package frankenphp

import (
	"strings"
	"sync"
	"testing"
	"time"

	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/testutil"
	"github.com/stretchr/testify/require"
)

func createPrometheusMetrics() *PrometheusMetrics {
	return &PrometheusMetrics{
		registry:     prometheus.NewRegistry(),
		totalThreads: prometheus.NewCounter(prometheus.CounterOpts{Name: "frankenphp_total_threads"}),
		busyThreads:  prometheus.NewGauge(prometheus.GaugeOpts{Name: "frankenphp_busy_threads"}),
		queueDepth:   prometheus.NewGauge(prometheus.GaugeOpts{Name: "frankenphp_queue_depth"}),
		mu:           sync.Mutex{},
	}
}

func TestPrometheusMetrics_TotalWorkers(t *testing.T) {
	m := createPrometheusMetrics()

	require.Nil(t, m.totalWorkers)
	require.Nil(t, m.busyWorkers)
	require.Nil(t, m.readyWorkers)
	require.Nil(t, m.workerCrashes)
	require.Nil(t, m.workerRestarts)
	require.Nil(t, m.workerRequestTime)
	require.Nil(t, m.workerRequestCount)

	m.TotalWorkers("test_worker", 2)

	require.NotNil(t, m.totalWorkers)
	require.NotNil(t, m.busyWorkers)
	require.NotNil(t, m.readyWorkers)
	require.NotNil(t, m.workerCrashes)
	require.NotNil(t, m.workerRestarts)
	require.NotNil(t, m.workerRequestTime)
	require.NotNil(t, m.workerRequestCount)
}

func TestPrometheusMetrics_StopWorkerRequest(t *testing.T) {
	m := createPrometheusMetrics()
	m.TotalWorkers("test_worker", 2)
	m.StopWorkerRequest("test_worker", 2*time.Second)

	inputs := []struct {
		name     string
		c        prometheus.Collector
		metadata string
		expect   string
	}{
		{
			name: "Testing WorkerRequestCount",
			c:    m.workerRequestCount,
			metadata: `
				# HELP frankenphp_worker_request_count
				# TYPE frankenphp_worker_request_count counter
			`,
			expect: `
				frankenphp_worker_request_count{worker="test_worker"} 1
			`,
		},
		{
			name: "Testing BusyWorkers",
			c:    m.busyWorkers,
			metadata: `
				# HELP frankenphp_busy_workers Number of busy PHP workers for this worker
				# TYPE frankenphp_busy_workers gauge
			`,
			expect: `
				frankenphp_busy_workers{worker="test_worker"} -1
			`,
		},
		{
			name: "Testing WorkerRequestTime",
			c:    m.workerRequestTime,
			metadata: `
				# HELP frankenphp_worker_request_time
				# TYPE frankenphp_worker_request_time counter
			`,
			expect: `
				frankenphp_worker_request_time{worker="test_worker"} 2
			`,
		},
	}

	for _, input := range inputs {
		t.Run(input.name, func(t *testing.T) {
			require.NoError(t, testutil.CollectAndCompare(input.c, strings.NewReader(input.metadata+input.expect)))
		})

	}
}

func TestPrometheusMetrics_StartWorkerRequest(t *testing.T) {
	m := createPrometheusMetrics()
	m.TotalWorkers("test_worker", 2)
	m.StartWorkerRequest("test_worker")

	inputs := []struct {
		name     string
		c        prometheus.Collector
		metadata string
		expect   string
	}{
		{
			name: "Testing BusyWorkers",
			c:    m.busyWorkers,
			metadata: `
				# HELP frankenphp_busy_workers Number of busy PHP workers for this worker
				# TYPE frankenphp_busy_workers gauge
			`,
			expect: `
				frankenphp_busy_workers{worker="test_worker"} 1
			`,
		},
	}

	for _, input := range inputs {
		t.Run(input.name, func(t *testing.T) {
			require.NoError(t, testutil.CollectAndCompare(input.c, strings.NewReader(input.metadata+input.expect)))
		})

	}
}

func TestPrometheusMetrics_TestStopReasonCrash(t *testing.T) {
	m := createPrometheusMetrics()
	m.TotalWorkers("test_worker", 2)
	m.StopWorker("test_worker", StopReasonCrash)

	inputs := []struct {
		name     string
		c        prometheus.Collector
		metadata string
		expect   string
	}{
		{
			name: "Testing BusyThreads",
			c:    m.busyThreads,
			metadata: `
				# HELP frankenphp_busy_threads
				# TYPE frankenphp_busy_threads gauge
			`,
			expect: `
				frankenphp_busy_threads -1
			`,
		},
		{
			name: "Testing TotalWorkers",
			c:    m.totalWorkers,
			metadata: `
				# HELP frankenphp_total_workers Total number of PHP workers for this worker
				# TYPE frankenphp_total_workers gauge
			`,
			expect: `
				frankenphp_total_workers{worker="test_worker"} -1
			`,
		},
		{
			name: "Testing ReadyWorkers",
			c:    m.readyWorkers,
			metadata: `
				# HELP frankenphp_ready_workers Running workers that have successfully called frankenphp_handle_request at least once
				# TYPE frankenphp_ready_workers gauge
			`,
			expect: `
				frankenphp_ready_workers{worker="test_worker"} -1
			`,
		},
		{
			name: "Testing WorkerCrashes",
			c:    m.workerCrashes,
			metadata: `
				# HELP frankenphp_worker_crashes Number of PHP worker crashes for this worker
				# TYPE frankenphp_worker_crashes counter
			`,
			expect: `
				frankenphp_worker_crashes{worker="test_worker"} 1
			`,
		},
	}

	for _, input := range inputs {
		t.Run(input.name, func(t *testing.T) {
			require.NoError(t, testutil.CollectAndCompare(input.c, strings.NewReader(input.metadata+input.expect)))
		})

	}
}