// 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.Utilities;
using System;
using System.Collections.Generic;
using System.Linq;

namespace Microsoft.DotNet.Build.Tasks.Packaging;

public class GetPackageFromModule : Task
{
    /// <summary>
    /// Modules referenced that need to be mapped to packages
    /// </summary>
    [Required]
    public ITaskItem[] ModulesReferenced { get; set; }

    /// <summary>
    /// Permitted package baseline versions.
    ///   Identity: module name
    ///   Package: package which contains the module
    /// </summary>
    public ITaskItem[] ModulePackages { get; set; }

    /// <summary>
    /// Package index files used to define module to package mapping.
    /// </summary>
    public ITaskItem[] PackageIndexes { get; set; }

    /// <summary>
    /// Packages containing the referenced modules
    /// </summary>
    [Output]
    public ITaskItem[] PackagesReferenced { get; set; }

    public override bool Execute()
    {
        IDictionary<string, string> modulesToPackages;

        if (PackageIndexes != null && PackageIndexes.Length > 0)
        {
            var index = PackageIndex.Load(PackageIndexes.Select(pi => pi.GetMetadata("FullPath")));

            modulesToPackages = index.ModulesToPackages;
        }
        else
        {
            modulesToPackages = new Dictionary<string, string>();

            foreach(var modulePackage in ModulePackages.NullAsEmpty())
            {
                modulesToPackages.Add(modulePackage.ItemSpec, modulePackage.GetMetadata("Package"));
            }
        }

        List<ITaskItem> packagesReferenced = new List<ITaskItem>();

        foreach(var moduleReferenced in ModulesReferenced)
        {
            string moduleName = moduleReferenced.ItemSpec;
            string packageId;

            if (modulesToPackages.TryGetValue(moduleName, out packageId))
            {
                var packageReferenced = new TaskItem(packageId);
                packageReferenced.SetMetadata("NativeLibrary", moduleName);
                moduleReferenced.CopyMetadataTo(packageReferenced);
                packagesReferenced.Add(packageReferenced);
            }
        }

        PackagesReferenced = packagesReferenced.ToArray();

        return !Log.HasLoggedErrors;
    }
}