package obfuscated2

import (
	"bytes"
	"strconv"
	"testing"

	"github.com/stretchr/testify/assert"

	"github.com/9seconds/mtg/mtproto"
)

func TestFrameKey(t *testing.T) {
	toCompare := make([]byte, 32)
	for i := 0; i < 32; i++ {
		toCompare[i] = byte(1)
	}

	assert.Equal(t, toCompare, makeFrame().Key())
}

func TestFrameIV(t *testing.T) {
	toCompare := make([]byte, 16)
	for i := 0; i < 16; i++ {
		toCompare[i] = byte(2)
	}

	assert.Equal(t, toCompare, makeFrame().IV())
}

func TestFrameMagic(t *testing.T) {
	toCompare := make([]byte, 4)
	for i := 0; i < 4; i++ {
		toCompare[i] = 0xee
	}

	assert.Equal(t, toCompare, makeFrame().Magic())
}

func TestFrameDC(t *testing.T) {
	assert.Equal(t, int16(771), makeFrame().DC())
}

func TestFrameValid(t *testing.T) {
	frame := makeFrame()
	connType, err := frame.ConnectionType()
	assert.Nil(t, err)
	assert.Equal(t, connType, mtproto.ConnectionTypeIntermediate)

	frame[8+32+16+2] = byte(3)
	_, err = frame.ConnectionType()
	assert.NotNil(t, err)
}

func TestFrameDoubleInvert(t *testing.T) {
	frame := makeFrame()
	assert.True(t, bytes.Equal(frame, frame.Invert().Invert()))
}

func TestFrameInvert(t *testing.T) {
	frame := makeFrame()
	reversed := frame.Invert()

	assert.Exactly(t, frame[:8], reversed[:8])
	assert.Exactly(t, frame[56:], reversed[56:])

	toCompare := make([]byte, 48)
	for i := 0; i < 48; i++ {
		toCompare[i] = frame[55-i]
	}
	assert.Equal(t, []byte(reversed[8:56]), toCompare)
}

func TestFrameGenerateValid(t *testing.T) {
	validTests := []mtproto.ConnectionType{
		mtproto.ConnectionTypeIntermediate,
		mtproto.ConnectionTypeAbridged,
	}
	for _, test := range validTests {
		t.Run(strconv.Itoa(int(test)), func(tt *testing.T) {
			frame := generateFrame(test)
			conType, err := frame.ConnectionType()
			assert.Nil(t, err)
			assert.Equal(t, conType, test)
		})
	}
}

func makeFrame() Frame {
	f := make(Frame, FrameLen)

	for i := 8; i < (8 + 32); i++ {
		f[i] = byte(1)
	}
	for i := (8 + 32); i < (8 + 32 + 16); i++ {
		f[i] = byte(2)
	}
	for i := (8 + 32 + 16); i < (8 + 32 + 16 + 4); i++ {
		f[i] = 0xee
	}
	for i := (8 + 32 + 16 + 4); i < (8 + 32 + 16 + 4 + 2); i++ {
		f[i] = byte(3)
	}

	return f
}