#include "asmcode.h"

#define WORD_SIZE 4

enum Opcode {
  C_PUSH_AX, C_PUSH_BX, C_PUSH_PBX,
  C_POP_AX, C_POP_BX, C_POP_CX,
  C_ADD, C_SUB, C_MUL,
  C_SETE, C_SETNE, C_SETL, C_SETG, C_SETLE, C_SETGE, C_AND_AX,
  C_LEA, C_MOV_PBX_CX, C_CALL,
  C_CMP_BX_CX, C_CMP_BX_0, C_JZ, C_JMP
};

int AsmCodeGen2::add(Opcode op)
{
}

int AsmCodeGen2::add(Opcode op, std::string param)
{
}

int AsmCodeGen2::add(std::string line)
{
}

void AsmCodeGen2::push(int n)
{
  add("push dword " + to_string(n)); // todo
}

void AsmCodeGen2::pop(ValueSize size)
{
  add("add esp, " + to_string(WORD_SIZE));
}

void AsmCodeGen2::binop(Opcode op)
{
  add(C_POP_CX);
  add(C_POP_BX);
  add(op, C_BX, C_CX);
  add(C_PUSH_BX);
}

void AsmCodeGen2::add(ValueSize l, ValueSize r)
{
  binop(C_ADD);
}

void AsmCodeGen2::sub(ValueSize l, ValueSize r)
{
  binop(C_SUB);
}

void AsmCodeGen2::mul()
{
  binop(C_MUL);
}

void AsmCodeGen2::div()
{
  add(C_POP_BX);
  add(C_POP_AX);
  add("cdq");
  add("idiv ebx");
  add(C_PUSH_AX);
}

void AsmCodeGen2::cmpop(Opcode op)
{
  add(C_POP_CX);
  add(C_POP_BX);
  add(C_CMP_BX_CX);
  add(op);
  add(C_AND_AX);
  add(C_PUSH, C_AX);
}

void AsmCodeGen2::cmp(ValueSize size, Keyword op)
{
  switch (op) {
  case LT:
    cmpop(C_SETL);
    break;
  case GT:
    cmpop(C_SETG);
    break;
  case LE:
    cmpop(C_SETLE);
    break;
  case GE:
    cmpop(C_SETGE);
    break;
  case EQ:
    cmpop(C_SETE);
    break;
  case NE:
    cmpop(C_SETNE);
    break;
  }
}

void AsmCodeGen2::index(ValueSize size)
{
  add(C_POP_CX);
  add(C_POP_BX);
  add(C_LEA, "[ebx + " + to_string(WORD_SIZE) + " * ecx]");
  add(C_PUSH, R_AX);
}

void AsmCodeGen2::enter(int stackSize)
{
  add("push ebp");
  add("mov ebp, esp");
  if (stackSize > 0) {
    add("sub esp, " + to_string(stackSize));
  }
}

void AsmCodeGen2::call(int paramSize)
{
  add(C_POP, R_CX);
  add(C_CALL);
  if (paramSize > 0) {
    add("add esp, " + to_string(paramSize));
  }
  add(C_PUSH, R_AX);
}

void AsmCodeGen2::ret()
{
  add(C_POP_AX);
  add("mov esp, ebp");
  add("pop ebp");
  add("ret");
}

void AsmCodeGen2::mov(ValueSize size)
{
  add(C_POP_CX);
  add(C_POP_BX);
  add(C_MOV_PBX_CX);
}

static std::string to_string(Addr *addr)
{
  if (addr == NULL)
    return "";
  switch (addr->type) {
  case O_GLOBAL:
  case O_CODE:
    return "[" + addr->name + "]";
  case O_PARAMS:
    return "[ebp + " + to_string(addr->offset + WORD_SIZE * 2) + "]";
  case O_LOCAL:
    return "[ebp - " + to_string(addr->offset) + "]";
  }
  return "";
}

int AsmCodeGen2::lea(Addr *addr)
{
  int ret = add(C_LEA, to_string(addr));
  add(C_PUSH, R_AX);
  return ret;
}

void AsmCodeGen2::ld(ValueSize size)
{
  add(C_POP, R_BX);
  add(C_PUSH_PBX);
}

void AsmCodeGen2::cast(ValueSize from, ValueSize to)
{
}

int AsmCodeGen2::jz(ValueSize size)
{
  add(C_POP_BX);
  add(C_CMP_BX_0);	
  return add(C_JZ);
}

int AsmCodeGen2::jmp()
{
  return add(C_JMP);
}

void AsmCodeGen2::print(std::string format)
{
  if (format == "c") {
    add("call _printChar");
  } else if (format == "s") {
    add("call _printString");
    pop(S_PTR);
  } else if (format == "d") {
    add("call _printNum");
    pop(S_INT);
  } else if (format == "p") {
    cast(S_PTR, S_INT);
    add("call _printNum");
    pop(S_INT);
  }
}

void AsmCodeGen2::println()
{
  add("push byte 10");
  add("call _printChar");
}

void AsmCodeGen2::setJump(int instruction, int addr)
{
  lines[instruction] += " _lbl" + to_string(addr);
}

void AsmCodeGen2::setAddr(int instruction, Addr *addr)
{
  lines[instruction] += to_string(addr);
}

void AsmCodeGen2::start()
{
  lines.push_back("global _start");
  lines.push_back("");
  lines.push_back("extern _GetStdHandle@4");
  lines.push_back("extern _WriteConsoleA@20");
  lines.push_back("extern _ExitProcess@4");
}

void AsmCodeGen2::data()
{
  lines.push_back("");
  lines.push_back("section .bss");
  add("_numCharsWritten: resd 1");
}

void AsmCodeGen2::global(std::string name, int size)
{
  add(name + ": resb " + to_string(size));
}

void AsmCodeGen2::code()
{
  lines.push_back("");
  lines.push_back("section .text");
}

void AsmCodeGen2::function(std::string name)
{
  lines.push_back("");
  add(name + ":");
}

void AsmCodeGen2::main()
{
  lines.push_back("");
  add("_start:");
}

void AsmCodeGen2::finish()
{
  add("push dword 0"); // todo: get from last var
  add("call _ExitProcess@4");
  lines.push_back("");
  add("_printChar:");
  add("push dword -11");
  add("call _GetStdHandle@4");
  add("lea  ebx, [esp + 4]");
  add("push dword 0");
  add("push _numCharsWritten");
  add("push dword 1");
  add("push ebx");
  add("push eax");
  add("call _WriteConsoleA@20");
  add("ret 4");
}

static int lblCount = 1;

int AsmCodeGen2::end()
{
  int l = lblCount++;
  add("_lbl" + to_string(l) + ":");
  return l;
}

void AsmCodeGen::print(const char *output)
{
  FILE *out = output == NULL ? stdout : fopen(output, "w+t");
  for (unsigned i = 0; i < lines.size(); i++) {
    fprintf(out, "%s\n", lines[i].c_str());
  }
  if (output) {
    fclose(out);
  }
}