package erasureencode

import (
	"bytes"
	"crypto/sha256"
	"testing"
)

func TestMerkle1(t *testing.T) {
	i1 := sha256sum([]byte("1input data1"))
	i2 := make([]byte, sha256.Size)
	expected := sha256sum(append(i1, i2...))
	input := [][]byte{i1}
	actual := merkleSha256(input)

	if !bytes.Equal(actual, expected) {
		t.Fatalf(`Expected %x to equal %x`, actual, expected)
	}
}

func TestMerkle2(t *testing.T) {
	i1 := sha256sum([]byte("1input data1"))
	i2 := sha256sum([]byte("2input data2"))
	expected := sha256sum(append(i1, i2...))
	input := [][]byte{i1, i2}
	actual := merkleSha256(input)

	if !bytes.Equal(actual, expected) {
		t.Fatalf(`Expected %x to equal %x`, actual, expected)
	}
}

func TestMerkle3(t *testing.T) {
	i1_1 := sha256sum([]byte("1input data1"))
	i1_2 := sha256sum([]byte("2input data2"))
	i1 := sha256sum(append(i1_1, i1_2...))

	i2_1 := sha256sum([]byte("3input data3"))
	i2_2 := make([]byte, sha256.Size)
	i2 := sha256sum(append(i2_1, i2_2...))

	expected := sha256sum(append(i1, i2...))
	input := [][]byte{i1_1, i1_2, i2_1}
	actual := merkleSha256(input)

	if !bytes.Equal(actual, expected) {
		t.Fatalf(`Expected %x to equal %x`, actual, expected)
	}
}

func TestMerkle4(t *testing.T) {
	i1_1 := sha256sum([]byte("1input data1"))
	i1_2 := sha256sum([]byte("2input data2"))
	i1 := sha256sum(append(i1_1, i1_2...))

	i2_1 := sha256sum([]byte("3input data3"))
	i2_2 := sha256sum([]byte("4input data4"))
	i2 := sha256sum(append(i2_1, i2_2...))

	expected := sha256sum(append(i1, i2...))
	input := [][]byte{i1_1, i1_2, i2_1, i2_2}
	actual := merkleSha256(input)

	if !bytes.Equal(actual, expected) {
		t.Fatalf(`Expected %x to equal %x`, actual, expected)
	}
}

func TestMerkle5(t *testing.T) {
	i1_1_1 := sha256sum([]byte("1input data1"))
	i1_1_2 := sha256sum([]byte("2input data2"))
	i1_2_1 := sha256sum([]byte("3input data3"))
	i1_2_2 := sha256sum([]byte("4input data4"))
	i1_1 := sha256sum(append(i1_1_1, i1_1_2...))
	i1_2 := sha256sum(append(i1_2_1, i1_2_2...))
	i1 := sha256sum(append(i1_1, i1_2...))

	i2_1 := sha256sum([]byte("5input data5"))
	i2_2 := make([]byte, sha256.Size)
	i2 := sha256sum(append(i2_1, i2_2...))

	expected := sha256sum(append(i1, i2...))
	input := [][]byte{i1_1, i1_2, i2_1, i2_2}
	actual := merkleSha256(input)

	if !bytes.Equal(actual, expected) {
		t.Fatalf(`Expected %x to equal %x`, actual, expected)
	}
}