////////////////////////////////////////////////////////////
//~ Transcode

String P_PackWorld(Arena *arena, P_World *src_world)
{
  String result = Zi;
  result.text = ArenaNext(arena, u8);
  TempArena scratch = BeginScratch(arena);
  P_Frame *src_frame = src_world->last_frame;

  result.len += StringF(arena, "version: %F\n", FmtUint(P_Tv_Latest)).len;

  result.len += StringF(arena, "\n").len;
  result.len += StringF(arena, "seed: 0x%F\n", FmtHex(src_world->seed)).len;
  result.len += StringF(arena, "tick: %F\n", FmtSint(src_frame->tick)).len;
  result.len += StringF(arena, "time: %F\n", FmtSint(src_frame->time_ns)).len;

  // Pack entities
  // FIXME: Precision
  result.len += PushString(arena, Lit("\nentities:\n")).len;
  result.len += PushString(arena, Lit("{\n")).len;
  for (P_Ent *ent = P_FirstEnt(src_frame); !P_IsEntNil(ent); ent = P_NextEnt(ent))
  {
    // TODO: Pack bullets
    if (!ent->is_bullet)
    {
      result.len += StringF(arena, "  0x%F:\n", FmtHex(ent->key.v)).len;
      result.len += PushString(arena, Lit("  {\n")).len;
      {
        result.len += StringF(arena, "    props: \n").len;
        result.len += StringF(arena, "    {\n").len;
        {
          if (ent->is_player)
          {
            result.len += PushString(arena, Lit("      player\n")).len;
          }
          if (ent->is_bullet)
          {
            result.len += PushString(arena, Lit("      bullet\n")).len;
          }
        }
        result.len += StringF(arena, "    }\n").len;
        result.len += StringF(arena, "    pos: \"%F\"\n", FmtFloat2(ent->xf.og)).len;
        result.len += StringF(arena, "    rot: \"%F\"\n", FmtFloat2(RightFromXform(ent->xf))).len;
        result.len += StringF(arena, "    exists: \"%F\"\n", FmtFloat(ent->exists)).len;
        result.len += StringF(arena, "    look: \"%F\"\n", FmtFloat2(ent->look)).len;
      }
      result.len += PushString(arena, Lit("  }\n")).len;
    }
  }
  result.len += PushString(arena, Lit("}\n")).len;

  // Pack tiles
  // TODO: Compress tile data
  result.len += PushString(arena, Lit("\ntiles:\n")).len;
  result.len += PushString(arena, Lit("{\n")).len;
  {
    String tiles_str = Base64FromString(scratch.arena, STRING(P_TilesCount, src_world->tiles));
    u64 tile_chars_per_line = 128;
    u64 tile_char_pos = 0;
    while (tile_char_pos < tiles_str.len)
    {
      result.len += PushString(arena, Lit("  ")).len;
      String src = STRING(tile_chars_per_line, tiles_str.text + tile_char_pos);
      src.len = MinU64(tile_chars_per_line, tiles_str.len - tile_char_pos);
      result.len += PushString(arena, src).len;
      result.len += PushString(arena, Lit("\n")).len;
      tile_char_pos += tile_chars_per_line;
    }

  }
  result.len += PushString(arena, Lit("}\n")).len;

  EndScratch(scratch);
  return result;
}

P_UnpackedWorld P_UnpackWorld(Arena *arena, String packed)
{
  P_UnpackedWorld result = Zi;
  TempArena scratch = BeginScratch(arena);

  CR_Item *root = CR_ItemFromString(scratch.arena, packed);

  // Unpack version
  P_Tv version = 0;
  for (CR_Item *root_item = root->first; root_item; root_item = root_item->next)
  {
    if (MatchString(root_item->name, Lit("version")))
    {
      version = CR_IntFromString(root_item->value);
      break;
    }
  }

  for (CR_Item *top_item = root->first; top_item; top_item = top_item->next)
  {
    // Unpack metadata
    if (MatchString(top_item->name, Lit("seed")))
    {
      result.seed = CR_IntFromString(top_item->value);
    }
    if (MatchString(top_item->name, Lit("tick")))
    {
      result.tick = CR_IntFromString(top_item->value);
    }
    if (MatchString(top_item->name, Lit("time")))
    {
      result.time_ns = CR_IntFromString(top_item->value);
    }

    // Unpack entities
    if (MatchString(top_item->name, Lit("entities")))
    {
      for (CR_Item *ent_item = top_item->first; ent_item; ent_item = ent_item->next)
      {
        P_Ent *ent = P_PushTempEnt(arena, &result.ents);
        ent->key = (P_Key) { .v = CR_IntFromString(ent_item->name) };
        for (CR_Item *attr = ent_item->first; attr; attr = attr->next)
        {
          if (MatchString(attr->name, Lit("props")))
          {
            for (CR_Item *prop = attr->first; prop; prop = prop->next)
            {
              if (MatchString(prop->value, Lit("player")))
              {
                ent->is_player = 1;
                ent->has_weapon = 1;
              }
              if (MatchString(prop->value, Lit("bullet")))
              {
                ent->is_bullet = 1;
              }
            }
          }
          if (MatchString(attr->name, Lit("pos")))
          {
            Vec2 pos = CR_Vec2FromString(attr->value);
            ent->xf.og = pos;
          }
          if (MatchString(attr->name, Lit("rot")))
          {
            Vec2 rot = CR_Vec2FromString(attr->value);
            ent->xf = XformWithWorldRotation(ent->xf, AngleFromVec2(rot));
          }
          if (MatchString(attr->name, Lit("exists")))
          {
            ent->exists = CR_FloatFromString(attr->value);
          }
          if (MatchString(attr->name, Lit("health")))
          {
            ent->health = CR_FloatFromString(attr->value);
          }
          if (MatchString(attr->name, Lit("look")))
          {
            Vec2 look = CR_Vec2FromString(attr->value);
            ent->look = look;
          }
        }
      }
    }

    // Parse tiles
    String tiles_base64 = Zi;
    tiles_base64.text = ArenaNext(scratch.arena, u8);
    for (CR_Item *tile_item = top_item->first; tile_item; tile_item = tile_item->next)
    {
      if (tile_item->name.len == 0)
      {
        tiles_base64.len += PushString(scratch.arena, tile_item->value).len;
      }
    }
    if (StringLenFromBase64Len(tiles_base64.len) == P_TilesCount)
    {
      result.tiles = StringFromBase64(arena, tiles_base64).text;
    }
  }

  if (!result.tiles)
  {
    result.tiles = PushStructs(arena, u8, P_TilesCount);
  }

  EndScratch(scratch);
  return result;
};