Add comprehensive metrics system to HAL

.gitignore

@@ -1,3 +1,9 @@
+# Binaries
+hal
+
+# Test coverage
 cover.out
+
+# Databases
 sqlite.db*
 test-results.json

cmd/hal/commands/stats.go

@@ -0,0 +1,174 @@
+package commands
+
+import (
+	"fmt"
+	"math"
+	"os"
+	"sort"
+	"strings"
+	"text/tabwriter"
+	"time"
+
+	"github.com/dansimau/hal/store"
+	"github.com/spf13/cobra"
+	"gorm.io/gorm"
+)
+
+type MetricSummary struct {
+	MetricType store.MetricType
+	LastMinute interface{}
+	LastHour   interface{}
+	LastDay    interface{}
+	LastMonth  interface{}
+}
+
+type TimePeriod struct {
+	Name     string
+	Duration time.Duration
+}
+
+// NewStatsCmd creates the stats command
+func NewStatsCmd() *cobra.Command {
+	var dbPath string
+
+	cmd := &cobra.Command{
+		Use:     "stats",
+		Aliases: []string{"stat"},
+		Short:   "Display HAL metrics statistics",
+		Long: `Display comprehensive metrics statistics for HAL automation system.
+Shows automation triggers, evaluations, and processing times across multiple time periods.`,
+		Example: `  hal stats                    # Show stats using default database
+  hal stats --db custom.db     # Show stats from custom database`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return runStatsCommand(dbPath)
+		},
+	}
+
+	cmd.Flags().StringVar(&dbPath, "db", "sqlite.db", "Database file path")
+	return cmd
+}
+
+func runStatsCommand(dbPath string) error {
+	// Open database connection
+	db, err := store.Open(dbPath)
+	if err != nil {
+		return fmt.Errorf("failed to open database: %w", err)
+	}
+
+	// Get stats for all metric types
+	metricTypes := []store.MetricType{
+		store.MetricTypeAutomationTriggered,
+		store.MetricTypeTickProcessingTime,
+	}
+
+	var summaries []MetricSummary
+
+	for _, metricType := range metricTypes {
+		summary := MetricSummary{MetricType: metricType}
+
+		if strings.Contains(string(metricType), "time") {
+			// Timer metrics - calculate p99
+			summary.LastMinute = calculateP99(db, metricType, time.Minute)
+			summary.LastHour = calculateP99(db, metricType, time.Hour)
+			summary.LastDay = calculateP99(db, metricType, 24*time.Hour)
+			summary.LastMonth = calculateP99(db, metricType, 30*24*time.Hour)
+		} else {
+			// Counter metrics - sum
+			summary.LastMinute = sumMetrics(db, metricType, time.Minute)
+			summary.LastHour = sumMetrics(db, metricType, time.Hour)
+			summary.LastDay = sumMetrics(db, metricType, 24*time.Hour)
+			summary.LastMonth = sumMetrics(db, metricType, 30*24*time.Hour)
+		}
+
+		summaries = append(summaries, summary)
+	}
+
+	// Print results in table format
+	return printTable(summaries)
+}
+
+func sumMetrics(db *gorm.DB, metricType store.MetricType, duration time.Duration) int64 {
+	since := time.Now().Add(-duration)
+	var result struct {
+		Total int64
+	}
+
+	db.Model(&store.Metric{}).
+		Select("COALESCE(SUM(value), 0) as total").
+		Where("metric_type = ? AND timestamp > ?", metricType, since).
+		Scan(&result)
+
+	return result.Total
+}
+
+func calculateP99(db *gorm.DB, metricType store.MetricType, duration time.Duration) string {
+	since := time.Now().Add(-duration)
+	var values []int64
+
+	db.Model(&store.Metric{}).
+		Select("value").
+		Where("metric_type = ? AND timestamp > ?", metricType, since).
+		Scan(&values)
+
+	if len(values) == 0 {
+		return "0ms"
+	}
+
+	sort.Slice(values, func(i, j int) bool {
+		return values[i] < values[j]
+	})
+
+	// Calculate p99 (99th percentile)
+	index := int(math.Ceil(float64(len(values))*0.99)) - 1
+	if index < 0 {
+		index = 0
+	}
+
+	p99Nanos := values[index]
+	return formatDuration(time.Duration(p99Nanos))
+}
+
+func formatDuration(d time.Duration) string {
+	if d < time.Microsecond {
+		return fmt.Sprintf("%.0fns", float64(d))
+	} else if d < time.Millisecond {
+		return fmt.Sprintf("%.1fμs", float64(d)/float64(time.Microsecond))
+	} else if d < time.Second {
+		return fmt.Sprintf("%.1fms", float64(d)/float64(time.Millisecond))
+	} else {
+		return fmt.Sprintf("%.2fs", d.Seconds())
+	}
+}
+
+func formatMetricType(metricType store.MetricType) string {
+	switch metricType {
+	case store.MetricTypeAutomationTriggered:
+		return "Automations Triggered"
+	case store.MetricTypeTickProcessingTime:
+		return "Tick Processing Time (p99)"
+	default:
+		return string(metricType)
+	}
+}
+
+func printTable(summaries []MetricSummary) error {
+	w := tabwriter.NewWriter(os.Stdout, 0, 0, 2, ' ', 0)
+	defer w.Flush()
+
+	// Print header
+	fmt.Fprintf(w, "Metric\tLast Minute\tLast Hour\tLast Day\tLast Month\n")
+	fmt.Fprintf(w, "------\t-----------\t---------\t--------\t----------\n")
+
+	// Print data rows
+	for _, summary := range summaries {
+		fmt.Fprintf(w, "%s\t%v\t%v\t%v\t%v\n",
+			formatMetricType(summary.MetricType),
+			summary.LastMinute,
+			summary.LastHour,
+			summary.LastDay,
+			summary.LastMonth,
+		)
+	}
+
+	return nil
+}