package nef

import (
	"encoding/base64"
	"encoding/json"
	"strconv"
	"testing"

	"github.com/nspcc-dev/neo-go/internal/testserdes"
	"github.com/stretchr/testify/require"
)

func TestEncodeDecodeBinary(t *testing.T) {
	script := []byte{12, 32, 84, 35, 14}
	expected := &File{
		Header: Header{
			Magic:    Magic,
			Compiler: "the best compiler ever",
			Version:  "1.2.3.4",
		},
		Script: script,
	}

	t.Run("invalid Magic", func(t *testing.T) {
		expected.Header.Magic = 123
		checkDecodeError(t, expected)
	})

	t.Run("invalid checksum", func(t *testing.T) {
		expected.Header.Magic = Magic
		expected.Checksum = 123
		checkDecodeError(t, expected)
	})

	t.Run("zero-length script", func(t *testing.T) {
		expected.Script = make([]byte, 0)
		expected.Checksum = expected.CalculateChecksum()
		checkDecodeError(t, expected)
	})

	t.Run("invalid script length", func(t *testing.T) {
		newScript := make([]byte, MaxScriptLength+1)
		expected.Script = newScript
		expected.Checksum = expected.CalculateChecksum()
		checkDecodeError(t, expected)
	})

	t.Run("positive", func(t *testing.T) {
		expected.Script = script
		expected.Checksum = expected.CalculateChecksum()
		expected.Header.Magic = Magic
		testserdes.EncodeDecodeBinary(t, expected, &File{})
	})
}

func checkDecodeError(t *testing.T, expected *File) {
	bytes, err := testserdes.EncodeBinary(expected)
	require.NoError(t, err)
	require.Error(t, testserdes.DecodeBinary(bytes, &File{}))
}

func TestBytesFromBytes(t *testing.T) {
	script := []byte{12, 32, 84, 35, 14}
	expected := File{
		Header: Header{
			Magic:    Magic,
			Compiler: "the best compiler ever",
			Version:  "1.2.3.4",
		},
		Script: script,
	}
	expected.Checksum = expected.CalculateChecksum()

	bytes, err := expected.Bytes()
	require.NoError(t, err)
	actual, err := FileFromBytes(bytes)
	require.NoError(t, err)
	require.Equal(t, expected, actual)
}

func TestMarshalUnmarshalJSON(t *testing.T) {
	expected := &File{
		Header: Header{
			Magic:    Magic,
			Compiler: "test.compiler",
			Version:  "test.ver",
		},
		Script: []byte{1, 2, 3, 4},
	}
	expected.Checksum = expected.CalculateChecksum()

	data, err := json.Marshal(expected)
	require.NoError(t, err)
	require.JSONEq(t, `{
		"magic":`+strconv.FormatUint(uint64(Magic), 10)+`,
		"compiler": "test.compiler",
		"version": "test.ver",
		"script": "`+base64.StdEncoding.EncodeToString(expected.Script)+`",
		"checksum":`+strconv.FormatUint(uint64(expected.Checksum), 10)+`}`, string(data))

	actual := new(File)
	require.NoError(t, json.Unmarshal(data, actual))
	require.Equal(t, expected, actual)
}