package observability

import (
	"strconv"
	"time"

	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promauto"
)

var (
	maintenancePolicyRuns = promauto.NewCounterVec(
		prometheus.CounterOpts{
			Namespace: namespace,
			Name:      "maintenance_policy_runs_total",
			Help:      "Maintenance policy executions by outcome.",
		},
		[]string{"policy_id", "action", "status", "dry_run"},
	)

	maintenancePolicyDuration = promauto.NewHistogramVec(
		prometheus.HistogramOpts{
			Namespace: namespace,
			Name:      "maintenance_policy_duration_seconds",
			Help:      "Maintenance policy execution duration.",
			Buckets:   prometheus.ExponentialBuckets(0.05, 2, 12),
		},
		[]string{"policy_id", "action"},
	)

	maintenanceRowsDeleted = promauto.NewCounterVec(
		prometheus.CounterOpts{
			Namespace: namespace,
			Name:      "maintenance_policy_rows_deleted_total",
			Help:      "Rows deleted by maintenance cleanup policies.",
		},
		[]string{"policy_id"},
	)

	maintenanceConfigChanges = promauto.NewCounterVec(
		prometheus.CounterOpts{
			Namespace: namespace,
			Name:      "maintenance_config_changes_total",
			Help:      "Maintenance policy configuration changes from UI/API.",
		},
		[]string{"action"},
	)
)

// RecordMaintenancePolicyRun updates run counters and histograms.
func RecordMaintenancePolicyRun(policyID, action, status string, dryRun bool, duration time.Duration, rowsDeleted int64) {
	if policyID == "" {
		policyID = "unknown"
	}
	if action == "" {
		action = "run"
	}
	dry := strconv.FormatBool(dryRun)
	maintenancePolicyRuns.WithLabelValues(policyID, action, status, dry).Inc()
	maintenancePolicyDuration.WithLabelValues(policyID, action).Observe(duration.Seconds())
	if rowsDeleted > 0 && !dryRun {
		maintenanceRowsDeleted.WithLabelValues(policyID).Add(float64(rowsDeleted))
	}
}

// IncMaintenanceConfigChange increments config audit metric.
func IncMaintenanceConfigChange(action string) {
	if action == "" {
		action = "unknown"
	}
	maintenanceConfigChanges.WithLabelValues(action).Inc()
}