// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using Microsoft.Build.Framework;
using Microsoft.Build.Construction;
using Microsoft.Build.Utilities;
using System.Collections.Generic;
using System.Linq;
using System.IO;

namespace Microsoft.DotNet.Arcade.Sdk;

/// <summary>
/// This task writes msbuild Items with their metadata to a props file.
/// Useful to statically save a status of an Item that will be used later on by just importing the generated file.
/// </summary>
[MSBuildMultiThreadableTask]
public class SaveItems : Task, IMultiThreadableTask
{
    /// <summary>Injected by MSBuild so paths resolve against the project directory in multithreaded builds.</summary>
    public TaskEnvironment TaskEnvironment { get; set; } = TaskEnvironment.Fallback;

    [Required]
    public string ItemName { get; set; }

    [Required]
    public ITaskItem[] Items { get; set; }

    [Output]
    [Required]
    public string File { get; set; }

    public override bool Execute()
    {
        var project = ProjectRootElement.Create();

        foreach (var item in Items)
        {
            var metadata = ((ITaskItem2)item).CloneCustomMetadataEscaped();

            if (!(metadata is IEnumerable<KeyValuePair<string, string>> metadataPairs))
            {
                metadataPairs = metadata.Keys.OfType<string>().Select(key => new KeyValuePair<string, string>(key, metadata[key] as string));
            }

            project.AddItem(ItemName, item.ItemSpec, metadataPairs);
        }

        AbsolutePath outputPath = TaskEnvironment.GetAbsolutePath(File);
        string path = Path.GetDirectoryName(outputPath);

        if (!string.IsNullOrEmpty(path))
        {
            Directory.CreateDirectory(path);
        }

        project.Save(outputPath);

        return !Log.HasLoggedErrors;
    }
}