using System;
using System.IO;
using LCU.Api.Internal.FileOperations.Services.FileActionServices;
using LCU.Library.Internal.FileOperationsModels.Models;
using LCU.Library.Internal.LCUServiceFactory.Configurations;
using Org.BouncyCastle.Bcpg;
using Org.BouncyCastle.Bcpg.OpenPgp;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Generators;
using Org.BouncyCastle.Crypto.Prng;
using Org.BouncyCastle.Security;

namespace LCU.API.Internal.FileOperations.IntegrationTests
{
    class FileDataEncryptionTests
    {
        private const string TestPassword = "password";
        private const string PrivateKeyFile = "TestPrivateKey";
        private const string PublicKeyFile = "TestPublicKey";
        private const string TestFile = "TestTextFile.txt";
        private const string TestFileContents = "This text will be saved to a temporary test file for encryption/comparison to resulting files from this integration test";
        private const string TestEncryptedFile = "TestTextFile.pgp";
        private const string TestDecryptedFile = "TestTextFile-Decrypted";
        private readonly string _basePath;
        private readonly EncryptFileDataService _encryptFileDataService;
        private readonly DecryptFileDataService _decryptFileDataService;
		private readonly ServicesFactoryConfiguration _servicesFactoryConfiguration;

		FileDataEncryptionTests()
        {
            _encryptFileDataService = new EncryptFileDataService(_servicesFactoryConfiguration);
            _decryptFileDataService = new DecryptFileDataService(_servicesFactoryConfiguration);
            _basePath = Path.Combine(Directory.GetCurrentDirectory(), "TempFileFolder");
            Directory.CreateDirectory(_basePath);
            GenerateTestKeys("Test@landmarkcu.com", TestPassword, Path.Combine(_basePath, PrivateKeyFile), Path.Combine(_basePath, PublicKeyFile));
            File.WriteAllText(Path.Combine(_basePath, TestFile), TestFileContents);
        }

        static void Main()
        {
            var fileDataEncryptionTests = new FileDataEncryptionTests();

            var encryptFileDataRequest = new EncryptFileDataRequest
            {
                SourcePath = fileDataEncryptionTests._basePath,
                SourceFile = TestFile,
                KeySourcePath = fileDataEncryptionTests._basePath,
                KeySourceFile = PublicKeyFile,
                DestinationPath = fileDataEncryptionTests._basePath
            };

            var decryptFileDataRequest = new DecryptFileDataRequest
            {
                SourcePath = fileDataEncryptionTests._basePath,
                SourceFile = TestEncryptedFile,
                KeySourcePath = fileDataEncryptionTests._basePath,
                KeySourceFile = PrivateKeyFile,
                DestinationPath = fileDataEncryptionTests._basePath,
                DestinationFile = TestDecryptedFile,
                PassPhrase = TestPassword
            };

            var encryptResult = fileDataEncryptionTests._encryptFileDataService.PerformRequest(encryptFileDataRequest);
            var decryptResult = fileDataEncryptionTests._decryptFileDataService.PerformRequest(decryptFileDataRequest);

            Console.WriteLine($"Encrypted Request Is Valid: {encryptResult.IsSuccessful}");
            Console.WriteLine($"Decrypted Request Is Valid: {decryptResult.IsSuccessful}");

            var encryptedFileContents = File.ReadAllText(Path.Combine(fileDataEncryptionTests._basePath, TestEncryptedFile));
            var decryptedFileContents = File.ReadAllText(Path.Combine(fileDataEncryptionTests._basePath, TestDecryptedFile));

            Console.WriteLine($"Test File Contents: {TestFileContents}");
            Console.WriteLine($"Encrypted File Contents: {encryptedFileContents}");
            Console.WriteLine($"Decrypted File Contents: {decryptedFileContents}");

            Console.WriteLine("Complete");
        }

        private static void GenerateTestKeys(string identity, string passPhrase, string secretKeyOutputPath, string publicKeyOutputPath)
        {
            var keyPairGenerator = new RsaKeyPairGenerator();
            keyPairGenerator.Init(new KeyGenerationParameters(new SecureRandom(new CryptoApiRandomGenerator()), 1024));
            var keyPair = keyPairGenerator.GenerateKeyPair();

            using var secretOut = new FileInfo(secretKeyOutputPath).OpenWrite();
            using var publicOut = new FileInfo(publicKeyOutputPath).OpenWrite();
            ExportGeneratedKeyPair(secretOut, publicOut, keyPair.Public, keyPair.Private, identity, passPhrase.ToCharArray(), true);
        }

        private static void ExportGeneratedKeyPair(
            Stream secretOut,
            Stream publicOut,
            AsymmetricKeyParameter publicKey,
            AsymmetricKeyParameter privateKey,
            string identity,
            char[] passPhrase,
            bool armor)
        {
            if (armor)
            {
                secretOut = new ArmoredOutputStream(secretOut);
            }

            var pgpSecretKey = new PgpSecretKey
            (
                PgpSignature.DefaultCertification,
                PublicKeyAlgorithmTag.RsaGeneral,
                publicKey,
                privateKey,
                DateTime.Now,
                identity,
                SymmetricKeyAlgorithmTag.Cast5,
                passPhrase,
                null,
                null,
                new SecureRandom()
            );

            pgpSecretKey.Encode(secretOut);
            secretOut.Close();

            if (armor)
            {
                publicOut = new ArmoredOutputStream(publicOut);
            }

            var pgpPublicKey = pgpSecretKey.PublicKey;
            pgpPublicKey.Encode(publicOut);
            publicOut.Close();
        }
    }
}