using Xunit;
using FluentAssertions;
using NSubstitute;
using FreeCode.Commands;
using FreeCode.Core.Enums;
using FreeCode.Core.Interfaces;
using FreeCode.Core.Models;
using FreeCode.Tests.Unit.Helpers;

namespace FreeCode.Tests.Unit.Commands;

public sealed class HelpCommandTests
{
    [Fact]
    public async Task ExecuteAsync_ReturnsFailureWhenCommandRegistryIsUnavailable()
    {
        var services = new SimpleServiceProvider();
        var command = new HelpCommand(services);

        var result = await command.ExecuteAsync(new CommandContext(Environment.CurrentDirectory, services));

        result.Success.Should().BeFalse();
        result.Output.Should().Be("Command registry is unavailable.");
    }

    [Fact]
    public async Task ExecuteAsync_ListsCommandsSortedByCategoryAndName()
    {
        var registry = new StubCommandRegistry
        {
            EnabledCommandsOverride =
            [
                new TestCommand("exit", "Exit app", CommandCategory.Local, ["quit"]),
                new TestCommand("help", "Show help", CommandCategory.Prompt)
            ]
        };
        var services = new SimpleServiceProvider().AddService(typeof(ICommandRegistry), registry);
        var command = new HelpCommand(services);

        var result = await command.ExecuteAsync(new CommandContext(Environment.CurrentDirectory, services));

        result.Success.Should().BeTrue();
        result.Output.Should().Contain("Available commands:");
        result.Output.Should().Contain("/help - Show help");
        result.Output.Should().Contain("/exit (quit) - Exit app");
    }

    [Fact]
    public async Task ExecuteAsync_WhenNoCommandsExist_ReturnsHeaderOnly()
    {
        var services = new SimpleServiceProvider().AddService(typeof(ICommandRegistry), new StubCommandRegistry());
        var command = new HelpCommand(services);

        var result = await command.ExecuteAsync(new CommandContext(Environment.CurrentDirectory, services));

        result.Success.Should().BeTrue();
        result.Output.Should().Be("Available commands:");
    }

    private sealed class TestCommand(string name, string description, CommandCategory category, string[]? aliases = null) : ICommand
    {
        public string Name => name;
        public string[]? Aliases => aliases;
        public string Description => description;
        public CommandCategory Category => category;
        public CommandAvailability Availability => CommandAvailability.Always;
        public bool IsEnabled() => true;
        public Task<CommandResult> ExecuteAsync(CommandContext context, string? args = null, CancellationToken ct = default)
            => Task.FromResult(new CommandResult(true));
    }
}