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

#nullable disable

using Microsoft.Build.Framework;

namespace Microsoft.AspNetCore.StaticWebAssets.Tasks;

[MSBuildMultiThreadableTask]
public class ComputeEndpointsForReferenceStaticWebAssets : Task, IMultiThreadableTask
{
    /// <inheritdoc/>
    public TaskEnvironment TaskEnvironment { get; set; } = TaskEnvironment.Fallback;

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

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

    [Output]
    public ITaskItem[] Endpoints { get; set; }

    public override bool Execute()
    {
        var assets = StaticWebAsset.ToAssetDictionary(Assets, TaskEnvironment);

        var result = CandidateEndpoints;

        var routeSegments = new List<PathTokenizer.Segment>();
        var basePathSegments = new List<PathTokenizer.Segment>();

        for (var i = 0; i < CandidateEndpoints.Length; i++)
        {
            var candidateEndpoint = StaticWebAssetEndpoint.FromTaskItem(CandidateEndpoints[i]);
            if (assets.TryGetValue(candidateEndpoint.AssetFile, out var asset))
            {
                // We need to adjust the path to include the base path for the asset, since this is going to be used
                // as a reference.
                // Note that the caller is responsible for ensuring that only assets meant for the current project and
                // destined to be used as a reference by other project are passed to this task.

                var oldRoute = candidateEndpoint.Route;
                if (StaticWebAssetEndpoint.RouteHasPathPrefix(oldRoute, asset.BasePath, routeSegments, basePathSegments))
                {
                    Log.LogMessage(MessageImportance.Low, "Skipping endpoint '{0}' because route '{1}' is already updated.", asset.Identity, oldRoute);
                }
                else
                {
                    candidateEndpoint.Route = StaticWebAsset.CombineNormalizedPaths("", asset.BasePath, candidateEndpoint.Route, '/');

                    for (var j = 0; j < candidateEndpoint.EndpointProperties.Length; j++)
                    {
                        ref var property = ref candidateEndpoint.EndpointProperties[j];
                        if (string.Equals(property.Name, "label", StringComparison.OrdinalIgnoreCase))
                        {
                            property.Value = StaticWebAsset.CombineNormalizedPaths("", asset.BasePath, property.Value, '/');
                            // We need to do this because we are modifying the properties in place.
                            // We could instead do candidateEndpoint.EndpointProperties = candidateEndpoint.EndpointProperties
                            // but that's more obscure than this.
                            candidateEndpoint.MarkProperiesAsModified();
                        }
                    }

                    Log.LogMessage(MessageImportance.Low, "Adding endpoint {0} for asset {1} with updated route {2}.", candidateEndpoint.Route, candidateEndpoint.AssetFile, candidateEndpoint.Route);

                    result[i] = candidateEndpoint.ToTaskItem();
                }
            }
            else
            {
                Log.LogMessage(MessageImportance.Low, "Skipping endpoint {0} because the asset {1} was not found.", candidateEndpoint.Route, candidateEndpoint.AssetFile);
                result[i] = null;
            }
        }

        Endpoints = result;

        return true;
    }
}