////////////////////////////////////////////////////////////
//~ Value conversion utilities

String CR_SanitizeString(Arena *arena, String str)
{
  String result = Zi;
  result.text = ArenaNext(arena, u8);
  for (u64 idx = 0; idx < str.len; ++idx)
  {
    u8 c = str.text[idx];
    String sanitized = Zi;
    switch (c)
    {
      default:
      {
        sanitized.text = &c;
        sanitized.len = 1;
      } break;

      case '\r':
      {
        // Ignore
      } break;

      case '\n':
      {
        sanitized = Lit("\\n");
      } break;

      case '\\':
      {
        sanitized = Lit("\\");
      } break;

      case '"':
      {
        sanitized = Lit("\\\"");
      } break;
    }
    result.len += PushString(arena, sanitized).len;
  }
  return result;
}

i64 CR_IntFromString(String str)
{
  i64 result = 0;

  b32 ok = 1;
  b32 is_hex = 0;

  u64 pos = 0;
  if (StringBeginsWith(str, Lit("0x")))
  {
    pos += 2;
    is_hex = 1;
  }

  // Eat sign
  i32 sign = 1;
  if (ok && !is_hex)
  {
    if (pos < str.len)
    {
      if (str.text[pos] == '-')
      {
        sign = -1;
        pos += 1;
      }
      else if (str.text[pos] == '+')
      {
        pos += 1;
      }
    }
  }

  // Parse number
  while (ok && pos < str.len)
  {
    u8 c = str.text[pos];
    u8 digit = 0;
    if (c >= '0' && c <= '9')
    {
      digit = c - '0';
    }
    else if (is_hex)
    {
      if (c >= 'a' && c <= 'f')
      {
        digit = 10 + c - 'a';
      }
      else if (c >= 'A' && c <= 'F')
      {
        digit = 10 + c - 'A';
      }
      else
      {
        ok = 0;
      }
    }
    else
    {
      ok = 0;
    }
    pos += 1;
    result += digit * PowU64(10 + is_hex * 6, str.len - pos);
  }

  if (ok)
  {
    result *= sign;
  }
  else
  {
    result = 0;
  }

  return result;
}

// TODO: Handle hexadecimal
f64 CR_FloatFromString(String str)
{
  f64 result = 0;

  b32 ok = 1;

  // Eat sign
  u64 whole_start_idx = 0;
  i32 sign = 1;
  if (ok && str.len > 0)
  {
    if (whole_start_idx < str.len)
    {
      u8 c = str.text[whole_start_idx];
      if (c == '-')
      {
        sign = -1;
        whole_start_idx += 1;
      }
      else if (c == '+')
      {
        whole_start_idx += 1;
      }
    }
  }

  // Find decimal place
  u64 frac_start_idx = whole_start_idx;
  for (; ok && frac_start_idx < str.len; ++frac_start_idx)
  {
    u8 c = str.text[frac_start_idx];
    if (c == '.')
    {
      break;
    }
  }

  // Parse whole part
  u64 whole_part = 0;
  for (u64 char_idx = whole_start_idx; ok && char_idx < frac_start_idx; ++char_idx)
  {
    u8 c = str.text[char_idx];
    if (c >= '0' && c <= '9')
    {
      u8 digit = c - '0';
      whole_part += digit * PowU64(10, frac_start_idx - (char_idx + 1));
    }
    else
    {
      ok = 0;
    }
  }

  // Parse frac part
  u64 frac_part = 0;
  for (u64 char_idx = frac_start_idx + 1; ok && char_idx < str.len; ++char_idx)
  {
    u8 c = str.text[char_idx];
    if (c >= '0' && c <= '9')
    {
      u8 digit = c - '0';
      frac_part += digit * PowU64(10, str.len - (char_idx + 1));
    }
    else
    {
      ok = 0;
    }
  }

  if (ok)
  {
    if (frac_part != 0)
    {
      result = ((f64)whole_part + ((f64)frac_part / PowU64(10, str.len - (frac_start_idx + 1)))) * sign;
    }
    else
    {
      result = (f64)whole_part * sign;
    }
  }
  else
  {
    result = 0;
  }

  return result;
}

b32 CR_BoolFromString(String str)
{
  return MatchString(str, Lit("true"));
}

Vec4 CR_Vec4FromString(String str)
{
  Vec4 result = Zi;

  b32 ok = 1;

  // if (StringBeginsWith(str, Lit("(")))
  // {
  //   str.text += 1;
  //   str.len -= 1;
  // }
  // if (StringEndsWith(str, Lit(")")))
  // {
  //   str.len -= 1;
  // }

  u64 pos = 0;
  u64 parts_found = 0;
  String part = Zi;
  part.text = str.text;
  if (StringBeginsWith(str, Lit("(")))
  {
    part.text += 1;
    pos += 1;
  }

  while (pos < str.len && parts_found < 4)
  {
    u8 c = str.text[pos];
    u8 next_c = 0;
    if (c == ',' || c == ')')
    {
      part.len = (str.text + pos) - part.text;
      f64 part_float = CR_FloatFromString(part);
      result.v[parts_found] = part_float;
      parts_found += 1;
      part.text = str.text + pos + 2;
      pos += 2;
    }
    else
    {
      pos += 1;
    }
  }

  return result;
}

Vec3 CR_Vec3FromString(String str)
{
  Vec4 v4 = CR_Vec4FromString(str);
  Vec3 result = Zi;
  result.x = v4.x;
  result.y = v4.y;
  result.z = v4.z;
  return result;
}

Vec2 CR_Vec2FromString(String str)
{
  Vec4 v4 = CR_Vec4FromString(str);
  Vec2 result = Zi;
  result.x = v4.x;
  result.y = v4.y;
  return result;
}

////////////////////////////////////////////////////////////
//~ Parse

CR_Item *CR_ItemFromString(Arena *arena, String str)
{
  CR_Item *result = PushStruct(arena, CR_Item);
  TempArena scratch = BeginScratch(arena);

  Enum(Mode)
  {
    Mode_None,

    Mode_Text,
    Mode_SingleLineComment,
    Mode_MultiLineComment,
  };
  Mode mode = Mode_None;

  Struct(ItemNode)
  {
    ItemNode *next;
    CR_Item *item;
  };
  // TODO: Reuse these
  ItemNode *top_item = PushStruct(scratch.arena, ItemNode);
  top_item->item = result;

  CR_Item *cur_item = 0;

  i64 text_start = 0;
  b32 text_is_string = 0;
  b32 text_has_name = 0;

  i64 pos = 0;
  b32 is_escaped = 0;
  while (pos < (i64)str.len)
  {
    u8 c = str.text[pos];
    u8 next_c = 0;
    if (pos + 1 < (i64)str.len)
    {
      next_c = str.text[pos + 1];
    }

    b32 is_eol = c == '\n' || c == '\r' || c == 0;
    b32 is_whitespace = c == ' ' || c == '\t' || is_eol;

    b32 next_is_eol = next_c == '\n' || next_c == '\r' || next_c == 0;
    b32 next_is_whitespace = next_c == ' ' || next_c == '\t' || next_is_eol;

    switch (mode)
    {
      case Mode_None:
      {
        if (c == '/' && next_c == '/')
        {
          mode = Mode_SingleLineComment;
          pos += 2;
        }
        else if (c == '/' && next_c == '*')
        {
          mode = Mode_MultiLineComment;
          pos += 2;
        }
        else if (!is_whitespace)
        {
          mode = Mode_Text;
          text_is_string = 0;
          text_start = pos;
        }
        else
        {
          pos += 1;
        }
      } break;

      case Mode_Text:
      {
        i64 text_end = -1;
        b32 is_name = 0;
        if (is_escaped)
        {
          is_escaped = 0;
        }
        else
        {
          if (c == '\\')
          {
            is_escaped = 1;
          }
          else if (c == '\"')
          {
            if (!text_is_string && pos == text_start)
            {
              text_is_string = 1;
              text_start = pos + 1;
            }
            else
            {
              text_end = pos;
            }
          }
          else if (next_c == ':')
          {
            text_end = pos + 1;
            is_name = 1;
          }
        }

        if (!text_is_string && next_is_whitespace)
        {
          text_end = pos + 1;
        }

        if (text_end != -1)
        {
          is_escaped = 0;

          String src_text = Zi;
          if (text_end > text_start)
          {
            src_text.len = text_end - text_start;
            src_text.text = str.text + text_start;
          }

          if (!cur_item)
          {
            cur_item = PushStruct(arena, CR_Item);
            cur_item->parent = top_item->item;
            DllQueuePush(cur_item->parent->first, cur_item->parent->last, cur_item);
            cur_item->parent->count += 1;
          }

          // FIXME: Arrays always have an item even if empty

          if (MatchString(src_text, Lit("{")))
          {
            ItemNode *n = PushStruct(scratch.arena, ItemNode);
            n->item = cur_item;
            SllStackPush(top_item, n);
            pos += 1;
            cur_item = 0;
          }
          else if (MatchString(src_text, Lit("}")))
          {
            SllStackPop(top_item);
            pos += 1;
            cur_item = 0;
          }
          else
          {
            // FIXME: Resolve escape sequences
            String final_text = PushString(arena, src_text);

            if (is_name)
            {
              cur_item->name = final_text;
            }
            else
            {
              cur_item->value = final_text;
              cur_item = 0;
            }

            if (is_name)
            {
              pos += 1;
            }
          }

          mode = Mode_None;
          text_is_string = 0;
        }

        pos += 1;
      } break;

      case Mode_SingleLineComment:
      {
        if (is_eol)
        {
          mode = Mode_None;
        }
        pos += 1;
      } break;

      case Mode_MultiLineComment:
      {
        if (!is_escaped && c == '*' && next_c == '/')
        {
          mode = Mode_None;
          pos += 2;
        }
        else
        {
          pos += 1;
        }
      } break;
    }
  }

  EndScratch(scratch);
  return result;
}