// This file is part of the Noddybox.Emulation C# suite.
//
// Noddybox.Emulation is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Noddybox.Emulation is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Foobar.  If not, see <http://www.gnu.org/licenses/>.
//
// Copyright (c) 2012 Ian Cowburn
//
using System;

namespace Noddybox.Emulation.EightBit.Z80
{
    public partial class Z80Cpu
    {
        /// <summary>
        /// Decode and execute an ED-shifted opcode.
        /// </summary>
        /// <param name="opcode">The opcode.</param>
        private void DecodeED(byte opcode)
        {
            ushort addr;
            byte b;

            switch(opcode)
            {
                case 0x40:  // IN B,(C)
                    clock.Add(12);
                    BC.high = device.Read(BC.reg);
                    F = Z80Flags.Carry | PSZtable[BC.high] | H35table[BC.high];
                    break;

                case 0x41:  // OUT (C),B
                    clock.Add(12);
                    device.Write(BC.reg, BC.high);
                    break;

                case 0x42:  // SBC HL,BC
                    clock.Add(15);
                    SBC(ref HL.reg, BC.reg);
                    break;

                case 0x43:  // LD (nnnn),BC
                    clock.Add(20);
                    addr = FetchWord();
                    memory.Write(addr++, BC.low);
                    memory.Write(addr, BC.high);
                    break;

                case 0x44:  // NEG
                    clock.Add(8);
                    b = A;
                    A = 0;
                    SUB8(b);
                    break;
                    
                case 0x45:  // RETN
                    clock.Add(14);
                    IFF1 = IFF2;
                    PC = POP();
                    break; 

                case 0x46:  // IM 0
                    clock.Add(8);
                    IM = 0;
                    break;

                case 0x47:  // LD I,A
                    clock.Add(9);
                    I = A;
                    break;

                case 0x48:  // IN C,(C)
                    clock.Add(12);
                    BC.low = device.Read(BC.reg);
                    F = Z80Flags.Carry | PSZtable[BC.low] | H35table[BC.low];
                    break;

                case 0x49:  // OUT (C),C
                    clock.Add(12);
                    device.Write(BC.reg, BC.low);
                    break;

                case 0x4a:  // ADC HL, BC
                    clock.Add(15);
                    ADC16(ref HL.reg, BC.reg);
                    break;

                case 0x4b:  // LD BC,(nnnn)
                    clock.Add(20);
                    addr = FetchWord();
                    BC.low = memory.Read(addr++);
                    BC.high = memory.Read(addr);
                    break;

                case 0x4c:  // NEG
                    clock.Add(8);
                    b = A;
                    A = 0;
                    SUB8(b);
                    break;
                    
                case 0x4d:  // RETI
                    clock.Add(14);
                    IFF1 = IFF2;
                    PC = POP();
                    break;

                case 0x4e:  // IM 0/1
                    clock.Add(8);
                    IM = 0;
                    break;

                case 0x4f:  // LD R,A
                    clock.Add(9);
                    R = A;
                    break;

                case 0x50:  // IN D,(C)
                    clock.Add(12);
                    DE.high = device.Read(BC.reg);
                    F = Z80Flags.Carry | PSZtable[DE.high] | H35table[DE.high];
                    break;

                case 0x51:  // OUT (C),D
                    clock.Add(12);
                    device.Write(BC.reg, DE.high);
                    break;

                default:
                    break;
            }
        }
    }
}