using FluentAssertions;
using ProposalSystem.Application.DTOs;
using ProposalSystem.Application.Validators;
using ProposalSystem.Domain.Entities;
using Xunit;

namespace ProposalSystem.Tests.Validators;

/// <summary>
/// PR5: Tests for CreatePricingLibraryItemValidator.
/// </summary>
public class CreatePricingLibraryItemValidatorTests
{
    private readonly CreatePricingLibraryItemValidator _sut = new();

    [Fact(DisplayName = "PR5: Valid pricing library item passes validation")]
    public void ValidRequest_Passes()
    {
        var request = new CreatePricingLibraryItemRequest(
            Title: "HVAC Filter Replacement",
            Description: "Standard 20x25x1 MERV-13 filter replacement",
            ServiceCategory: ServiceCategory.HVAC,
            Unit: "ea",
            UnitPrice: 45.00m,
            Keywords: "filter HVAC maintenance preventive",
            Source: "Manual"
        );

        var result = _sut.Validate(request);

        result.IsValid.Should().BeTrue();
    }

    [Fact(DisplayName = "PR5: Empty title fails validation")]
    public void EmptyTitle_Fails()
    {
        var request = new CreatePricingLibraryItemRequest(
            Title: "",
            Description: null,
            ServiceCategory: ServiceCategory.General,
            Unit: null,
            UnitPrice: null,
            Keywords: null,
            Source: null
        );

        var result = _sut.Validate(request);

        result.IsValid.Should().BeFalse();
        result.Errors.Should().Contain(e => e.PropertyName == "Title");
    }

    [Fact(DisplayName = "PR5: Title exceeding 200 chars fails")]
    public void Title_TooLong_Fails()
    {
        var request = new CreatePricingLibraryItemRequest(
            Title: new string('X', 201),
            Description: null,
            ServiceCategory: ServiceCategory.General,
            Unit: null,
            UnitPrice: null,
            Keywords: null,
            Source: null
        );

        var result = _sut.Validate(request);

        result.IsValid.Should().BeFalse();
        result.Errors.Should().Contain(e => e.PropertyName == "Title");
    }

    [Fact(DisplayName = "PR5: Description exceeding 5000 chars fails")]
    public void Description_TooLong_Fails()
    {
        var request = new CreatePricingLibraryItemRequest(
            Title: "Valid Title",
            Description: new string('X', 5001),
            ServiceCategory: ServiceCategory.General,
            Unit: null,
            UnitPrice: null,
            Keywords: null,
            Source: null
        );

        var result = _sut.Validate(request);

        result.IsValid.Should().BeFalse();
        result.Errors.Should().Contain(e => e.PropertyName == "Description");
    }

    [Fact(DisplayName = "PR5: Negative UnitPrice fails")]
    public void NegativeUnitPrice_Fails()
    {
        var request = new CreatePricingLibraryItemRequest(
            Title: "Valid Title",
            Description: null,
            ServiceCategory: ServiceCategory.Plumbing,
            Unit: "hr",
            UnitPrice: -10.00m,
            Keywords: null,
            Source: null
        );

        var result = _sut.Validate(request);

        result.IsValid.Should().BeFalse();
        result.Errors.Should().Contain(e => e.PropertyName == "UnitPrice");
    }

    [Fact(DisplayName = "PR5: Zero UnitPrice is valid")]
    public void ZeroUnitPrice_Passes()
    {
        var request = new CreatePricingLibraryItemRequest(
            Title: "Complimentary Inspection",
            Description: null,
            ServiceCategory: ServiceCategory.General,
            Unit: "ea",
            UnitPrice: 0m,
            Keywords: null,
            Source: null
        );

        var result = _sut.Validate(request);

        result.IsValid.Should().BeTrue();
    }

    [Fact(DisplayName = "PR5: Null UnitPrice is valid")]
    public void NullUnitPrice_Passes()
    {
        var request = new CreatePricingLibraryItemRequest(
            Title: "Variable Price Item",
            Description: null,
            ServiceCategory: ServiceCategory.General,
            Unit: null,
            UnitPrice: null,
            Keywords: null,
            Source: null
        );

        var result = _sut.Validate(request);

        result.IsValid.Should().BeTrue();
    }

    [Fact(DisplayName = "PR5: Keywords exceeding 2000 chars fails")]
    public void Keywords_TooLong_Fails()
    {
        var request = new CreatePricingLibraryItemRequest(
            Title: "Valid Title",
            Description: null,
            ServiceCategory: ServiceCategory.General,
            Unit: null,
            UnitPrice: null,
            Keywords: new string('X', 2001),
            Source: null
        );

        var result = _sut.Validate(request);

        result.IsValid.Should().BeFalse();
        result.Errors.Should().Contain(e => e.PropertyName == "Keywords");
    }

    [Fact(DisplayName = "PR5: Invalid ServiceCategory enum value fails")]
    public void InvalidServiceCategory_Fails()
    {
        var request = new CreatePricingLibraryItemRequest(
            Title: "Valid Title",
            Description: null,
            ServiceCategory: (ServiceCategory)999,
            Unit: null,
            UnitPrice: null,
            Keywords: null,
            Source: null
        );

        var result = _sut.Validate(request);

        result.IsValid.Should().BeFalse();
        result.Errors.Should().Contain(e => e.PropertyName == "ServiceCategory");
    }

    [Fact(DisplayName = "PR5: Unit exceeding 50 chars fails")]
    public void Unit_TooLong_Fails()
    {
        var request = new CreatePricingLibraryItemRequest(
            Title: "Valid Title",
            Description: null,
            ServiceCategory: ServiceCategory.General,
            Unit: new string('X', 51),
            UnitPrice: null,
            Keywords: null,
            Source: null
        );

        var result = _sut.Validate(request);

        result.IsValid.Should().BeFalse();
        result.Errors.Should().Contain(e => e.PropertyName == "Unit");
    }

    [Fact(DisplayName = "PR5: Source exceeding 100 chars fails")]
    public void Source_TooLong_Fails()
    {
        var request = new CreatePricingLibraryItemRequest(
            Title: "Valid Title",
            Description: null,
            ServiceCategory: ServiceCategory.General,
            Unit: null,
            UnitPrice: null,
            Keywords: null,
            Source: new string('X', 101)
        );

        var result = _sut.Validate(request);

        result.IsValid.Should().BeFalse();
        result.Errors.Should().Contain(e => e.PropertyName == "Source");
    }

    [Fact(DisplayName = "PR5: Minimal valid request (title + category only) passes")]
    public void MinimalValidRequest_Passes()
    {
        var request = new CreatePricingLibraryItemRequest(
            Title: "Basic Item",
            Description: null,
            ServiceCategory: ServiceCategory.Other,
            Unit: null,
            UnitPrice: null,
            Keywords: null,
            Source: null
        );

        var result = _sut.Validate(request);

        result.IsValid.Should().BeTrue();
    }
}