package agent

import (
	"net"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"

	"github.com/henrygd/beszel/internal/entities/probe"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestProbeTaskAggregateLockedUsesRawSamplesForShortWindows(t *testing.T) {
	now := time.Date(2026, time.April, 21, 12, 0, 0, 0, time.UTC)
	task := &probeTask{}

	task.addSampleLocked(probeSample{responseMs: 10, timestamp: now.Add(-90 * time.Second)})
	task.addSampleLocked(probeSample{responseMs: 20, timestamp: now.Add(-30 * time.Second)})
	task.addSampleLocked(probeSample{responseMs: -1, timestamp: now.Add(-10 * time.Second)})

	agg := task.aggregateLocked(time.Minute, now)
	require.True(t, agg.hasData())
	assert.Equal(t, 2, agg.totalCount)
	assert.Equal(t, 1, agg.successCount)
	assert.Equal(t, 20.0, agg.result()[0])
	assert.Equal(t, 20.0, agg.result()[1])
	assert.Equal(t, 20.0, agg.result()[2])
	assert.Equal(t, 50.0, agg.result()[3])
}

func TestProbeTaskAggregateLockedUsesMinuteBucketsForLongWindows(t *testing.T) {
	now := time.Date(2026, time.April, 21, 12, 0, 30, 0, time.UTC)
	task := &probeTask{}

	task.addSampleLocked(probeSample{responseMs: 10, timestamp: now.Add(-11 * time.Minute)})
	task.addSampleLocked(probeSample{responseMs: 20, timestamp: now.Add(-9 * time.Minute)})
	task.addSampleLocked(probeSample{responseMs: 40, timestamp: now.Add(-5 * time.Minute)})
	task.addSampleLocked(probeSample{responseMs: -1, timestamp: now.Add(-90 * time.Second)})
	task.addSampleLocked(probeSample{responseMs: 30, timestamp: now.Add(-30 * time.Second)})

	agg := task.aggregateLocked(10*time.Minute, now)
	require.True(t, agg.hasData())
	assert.Equal(t, 4, agg.totalCount)
	assert.Equal(t, 3, agg.successCount)
	assert.Equal(t, 30.0, agg.result()[0])
	assert.Equal(t, 20.0, agg.result()[1])
	assert.Equal(t, 40.0, agg.result()[2])
	assert.Equal(t, 25.0, agg.result()[3])
}

func TestProbeTaskAddSampleLockedTrimsRawSamplesButKeepsBucketHistory(t *testing.T) {
	now := time.Date(2026, time.April, 21, 12, 0, 0, 0, time.UTC)
	task := &probeTask{}

	task.addSampleLocked(probeSample{responseMs: 10, timestamp: now.Add(-10 * time.Minute)})
	task.addSampleLocked(probeSample{responseMs: 20, timestamp: now})

	require.Len(t, task.samples, 1)
	assert.Equal(t, 20.0, task.samples[0].responseMs)

	agg := task.aggregateLocked(10*time.Minute, now)
	require.True(t, agg.hasData())
	assert.Equal(t, 2, agg.totalCount)
	assert.Equal(t, 2, agg.successCount)
	assert.Equal(t, 15.0, agg.result()[0])
	assert.Equal(t, 10.0, agg.result()[1])
	assert.Equal(t, 20.0, agg.result()[2])
	assert.Equal(t, 0.0, agg.result()[3])
}

func TestProbeManagerGetResultsIncludesHourResponseRange(t *testing.T) {
	now := time.Now().UTC()
	task := &probeTask{}
	task.addSampleLocked(probeSample{responseMs: 10, timestamp: now.Add(-30 * time.Minute)})
	task.addSampleLocked(probeSample{responseMs: 20, timestamp: now.Add(-9 * time.Minute)})
	task.addSampleLocked(probeSample{responseMs: 40, timestamp: now.Add(-5 * time.Minute)})
	task.addSampleLocked(probeSample{responseMs: -1, timestamp: now.Add(-90 * time.Second)})
	task.addSampleLocked(probeSample{responseMs: 30, timestamp: now.Add(-30 * time.Second)})

	pm := &ProbeManager{probes: map[string]*probeTask{"icmp:example.com": task}}

	results := pm.GetResults(uint16(time.Minute / time.Millisecond))
	result, ok := results["icmp:example.com"]
	require.True(t, ok)
	require.Len(t, result, 5)
	assert.Equal(t, 30.0, result[0])
	assert.Equal(t, 25.0, result[1])
	assert.Equal(t, 10.0, result[2])
	assert.Equal(t, 40.0, result[3])
	assert.Equal(t, 20.0, result[4])
}

func TestProbeManagerGetResultsIncludesLossOnlyHourData(t *testing.T) {
	now := time.Now().UTC()
	task := &probeTask{}
	task.addSampleLocked(probeSample{responseMs: -1, timestamp: now.Add(-30 * time.Second)})
	task.addSampleLocked(probeSample{responseMs: -1, timestamp: now.Add(-10 * time.Second)})

	pm := &ProbeManager{probes: map[string]*probeTask{"icmp:example.com": task}}

	results := pm.GetResults(uint16(time.Minute / time.Millisecond))
	result, ok := results["icmp:example.com"]
	require.True(t, ok)
	require.Len(t, result, 5)
	assert.Equal(t, 0.0, result[0])
	assert.Equal(t, 0.0, result[1])
	assert.Equal(t, 0.0, result[2])
	assert.Equal(t, 0.0, result[3])
	assert.Equal(t, 100.0, result[4])
}

func TestProbeManagerSyncProbesStopsRemovedTasksButKeepsExisting(t *testing.T) {
	keepCfg := probe.Config{Target: "https://example.com", Protocol: "http", Interval: 10}
	removeCfg := probe.Config{Target: "1.1.1.1", Protocol: "icmp", Interval: 10}

	keptTask := &probeTask{config: keepCfg, cancel: make(chan struct{})}
	removedTask := &probeTask{config: removeCfg, cancel: make(chan struct{})}
	pm := &ProbeManager{
		probes: map[string]*probeTask{
			keepCfg.Key():   keptTask,
			removeCfg.Key(): removedTask,
		},
	}

	pm.SyncProbes([]probe.Config{keepCfg})

	assert.Same(t, keptTask, pm.probes[keepCfg.Key()])
	_, exists := pm.probes[removeCfg.Key()]
	assert.False(t, exists)

	select {
	case <-removedTask.cancel:
	default:
		t.Fatal("expected removed probe task to be cancelled")
	}

	select {
	case <-keptTask.cancel:
		t.Fatal("expected existing probe task to remain active")
	default:
	}
}

func TestProbeHTTP(t *testing.T) {
	t.Run("success", func(t *testing.T) {
		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			w.WriteHeader(http.StatusNoContent)
		}))
		defer server.Close()

		responseMs := probeHTTP(server.Client(), server.URL)
		assert.GreaterOrEqual(t, responseMs, 0.0)
	})

	t.Run("server error", func(t *testing.T) {
		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			http.Error(w, "boom", http.StatusInternalServerError)
		}))
		defer server.Close()

		assert.Equal(t, -1.0, probeHTTP(server.Client(), server.URL))
	})
}

func TestProbeTCP(t *testing.T) {
	t.Run("success", func(t *testing.T) {
		listener, err := net.Listen("tcp", "127.0.0.1:0")
		require.NoError(t, err)
		defer listener.Close()

		accepted := make(chan struct{})
		go func() {
			defer close(accepted)
			conn, err := listener.Accept()
			if err == nil {
				_ = conn.Close()
			}
		}()

		port := uint16(listener.Addr().(*net.TCPAddr).Port)
		responseMs := probeTCP("127.0.0.1", port)
		assert.GreaterOrEqual(t, responseMs, 0.0)
		<-accepted
	})

	t.Run("connection failure", func(t *testing.T) {
		listener, err := net.Listen("tcp", "127.0.0.1:0")
		require.NoError(t, err)

		port := uint16(listener.Addr().(*net.TCPAddr).Port)
		require.NoError(t, listener.Close())

		assert.Equal(t, -1.0, probeTCP("127.0.0.1", port))
	})
}