/*
NAME
  revid_test.go

DESCRIPTION
  See Readme.md

AUTHORS
  Saxon A. Nelson-Milton <saxon@ausocean.org>
  Alan Noble <alan@ausocean.org>

LICENSE
  This is Copyright (C) 2019 the Australian Ocean Lab (AusOcean).

  It is free software: you can redistribute it and/or modify them
  under the terms of the GNU General Public License as published by the
  Free Software Foundation, either version 3 of the License, or (at your
  option) any later version.

  It is distributed in the hope that it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  for more details.

  You should have received a copy of the GNU General Public License
  in gpl.txt.  If not, see http://www.gnu.org/licenses.
*/

package revid

import (
	"fmt"
	"io"
	"os"
	"testing"

	"bitbucket.org/ausocean/av/revid/config"
	"bitbucket.org/ausocean/iot/pi/netsender"
)

const raspividPath = "/usr/local/bin/raspivid"

// Suppress all test logging, except for t.Errorf output.
var silent = true

// TestRaspivid tests that raspivid starts correctly.
// It is intended to be run on a Raspberry Pi.
func TestRaspivid(t *testing.T) {
	if _, err := os.Stat(raspividPath); os.IsNotExist(err) {
		t.Skip("Skipping TestRaspivid since no raspivid found.")
	}

	var logger testLogger
	ns, err := netsender.New(&logger, nil, nil, nil)
	if err != nil {
		t.Errorf("netsender.New failed with error %v", err)
	}

	var c config.Config
	c.Logger = &logger
	c.Input = config.InputRaspivid

	rv, err := New(c, ns)
	if err != nil {
		t.Errorf("revid.New failed with error %v", err)
	}

	err = rv.Start()
	if err != nil {
		t.Errorf("revid.Start failed with error %v", err)
	}
}

// tstMtsEncoder emulates the mts.Encoder to the extent of the dst field.
// This will allow access to the dst to check that it has been set corrctly.
type tstMtsEncoder struct {
	// dst is here solely to detect the type stored in the encoder.
	// No data is written to dst.
	dst io.WriteCloser
}

func (e *tstMtsEncoder) Write(d []byte) (int, error) { return len(d), nil }
func (e *tstMtsEncoder) Close() error                { return nil }

// tstFlvEncoder emulates the flv.Encoder to the extent of the dst field.
// This will allow access to the dst to check that it has been set corrctly.
type tstFlvEncoder struct {
	// dst is here solely to detect the type stored in the encoder.
	// No data is written to dst.
	dst io.WriteCloser
}

func (e *tstFlvEncoder) Write(d []byte) (int, error) { return len(d), nil }
func (e *tstFlvEncoder) Close() error                { return nil }

// dummyMultiWriter emulates the MultiWriter provided by std lib, so that we
// can access the destinations.
type dummyMultiWriter struct {
	// dst is here solely to detect the types stored in the multiWriter.
	// No data is written to dst.
	dst []io.WriteCloser
}

func (w *dummyMultiWriter) Write(d []byte) (int, error) { return len(d), nil }
func (w *dummyMultiWriter) Close() error                { return nil }

// TestResetEncoderSenderSetup checks that revid.reset() correctly sets up the
// revid.encoder slice and the senders the encoders write to.
func TestResetEncoderSenderSetup(t *testing.T) {
	// We will use these to indicate types after assertion.
	const (
		mtsSenderStr  = "*revid.mtsSender"
		rtpSenderStr  = "*revid.rtpSender"
		rtmpSenderStr = "*revid.rtmpSender"
		mtsEncoderStr = "*revid.tstMtsEncoder"
		flvEncoderStr = "*revid.tstFlvEncoder"
	)

	// Struct that will be used to format test cases nicely below.
	type encoder struct {
		encoderType  string
		destinations []string
	}

	tests := []struct {
		outputs  []uint8
		encoders []encoder
	}{
		{
			outputs: []uint8{config.OutputHTTP},
			encoders: []encoder{
				{
					encoderType:  mtsEncoderStr,
					destinations: []string{mtsSenderStr},
				},
			},
		},
		{
			outputs: []uint8{config.OutputRTMP},
			encoders: []encoder{
				{
					encoderType:  flvEncoderStr,
					destinations: []string{rtmpSenderStr},
				},
			},
		},
		{
			outputs: []uint8{config.OutputRTP},
			encoders: []encoder{
				{
					encoderType:  mtsEncoderStr,
					destinations: []string{rtpSenderStr},
				},
			},
		},
		{
			outputs: []uint8{config.OutputHTTP, config.OutputRTMP},
			encoders: []encoder{
				{
					encoderType:  mtsEncoderStr,
					destinations: []string{mtsSenderStr},
				},
				{
					encoderType:  flvEncoderStr,
					destinations: []string{rtmpSenderStr},
				},
			},
		},
		{
			outputs: []uint8{config.OutputHTTP, config.OutputRTP, config.OutputRTMP},
			encoders: []encoder{
				{
					encoderType:  mtsEncoderStr,
					destinations: []string{mtsSenderStr, rtpSenderStr},
				},
				{
					encoderType:  flvEncoderStr,
					destinations: []string{rtmpSenderStr},
				},
			},
		},
		{
			outputs: []uint8{config.OutputRTP, config.OutputRTMP},
			encoders: []encoder{
				{
					encoderType:  mtsEncoderStr,
					destinations: []string{rtpSenderStr},
				},
				{
					encoderType:  flvEncoderStr,
					destinations: []string{rtmpSenderStr},
				},
			},
		},
	}

	rv, err := New(config.Config{Logger: &testLogger{}}, nil)
	if err != nil {
		t.Fatalf("unexpected err: %v", err)
	}

	// Go through our test cases.
	for testNum, test := range tests {
		// Create a new config and reset revid with it.
		const dummyURL = "rtmp://dummy"
		c := config.Config{Logger: &testLogger{}, Outputs: test.outputs, RTMPURL: []string{dummyURL}}
		err := rv.setConfig(c)
		if err != nil {
			t.Fatalf("unexpected error: %v for test %v", err, testNum)
		}

		// This logic is what we want to check.
		err = rv.setupPipeline(
			func(dst io.WriteCloser, rate float64) (io.WriteCloser, error) {
				return &tstMtsEncoder{dst: dst}, nil
			},
			func(dst io.WriteCloser, rate int) (io.WriteCloser, error) {
				return &tstFlvEncoder{dst: dst}, nil
			},
			func(writers ...io.WriteCloser) io.WriteCloser {
				return &dummyMultiWriter{dst: writers}
			},
		)
		if err != nil {
			t.Fatalf("unexpected error: %v for test %v", err, testNum)
		}

		// First check that we have the correct number of encoders.
		got := len(rv.encoders.(*dummyMultiWriter).dst)
		want := len(test.encoders)
		if got != want {
			t.Errorf("incorrect number of encoders in revid for test: %v. \nGot: %v\nWant: %v\n", testNum, got, want)
		}

		// Now check the correctness of encoders and their destinations.
		for _, e := range rv.encoders.(*dummyMultiWriter).dst {
			// Get e's type.
			encoderType := fmt.Sprintf("%T", e)

			// Check that we expect this encoder to be here.
			idx := -1
			for i, expect := range test.encoders {
				if expect.encoderType == encoderType {
					idx = i
				}
			}
			if idx == -1 {
				t.Fatalf("encoder %v isn't expected in test %v", encoderType, testNum)
			}

			// Now check that this encoder has correct number of destinations (senders).
			var ms io.WriteCloser
			switch encoderType {
			case mtsEncoderStr:
				ms = e.(*tstMtsEncoder).dst
			case flvEncoderStr:
				ms = e.(*tstFlvEncoder).dst
			}

			senders := ms.(*dummyMultiWriter).dst
			got = len(senders)
			want = len(test.encoders[idx].destinations)
			if got != want {
				t.Errorf("did not get expected number of senders in test %v. \nGot: %v\nWant: %v\n", testNum, got, want)
			}

			// Check that destinations are as expected.
			for _, expectDst := range test.encoders[idx].destinations {
				ok := false
				for _, dst := range senders {
					// Get type of sender.
					senderType := fmt.Sprintf("%T", dst)

					// If it's one we want, indicate.
					if senderType == expectDst {
						ok = true
					}
				}

				// If not okay then we couldn't find expected sender.
				if !ok {
					t.Errorf("could not find expected destination %v, for test %v", expectDst, testNum)
				}
			}
		}
	}
}