using ChatBot.Models.Configuration;
using ChatBot.Models.Configuration.Validators;
using FluentAssertions;
using Microsoft.Extensions.Options;

namespace ChatBot.Tests.Configuration.Validators;

public class TelegramBotSettingsValidatorTests
{
    private readonly TelegramBotSettingsValidator _validator;

    public TelegramBotSettingsValidatorTests()
    {
        _validator = new TelegramBotSettingsValidator();
    }

    [Fact]
    public void Validate_WithValidSettings_ShouldReturnSuccess()
    {
        // Arrange
        var settings = CreateValidTelegramBotSettings();

        // Act
        var result = _validator.Validate(null, settings);

        // Assert
        result.Succeeded.Should().BeTrue();
        result.Failed.Should().BeFalse();
        result.FailureMessage.Should().BeNullOrEmpty();
    }

    [Fact]
    public void Validate_WithEmptyBotToken_ShouldReturnFailure()
    {
        // Arrange
        var settings = CreateValidTelegramBotSettings();
        settings.BotToken = string.Empty;

        // Act
        var result = _validator.Validate(null, settings);

        // Assert
        result.Succeeded.Should().BeFalse();
        result.Failed.Should().BeTrue();
        result.FailureMessage.Should().Contain("Telegram bot token is required");
    }

    [Fact]
    public void Validate_WithNullBotToken_ShouldReturnFailure()
    {
        // Arrange
        var settings = CreateValidTelegramBotSettings();
        settings.BotToken = null!;

        // Act
        var result = _validator.Validate(null, settings);

        // Assert
        result.Succeeded.Should().BeFalse();
        result.Failed.Should().BeTrue();
        result.FailureMessage.Should().Contain("Telegram bot token is required");
    }

    [Fact]
    public void Validate_WithWhitespaceBotToken_ShouldReturnFailure()
    {
        // Arrange
        var settings = CreateValidTelegramBotSettings();
        settings.BotToken = "   ";

        // Act
        var result = _validator.Validate(null, settings);

        // Assert
        result.Succeeded.Should().BeFalse();
        result.Failed.Should().BeTrue();
        result.FailureMessage.Should().Contain("Telegram bot token is required");
    }

    [Theory]
    [InlineData("")]
    [InlineData("   ")]
    [InlineData("\t")]
    [InlineData("\n")]
    [InlineData("\r\n")]
    public void Validate_WithVariousEmptyStrings_ShouldReturnFailure(string emptyString)
    {
        // Arrange
        var settings = CreateValidTelegramBotSettings();
        settings.BotToken = emptyString;

        // Act
        var result = _validator.Validate(null, settings);

        // Assert
        result.Succeeded.Should().BeFalse();
        result.Failed.Should().BeTrue();
        result.FailureMessage.Should().Contain("Telegram bot token is required");
    }

    [Theory]
    [InlineData("123456789012345678901234567890123456789")] // 39 characters
    [InlineData("12345678901234567890123456789012345678")] // 38 characters
    [InlineData("1234567890123456789012345678901234567")] // 37 characters
    [InlineData("123456789012345678901234567890123456")] // 36 characters
    [InlineData("12345678901234567890123456789012345")] // 35 characters
    [InlineData("1234567890123456789012345678901234")] // 34 characters
    [InlineData("123456789012345678901234567890123")] // 33 characters
    [InlineData("12345678901234567890123456789012")] // 32 characters
    [InlineData("1234567890123456789012345678901")] // 31 characters
    [InlineData("123456789012345678901234567890")] // 30 characters
    [InlineData("12345678901234567890123456789")] // 29 characters
    [InlineData("1234567890123456789012345678")] // 28 characters
    [InlineData("123456789012345678901234567")] // 27 characters
    [InlineData("12345678901234567890123456")] // 26 characters
    [InlineData("1234567890123456789012345")] // 25 characters
    [InlineData("123456789012345678901234")] // 24 characters
    [InlineData("12345678901234567890123")] // 23 characters
    [InlineData("1234567890123456789012")] // 22 characters
    [InlineData("123456789012345678901")] // 21 characters
    [InlineData("12345678901234567890")] // 20 characters
    [InlineData("1234567890123456789")] // 19 characters
    [InlineData("123456789012345678")] // 18 characters
    [InlineData("12345678901234567")] // 17 characters
    [InlineData("1234567890123456")] // 16 characters
    [InlineData("123456789012345")] // 15 characters
    [InlineData("12345678901234")] // 14 characters
    [InlineData("1234567890123")] // 13 characters
    [InlineData("123456789012")] // 12 characters
    [InlineData("12345678901")] // 11 characters
    [InlineData("1234567890")] // 10 characters
    [InlineData("123456789")] // 9 characters
    [InlineData("12345678")] // 8 characters
    [InlineData("1234567")] // 7 characters
    [InlineData("123456")] // 6 characters
    [InlineData("12345")] // 5 characters
    [InlineData("1234")] // 4 characters
    [InlineData("123")] // 3 characters
    [InlineData("12")] // 2 characters
    [InlineData("1")] // 1 character
    public void Validate_WithTooShortBotToken_ShouldReturnFailure(string shortToken)
    {
        // Arrange
        var settings = CreateValidTelegramBotSettings();
        settings.BotToken = shortToken;

        // Act
        var result = _validator.Validate(null, settings);

        // Assert
        result.Succeeded.Should().BeFalse();
        result.Failed.Should().BeTrue();
        result.FailureMessage.Should().Contain("Telegram bot token must be at least 40 characters");
    }

    [Theory]
    [InlineData("1234567890123456789012345678901234567890")] // 40 characters
    [InlineData("12345678901234567890123456789012345678901")] // 41 characters
    [InlineData("123456789012345678901234567890123456789012")] // 42 characters
    [InlineData("1234567890123456789012345678901234567890123")] // 43 characters
    [InlineData("12345678901234567890123456789012345678901234")] // 44 characters
    [InlineData("123456789012345678901234567890123456789012345")] // 45 characters
    [InlineData("1234567890123456789012345678901234567890123456")] // 46 characters
    [InlineData("12345678901234567890123456789012345678901234567")] // 47 characters
    [InlineData("123456789012345678901234567890123456789012345678")] // 48 characters
    [InlineData("1234567890123456789012345678901234567890123456789")] // 49 characters
    [InlineData("12345678901234567890123456789012345678901234567890")] // 50 characters
    public void Validate_WithValidLengthBotToken_ShouldReturnSuccess(string validToken)
    {
        // Arrange
        var settings = CreateValidTelegramBotSettings();
        settings.BotToken = validToken;

        // Act
        var result = _validator.Validate(null, settings);

        // Assert
        result.Succeeded.Should().BeTrue();
        result.Failed.Should().BeFalse();
        result.FailureMessage.Should().BeNullOrEmpty();
    }

    [Theory]
    [InlineData("1234567890123456789012345678901234567890")]
    [InlineData("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz")]
    [InlineData("12345678901234567890123456789012345678901234567890")]
    [InlineData("abcdefghijklmnopqrstuvwxyz12345678901234567890")]
    [InlineData("123456789012345678901234567890123456789012345678901234567890")]
    public void Validate_WithVariousValidTokens_ShouldReturnSuccess(string validToken)
    {
        // Arrange
        var settings = CreateValidTelegramBotSettings();
        settings.BotToken = validToken;

        // Act
        var result = _validator.Validate(null, settings);

        // Assert
        result.Succeeded.Should().BeTrue();
        result.Failed.Should().BeFalse();
        result.FailureMessage.Should().BeNullOrEmpty();
    }

    [Fact]
    public void Validate_WithNullSettings_ShouldThrowException()
    {
        // Arrange & Act & Assert
        var act = () => _validator.Validate(null, null!);
        act.Should().Throw<NullReferenceException>();
    }

    [Fact]
    public void ValidateOptionsResult_Success_ShouldHaveCorrectProperties()
    {
        // Arrange
        var settings = CreateValidTelegramBotSettings();

        // Act
        var result = _validator.Validate(null, settings);

        // Assert
        result.Succeeded.Should().BeTrue();
        result.Failed.Should().BeFalse();
        result.FailureMessage.Should().BeNullOrEmpty();
    }

    [Fact]
    public void ValidateOptionsResult_Failure_ShouldHaveCorrectProperties()
    {
        // Arrange
        var settings = new TelegramBotSettings { BotToken = string.Empty };

        // Act
        var result = _validator.Validate(null, settings);

        // Assert
        result.Succeeded.Should().BeFalse();
        result.Failed.Should().BeTrue();
        result.FailureMessage.Should().NotBeNullOrEmpty();
        result.FailureMessage.Should().Contain("Telegram bot token is required");
    }

    [Fact]
    public void Validator_ShouldImplementIValidateOptions()
    {
        // Arrange & Act
        var validator = new TelegramBotSettingsValidator();

        // Assert
        validator.Should().BeAssignableTo<IValidateOptions<TelegramBotSettings>>();
    }

    [Fact]
    public void Validate_WithVeryLongValidToken_ShouldReturnSuccess()
    {
        // Arrange
        var settings = CreateValidTelegramBotSettings();
        settings.BotToken = new string('A', 1000); // Very long token

        // Act
        var result = _validator.Validate(null, settings);

        // Assert
        result.Succeeded.Should().BeTrue();
        result.Failed.Should().BeFalse();
        result.FailureMessage.Should().BeNullOrEmpty();
    }

    [Fact]
    public void Validate_WithTokenContainingSpecialCharacters_ShouldReturnSuccess()
    {
        // Arrange
        var settings = CreateValidTelegramBotSettings();
        settings.BotToken = "1234567890123456789012345678901234567890!@#$%^&*()";

        // Act
        var result = _validator.Validate(null, settings);

        // Assert
        result.Succeeded.Should().BeTrue();
        result.Failed.Should().BeFalse();
        result.FailureMessage.Should().BeNullOrEmpty();
    }

    [Fact]
    public void Validate_WithTokenContainingSpaces_ShouldReturnSuccess()
    {
        // Arrange
        var settings = CreateValidTelegramBotSettings();
        settings.BotToken = "1234567890123456789012345678901234567890 ";

        // Act
        var result = _validator.Validate(null, settings);

        // Assert
        result.Succeeded.Should().BeTrue();
        result.Failed.Should().BeFalse();
        result.FailureMessage.Should().BeNullOrEmpty();
    }

    [Fact]
    public void Validate_WithTokenContainingUnicodeCharacters_ShouldReturnSuccess()
    {
        // Arrange
        var settings = CreateValidTelegramBotSettings();
        settings.BotToken = "1234567890123456789012345678901234567890абвгд";

        // Act
        var result = _validator.Validate(null, settings);

        // Assert
        result.Succeeded.Should().BeTrue();
        result.Failed.Should().BeFalse();
        result.FailureMessage.Should().BeNullOrEmpty();
    }

    [Fact]
    public void Validate_WithExactMinimumLengthToken_ShouldReturnSuccess()
    {
        // Arrange
        var settings = CreateValidTelegramBotSettings();
        settings.BotToken = "1234567890123456789012345678901234567890"; // Exactly 40 characters

        // Act
        var result = _validator.Validate(null, settings);

        // Assert
        result.Succeeded.Should().BeTrue();
        result.Failed.Should().BeFalse();
        result.FailureMessage.Should().BeNullOrEmpty();
    }

    [Fact]
    public void Validate_WithOneCharacterLessThanMinimum_ShouldReturnFailure()
    {
        // Arrange
        var settings = CreateValidTelegramBotSettings();
        settings.BotToken = "123456789012345678901234567890123456789"; // 39 characters

        // Act
        var result = _validator.Validate(null, settings);

        // Assert
        result.Succeeded.Should().BeFalse();
        result.Failed.Should().BeTrue();
        result.FailureMessage.Should().Contain("Telegram bot token must be at least 40 characters");
    }

    private static TelegramBotSettings CreateValidTelegramBotSettings()
    {
        return new TelegramBotSettings
        {
            BotToken = "1234567890123456789012345678901234567890", // 40 characters
        };
    }
}