#include "../../../vm/vm.h"
#include "../../../tools/compiler/compiler.h"
#include <stdio.h>

#define MEMORY_SIZE 65536
#define CODE_SIZE 8192
#define STACK_SIZE 1024

u8 lmem[MEMORY_SIZE] = {0};
u8 lcode[CODE_SIZE] = {0};
u32 lstack[STACK_SIZE] = {0};
Frame lframes[STACK_SIZE] = {0};

void reset() {
  pc = 0;
  cp = 0;
  mp = 0;
  fp = 0;
  sp = 0;
  interrupt = 0;
  status = 0;
}

bool init_vm() {
  mem = lmem;
  code = lcode;
  stack = lstack;
  frames = lframes;
  reset();
  return true;
}

void error(const char* msg) {
  printf("%s", msg);
}

bool table_realloc(ScopeTable *table) {
  USED(table);
  // static so do nothing;
  return true;
}

u32 syscall(u32 id, u32 mem_ptr) {
  u32 size;
  switch(id) {
    case SYSCALL_CONSOLE_WRITE: {
      u32 size = *(u32*)&mem[mem_ptr];
      u8 *ptr = &mem[mem_ptr + 4];
      for (u32 i = 0; i < size; i++) {
        putchar(*(ptr++));
      }
      return 0;
    }
    case SYSCALL_CONSOLE_READ: {
      u8 *ptr = &mem[mp];
      mcpy(ptr, &size, sizeof(u32));
      ptr += 4;
      for (u32 i = 0; i < size; i++) {
        u8 ch = getchar();
        if (ch == '\0')
          break;
        if (ch == '\n')
          break;
        *(ptr++) = ch;
      }
      ptr[size] = '\0';
      mp += 4 + size + 1;
    }
  }

  return 1; // generic error
}

static void repl() {
  ScopeTable st;
  char line[1024];
  for (;;) {
    printf("> ");

    if (!fgets(line, sizeof(line), stdin)) {
      printf("\n");
      break;
    }

    reset();

    compile(&st, line);

    while(step_vm()) {}
    
    syscall(SYSCALL_CONSOLE_WRITE, stack[0]);
  }
}

i32 main() {
  init_vm();

  repl();

  return 0;
}