalRuns, totalTools, totalErrors int
+
+	for rows.Next() {
+		var fw string
+		var fs FrameworkStats
+		if err := rows.Scan(&fw, &fs.Runs, &fs.Tools, &fs.Errors); err != nil {
+			return nil, err
+		}
+		byFramework[fw] = fs
+		totalRuns += fs.Runs
+		totalTools += fs.Tools
+		totalErrors += fs.Errors
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+
+	return &Summary{
+		ActiveSessions: activeSessions,
+		RunsToday:      totalRuns,
+		ToolCallsToday: totalTools,
+		ErrorsToday:    totalErrors,
+		ByFramework:    byFramework,
+	}, nil
+}
+
+func bucketForWindow(window string) string {
+	switch window {
+	case "1h":
+		return "1 minute"
+	case "6h":
+		return "5 minutes"
+	case "7d":
+		return "1 hour"
+	default: // "24h"
+		return "15 minutes"
+	}
+}
+
+func durationForWindow(window string) time.Duration {
+	switch window {
+	case "1h":
+		return 1 * time.Hour
+	case "6h":
+		return 6 * time.Hour
+	case "7d":
+		return 7 * 24 * time.Hour
+	default: // "24h"
+		return 24 * time.Hour
+	}
+}
+
+func bucketLabelForWindow(window string) string {
+	switch window {
+	case "1h":
+		return "1m"
+	case "6h":
+		return "5m"
+	case "7d":
+		return "1h"
+	default: // "24h"
+		return "15m"
+	}
+}
+
+func (d *DB) GetTimeseries(ctx context.Context, window string) (*TimeseriesResult, error) {
+	bucket := bucketForWindow(window)
+	dur := durationForWindow(window)
+	since := time.Now().Add(-dur)
+
+	q := `
+		SELECT
+			date_bin($1::interval, ts, '2000-01-01'::timestamptz) AS bucket_ts,
+			COUNT(*) FILTER (WHERE type = 'run.start')             AS runs,
+			COUNT(*) FILTER (WHERE type = 'span.end'
+			                   AND payload->'attributes'->>'span_kind' = 'tool') AS tools,
+			COUNT(*) FILTER (WHERE type = 'error')                 AS errors
+		FROM events
+		WHERE ts >= $2
+		GROUP BY bucket_ts
+		ORDER BY bucket_ts ASC
+	`
+
+	rows, err := d.sql.QueryContext(ctx, q, bucket, since)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var series []TimeseriesBucket
+	for rows.Next() {
+		var b TimeseriesBucket
+		if err := rows.Scan(&b.TS, &b.Runs, &b.Tools, &b.Errors); err != nil {
+			return nil, err
+		}
+		series = append(series, b)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+
+	return &TimeseriesResult{
+		Window: window,
+		Bucket: bucketLabelForWindow(window),
+		Series: series,
+	}, nil
+}