using System;
using System.IO;
using finskaybank;
using NUnit.Framework;

namespace BankAccountTests
{
    [TestFixture]
    public class BankAccountOperationsTests
    {
        private account[] _accounts;
        private StringReader _inputSimulator;
        private StringWriter _outputCapture;

        [SetUp]
        public void InitializeTestEnvironment()
        {
            _accounts = new account[100];
            _outputCapture = new StringWriter();
            Console.SetOut(_outputCapture);
        }

        [TearDown]
        public void CleanupTestEnvironment()
        {
            _outputCapture?.Dispose();
            _inputSimulator?.Dispose();
        }

        [Test]
        public void otk_ValidInput_SetsCorrectProperties()
        {
            _inputSimulator = new StringReader("fio\n1500\n");
            Console.SetIn(_inputSimulator);

            _accounts[0] = new account();
            _accounts[0].otk();

            Assert.That(_accounts[0].GetName(), Is.EqualTo("fio"));
            Assert.That(_accounts[0].GetSum(), Is.EqualTo(1500.00));
            Assert.That(_accounts[0].GetNum(), Is.Not.Empty);
        }

        [Test]
        public void otk_InsufficientDeposit_PrintsRetryMessage()
        {
            _inputSimulator = new StringReader("fio\n500\nfio1\n2000\n");
            Console.SetIn(_inputSimulator);

            _accounts[0] = new account();
            _accounts[0].otk();

            string consoleOutput = _outputCapture.ToString();
            Assert.That(consoleOutput, Does.Contain("Сумма слишком мала, попробуйте ещё раз!"));
        }

        [Test]
        public void otk_NumericNameInput_StoresNameCorrectly()
        {
            _inputSimulator = new StringReader("12345\n2500\n");
            Console.SetIn(_inputSimulator);

            _accounts[0] = new account();
            _accounts[0].otk();

            Assert.That(_accounts[0].GetName(), Is.EqualTo("12345"));
        }

        [Test]
        public void otk_InvalidDepositInput_ThrowsFormatException()
        {
            _inputSimulator = new StringReader("fio\ninvalidAmount\n");
            Console.SetIn(_inputSimulator);

            _accounts[0] = new account();

            Assert.Throws<FormatException>(() => _accounts[0].otk());
        }

        [Test]
        public void num_gen_GeneratesTwentyDigitNumber()
        {
            _accounts[0] = new account();
            _accounts[0].num_gen();

            Assert.That(_accounts[0].GetNum().Length, Is.EqualTo(20));
        }

        [Test]
        public void otk_AfterCreation_AccountFileContainsCorrectInfo()
        {
            _inputSimulator = new StringReader("fio\n3000\n");
            Console.SetIn(_inputSimulator);

            _accounts[0] = new account();
            _accounts[0].otk();

            string accountFile = $"{_accounts[0].GetNum()}.txt";
            Assert.That(File.Exists(accountFile), Is.True);

            string fileContents = File.ReadAllText(accountFile);
            Assert.That(fileContents, Does.Contain(_accounts[0].GetNum()));
            Assert.That(fileContents, Does.Contain(_accounts[0].GetName()));
            Assert.That(fileContents, Does.Contain(_accounts[0].GetSum().ToString()));
        }

        [Test]
        public void top_up_PositiveAmount_IncreasesBalance()
        {
            _inputSimulator = new StringReader("fio\n1000\n750\n");
            Console.SetIn(_inputSimulator);

            _accounts[0] = new account();
            _accounts[0].otk();

            float expected = _accounts[0].GetSum() + 750;
            _accounts[0].top_up();

            Assert.That(_accounts[0].GetSum(), Is.EqualTo(expected));
        }

        [Test]
        public void top_up_NegativeAmount_DecreasesBalance()
        {
            _inputSimulator = new StringReader("fio\n2000\n-500\n");
            Console.SetIn(_inputSimulator);

            _accounts[0] = new account();
            _accounts[0].otk();

            float expected = _accounts[0].GetSum() - 500;
            _accounts[0].top_up();

            Assert.That(_accounts[0].GetSum(), Is.EqualTo(expected));
        }

        [Test]
        public void top_up_ZeroAmount_LeavesBalanceUnchanged()
        {
            _inputSimulator = new StringReader("fio\n1500\n0\n");
            Console.SetIn(_inputSimulator);

            _accounts[0] = new account();
            _accounts[0].otk();

            float original = _accounts[0].GetSum();
            _accounts[0].top_up();

            Assert.That(_accounts[0].GetSum(), Is.EqualTo(original));
        }

        [Test]
        public void top_up_InvalidInput_ThrowsFormatException()
        {
            _inputSimulator = new StringReader("fio\n1000\nnotANumber\n");
            Console.SetIn(_inputSimulator);

            _accounts[0] = new account();
            _accounts[0].otk();

            Assert.Throws<FormatException>(() => _accounts[0].top_up());
        }

        [Test]
        public void umen_PositiveAmount_DecreasesBalance()
        {
            _inputSimulator = new StringReader("fio\n3000\n1000\n");
            Console.SetIn(_inputSimulator);

            _accounts[0] = new account();
            _accounts[0].otk();

            float expected = _accounts[0].GetSum() - 1000;
            _accounts[0].umen();

            Assert.That(_accounts[0].GetSum(), Is.EqualTo(expected));
        }

        [Test]
        public void umen_NegativeAmount_IncreasesBalance()
        {
            _inputSimulator = new StringReader("fio\n4000\n-1000\n");
            Console.SetIn(_inputSimulator);

            _accounts[0] = new account();
            _accounts[0].otk();

            float expected = _accounts[0].GetSum() + 1000;
            _accounts[0].umen();

            Assert.That(_accounts[0].GetSum(), Is.EqualTo(expected));
        }

        [Test]
        public void umen_ZeroAmount_LeavesBalanceUnchanged()
        {
            _inputSimulator = new StringReader("fio\n2500\n0\n");
            Console.SetIn(_inputSimulator);

            _accounts[0] = new account();
            _accounts[0].otk();

            float original = _accounts[0].GetSum();
            _accounts[0].umen();

            Assert.That(_accounts[0].GetSum(), Is.EqualTo(original));
        }

        [Test]
        public void umen_InvalidInput_ThrowsFormatException()
        {
            _inputSimulator = new StringReader("fio\n2000\nabc\n");
            Console.SetIn(_inputSimulator);

            _accounts[0] = new account();
            _accounts[0].otk();

            Assert.Throws<FormatException>(() => _accounts[0].umen());
        }

        [Test]
        public void obnul_ClearsBalanceToZero()
        {
            _inputSimulator = new StringReader("fio\n5000\n");
            Console.SetIn(_inputSimulator);

            _accounts[0] = new account();
            _accounts[0].otk();

            _accounts[0].obnul();

            Assert.That(_accounts[0].GetSum(), Is.EqualTo(0.00));
        }

        [Test]
        public void perevod_SufficientFunds_TransfersAmountCorrectly()
        {
            _inputSimulator = new StringReader("fio\n5000\nfio1\n3000\n2000\n1\n");
            Console.SetIn(_inputSimulator);

            _accounts[0] = new account();
            _accounts[0].otk();

            _accounts[1] = new account();
            _accounts[1].otk();

            float senderExpected = _accounts[0].GetSum() - 2000;
            float recipientExpected = _accounts[1].GetSum() + 2000;

            _accounts[0].perevod();
            _accounts[1].sum += 2000;

            Assert.That(_accounts[0].GetSum(), Is.EqualTo(senderExpected));
            Assert.That(_accounts[1].GetSum(), Is.EqualTo(recipientExpected));
        }

        [Test]
        public void perevod_InsufficientFunds_PrintsErrorMessage()
        {
            _inputSimulator = new StringReader("fio\n1000\nfio1\n5000\n2000\n1\n");
            Console.SetIn(_inputSimulator);

            _accounts[0] = new account();
            _accounts[0].otk();

            _accounts[1] = new account();
            _accounts[1].otk();

            _accounts[0].perevod();

            string output = _outputCapture.ToString();
            Assert.That(output, Does.Contain("На счету недостаточно средств!"));
        }

        [Test]
        public void perevod_InvalidAmount_ThrowsFormatException()
        {
            _inputSimulator = new StringReader("fio\n3000\nfio1\n5000\ninvalid\n1\n");
            Console.SetIn(_inputSimulator);

            _accounts[0] = new account();
            _accounts[0].otk();

            _accounts[1] = new account();
            _accounts[1].otk();

            Assert.Throws<FormatException>(() => _accounts[0].perevod());
        }
    }
}