package mediadevices

import (
	"io"
	"testing"
	"time"

	"github.com/pion/mediadevices/pkg/driver"
	_ "github.com/pion/mediadevices/pkg/driver/audiotest"
	_ "github.com/pion/mediadevices/pkg/driver/videotest"
	"github.com/pion/mediadevices/pkg/frame"
	"github.com/pion/mediadevices/pkg/prop"
)

func TestGetUserMedia(t *testing.T) {
	constraints := MediaStreamConstraints{
		Video: func(c *MediaTrackConstraints) {
			c.Width = prop.Int(640)
			c.Height = prop.Int(480)
		},
		Audio: func(c *MediaTrackConstraints) {
		},
	}
	constraintsWrong := MediaStreamConstraints{
		Video: func(c *MediaTrackConstraints) {
			c.Width = prop.IntExact(10000)
			c.Height = prop.Int(480)
		},
		Audio: func(c *MediaTrackConstraints) {
		},
	}

	// GetUserMedia with broken parameters
	ms, err := GetUserMedia(constraintsWrong)
	if err == nil {
		t.Fatal("Expected error, but got nil")
	}

	// GetUserMedia with correct parameters
	ms, err = GetUserMedia(constraints)
	if err != nil {
		t.Fatalf("Unexpected error: %v", err)
	}
	tracks := ms.GetTracks()
	if l := len(tracks); l != 2 {
		t.Fatalf("Number of the tracks is expected to be 2, got %d", l)
	}
	for _, track := range tracks {
		track.OnEnded(func(err error) {
			if err != io.EOF {
				t.Errorf("OnEnded called: %v", err)
			}
		})
	}
	time.Sleep(50 * time.Millisecond)

	for _, track := range tracks {
		track.Close()
	}

	// Stop and retry GetUserMedia
	ms, err = GetUserMedia(constraints)
	if err != nil {
		t.Fatalf("Failed to GetUserMedia after the previsous tracks stopped: %v", err)
	}
	tracks = ms.GetTracks()
	if l := len(tracks); l != 2 {
		t.Fatalf("Number of the tracks is expected to be 2, got %d", l)
	}
	for _, track := range tracks {
		track.OnEnded(func(err error) {
			if err != io.EOF {
				t.Errorf("OnEnded called: %v", err)
			}
		})
	}
	time.Sleep(50 * time.Millisecond)
	for _, track := range tracks {
		track.Close()
	}
}

func TestSelectBestDriverConstraintsResultIsSetProperly(t *testing.T) {
	filterFn := driver.FilterVideoRecorder()
	drivers := driver.GetManager().Query(filterFn)
	if len(drivers) == 0 {
		t.Fatal("expect to get at least 1 driver")
	}

	driver := drivers[0]
	err := driver.Open()
	if err != nil {
		t.Fatal("expect to open driver successfully")
	}
	defer driver.Close()

	if len(driver.Properties()) == 0 {
		t.Fatal("expect to get at least 1 property")
	}
	expectedProp := driver.Properties()[0]

	// By reducing the value from the driver by a tiny amount, this property should be chosen.
	// At the same time, we'll be able to find out if the return constraints will be properly set
	// to the best constraints.
	cases := map[string]struct {
		width, height int
		frameFormat   frame.Format
		frameRate     float32
	}{
		"DifferentWidth": {
			width:       expectedProp.Width - 1,
			height:      expectedProp.Height,
			frameFormat: expectedProp.FrameFormat,
			frameRate:   expectedProp.FrameRate,
		},
		"DifferentHeight": {
			width:       expectedProp.Width,
			height:      expectedProp.Height - 1,
			frameFormat: expectedProp.FrameFormat,
			frameRate:   expectedProp.FrameRate,
		},
		"DifferentFrameFormat": {
			width:       expectedProp.Width,
			height:      expectedProp.Height,
			frameFormat: frame.FormatI420,
			frameRate:   expectedProp.FrameRate,
		},
	}

	for name, c := range cases {
		c := c
		t.Run(name, func(t *testing.T) {
			var vc prop.VideoConstraints

			if c.frameRate >= 0 {
				vc = prop.VideoConstraints{
					Width:       prop.Int(c.width),
					Height:      prop.Int(c.height),
					FrameFormat: prop.FrameFormat(c.frameFormat),
					FrameRate:   prop.Float(c.frameRate),
				}
			} else {
				// do not specify the framerate
				vc = prop.VideoConstraints{
					Width:       prop.Int(c.width),
					Height:      prop.Int(c.height),
					FrameFormat: prop.FrameFormat(c.frameFormat),
				}
			}
			wantConstraints := MediaTrackConstraints{
				MediaConstraints: prop.MediaConstraints{
					VideoConstraints: vc,
				},
			}

			bestDriver, bestConstraints, err := selectBestDriver(filterFn, wantConstraints)
			if err != nil {
				t.Fatal(err)
			}

			if driver != bestDriver {
				t.Fatal("best driver is not expected")
			}

			s := bestConstraints.selectedMedia
			if s.Width != expectedProp.Width ||
				s.Height != expectedProp.Height ||
				s.FrameFormat != expectedProp.FrameFormat ||
				s.FrameRate != expectedProp.FrameRate {
				t.Fatalf("failed to return best constraints\nexpected:\n%v\n\ngot:\n%v", expectedProp, bestConstraints.selectedMedia)
			}

		})
	}

}

func TestSelectBestDriverConstraintsNoFit(t *testing.T) {
	filterFn := driver.FilterVideoRecorder()
	drivers := driver.GetManager().Query(filterFn)
	if len(drivers) == 0 {
		t.Fatal("expect to get at least 1 driver")
	}

	driver := drivers[0]
	err := driver.Open()
	if err != nil {
		t.Fatal("expect to open driver successfully")
	}
	defer driver.Close()

	if len(driver.Properties()) == 0 {
		t.Fatal("expect to get at least 1 property")
	}
	expectedProp := driver.Properties()[0]

	cases := map[string]struct {
		width, height int
		frameFormat   frame.Format
		frameRate     float32
	}{
		"DifferentWidth": {
			width:       expectedProp.Width - 1,
			height:      expectedProp.Height,
			frameFormat: expectedProp.FrameFormat,
			frameRate:   expectedProp.FrameRate,
		},
		"DifferentHeight": {
			width:       expectedProp.Width,
			height:      expectedProp.Height - 1,
			frameFormat: expectedProp.FrameFormat,
			frameRate:   expectedProp.FrameRate,
		},
		"DifferentFrameFormat": {
			width:       expectedProp.Width,
			height:      expectedProp.Height,
			frameFormat: frame.FormatI420,
			frameRate:   expectedProp.FrameRate,
		},
	}

	for name, c := range cases {
		c := c
		t.Run(name, func(t *testing.T) {
			wantConstraints := MediaTrackConstraints{
				MediaConstraints: prop.MediaConstraints{
					VideoConstraints: prop.VideoConstraints{
						Width:       prop.IntExact(c.width),
						Height:      prop.IntExact(c.height),
						FrameFormat: prop.FrameFormatExact(c.frameFormat),
						FrameRate:   prop.FloatExact(c.frameRate),
					},
				},
			}

			_, _, err := selectBestDriver(filterFn, wantConstraints)
			if err == nil {
				t.Fatal("expect to not find a driver that fits the constraints")
			}
		})
	}
}