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

using System.Dynamic.Utils;

namespace System.Linq.Expressions.Interpreter
{
    internal abstract class NotInstruction : Instruction
    {
        public static Instruction? s_Boolean, s_Int64, s_Int32, s_Int16, s_UInt64, s_UInt32, s_UInt16, s_Byte, s_SByte;

        private NotInstruction() { }

        public override int ConsumedStack => 1;
        public override int ProducedStack => 1;
        public override string InstructionName => "Not";

        private sealed class NotBoolean : NotInstruction
        {
            public override int Run(InterpretedFrame frame)
            {
                object? value = frame.Pop();
                if (value == null)
                {
                    frame.Push(null);
                }
                else
                {
                    frame.Push(!(bool)value);
                }
                return 1;
            }
        }

        private sealed class NotInt64 : NotInstruction
        {
            public override int Run(InterpretedFrame frame)
            {
                object? value = frame.Pop();
                if (value == null)
                {
                    frame.Push(null);
                }
                else
                {
                    frame.Push(~(long)value);
                }
                return 1;
            }
        }

        private sealed class NotInt32 : NotInstruction
        {
            public override int Run(InterpretedFrame frame)
            {
                object? value = frame.Pop();
                if (value == null)
                {
                    frame.Push(null);
                }
                else
                {
                    frame.Push(~(int)value);
                }
                return 1;
            }
        }

        private sealed class NotInt16 : NotInstruction
        {
            public override int Run(InterpretedFrame frame)
            {
                object? value = frame.Pop();
                if (value == null)
                {
                    frame.Push(null);
                }
                else
                {
                    frame.Push((short)(~(short)value));
                }
                return 1;
            }
        }

        private sealed class NotUInt64 : NotInstruction
        {
            public override int Run(InterpretedFrame frame)
            {
                object? value = frame.Pop();
                if (value == null)
                {
                    frame.Push(null);
                }
                else
                {
                    frame.Push(~(ulong)value);
                }
                return 1;
            }
        }

        private sealed class NotUInt32 : NotInstruction
        {
            public override int Run(InterpretedFrame frame)
            {
                object? value = frame.Pop();
                if (value == null)
                {
                    frame.Push(null);
                }
                else
                {
                    frame.Push(~(uint)value);
                }
                return 1;
            }
        }

        private sealed class NotUInt16 : NotInstruction
        {
            public override int Run(InterpretedFrame frame)
            {
                object? value = frame.Pop();
                if (value == null)
                {
                    frame.Push(null);
                }
                else
                {
                    frame.Push(unchecked((ushort)(~(ushort)value)));
                }
                return 1;
            }
        }

        private sealed class NotByte : NotInstruction
        {
            public override int Run(InterpretedFrame frame)
            {
                object? value = frame.Pop();
                if (value == null)
                {
                    frame.Push(null);
                }
                else
                {
                    frame.Push(unchecked((byte)(~(byte)value)));
                }
                return 1;
            }
        }

        private sealed class NotSByte : NotInstruction
        {
            public override int Run(InterpretedFrame frame)
            {
                object? value = frame.Pop();
                if (value == null)
                {
                    frame.Push(null);
                }
                else
                {
                    frame.Push((sbyte)(~(sbyte)value));
                }
                return 1;
            }
        }

        public static Instruction Create(Type type) =>
            type.GetNonNullableType().GetTypeCode() switch
            {
                TypeCode.Boolean => s_Boolean ??= new NotBoolean(),
                TypeCode.Int64 => s_Int64 ??= new NotInt64(),
                TypeCode.Int32 => s_Int32 ??= new NotInt32(),
                TypeCode.Int16 => s_Int16 ??= new NotInt16(),
                TypeCode.UInt64 => s_UInt64 ??= new NotUInt64(),
                TypeCode.UInt32 => s_UInt32 ??= new NotUInt32(),
                TypeCode.UInt16 => s_UInt16 ??= new NotUInt16(),
                TypeCode.Byte => s_Byte ??= new NotByte(),
                TypeCode.SByte => s_SByte ??= new NotSByte(),
                _ => throw ContractUtils.Unreachable,
            };
    }
}