package go_encryption

import (
	"bytes"
	"encoding/hex"
	"os"
	"path/filepath"
	"strings"
	"sync"
	"testing"
)

func Test_GlobalSetProvider(t *testing.T) {
	SetProvider(NewAES128EncryptionProvider())

	wg := sync.WaitGroup{}
	wg.Add(1)
	var err any

	go func() {
		defer func() {
			err = recover()
			wg.Done()
		}()
		SetProvider(nil)
	}()

	wg.Wait()

	if err == nil {
		t.FailNow()
	}
}

func Test_GlobalSetEncryptionKey(t *testing.T) {
	binaryKey := append([]byte{}, std.(*aes128encryption).encryptionKey...)
	SetEncryptionKey(binaryKey)
	if !strings.EqualFold(defaultEncryptionKey, hex.EncodeToString(std.(*aes128encryption).encryptionKey)) {
		t.Error("Test_GlobalSetEncryptionKey: test case 1: encryption key should not have changed")
	}

	binaryKey[4] = 42
	binaryKey[5] = 42
	binaryKey[6] = 42
	SetEncryptionKey(binaryKey)
	if strings.EqualFold(defaultEncryptionKey, hex.EncodeToString(std.(*aes128encryption).encryptionKey)) {
		t.Error("Test_GlobalSetEncryptionKey: test case 2: encryption key was not changed")
	}

	binaryKey = binaryKey[:3]
	SetEncryptionKey(binaryKey)
	if strings.EqualFold(defaultEncryptionKey, hex.EncodeToString(std.(*aes128encryption).encryptionKey)) {
		t.Error("Test_GlobalSetEncryptionKey: test case 3: encryption key was not changed")
	}

	if binaryKey, err := hex.DecodeString(defaultEncryptionKey); err == nil {
		SetEncryptionKey(binaryKey)
		if !strings.EqualFold(defaultEncryptionKey, hex.EncodeToString(std.(*aes128encryption).encryptionKey)) {
			t.Error("Test_GlobalSetEncryptionKey: test case 4.2: Failed to reset encryption key")
		}
	} else {
		t.Error("Test_GlobalSetEncryptionKey: test case 4.1: Failed to reset encryption key")
	}
}

func Fuzz_GlobalSetContext(f *testing.F) {
	testCases := [][]byte{
		nil,
		{},
		{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12},
		{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16},
		{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17},
	}
	for i := 0; i < 5; i++ {
		testCases = append(testCases, randomByteArray())
	}
	for _, tc := range testCases {
		f.Add(tc)
	}
	f.Fuzz(func(t *testing.T, a []byte) {
		result := SetContext(a)
		if 12 > len(a) || len(a) > 16 {
			if result == nil {
				t.Errorf("got no error for %v", a)
			}
		} else if result != nil {
			t.Errorf("got an error for %v", a)
		}
	})
	if SetContext(defaultContext) != nil {
		f.Error("unable to reset context")
	}
}

func Test_GlobalEncryptData(t *testing.T) {
	if encrypted, err := EncryptData(defaultTestStruct); err != nil {
		t.Error("unexpected error in default data encryption")
	} else if !bytes.Equal(encrypted, []byte(defaultTestStructEncrypted)) {
		t.Error("unexpected data for encrypted content")
	}
}

func Test_GlobalDecryptData(t *testing.T) {
	target := &testStruct{}
	if err := DecryptData([]byte(defaultTestStructEncrypted), target); err != nil {
		t.Error("unexpected error in default data decryption")
	} else if target.BoolVal != defaultTestStruct.BoolVal ||
		target.FloatVal != defaultTestStruct.FloatVal ||
		target.IntVal != defaultTestStruct.IntVal ||
		target.StringVal != defaultTestStruct.StringVal {
		t.Error("retrieved struct does not match the expectations")
	}
}

func getTestFilePathGlobal(encrypt bool) string {
	fileName := "global_encryption_test_encrypted.data"
	if !encrypt {
		fileName = "global_encryption_test_decryptable.data"
	}
	return filepath.Join(os.Getenv("temp"), fileName)
}

func Test_GlobalEncryptToFile(t *testing.T) {
	targetPath := getTestFilePathGlobal(true)
	if err := EncryptToFile(defaultTestStruct, targetPath); err != nil {
		t.Error("unexpected error in default encryption")
	} else if encrypted, errRead := os.ReadFile(targetPath); errRead == nil {
		os.Remove(targetPath)
		if !bytes.Equal(encrypted, []byte(defaultTestStructEncrypted)) {
			t.Error("unexpected data for encrypted content")
		}
	} else {
		t.Errorf("expected file could not be read: %s", errRead)
		if !os.IsNotExist(errRead) {
			os.Remove(targetPath)
		}
	}
}

func Test_GlobalDecryptFile(t *testing.T) {
	sourcePath := getTestFilePathGlobal(false)
	if os.WriteFile(sourcePath, []byte(defaultTestStructEncrypted), os.ModePerm) == nil {
		target := &testStruct{}
		if err := DecryptFile(sourcePath, target); err != nil {
			t.Error("unexpected error in default decryption")
		} else if target.BoolVal != defaultTestStruct.BoolVal ||
			target.FloatVal != defaultTestStruct.FloatVal ||
			target.IntVal != defaultTestStruct.IntVal ||
			target.StringVal != defaultTestStruct.StringVal {
			t.Error("retrieved struct does not match the expectations")
		}
		os.Remove(sourcePath)
	} else {
		t.Error("could not prepare test file for decryption")
	}
}