package rtc

import (
	"sort"
	"sync"
	"testing"
	"time"

	"github.com/livekit/livekit-server/pkg/rtc/types"
	"github.com/livekit/protocol/livekit"
	"github.com/pion/webrtc/v3"
	"github.com/stretchr/testify/require"
)

func TestSubscribedMaxQuality(t *testing.T) {
	subscribedCodecsAsString := func(c1 []*livekit.SubscribedCodec) string {
		sort.Slice(c1, func(i, j int) bool { return c1[i].Codec < c1[j].Codec })
		var s1 string
		for _, c := range c1 {
			s1 += c.String()
		}
		return s1
	}
	t.Run("subscribers muted", func(t *testing.T) {
		dm := NewDynacastManager(DynacastManagerParams{})
		var lock sync.Mutex
		actualSubscribedQualities := make([]*livekit.SubscribedCodec, 0)
		dm.OnSubscribedMaxQualityChange(func(subscribedQualities []*livekit.SubscribedCodec, _maxSubscribedQualities []types.SubscribedCodecQuality) {
			lock.Lock()
			actualSubscribedQualities = subscribedQualities
			lock.Unlock()
		})

		dm.NotifySubscriberMaxQuality("s1", webrtc.MimeTypeVP8, livekit.VideoQuality_HIGH)
		dm.NotifySubscriberMaxQuality("s2", webrtc.MimeTypeAV1, livekit.VideoQuality_HIGH)

		// mute all subscribers of vp8
		dm.NotifySubscriberMaxQuality("s1", webrtc.MimeTypeVP8, livekit.VideoQuality_OFF)

		expectedSubscribedQualities := []*livekit.SubscribedCodec{
			{
				Codec: webrtc.MimeTypeVP8,
				Qualities: []*livekit.SubscribedQuality{
					{Quality: livekit.VideoQuality_LOW, Enabled: false},
					{Quality: livekit.VideoQuality_MEDIUM, Enabled: false},
					{Quality: livekit.VideoQuality_HIGH, Enabled: false},
				},
			},
			{
				Codec: webrtc.MimeTypeAV1,
				Qualities: []*livekit.SubscribedQuality{
					{Quality: livekit.VideoQuality_LOW, Enabled: true},
					{Quality: livekit.VideoQuality_MEDIUM, Enabled: true},
					{Quality: livekit.VideoQuality_HIGH, Enabled: true},
				},
			},
		}
		require.Eventually(t, func() bool {
			lock.Lock()
			defer lock.Unlock()

			return subscribedCodecsAsString(expectedSubscribedQualities) == subscribedCodecsAsString(actualSubscribedQualities)
		}, 10*time.Second, 100*time.Millisecond)
	})

	t.Run("subscribers max quality", func(t *testing.T) {
		dm := NewDynacastManager(DynacastManagerParams{
			DynacastPauseDelay: 100 * time.Millisecond,
		})

		lock := sync.RWMutex{}
		lock.Lock()
		actualSubscribedQualities := make([]*livekit.SubscribedCodec, 0)
		lock.Unlock()
		dm.OnSubscribedMaxQualityChange(func(subscribedQualities []*livekit.SubscribedCodec, _maxSubscribedQualities []types.SubscribedCodecQuality) {
			lock.Lock()
			actualSubscribedQualities = subscribedQualities
			lock.Unlock()
		})

		dm.maxSubscribedQuality = map[string]livekit.VideoQuality{
			webrtc.MimeTypeVP8: livekit.VideoQuality_LOW,
			webrtc.MimeTypeAV1: livekit.VideoQuality_LOW,
		}
		dm.NotifySubscriberMaxQuality("s1", webrtc.MimeTypeVP8, livekit.VideoQuality_HIGH)
		dm.NotifySubscriberMaxQuality("s2", webrtc.MimeTypeVP8, livekit.VideoQuality_MEDIUM)
		dm.NotifySubscriberMaxQuality("s3", webrtc.MimeTypeAV1, livekit.VideoQuality_MEDIUM)

		expectedSubscribedQualities := []*livekit.SubscribedCodec{
			{
				Codec: webrtc.MimeTypeVP8,
				Qualities: []*livekit.SubscribedQuality{
					{Quality: livekit.VideoQuality_LOW, Enabled: true},
					{Quality: livekit.VideoQuality_MEDIUM, Enabled: true},
					{Quality: livekit.VideoQuality_HIGH, Enabled: true},
				},
			},
			{
				Codec: webrtc.MimeTypeAV1,
				Qualities: []*livekit.SubscribedQuality{
					{Quality: livekit.VideoQuality_LOW, Enabled: true},
					{Quality: livekit.VideoQuality_MEDIUM, Enabled: true},
					{Quality: livekit.VideoQuality_HIGH, Enabled: false},
				},
			},
		}
		require.Eventually(t, func() bool {
			lock.Lock()
			defer lock.Unlock()

			return subscribedCodecsAsString(expectedSubscribedQualities) == subscribedCodecsAsString(actualSubscribedQualities)
		}, 10*time.Second, 100*time.Millisecond)

		// "s1" dropping to MEDIUM should disable HIGH layer
		dm.NotifySubscriberMaxQuality("s1", webrtc.MimeTypeVP8, livekit.VideoQuality_MEDIUM)

		expectedSubscribedQualities = []*livekit.SubscribedCodec{
			{
				Codec: webrtc.MimeTypeVP8,
				Qualities: []*livekit.SubscribedQuality{
					{Quality: livekit.VideoQuality_LOW, Enabled: true},
					{Quality: livekit.VideoQuality_MEDIUM, Enabled: true},
					{Quality: livekit.VideoQuality_HIGH, Enabled: false},
				},
			},
			{
				Codec: webrtc.MimeTypeAV1,
				Qualities: []*livekit.SubscribedQuality{
					{Quality: livekit.VideoQuality_LOW, Enabled: true},
					{Quality: livekit.VideoQuality_MEDIUM, Enabled: true},
					{Quality: livekit.VideoQuality_HIGH, Enabled: false},
				},
			},
		}
		require.Eventually(t, func() bool {
			lock.Lock()
			defer lock.Unlock()

			return subscribedCodecsAsString(expectedSubscribedQualities) == subscribedCodecsAsString(actualSubscribedQualities)
		}, 10*time.Second, 100*time.Millisecond)

		// "s1" , "s2" , "s3" dropping to LOW should disable HIGH & MEDIUM
		dm.NotifySubscriberMaxQuality("s1", webrtc.MimeTypeVP8, livekit.VideoQuality_LOW)
		dm.NotifySubscriberMaxQuality("s2", webrtc.MimeTypeVP8, livekit.VideoQuality_LOW)
		dm.NotifySubscriberMaxQuality("s3", webrtc.MimeTypeAV1, livekit.VideoQuality_LOW)

		expectedSubscribedQualities = []*livekit.SubscribedCodec{
			{
				Codec: webrtc.MimeTypeVP8,
				Qualities: []*livekit.SubscribedQuality{
					{Quality: livekit.VideoQuality_LOW, Enabled: true},
					{Quality: livekit.VideoQuality_MEDIUM, Enabled: false},
					{Quality: livekit.VideoQuality_HIGH, Enabled: false},
				},
			},
			{
				Codec: webrtc.MimeTypeAV1,
				Qualities: []*livekit.SubscribedQuality{
					{Quality: livekit.VideoQuality_LOW, Enabled: true},
					{Quality: livekit.VideoQuality_MEDIUM, Enabled: false},
					{Quality: livekit.VideoQuality_HIGH, Enabled: false},
				},
			},
		}
		require.Eventually(t, func() bool {
			lock.Lock()
			defer lock.Unlock()

			return subscribedCodecsAsString(expectedSubscribedQualities) == subscribedCodecsAsString(actualSubscribedQualities)
		}, 10*time.Second, 100*time.Millisecond)

		// muting "s2" only should not disable all qualities of vp8, no change of expected qualities
		dm.NotifySubscriberMaxQuality("s2", webrtc.MimeTypeVP8, livekit.VideoQuality_OFF)

		time.Sleep(100 * time.Millisecond)
		require.Eventually(t, func() bool {
			lock.Lock()
			defer lock.Unlock()

			return subscribedCodecsAsString(expectedSubscribedQualities) == subscribedCodecsAsString(actualSubscribedQualities)
		}, 10*time.Second, 100*time.Millisecond)

		// muting "s1" and s3 also should disable all qualities
		dm.NotifySubscriberMaxQuality("s1", webrtc.MimeTypeVP8, livekit.VideoQuality_OFF)
		dm.NotifySubscriberMaxQuality("s3", webrtc.MimeTypeAV1, livekit.VideoQuality_OFF)

		expectedSubscribedQualities = []*livekit.SubscribedCodec{
			{
				Codec: webrtc.MimeTypeVP8,
				Qualities: []*livekit.SubscribedQuality{
					{Quality: livekit.VideoQuality_LOW, Enabled: false},
					{Quality: livekit.VideoQuality_MEDIUM, Enabled: false},
					{Quality: livekit.VideoQuality_HIGH, Enabled: false},
				},
			},
			{
				Codec: webrtc.MimeTypeAV1,
				Qualities: []*livekit.SubscribedQuality{
					{Quality: livekit.VideoQuality_LOW, Enabled: false},
					{Quality: livekit.VideoQuality_MEDIUM, Enabled: false},
					{Quality: livekit.VideoQuality_HIGH, Enabled: false},
				},
			},
		}
		require.Eventually(t, func() bool {
			lock.Lock()
			defer lock.Unlock()

			return subscribedCodecsAsString(expectedSubscribedQualities) == subscribedCodecsAsString(actualSubscribedQualities)
		}, 10*time.Second, 100*time.Millisecond)

		// unmuting "s1" should enable vp8 previously set max quality
		dm.NotifySubscriberMaxQuality("s1", webrtc.MimeTypeVP8, livekit.VideoQuality_LOW)

		expectedSubscribedQualities = []*livekit.SubscribedCodec{
			{
				Codec: webrtc.MimeTypeVP8,
				Qualities: []*livekit.SubscribedQuality{
					{Quality: livekit.VideoQuality_LOW, Enabled: true},
					{Quality: livekit.VideoQuality_MEDIUM, Enabled: false},
					{Quality: livekit.VideoQuality_HIGH, Enabled: false},
				},
			},
			{
				Codec: webrtc.MimeTypeAV1,
				Qualities: []*livekit.SubscribedQuality{
					{Quality: livekit.VideoQuality_LOW, Enabled: false},
					{Quality: livekit.VideoQuality_MEDIUM, Enabled: false},
					{Quality: livekit.VideoQuality_HIGH, Enabled: false},
				},
			},
		}
		require.Eventually(t, func() bool {
			lock.Lock()
			defer lock.Unlock()

			return subscribedCodecsAsString(expectedSubscribedQualities) == subscribedCodecsAsString(actualSubscribedQualities)
		}, 10*time.Second, 100*time.Millisecond)

		// a higher quality from a different node should trigger that quality
		dm.NotifySubscriberNodeMaxQuality("n1", []types.SubscribedCodecQuality{
			{CodecMime: webrtc.MimeTypeVP8, Quality: livekit.VideoQuality_HIGH},
			{CodecMime: webrtc.MimeTypeAV1, Quality: livekit.VideoQuality_MEDIUM},
		})

		expectedSubscribedQualities = []*livekit.SubscribedCodec{
			{
				Codec: webrtc.MimeTypeVP8,
				Qualities: []*livekit.SubscribedQuality{
					{Quality: livekit.VideoQuality_LOW, Enabled: true},
					{Quality: livekit.VideoQuality_MEDIUM, Enabled: true},
					{Quality: livekit.VideoQuality_HIGH, Enabled: true},
				},
			},
			{
				Codec: webrtc.MimeTypeAV1,
				Qualities: []*livekit.SubscribedQuality{
					{Quality: livekit.VideoQuality_LOW, Enabled: true},
					{Quality: livekit.VideoQuality_MEDIUM, Enabled: true},
					{Quality: livekit.VideoQuality_HIGH, Enabled: false},
				},
			},
		}
		require.Eventually(t, func() bool {
			lock.Lock()
			defer lock.Unlock()

			return subscribedCodecsAsString(expectedSubscribedQualities) == subscribedCodecsAsString(actualSubscribedQualities)
		}, 10*time.Second, 100*time.Millisecond)
	})
}