// Copyright (c) Microsoft Corporation. All rights reserved.

// Licensed under the MIT license.

using System;

using System.Collections.Generic;

using System.Diagnostics;

using System.Linq;

using System.Reflection;

using System.Runtime.CompilerServices;

using Microsoft.ClearScript.Util;

namespace Microsoft.ClearScript

{

internal sealed class ExtensionMethodTable

{

private readonly Dictionary<Type, MethodInfo[]> table = new Dictionary<Type, MethodInfo[]>();

public ExtensionMethodSummary Summary { get; private set; } = new ExtensionMethodSummary();

public bool ProcessType(Type type, Type accessContext, ScriptAccess defaultAccess)

{

Debug.Assert(type.IsSpecific());

if (!table.ContainsKey(type) && type.HasExtensionMethods())

{

const BindingFlags bindFlags = BindingFlags.Public | BindingFlags.Static;

table[type] = type.GetMethods(bindFlags).Where(method => IsScriptableExtensionMethod(method, accessContext, defaultAccess)).ToArray();

RebuildSummary();

return true;

}

return false;

}

public void RebuildSummary()

{

Summary = new ExtensionMethodSummary(table);

}

private static bool IsScriptableExtensionMethod(MethodInfo method, Type accessContext, ScriptAccess defaultAccess)

{

return method.IsScriptable(accessContext, defaultAccess) && method.IsDefined(typeof(ExtensionAttribute), false);

}

}

internal sealed class ExtensionMethodSummary

{

public ExtensionMethodSummary()

{

Types = ArrayHelpers.GetEmptyArray<Type>();

Methods = ArrayHelpers.GetEmptyArray<MethodInfo>();

MethodNames = ArrayHelpers.GetEmptyArray<string>();

}

public ExtensionMethodSummary(Dictionary<Type, MethodInfo[]> table)

{

Types = table.Keys.ToArray();

Methods = table.SelectMany(pair => pair.Value).ToArray();

MethodNames = Methods.Select(method => method.GetScriptName()).ToArray();

}

public Type[] Types { get; }

public MethodInfo[] Methods { get; }

public string[] MethodNames { get; }

}

}