// Copyright (c) 2020 Siegfried Pammer
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
// without restriction, including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// to whom the Software is furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

using ICSharpCode.Decompiler.Util;

using NuGet.Common;
using NuGet.Packaging;
using NuGet.Protocol;
using NuGet.Protocol.Core.Types;
using NuGet.Versioning;

namespace ICSharpCode.Decompiler.Tests.Helpers
{
	abstract class AbstractToolset
	{
		readonly SourceCacheContext cache;
		readonly SourceRepository repository;
		readonly FindPackageByIdResource resource;
		protected readonly string baseDir;

		public AbstractToolset(string baseDir)
		{
			this.cache = new SourceCacheContext();
			this.repository = Repository.Factory.GetCoreV3("https://api.nuget.org/v3/index.json");
			this.resource = repository.GetResource<FindPackageByIdResource>();
			this.baseDir = baseDir;
		}

		protected async Task FetchPackage(string packageName, string version, string outputPath)
		{
			ILogger logger = NullLogger.Instance;
			CancellationToken cancellationToken = CancellationToken.None;
			using MemoryStream packageStream = new MemoryStream();

			await resource.CopyNupkgToStreamAsync(
				packageName,
				NuGetVersion.Parse(version),
				packageStream,
				cache,
				logger,
				cancellationToken).ConfigureAwait(false);

			using PackageArchiveReader packageReader = new PackageArchiveReader(packageStream);
			NuspecReader nuspecReader = await packageReader.GetNuspecReaderAsync(cancellationToken).ConfigureAwait(false);

			var files = await packageReader.GetFilesAsync(cancellationToken).ConfigureAwait(false);
			files = files.Where(f => f.StartsWith("tools", StringComparison.OrdinalIgnoreCase));
			await packageReader.CopyFilesAsync(outputPath, files,
				(sourceFile, targetPath, fileStream) => {
					fileStream.CopyToFile(targetPath);
					return targetPath;
				},
				logger, cancellationToken).ConfigureAwait(false);
		}
	}

	class RoslynToolset : AbstractToolset
	{
		readonly Dictionary<string, string> installedCompilers = new Dictionary<string, string> {
			{ "legacy", Environment.ExpandEnvironmentVariables(@"%WINDIR%\Microsoft.NET\Framework\v4.0.30319") }
		};

		public RoslynToolset()
			: base(Path.Combine(AppContext.BaseDirectory, "roslyn"))
		{
		}

		public async Task Fetch(string version)
		{
			string path = Path.Combine(baseDir, version, "tools");
			if (!Directory.Exists(path))
			{
				await FetchPackage("Microsoft.Net.Compilers", version, Path.Combine(baseDir, version)).ConfigureAwait(false);
			}

			installedCompilers.Add(version, path);
		}

		public string GetCSharpCompiler(string version)
		{
			return GetCompiler("csc.exe", version);
		}

		public string GetVBCompiler(string version)
		{
			return GetCompiler("vbc.exe", version);
		}

		string GetCompiler(string compiler, string version)
		{
			if (installedCompilers.TryGetValue(version, out var path))
				return Path.Combine(path, compiler);
			throw new NotSupportedException($"Cannot find {compiler} {version}, please add it to the initialization.");
		}
	}

	class VsWhereToolset : AbstractToolset
	{
		string vswherePath;

		public VsWhereToolset()
			: base(Path.Combine(AppContext.BaseDirectory, "vswhere"))
		{
		}

		public async Task Fetch()
		{
			string path = Path.Combine(baseDir, "tools");
			if (!Directory.Exists(path))
			{
				await FetchPackage("vswhere", "2.8.4", baseDir).ConfigureAwait(false);
			}
			vswherePath = Path.Combine(path, "vswhere.exe");
		}

		public string GetVsWhere() => vswherePath;
	}
}