package app

import (
	"sync/atomic"
	"time"
)

type MonitoringHeartbeatSnapshotMetricsSnapshot struct {
	PlatformReportedTotal      int64   `json:"platform_reported_total"`
	TransactionOpenedTotal     int64   `json:"transaction_opened_total"`
	SnapshotInsertedTotal      int64   `json:"snapshot_inserted_total"`
	SnapshotUpdatedTotal       int64   `json:"snapshot_updated_total"`
	SnapshotRefreshedTotal     int64   `json:"snapshot_refreshed_total"`
	SnapshotSkippedTotal       int64   `json:"snapshot_skipped_total"`
	ReconciledSkippedTaskTotal int64   `json:"reconciled_skipped_task_total"`
	ProjectionRebuildTotal     int64   `json:"projection_rebuild_total"`
	ErrorTotal                 int64   `json:"error_total"`
	DurationCount              int64   `json:"duration_count"`
	DurationSumSeconds         float64 `json:"duration_sum_seconds"`
	LastDurationSeconds        float64 `json:"last_duration_seconds"`
	LastErrorCode              string  `json:"last_error_code,omitempty"`
	LastErrorMessage           string  `json:"last_error_message,omitempty"`
}

type monitoringHeartbeatSnapshotMetricsEvent struct {
	Active                     bool
	PlatformCount              int
	TransactionOpened          bool
	SnapshotInsertedCount      int64
	SnapshotUpdatedCount       int64
	SnapshotRefreshedCount     int64
	SnapshotSkippedCount       int64
	ReconciledSkippedTaskCount int64
	ProjectionRebuildCount     int64
	Duration                   time.Duration
	Err                        error
}

type monitoringHeartbeatSnapshotMetricsRecorder struct {
	platformReportedTotal      atomic.Int64
	transactionOpenedTotal     atomic.Int64
	snapshotInsertedTotal      atomic.Int64
	snapshotUpdatedTotal       atomic.Int64
	snapshotRefreshedTotal     atomic.Int64
	snapshotSkippedTotal       atomic.Int64
	reconciledSkippedTaskTotal atomic.Int64
	projectionRebuildTotal     atomic.Int64
	errorTotal                 atomic.Int64
	durationCount              atomic.Int64
	durationSumNanos           atomic.Int64
	lastDurationNanos          atomic.Int64
	lastErrorCode              atomic.Value
	lastErrorMessage           atomic.Value
}

var monitoringHeartbeatSnapshotMetrics = newMonitoringHeartbeatSnapshotMetricsRecorder()

func newMonitoringHeartbeatSnapshotMetricsRecorder() *monitoringHeartbeatSnapshotMetricsRecorder {
	return &monitoringHeartbeatSnapshotMetricsRecorder{}
}

func recordMonitoringHeartbeatSnapshotMetrics(event monitoringHeartbeatSnapshotMetricsEvent) {
	monitoringHeartbeatSnapshotMetrics.record(event)
}

func MonitoringHeartbeatSnapshotMetricsSnapshotValue() MonitoringHeartbeatSnapshotMetricsSnapshot {
	return monitoringHeartbeatSnapshotMetrics.snapshot()
}

func resetMonitoringHeartbeatSnapshotMetricsForTest() {
	monitoringHeartbeatSnapshotMetrics = newMonitoringHeartbeatSnapshotMetricsRecorder()
}

func (r *monitoringHeartbeatSnapshotMetricsRecorder) record(event monitoringHeartbeatSnapshotMetricsEvent) {
	if r == nil {
		return
	}
	if event.Duration < 0 {
		event.Duration = 0
	}
	r.platformReportedTotal.Add(int64(event.PlatformCount))
	if event.TransactionOpened {
		r.transactionOpenedTotal.Add(1)
	}
	r.snapshotInsertedTotal.Add(event.SnapshotInsertedCount)
	r.snapshotUpdatedTotal.Add(event.SnapshotUpdatedCount)
	r.snapshotRefreshedTotal.Add(event.SnapshotRefreshedCount)
	r.snapshotSkippedTotal.Add(event.SnapshotSkippedCount)
	r.reconciledSkippedTaskTotal.Add(event.ReconciledSkippedTaskCount)
	r.projectionRebuildTotal.Add(event.ProjectionRebuildCount)
	r.durationCount.Add(1)
	r.durationSumNanos.Add(event.Duration.Nanoseconds())
	r.lastDurationNanos.Store(event.Duration.Nanoseconds())

	if event.Err != nil {
		code, message := monitoringDailyMetricError(event.Err)
		r.errorTotal.Add(1)
		r.lastErrorCode.Store(code)
		r.lastErrorMessage.Store(message)
	}
}

func (r *monitoringHeartbeatSnapshotMetricsRecorder) snapshot() MonitoringHeartbeatSnapshotMetricsSnapshot {
	if r == nil {
		return MonitoringHeartbeatSnapshotMetricsSnapshot{}
	}
	return MonitoringHeartbeatSnapshotMetricsSnapshot{
		PlatformReportedTotal:      r.platformReportedTotal.Load(),
		TransactionOpenedTotal:     r.transactionOpenedTotal.Load(),
		SnapshotInsertedTotal:      r.snapshotInsertedTotal.Load(),
		SnapshotUpdatedTotal:       r.snapshotUpdatedTotal.Load(),
		SnapshotRefreshedTotal:     r.snapshotRefreshedTotal.Load(),
		SnapshotSkippedTotal:       r.snapshotSkippedTotal.Load(),
		ReconciledSkippedTaskTotal: r.reconciledSkippedTaskTotal.Load(),
		ProjectionRebuildTotal:     r.projectionRebuildTotal.Load(),
		ErrorTotal:                 r.errorTotal.Load(),
		DurationCount:              r.durationCount.Load(),
		DurationSumSeconds:         float64(r.durationSumNanos.Load()) / float64(time.Second),
		LastDurationSeconds:        float64(r.lastDurationNanos.Load()) / float64(time.Second),
		LastErrorCode:              monitoringDailyLoadString(&r.lastErrorCode),
		LastErrorMessage:           monitoringDailyLoadString(&r.lastErrorMessage),
	}
}