// Copyright (c) .NET Foundation and contributors. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.

//
// CleanStep.cs
//
// Author:
//   Jb Evain (jbevain@gmail.com)
//
// (C) 2006 Jb Evain
//
// 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 Mono.Cecil;

namespace Mono.Linker.Steps
{

    public class CleanStep : BaseStep
    {

        protected override void ProcessAssembly(AssemblyDefinition assembly)
        {
            if (Annotations.GetAction(assembly) == AssemblyAction.Link)
                CleanAssembly(assembly);
        }

        static void CleanAssembly(AssemblyDefinition asm)
        {
            foreach (TypeDefinition type in asm.MainModule.Types)
                CleanType(type);
        }

        static void CleanType(TypeDefinition type)
        {
            if (type.HasProperties)
                CleanProperties(type);
            if (type.HasEvents)
                CleanEvents(type);

            if (type.HasNestedTypes)
                foreach (var nested in type.NestedTypes)
                    CleanType(nested);
        }

        static MethodDefinition? CheckMethod(TypeDefinition type, MethodDefinition method)
        {
            if (method == null)
                return null;

            return type.Methods.Contains(method) ? method : null;
        }

        static void CleanEvents(TypeDefinition type)
        {
            var events = type.Events;

            for (int i = 0; i < events.Count; i++)
            {
                var evt = events[i];
                evt.AddMethod = CheckMethod(type, evt.AddMethod);
                evt.InvokeMethod = CheckMethod(type, evt.InvokeMethod);
                evt.RemoveMethod = CheckMethod(type, evt.RemoveMethod);

                if (!IsEventUsed(evt))
                    events.RemoveAt(i--);
            }
        }

        static bool IsEventUsed(EventDefinition evt)
        {
            return evt.AddMethod != null || evt.InvokeMethod != null || evt.RemoveMethod != null;
        }

        static void CleanProperties(TypeDefinition type)
        {
            var properties = type.Properties;

            for (int i = 0; i < properties.Count; i++)
            {
                var prop = properties[i];
                prop.GetMethod = CheckMethod(type, prop.GetMethod);
                prop.SetMethod = CheckMethod(type, prop.SetMethod);

                if (!IsPropertyUsed(prop))
                    properties.RemoveAt(i--);
            }
        }

        static bool IsPropertyUsed(PropertyDefinition prop)
        {
            return prop.GetMethod != null || prop.SetMethod != null;
        }
    }
}