#include <Core.hpp>
#include <jit/helpers.hpp>

namespace n64 {
#ifndef __aarch64__
JIT::JIT(Mem& mem, Registers& regs) : regs(regs), mem(mem) {
  regs.SetJIT(this);
  mem.SetJIT(this);
  blockCache.resize(kUpperSize);
  if (cs_open(CS_ARCH_MIPS, static_cast<cs_mode>(CS_MODE_MIPS64 | CS_MODE_BIG_ENDIAN), &disassemblerMips) !=
      CS_ERR_OK) {
    panic("Failed to initialize MIPS disassembler");
  }

  if (cs_open(CS_ARCH_X86, static_cast<cs_mode>(CS_MODE_64 | CS_MODE_LITTLE_ENDIAN), &disassemblerX86) != CS_ERR_OK) {
    panic("Failed to initialize x86 disassembler");
  }
}

bool JIT::ShouldServiceInterrupt() const {
  const bool interrupts_pending = (regs.cop0.status.im & regs.cop0.cause.interruptPending) != 0;
  const bool interrupts_enabled = regs.cop0.status.ie == 1;
  const bool currently_handling_exception = regs.cop0.status.exl == 1;
  const bool currently_handling_error = regs.cop0.status.erl == 1;

  return interrupts_pending && interrupts_enabled && !currently_handling_exception && !currently_handling_error;
}

void JIT::CheckCompareInterrupt() const {
  regs.cop0.count++;
  regs.cop0.count &= 0x1FFFFFFFF;
  if (regs.cop0.count == static_cast<u64>(regs.cop0.compare) << 1) {
    regs.cop0.cause.ip7 = 1;
    Core::GetMem().mmio.mi.UpdateInterrupt();
  }
}

void JIT::InvalidateBlock(const u32 paddr) {
  if (const u32 index = paddr >> kUpperShift; !blockCache[index].empty())
    blockCache[index] = {};
}

std::optional<u32> JIT::FetchInstruction(s64 vaddr) {
  u32 paddr = 0;

  if (check_address_error(0b11, vaddr)) [[unlikely]] {
    /*regs.cop0.HandleTLBException(blockPC);
    regs.cop0.FireException(ExceptionCode::AddressErrorLoad, 0, blockPC);
    return 1;*/
    Util::Error::GetInstance().Throw(
      {Util::Error::Severity::NON_FATAL}, {Util::Error::Type::UNHANDLED_EXCEPTION}, blockPC, {},
      "[JIT]: Unhandled exception ADL due to unaligned PC virtual value!");
    return std::nullopt;
  }

  if (!regs.cop0.MapVAddr(Cop0::LOAD, vaddr, paddr)) {
    /*regs.cop0.HandleTLBException(blockPC);
    regs.cop0.FireException(Cop0::GetTLBExceptionCode(regs.cop0.tlbError, Cop0::LOAD), 0, blockPC);
    return 1;*/
    Util::Error::GetInstance().Throw(
      {Util::Error::Severity::NON_FATAL}, {Util::Error::Type::UNHANDLED_EXCEPTION}, blockPC, {},
      "[JIT]: Unhandled exception TLB exception {} when retrieving PC physical address!",
      static_cast<int>(Cop0::GetTLBExceptionCode(regs.cop0.tlbError, Cop0::LOAD)));
    return std::nullopt;
  }

  const u32 instr = Core::GetMem().Read<u32>(paddr);

  info("{}", Disassembler::GetInstance().DisassembleSimple(paddr, instr).full);

  return instr;
}

void JIT::SetPC32(const s32 val) {
  code.mov(code.SCR1, code.qword[code.rbp + PC_OFFSET]);
  code.mov(code.qword[code.rbp + OLD_PC_OFFSET], code.SCR1);
  code.mov(code.SCR1.cvt32(), val);
  code.movsxd(code.SCR1.cvt64(), code.SCR1.cvt32());
  code.mov(code.qword[code.rbp + PC_OFFSET], code.SCR1);
  code.mov(code.SCR1.cvt32(), val + 4);
  code.movsxd(code.SCR1.cvt64(), code.SCR1.cvt32());
  code.mov(code.qword[code.rbp + NEXT_PC_OFFSET], code.SCR1);
}

void JIT::SetPC64(const s64 val) {
  code.mov(code.SCR1, code.qword[code.rbp + PC_OFFSET]);
  code.mov(code.qword[code.rbp + OLD_PC_OFFSET], code.SCR1);
  code.mov(code.SCR1, val);
  code.mov(code.qword[code.rbp + PC_OFFSET], code.SCR1);
  code.mov(code.SCR1, val + 4);
  code.mov(code.qword[code.rbp + NEXT_PC_OFFSET], code.SCR1);
}

void JIT::SetPC32(const Xbyak::Reg32& val) {
  code.mov(code.SCR1, code.qword[code.rbp + PC_OFFSET]);
  code.mov(code.qword[code.rbp + OLD_PC_OFFSET], code.SCR1);
  code.movsxd(val.cvt64(), val);
  code.mov(code.qword[code.rbp + PC_OFFSET], val);
  code.add(val, 4);
  code.mov(code.qword[code.rbp + NEXT_PC_OFFSET], val);
}

void JIT::SetPC64(const Xbyak::Reg64& val) {
  code.mov(code.SCR1, code.qword[code.rbp + PC_OFFSET]);
  code.mov(code.qword[code.rbp + OLD_PC_OFFSET], code.SCR1);
  code.mov(code.qword[code.rbp + PC_OFFSET], val);
  code.add(val, 4);
  code.mov(code.qword[code.rbp + NEXT_PC_OFFSET], val);
}

u32 JIT::Step() {
  blockOldPC = regs.oldPC;
  blockPC = regs.pc;
  blockNextPC = regs.nextPC;
  u32 paddr = 0;

  if (!regs.cop0.MapVAddr(Cop0::LOAD, blockPC, paddr)) {
    /*regs.cop0.HandleTLBException(blockPC);
    regs.cop0.FireException(Cop0::GetTLBExceptionCode(regs.cop0.tlbError, Cop0::LOAD), 0, blockPC);
    return 1;*/
    Util::Error::GetInstance().Throw({Util::Error::Severity::NON_FATAL}, {Util::Error::Type::UNHANDLED_EXCEPTION},
                                     blockPC, {},
                                     "[JIT]: Unhandled exception TLB exception {} when retrieving PC physical address!",
                                     static_cast<int>(Cop0::GetTLBExceptionCode(regs.cop0.tlbError, Cop0::LOAD)));
    return 0;
  }

  const u32 upperIndex = paddr >> kUpperShift;
  const u32 lowerIndex = paddr & kLowerMask;

  if (!blockCache[upperIndex].empty()) {
    if (blockCache[upperIndex][lowerIndex]) {
      // trace("[JIT]: Executing already compiled block @ 0x{:016X}", blockPC);
      return blockCache[upperIndex][lowerIndex]();
    }
  } else {
    blockCache[upperIndex].resize(kLowerSize);
  }

  info("[JIT]: Compiling block @ 0x{:016X}:", static_cast<u64>(blockPC));
  const auto blockInfo = code.getCurr();
  const auto block = code.getCurr<BlockFn>();
  blockCache[upperIndex][lowerIndex] = block;

  code.setProtectModeRW();

  u32 instructionsInBlock = 0;

  bool instrEndsBlock = false;

  code.sub(code.rsp, 8);
  code.push(code.rbp);
  code.mov(code.rbp, reinterpret_cast<uintptr_t>(this)); // Load context pointer

  cs_insn *insn;
  info("\tMIPS code (guest PC = 0x{:016X}):", static_cast<u64>(blockPC));
  
  emitMemberFunctionCall(&JIT::AdvanceDelaySlot, this);

  while (true) {
    paddr = 0;

    auto instruction = FetchInstruction(blockPC);

    if(!instruction)
      return 0;

    instructionsInBlock++;

    blockOldPC = blockPC;
    blockPC = blockNextPC;
    blockNextPC += 4;

    if(InstrEndsBlock(instruction.value())) {
      const auto delay_instruction = FetchInstruction(blockPC); // get instruction in delay slot
      if(!delay_instruction)
        return 0;

      if(InstrEndsBlock(delay_instruction.value())) {
        Util::Error::GetInstance().Throw(
          {Util::Error::Severity::NON_FATAL}, {Util::Error::Type::JIT_BRANCH_INSIDE_DELAY_SLOT},
          blockPC, {}, "[JIT]: Unhandled case of branch from delay slot!");
        return 0;
      }

      instructionsInBlock++;

      blockOldPC = blockPC;
      blockPC = blockNextPC;
      blockNextPC += 4;

      Emit(delay_instruction.value());
      Emit(instruction.value());

      if(!branch_taken) {
        Xbyak::Label runtime_branch_taken;
        code.mov(code.SCR1, code.byte[code.rbp + BRANCH_TAKEN_OFFSET]);
        code.cmp(code.SCR1, 0);
        code.jne(runtime_branch_taken);
        code.mov(code.SCR1, blockOldPC);
        code.mov(code.qword[code.rbp + OLD_PC_OFFSET], code.SCR1);
        code.mov(code.SCR1, blockPC);
        code.mov(code.qword[code.rbp + PC_OFFSET], code.SCR1);
        code.mov(code.SCR1, blockNextPC);
        code.mov(code.qword[code.rbp + NEXT_PC_OFFSET], code.SCR1);
        code.L(runtime_branch_taken);
      }

      if(branch_taken) branch_taken = false;
      
      emitMemberFunctionCall(&JIT::AdvanceDelaySlot, this);

      break;
    }

    Emit(instruction.value());

    emitMemberFunctionCall(&JIT::AdvanceDelaySlot, this);
  }

  code.mov(code.rax, instructionsInBlock);
  code.pop(code.rbp);
  code.add(code.rsp, 8);
  code.ret();
  code.setProtectModeRE();
  static size_t blockInfoSize = 0;
  blockInfoSize = code.getSize() - blockInfoSize;

  info("\tX86 code (block address = 0x{:016X}):", reinterpret_cast<uintptr_t>(block));
  const auto count = cs_disasm(disassemblerX86, blockInfo, blockInfoSize, reinterpret_cast<uintptr_t>(block), 0, &insn);
  if (count > 0) {
    for (size_t j = 0; j < count; j++) {
      info("\t\t0x{:016X}:\t{}\t\t{}", insn[j].address, insn[j].mnemonic, insn[j].op_str);
    }
  
    cs_free(insn, count);
  }
  //  panic("");
  return block();
}
#endif

void JIT::DumpBlockCacheToDisk() const {
  Util::WriteFileBinary(code.getCode<u8*>(), code.getSize(), "jit.dump");
}
} // namespace n64