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

namespace ChatBot.Tests.Configuration.Validators;

public class OllamaSettingsValidatorTests
{
    private readonly OllamaSettingsValidator _validator;

    public OllamaSettingsValidatorTests()
    {
        _validator = new OllamaSettingsValidator();
    }

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

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

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

    [Fact]
    public void Validate_WithEmptyUrl_ShouldReturnFailure()
    {
        // Arrange
        var settings = CreateValidOllamaSettings();
        settings.Url = string.Empty;

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

        // Assert
        result.Succeeded.Should().BeFalse();
        result.Failed.Should().BeTrue();
        result.FailureMessage.Should().Contain("Ollama URL is required");
    }

    [Fact]
    public void Validate_WithNullUrl_ShouldReturnFailure()
    {
        // Arrange
        var settings = CreateValidOllamaSettings();
        settings.Url = null!;

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

        // Assert
        result.Succeeded.Should().BeFalse();
        result.Failed.Should().BeTrue();
        result.FailureMessage.Should().Contain("Ollama URL is required");
    }

    [Fact]
    public void Validate_WithWhitespaceUrl_ShouldReturnFailure()
    {
        // Arrange
        var settings = CreateValidOllamaSettings();
        settings.Url = "   ";

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

        // Assert
        result.Succeeded.Should().BeFalse();
        result.Failed.Should().BeTrue();
        result.FailureMessage.Should().Contain("Ollama URL is required");
    }

    [Theory]
    [InlineData("invalid-url")]
    [InlineData("not-a-url")]
    [InlineData("://invalid")]
    [InlineData("http://")]
    [InlineData("https://")]
    public void Validate_WithInvalidUrlFormat_ShouldReturnFailure(string invalidUrl)
    {
        // Arrange
        var settings = CreateValidOllamaSettings();
        settings.Url = invalidUrl;

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

        // Assert
        result.Succeeded.Should().BeFalse();
        result.Failed.Should().BeTrue();
        result.FailureMessage.Should().Contain($"Invalid Ollama URL format: {invalidUrl}");
    }

    [Theory]
    [InlineData("http://localhost:11434")]
    [InlineData("https://localhost:11434")]
    [InlineData("http://127.0.0.1:11434")]
    [InlineData("https://ollama.example.com")]
    [InlineData("http://192.168.1.100:11434")]
    [InlineData("https://api.ollama.com")]
    public void Validate_WithValidUrlFormat_ShouldReturnSuccess(string validUrl)
    {
        // Arrange
        var settings = CreateValidOllamaSettings();
        settings.Url = validUrl;

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

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

    [Fact]
    public void Validate_WithEmptyDefaultModel_ShouldReturnFailure()
    {
        // Arrange
        var settings = CreateValidOllamaSettings();
        settings.DefaultModel = string.Empty;

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

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

    [Fact]
    public void Validate_WithNullDefaultModel_ShouldReturnFailure()
    {
        // Arrange
        var settings = CreateValidOllamaSettings();
        settings.DefaultModel = null!;

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

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

    [Fact]
    public void Validate_WithWhitespaceDefaultModel_ShouldReturnFailure()
    {
        // Arrange
        var settings = CreateValidOllamaSettings();
        settings.DefaultModel = "   ";

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

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

    [Theory]
    [InlineData("llama3")]
    [InlineData("llama3.1")]
    [InlineData("llama3.2")]
    [InlineData("codellama")]
    [InlineData("mistral")]
    [InlineData("phi3")]
    [InlineData("gemma")]
    [InlineData("qwen")]
    public void Validate_WithValidDefaultModel_ShouldReturnSuccess(string validModel)
    {
        // Arrange
        var settings = CreateValidOllamaSettings();
        settings.DefaultModel = validModel;

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

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

    [Fact]
    public void Validate_WithMultipleValidationErrors_ShouldReturnAllErrors()
    {
        // Arrange
        var settings = new OllamaSettings
        {
            Url = "invalid-url", // Invalid
            DefaultModel = string.Empty, // Invalid
        };

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

        // Assert
        result.Succeeded.Should().BeFalse();
        result.Failed.Should().BeTrue();
        result.FailureMessage.Should().Contain("Invalid Ollama URL format: invalid-url");
        result.FailureMessage.Should().Contain("DefaultModel is required");
    }

    [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 = CreateValidOllamaSettings();

        // 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 OllamaSettings { Url = "invalid-url", DefaultModel = 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("Invalid Ollama URL format: invalid-url");
        result.FailureMessage.Should().Contain("DefaultModel is required");
    }

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

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

    [Theory]
    [InlineData("http://localhost")]
    [InlineData("https://localhost")]
    [InlineData("http://localhost:8080")]
    [InlineData("https://localhost:8080")]
    [InlineData("http://example.com")]
    [InlineData("https://example.com")]
    [InlineData("http://192.168.1.1")]
    [InlineData("https://192.168.1.1")]
    [InlineData("http://10.0.0.1:11434")]
    [InlineData("https://10.0.0.1:11434")]
    public void Validate_WithVariousValidUrls_ShouldReturnSuccess(string validUrl)
    {
        // Arrange
        var settings = CreateValidOllamaSettings();
        settings.Url = validUrl;

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

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

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

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

        // Assert
        result.Succeeded.Should().BeFalse();
        result.Failed.Should().BeTrue();
        result.FailureMessage.Should().Contain("Ollama URL is required");
        result.FailureMessage.Should().Contain("DefaultModel is required");
    }

    [Fact]
    public void Validate_WithVeryLongValidUrl_ShouldReturnSuccess()
    {
        // Arrange
        var settings = CreateValidOllamaSettings();
        settings.Url = "https://very-long-subdomain-name.example.com:11434/api/v1/ollama";

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

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

    [Fact]
    public void Validate_WithVeryLongValidModel_ShouldReturnSuccess()
    {
        // Arrange
        var settings = CreateValidOllamaSettings();
        settings.DefaultModel = "very-long-model-name-with-many-parts-and-version-numbers";

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

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

    private static OllamaSettings CreateValidOllamaSettings()
    {
        return new OllamaSettings { Url = "http://localhost:11434", DefaultModel = "llama3" };
    }
}