#include <stdio.h>
#include <string.h>
#include <vm/fzl_vm.h>
#include <vm/internals/opcode.h>

char build_result[512];

// Build string from specified count using stack values
int op_build_str(fzl_vm_t *vm)
{
  uint64_t n = vm->ops[++vm->ip];
  if (vm->dtop < n)
  {
    snprintf(last_err, sizeof(last_err),
             "runtime error - expected %zu value(s) in dstack", n);
    print_err_data(vm);
    return -1;
  }

  char temp[64];
  size_t gi = 0;
  memset(build_result, 0, sizeof(build_result));
  for (size_t i = 0; i < n; i++)
  {
    if (gi >= 512)
    {
      for (size_t i = 511; i > 508; i--)
        build_result[i] = '.';
      break;
    }

    memset(temp, 0, sizeof(temp));
    fzl_value_t val = vm->dstack[vm->dtop - n + i];

    switch (val.type)
    {
      case FZL_TYPE_UINT:
        snprintf(temp, sizeof(temp), "%zu", val.as.u);
        strcpy(build_result + gi, temp);
        gi += strlen(temp);
        break;

      case FZL_TYPE_UINT64:
        snprintf(temp, sizeof(temp), "%lu", val.as.u64);
        strcpy(build_result + gi, temp);
        gi += strlen(temp);
        break;

      case FZL_TYPE_UINT32:
        snprintf(temp, sizeof(temp), "%u", val.as.u32);
        strcpy(build_result + gi, temp);
        gi += strlen(temp);
        break;

      case FZL_TYPE_UINT16:
        snprintf(temp, sizeof(temp), "%u", val.as.u16);
        strcpy(build_result + gi, temp);
        gi += strlen(temp);
        break;

      case FZL_TYPE_UINT8:
        snprintf(temp, sizeof(temp), "%u", val.as.u8);
        strcpy(build_result + gi, temp);
        gi += strlen(temp);
        break;

      case FZL_TYPE_INT:
        snprintf(temp, sizeof(temp), "%zd", val.as.i);
        strcpy(build_result + gi, temp);
        gi += strlen(temp);
        break;

      case FZL_TYPE_INT64:
        snprintf(temp, sizeof(temp), "%ld", val.as.i64);
        strcpy(build_result + gi, temp);
        gi += strlen(temp);
        break;

      case FZL_TYPE_INT32:
        snprintf(temp, sizeof(temp), "%d", val.as.i32);
        strcpy(build_result + gi, temp);
        gi += strlen(temp);
        break;

      case FZL_TYPE_INT16:
        snprintf(temp, sizeof(temp), "%d", val.as.i16);
        strcpy(build_result + gi, temp);
        gi += strlen(temp);
        break;

      case FZL_TYPE_INT8:
        snprintf(temp, sizeof(temp), "%d", val.as.i8);
        strcpy(build_result + gi, temp);
        gi += strlen(temp);
        break;

      case FZL_TYPE_BOOL:
        snprintf(build_result + gi, sizeof(build_result) - gi, "%s",
                 val.as.b ? "true" : "false");
        gi += val.as.b ? 4 : 5;
        break;

      case FZL_TYPE_CHAR:
        snprintf(build_result + gi, sizeof(build_result) - gi, "%d", val.as.c);
        gi += 1;
        break;

      case FZL_TYPE_STRING:
        snprintf(build_result + gi, sizeof(build_result) - gi, "%s",
                 val.as.s.value);
        gi += val.as.s.length;
        break;

      case FZL_TYPE_EXTERN_FN:
        snprintf(temp, sizeof(temp), "<extern:%zu>", val.as.u);
        strcpy(build_result + gi, temp);
        gi += strlen(temp);
        break;

      case FZL_TYPE_OBJECT:
        snprintf(temp, sizeof(temp), "<ref:%p>", val.as.obj);
        strcpy(build_result + gi, temp);
        gi += strlen(temp);
        break;

      case FZL_TYPE_NULL:
        snprintf(build_result + gi, sizeof(build_result) - gi, "<null>");
        gi += 6;
        break;
    }
  }

  vm->dtop -= n;
  vm->dstack[vm->dtop++] = (fzl_value_t){.type        = FZL_TYPE_STRING,
                                         .as.s.length = strlen(build_result),
                                         .as.s.value  = build_result};
  return 0;
}