using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Threading.Tasks;
using CliFx.Infrastructure;
using CliFx.Tests.Utils;
using CliFx.Tests.Utils.Extensions;
using CliWrap;
using CliWrap.Buffered;
using FluentAssertions;
using Xunit;
using Xunit.Abstractions;

namespace CliFx.Tests;

public class ConsoleSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
{
    [Fact(Timeout = 15000)]
    public async Task I_can_run_the_application_with_the_default_console_implementation_to_interact_with_the_system_console()
    {
        // Can't verify our own console output, so using an external process for this test

        // Arrange
        var command =
            "Hello world" | Cli.Wrap(Dummy.Program.FilePath).WithArguments("console-test");

        // Act
        var result = await command.ExecuteBufferedAsync();

        // Assert
        result.StandardOutput.Trim().Should().Be("Hello world");
        result.StandardError.Trim().Should().Be("Hello world");
    }

    [Fact]
    public void I_can_run_the_application_on_a_system_with_a_custom_console_encoding_and_not_get_corrupted_output()
    {
        // Arrange
        using var buffer = new MemoryStream();
        using var consoleWriter = new ConsoleWriter(FakeConsole, buffer, Encoding.UTF8);

        // Act
        consoleWriter.Write("Hello world");
        consoleWriter.Flush();

        // Assert
        var outputBytes = buffer.ToArray();
        outputBytes.Should().NotContain(Encoding.UTF8.GetPreamble());

        var output = consoleWriter.Encoding.GetString(outputBytes);
        output.Should().Be("Hello world");
    }

    [Fact]
    public async Task I_can_run_the_application_with_the_fake_console_implementation_to_isolate_console_interactions()
    {
        // Arrange
        var commandType = DynamicCommandBuilder.Compile(
            // lang=csharp
            """
            [Command]
            public class Command : ICommand
            {
                public ValueTask ExecuteAsync(IConsole console)
                {
                    console.ResetColor();
                    console.ForegroundColor = ConsoleColor.DarkMagenta;
                    console.BackgroundColor = ConsoleColor.DarkMagenta;
                    console.WindowWidth = 100;
                    console.WindowHeight = 25;
                    console.CursorLeft = 42;
                    console.CursorTop = 24;

                    console.Output.WriteLine("Hello ");
                    console.Error.WriteLine("world!");

                    return default;
                }
            }
            """
        );

        var application = new CliApplicationBuilder()
            .AddCommand(commandType)
            .UseConsole(FakeConsole)
            .Build();

        // Act
        var exitCode = await application.RunAsync(
            [],
            new Dictionary<string, string>()
        );

        // Assert
        exitCode.Should().Be(0);

        Console.OpenStandardInput().Should().NotBeSameAs(FakeConsole.Input.BaseStream);
        Console.OpenStandardOutput().Should().NotBeSameAs(FakeConsole.Output.BaseStream);
        Console.OpenStandardError().Should().NotBeSameAs(FakeConsole.Error.BaseStream);

        Console.ForegroundColor.Should().NotBe(ConsoleColor.DarkMagenta);
        Console.BackgroundColor.Should().NotBe(ConsoleColor.DarkMagenta);

        // This fails because tests don't spawn a console window
        //Console.WindowWidth.Should().Be(100);
        //Console.WindowHeight.Should().Be(25);
        //Console.CursorLeft.Should().NotBe(42);
        //Console.CursorTop.Should().NotBe(24);

        FakeConsole.IsInputRedirected.Should().BeTrue();
        FakeConsole.IsOutputRedirected.Should().BeTrue();
        FakeConsole.IsErrorRedirected.Should().BeTrue();
    }

    [Fact]
    public async Task I_can_run_the_application_with_the_fake_console_implementation_and_simulate_stream_interactions()
    {
        // Arrange
        var commandType = DynamicCommandBuilder.Compile(
            // lang=csharp
            """
            [Command]
            public class Command : ICommand
            {
                public ValueTask ExecuteAsync(IConsole console)
                {
                    var input = console.Input.ReadToEnd();
                    console.Output.WriteLine(input);
                    console.Error.WriteLine(input);

                    return default;
                }
            }
            """
        );

        var application = new CliApplicationBuilder()
            .AddCommand(commandType)
            .UseConsole(FakeConsole)
            .Build();

        // Act
        FakeConsole.WriteInput("Hello world");

        var exitCode = await application.RunAsync(
            [],
            new Dictionary<string, string>()
        );

        // Assert
        exitCode.Should().Be(0);

        var stdOut = FakeConsole.ReadOutputString();
        stdOut.Trim().Should().Be("Hello world");

        var stdErr = FakeConsole.ReadErrorString();
        stdErr.Trim().Should().Be("Hello world");
    }

    [Fact]
    public async Task I_can_run_the_application_with_the_fake_console_implementation_and_simulate_key_presses()
    {
        // Arrange
        var commandType = DynamicCommandBuilder.Compile(
            // lang=csharp
            """
            [Command]
            public class Command : ICommand
            {
                public ValueTask ExecuteAsync(IConsole console)
                {
                    console.WriteLine(console.ReadKey().Key);
                    console.WriteLine(console.ReadKey().Key);
                    console.WriteLine(console.ReadKey().Key);

                    return default;
                }
            }
            """
        );

        var application = new CliApplicationBuilder()
            .AddCommand(commandType)
            .UseConsole(FakeConsole)
            .Build();

        // Act
        FakeConsole.EnqueueKey(new ConsoleKeyInfo('0', ConsoleKey.D0, false, false, false));
        FakeConsole.EnqueueKey(new ConsoleKeyInfo('a', ConsoleKey.A, false, false, false));
        FakeConsole.EnqueueKey(new ConsoleKeyInfo('\0', ConsoleKey.Backspace, false, false, false));

        var exitCode = await application.RunAsync(
            [],
            new Dictionary<string, string>()
        );

        // Assert
        exitCode.Should().Be(0);

        var stdOut = FakeConsole.ReadOutputString();
        stdOut.Trim().Should().ConsistOfLines("D0", "A", "Backspace");
    }
}