using System;
using System.IO;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

using CliWrap;
using CliWrap.Exceptions;

using Xunit;

namespace MfGames.ToolBuilder.Tests
{
    /// <summary>
    /// Tests the SampleTool in the tests directory to make sure the
    /// basic functionality is correct.
    /// </summary>
    public class SampleToolTests
    {
        [Fact]
        public async Task CrashCommandFails()
        {
            // Run the executable using CliWrap.
            FileInfo projectFile = GetProjectFile();
            StringBuilder output = new();
            CancellationToken cancellationToken =
                new CancellationTokenSource(TimeSpan.FromSeconds(20))
                    .Token;

            var exception = Assert.ThrowsAsync<CommandExecutionException>(
                async () => await Cli.Wrap("dotnet")
                    .WithArguments(
                        new[]
                        {
                            "run", "--project", projectFile.FullName, "--",
                            "crash",
                        })
                    .WithWorkingDirectory(projectFile.DirectoryName!)
                    .WithStandardOutputPipe(PipeTarget.ToStringBuilder(output))
                    .ExecuteAsync(cancellationToken)
                    .ConfigureAwait(false));

            // Verify the return code.
            Assert.NotNull(exception);
        }

        [Fact]
        public async Task TableCommandWorks()
        {
            // Run the executable using CliWrap.
            FileInfo projectFile = GetProjectFile();
            StringBuilder output = new();
            CancellationToken cancellationToken =
                new CancellationTokenSource(TimeSpan.FromSeconds(20))
                    .Token;

            CommandResult result = await Cli.Wrap("dotnet")
                .WithArguments(
                    new[]
                    {
                        "run", "--project", projectFile.FullName, "--", "table",
                    })
                .WithWorkingDirectory(projectFile.DirectoryName!)
                .WithStandardOutputPipe(PipeTarget.ToStringBuilder(output))
                .ExecuteAsync(cancellationToken)
                .ConfigureAwait(false);

            // Verify the return code.
            Assert.Equal(0, result.ExitCode);

            // Check the output.
            Assert.Equal(
                new[]
                {
                    "DefaultString DefaultInt32",
                    "-------------+------------",
                    "Row 1                    1",
                    "Row 2                   10",
                    "Row 3                  100",
                    "",
                },
                output.ToString().Split("\n"));
        }

        /// <summary>
        /// Gets the file object representing the sample tool's project.
        /// </summary>
        private static FileInfo GetProjectFile()
        {
            // Loop up until we find the directory that contains it.
            var parent = new DirectoryInfo(Environment.CurrentDirectory);

            while (parent?.GetDirectories("SampleTool").Length == 0)
            {
                parent = parent.Parent;
            }

            // If we got a null, we can't find it.
            if (parent == null)
            {
                throw new DirectoryNotFoundException(
                    "Cannot find sample tool directory from "
                    + Environment.CurrentDirectory);
            }

            // Get the project file inside there.
            DirectoryInfo directory = parent.GetDirectories("SampleTool")[0];
            FileInfo file = directory.GetFiles("SampleTool.csproj")[0];

            return file;
        }
    }
}