#include "InstructionModifierLookup.h"

#include "CPUContext.h"
#include "Instruction.h"
#include "Bus.h"

#include <array>
#include <cstdint>
#include <utility>
#include <cstring>
#include <iostream>

void Mod32_SIB(CPUContext &cc) {
  std::cout << "[Mod32_SIB] SIB byte encountered." << std::endl; 
}

void Mod32_LR(CPUContext& cc) {
  std::cout << "[Mod32_LR] Executed." << std::endl;
  if (cc.m_Instruction.m_ModRM.m_SIB) {
    uint32_t src = cc.m_Bus->AccessX<uint32_t>(cc.m_InstructionPointer + cc.m_Instruction.m_Length);
    std::memcpy(&cc.m_Instruction.m_Displacement, &src, 4);
    Mod32_SIB(cc);
  }    
}

void Mod32_DISP32(CPUContext& cc) {
  uint32_t src = cc.m_Bus->AccessX<uint32_t>(cc.m_InstructionPointer + cc.m_Instruction.m_Length);
  std::memcpy(&cc.m_Instruction.m_Displacement, &src, 4);
  cc.m_Instruction.m_Length += 4;
  if (cc.m_Instruction.m_ModRM.m_SIB)
    Mod32_SIB(cc);    
}

template<uint8_t RM>
void Mod32_LRDISP32(CPUContext& cc) {
  uint32_t disp = cc.m_Registers[RM] + cc.m_Bus->AccessX<uint32_t>(cc.m_Instruction.m_Length);
  std::memcpy(&cc.m_Instruction.m_Displacement, &disp, 4);
  cc.m_Instruction.m_Length += 4;
  if (cc.m_Instruction.m_ModRM.m_SIB)
    Mod32_SIB(cc);    
 }

template<uint8_t RM>
void Mod32_LRDISP8(CPUContext& cc) {
  uint32_t disp = cc.m_Registers[RM] + cc.m_Bus->AccessX<uint8_t>(cc.m_Instruction.m_Length);
  cc.m_Instruction.m_Displacement[0] = disp;
  cc.m_Instruction.m_Length += 1;
  if (cc.m_Instruction.m_ModRM.m_SIB)
    Mod32_SIB(cc);  
}

void Mod32_R(CPUContext& cc) {
  std::cout << "[Mod32_R] Executed." << std::endl;
}
  
template<uint8_t...Is>
static constexpr std::array<ModifierEntry, 256> GenerateModRM32(std::integer_sequence<uint8_t, Is...>) {
  return std::array<ModifierEntry, 256>{
    ([]<uint8_t I>() {
      constexpr auto modrm = x86::ProcessMODRM(I);

      switch (modrm.m_State) {
      case x86::ModRMState::LR:           return Mod32_LR;
      case x86::ModRMState::LR_DISP32:    return Mod32_LRDISP32<modrm.m_Rm>;
      case x86::ModRMState::LR_DISP8:     return Mod32_LRDISP8<modrm.m_Rm>;
      case x86::ModRMState::DISP32:       return Mod32_DISP32;
      case x86::ModRMState::R:            return Mod32_R;
      }

    }.template operator()<Is>())... // provide the lambda with a proper template argument
  };
}

static constexpr std::array<ModifierEntry, 256> s_ModRM32 = GenerateModRM32(std::make_integer_sequence<uint8_t, 255>{});

std::array<ModifierEntry, 256> GetMod32Table() { return s_ModRM32; }