package hook

import (
	"sync"
	"sync/atomic"
	"time"
)

type Metrics struct {
	totalCalls  atomic.Int64
	failedCalls atomic.Int64
	totalTime   atomic.Int64
	hookMetrics map[string]*hookMetric
	mu          sync.RWMutex
}

type hookMetric struct {
	calls      atomic.Int64
	failures   atomic.Int64
	totalTime  atomic.Int64
	lastCalled atomic.Int64
}

func NewMetrics() *Metrics {
	return &Metrics{
		hookMetrics: make(map[string]*hookMetric),
	}
}

func (m *Metrics) RecordHookExecution(name string, hookType HookType, duration time.Duration, success bool) {
	m.totalCalls.Add(1)
	m.totalTime.Add(int64(duration))

	if !success {
		m.failedCalls.Add(1)
	}

	key := string(hookType) + ":" + name

	m.mu.Lock()
	metric, ok := m.hookMetrics[key]
	if !ok {
		metric = &hookMetric{}
		m.hookMetrics[key] = metric
	}
	m.mu.Unlock()

	metric.calls.Add(1)
	metric.totalTime.Add(int64(duration))
	metric.lastCalled.Store(time.Now().Unix())

	if !success {
		metric.failures.Add(1)
	}
}

type MetricSnapshot struct {
	Name       string
	Type       HookType
	Calls      int64
	Failures   int64
	TotalTime  time.Duration
	AvgTime    time.Duration
	LastCalled time.Time
}

func (m *Metrics) GetTotalCalls() int64 {
	return m.totalCalls.Load()
}

func (m *Metrics) GetFailedCalls() int64 {
	return m.failedCalls.Load()
}

func (m *Metrics) GetTotalTime() time.Duration {
	return time.Duration(m.totalTime.Load())
}

func (m *Metrics) GetHookMetrics() []MetricSnapshot {
	m.mu.RLock()
	defer m.mu.RUnlock()

	var snapshots []MetricSnapshot
	for key, metric := range m.hookMetrics {
		calls := metric.calls.Load()
		var avgTime time.Duration
		if calls > 0 {
			avgTime = time.Duration(metric.totalTime.Load() / calls)
		}

		hookType, name := parseKey(key)
		snapshots = append(snapshots, MetricSnapshot{
			Name:       name,
			Type:       hookType,
			Calls:      calls,
			Failures:   metric.failures.Load(),
			TotalTime:  time.Duration(metric.totalTime.Load()),
			AvgTime:    avgTime,
			LastCalled: time.Unix(metric.lastCalled.Load(), 0),
		})
	}
	return snapshots
}

func parseKey(key string) (HookType, string) {
	for i := 0; i < len(key); i++ {
		if key[i] == ':' {
			return HookType(key[:i]), key[i+1:]
		}
	}
	return HookType(key), ""
}

func (m *Metrics) Reset() {
	m.totalCalls.Store(0)
	m.failedCalls.Store(0)
	m.totalTime.Store(0)

	m.mu.Lock()
	m.hookMetrics = make(map[string]*hookMetric)
	m.mu.Unlock()
}