#ifndef INC_6502_C_C64_HPP
#define INC_6502_C_C64_HPP

#include "../personality.hpp"

struct C64 : Personality
{

  void insert_autostart_sequence(std::vector<mos6502> &new_instructions) const override
  {
    constexpr static auto start_address = 0x0801;

    // first 2 bytes is the load address for a PRG file.
    new_instructions.emplace_back(ASMLine::Type::Directive, ".word " + std::to_string(start_address));
    new_instructions.emplace_back(ASMLine::Type::Directive, "* = " + std::to_string(start_address));
    new_instructions.emplace_back(ASMLine::Type::Directive, "; jmp to start of program with BASIC");
    new_instructions.emplace_back(ASMLine::Type::Directive, ".byt $0B,$08,$0A,$00,$9E,$32,$30,$36,$31,$00,$00,$00");

    // load start of stack space into stack address pointers
    new_instructions.emplace_back(mos6502::OpCode::lda, Operand(Operand::Type::literal, "#$FF"));
    new_instructions.emplace_back(mos6502::OpCode::sta, Operand(Operand::Type::literal, std::string{stack_low_address()}));
    new_instructions.emplace_back(mos6502::OpCode::lda, Operand(Operand::Type::literal, "#$CF"));
    new_instructions.emplace_back(mos6502::OpCode::sta, Operand(Operand::Type::literal, std::string{ stack_high_address() }));
  }

  [[nodiscard]] std::string_view stack_low_address() const override
  {
    return "$02";
  }
  [[nodiscard]] std::string_view stack_high_address() const override
  {
    return "$03";
  }

  [[nodiscard]] Operand get_register(const int reg_num) const override
  {
    switch (reg_num) {
      //  http://sta.c64.org/cbm64mem.html
    case 0:
      return Operand(Operand::Type::literal, "$a7");// bit buffer for rs232
    case 1:
      return Operand(Operand::Type::literal, "$a8");// counter for rs232
    case 2:
      return Operand(Operand::Type::literal, "$05");// unused, int->fp routine pointer
    case 3:
      return Operand(Operand::Type::literal, "$06");
    case 4:
      return Operand(Operand::Type::literal, "$fb");// unused
    case 5:
      return Operand(Operand::Type::literal, "$fc");// unused
    case 6:
      return Operand(Operand::Type::literal, "$fd");// unused
    case 7:
      return Operand(Operand::Type::literal, "$fe");// unused
    case 8:
      return Operand(Operand::Type::literal, "$22");// unused
    case 9:
      return Operand(Operand::Type::literal, "$23");// unused
    case 10:
      return Operand(Operand::Type::literal, "$39");// Current BASIC line number
    case 11:
      return Operand(Operand::Type::literal, "$3a");// Current BASIC line number
    case 12:
      return Operand(Operand::Type::literal, "$61");// arithmetic register #1
    case 13:
      return Operand(Operand::Type::literal, "$62");
    case 14:
      return Operand(Operand::Type::literal, "$63");
    case 15:
      return Operand(Operand::Type::literal, "$64");
    case 16:
      return Operand(Operand::Type::literal, "$65");
    case 17:
      return Operand(Operand::Type::literal, "$69");// arithmetic register #2
    case 18:
      return Operand(Operand::Type::literal, "$6a");
    case 19:
      return Operand(Operand::Type::literal, "$6b");
    case 20:
      return Operand(Operand::Type::literal, "$6c");
    case 21:
      return Operand(Operand::Type::literal, "$6d");
    case 22:
      return Operand(Operand::Type::literal, "$57");// arithmetic register #3
    case 23:
      return Operand(Operand::Type::literal, "$58");
    case 24:
      return Operand(Operand::Type::literal, "$59");
    case 25:
      return Operand(Operand::Type::literal, "$5a");
    case 26:
      return Operand(Operand::Type::literal, "$5b");
    case 27:
      return Operand(Operand::Type::literal, "$5c");// arithmetic register #4
    case 28:
      return Operand(Operand::Type::literal, "$5d");
    case 29:
      return Operand(Operand::Type::literal, "$5e");
    case 30:
      return Operand(Operand::Type::literal, "$5f");
    case 31:
      return Operand(Operand::Type::literal, "$60");
    }
    throw std::runtime_error("Unhandled register number: " + std::to_string(reg_num));
  }
};

#endif//INC_6502_C_C64_HPP