feat: add dashboard metrics service

internal/services/metrics_service.go

@@ -0,0 +1,144 @@
+package services
+
+import (
+	"cmbone/internal/models"
+	"database/sql"
+	"time"
+)
+
+const (
+	defaultTrendDays      = 7
+	maxTrendDays          = 30
+	imageTaskStatusFailed = "failed"
+)
+
+type MetricsService struct {
+	store *SuiStore
+}
+
+func NewMetricsService(store *SuiStore) *MetricsService {
+	return &MetricsService{store: store}
+}
+
+func (s *MetricsService) GetDashboardMetrics() (models.DashboardMetrics, error) {
+	start := localDayStart(time.Now())
+	end := start.AddDate(0, 0, 1)
+
+	taskMetric, err := s.queryTaskMetric(start, end)
+	if err != nil {
+		return models.DashboardMetrics{}, err
+	}
+
+	auditLogs, err := s.countAuditLogs(start, end)
+	if err != nil {
+		return models.DashboardMetrics{}, err
+	}
+
+	return models.DashboardMetrics{
+		TodayProcessedImages: taskMetric.ProcessedImages,
+		SuccessRate:          successRate(taskMetric.SucceededTasks, taskMetric.ProcessedImages),
+		AverageDurationMs:    taskMetric.AverageDuration,
+		FailedTasks:          taskMetric.FailedTasks,
+		TodayAuditLogs:       auditLogs,
+	}, nil
+}
+
+func (s *MetricsService) GetProcessingTrend(days int) ([]models.DailyMetric, error) {
+	days = normalizeTrendDays(days)
+	today := localDayStart(time.Now())
+	start := today.AddDate(0, 0, -days+1)
+
+	trend := make([]models.DailyMetric, 0, days)
+	for i := 0; i < days; i++ {
+		dayStart := start.AddDate(0, 0, i)
+		dayEnd := dayStart.AddDate(0, 0, 1)
+
+		taskMetric, err := s.queryTaskMetric(dayStart, dayEnd)
+		if err != nil {
+			return nil, err
+		}
+		auditLogs, err := s.countAuditLogs(dayStart, dayEnd)
+		if err != nil {
+			return nil, err
+		}
+
+		trend = append(trend, models.DailyMetric{
+			Date:              dayStart.Format("2006-01-02"),
+			ProcessedImages:   taskMetric.ProcessedImages,
+			SucceededTasks:    taskMetric.SucceededTasks,
+			FailedTasks:       taskMetric.FailedTasks,
+			AverageDurationMs: taskMetric.AverageDuration,
+			AuditLogs:         auditLogs,
+		})
+	}
+	return trend, nil
+}
+
+type taskMetric struct {
+	ProcessedImages int64
+	SucceededTasks  int64
+	FailedTasks     int64
+	AverageDuration float64
+}
+
+func (s *MetricsService) queryTaskMetric(start time.Time, end time.Time) (taskMetric, error) {
+	var metric taskMetric
+	var average sql.NullFloat64
+	err := s.store.DB.QueryRow(`
+		SELECT
+			COUNT(*),
+			COALESCE(SUM(CASE WHEN status = ? THEN 1 ELSE 0 END), 0),
+			COALESCE(SUM(CASE WHEN status = ? THEN 1 ELSE 0 END), 0),
+			AVG(CASE WHEN duration_ms > 0 THEN duration_ms END)
+		FROM image_tasks
+		WHERE created_at >= ? AND created_at < ?
+	`, imageTaskStatusSucceeded, imageTaskStatusFailed, formatMetricTime(start), formatMetricTime(end)).Scan(
+		&metric.ProcessedImages,
+		&metric.SucceededTasks,
+		&metric.FailedTasks,
+		&average,
+	)
+	if err != nil {
+		return taskMetric{}, err
+	}
+	if average.Valid {
+		metric.AverageDuration = average.Float64
+	}
+	return metric, nil
+}
+
+func (s *MetricsService) countAuditLogs(start time.Time, end time.Time) (int64, error) {
+	var count int64
+	err := s.store.DB.QueryRow(`
+		SELECT COUNT(*)
+		FROM audit_logs
+		WHERE created_at >= ? AND created_at < ?
+	`, formatMetricTime(start), formatMetricTime(end)).Scan(&count)
+	return count, err
+}
+
+func normalizeTrendDays(days int) int {
+	if days <= 0 {
+		return defaultTrendDays
+	}
+	if days > maxTrendDays {
+		return maxTrendDays
+	}
+	return days
+}
+
+func localDayStart(now time.Time) time.Time {
+	local := now.In(time.Local)
+	return time.Date(local.Year(), local.Month(), local.Day(), 0, 0, 0, 0, local.Location())
+}
+
+func formatMetricTime(value time.Time) string {
+	return value.UTC().Format(time.RFC3339)
+}
+
+func successRate(succeeded int64, total int64) float64 {
+	if total <= 0 {
+		return 0
+	}
+	return float64(succeeded) * 100 / float64(total)
+}