#include <Core.hpp>
#include <Scheduler.hpp>

namespace n64 {
u32 extraCycles = 0;

void CpuStall(u32 cycles) {
  extraCycles += cycles;
}

u32 PopStalledCycles() {
  u32 ret = extraCycles;
  extraCycles = 0;
  return ret;
}

Core::Core() {
  if(SDL_GameControllerAddMappingsFromFile("resources/gamecontrollerdb.txt") < 0) {
    Util::warn("Failed to load game controller DB");
  }

  cpu = std::make_unique<Interpreter>();
}

void Core::Stop() {
  pause = true;
  romLoaded = false;
  cpu->Reset();
  cpu->mem.Reset();
}

void Core::LoadROM(const std::string& rom_) {
  pause = true;
  rom = rom_;
  cpu->Reset();
  romLoaded = true;

  std::string archive_types[] = {".zip",".7z",".rar",".tar"};

  auto extension = fs::path(rom).extension().string();
  bool isArchive = std::any_of(std::begin(archive_types), std::end(archive_types), [&extension](const auto& e) {
    return e == extension;
  });

  cpu->mem.LoadROM(isArchive, rom);
  GameDB::match(cpu->mem);
  cpu->mem.mmio.vi.isPal = cpu->mem.IsROMPAL();
  cpu->mem.mmio.si.pif.InitDevices(cpu->mem.saveType);
  cpu->mem.mmio.si.pif.mempakPath = rom;
  cpu->mem.mmio.si.pif.LoadEeprom(cpu->mem.saveType, rom);
  cpu->mem.flash.Load(cpu->mem.saveType, rom);
  cpu->mem.LoadSRAM(cpu->mem.saveType, rom);
  PIF::ExecutePIF(cpu->mem, cpu->regs);
  pause = false;
}

void Core::Run(float volumeL, float volumeR) {
  Mem& mem = cpu->mem;
  MMIO& mmio = mem.mmio;
  Registers& regs = cpu->regs;

  for (int field = 0; field < mmio.vi.numFields; field++) {
    u32 frameCycles = 0;
    for (int i = 0; i < mmio.vi.numHalflines; i++) {
      mmio.vi.current = (i << 1) + field;

      if ((mmio.vi.current & 0x3FE) == mmio.vi.intr) {
        InterruptRaise(mmio.mi, regs, Interrupt::VI);
      }

      for(; cycles < mem.mmio.vi.cyclesPerHalfline; cycles++, frameCycles++) {
        u32 taken = cpu->Step();
        taken += PopStalledCycles();
        static u32 cpuSteps = 0;
        cpuSteps += taken;
        if(mmio.rsp.spStatus.halt) {
          cpuSteps = 0;
          mmio.rsp.steps = 0;
        } else {
          while(cpuSteps > 2) {
            mmio.rsp.steps += 2;
            cpuSteps -= 3;
          }

          while(mmio.rsp.steps > 0) {
            mmio.rsp.steps--;
            mmio.rsp.Step(regs, mem);
          }
        }

        cycles += taken;
        frameCycles += taken;
        scheduler.tick(taken, mem, regs);
      }

      cycles -= mmio.vi.cyclesPerHalfline;
    }

    if ((mmio.vi.current & 0x3FE) == mmio.vi.intr) {
      InterruptRaise(mmio.mi, regs, Interrupt::VI);
    }

    mmio.ai.Step(cpu->mem, regs, frameCycles, volumeL, volumeR);
    scheduler.tick(frameCycles, mem, regs);
  }
}

void Core::Serialize() {
  auto sMEM = cpu->mem.Serialize();
  auto sCPU = cpu->Serialize();
  auto sVER = std::vector<u8>{KAIZEN_VERSION >> 8, KAIZEN_VERSION >> 4, KAIZEN_VERSION & 0xFF};
  memSize = sMEM.size();
  cpuSize = sCPU.size();
  verSize = sVER.size();
  serialized[slot].insert(serialized[slot].begin(), sVER.begin(), sVER.end());
  serialized[slot].insert(serialized[slot].end(), sMEM.begin(), sMEM.end());
  serialized[slot].insert(serialized[slot].end(), sCPU.begin(), sCPU.end());
}

void Core::Deserialize() {
  std::vector<u8> dVER(serialized[slot].begin(), serialized[slot].begin() + verSize);
  if(dVER[0] != (KAIZEN_VERSION >> 8)
  || dVER[1] != (KAIZEN_VERSION >> 4)
  || dVER[2] != (KAIZEN_VERSION & 0xFF)) {
    Util::panic("PROBLEMI!");
  }

  cpu->mem.Deserialize(std::vector<u8>(serialized[slot].begin() + verSize, serialized[slot].begin() + verSize + memSize));
  cpu->Deserialize(std::vector<u8>(serialized[slot].begin() + verSize + memSize, serialized[slot].begin() + verSize + memSize + cpuSize));
  serialized[slot].erase(serialized[slot].begin(), serialized[slot].end());
}
}