// Copyright (c) .NET Foundation. All rights reserved.

// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;

using System.Collections;

using System.Collections.Generic;

using System.IO;

using System.Reflection;

using Microsoft.EntityFrameworkCore.Internal;

namespace Microsoft.EntityFrameworkCore.Tools

{

internal class ReflectionOperationExecutor : OperationExecutorBase

{

private readonly object _executor;

private readonly Assembly _commandsAssembly;

private const string ReportHandlerTypeName = "Microsoft.EntityFrameworkCore.Design.OperationReportHandler";

private const string ResultHandlerTypeName = "Microsoft.EntityFrameworkCore.Design.OperationResultHandler";

private readonly Type _resultHandlerType;

public ReflectionOperationExecutor(

string assembly,

string startupAssembly,

string projectDir,

string dataDirectory,

string rootNamespace,

string language)

: base(assembly, startupAssembly, projectDir, dataDirectory, rootNamespace, language)

{

AppDomain.CurrentDomain.AssemblyResolve += ResolveAssembly;

_commandsAssembly = Assembly.Load(new AssemblyName { Name = DesignAssemblyName });

var reportHandlerType = _commandsAssembly.GetType(ReportHandlerTypeName, throwOnError: true, ignoreCase: false);

var reportHandler = Activator.CreateInstance(

reportHandlerType,

(Action<string>)Reporter.WriteError,

(Action<string>)Reporter.WriteWarning,

(Action<string>)Reporter.WriteInformation,

(Action<string>)Reporter.WriteVerbose);

_executor = Activator.CreateInstance(

_commandsAssembly.GetType(ExecutorTypeName, throwOnError: true, ignoreCase: false),

reportHandler,

new Dictionary<string, string>

{

{ "targetName", AssemblyFileName },

{ "startupTargetName", StartupAssemblyFileName },

{ "projectDir", ProjectDirectory },

{ "rootNamespace", RootNamespace },

{ "language", Language },

{ "toolsVersion", ProductInfo.GetVersion() }

});

_resultHandlerType = _commandsAssembly.GetType(ResultHandlerTypeName, throwOnError: true, ignoreCase: false);

}

protected override object CreateResultHandler()

=> Activator.CreateInstance(_resultHandlerType);

protected override void Execute(string operationName, object resultHandler, IDictionary arguments)

=> Activator.CreateInstance(

_commandsAssembly.GetType(ExecutorTypeName + "+" + operationName, throwOnError: true, ignoreCase: true),

_executor,

resultHandler,

arguments);

private Assembly ResolveAssembly(object sender, ResolveEventArgs args)

{

var assemblyName = new AssemblyName(args.Name);

foreach (var extension in new[] { ".dll", ".exe" })

{

var path = Path.Combine(AppBasePath, assemblyName.Name + extension);

if (File.Exists(path))

{

try

{

return Assembly.LoadFrom(path);

}

catch

{

}

}

}

return null;

}

public override void Dispose()

=> AppDomain.CurrentDomain.AssemblyResolve -= ResolveAssembly;

}

}