export const FAVORITE_SERVERS_STORAGE_KEY = "minetrack_favorite_servers";

export class FavoritesManager {
  constructor(app) {
    this._app = app;
  }

  loadLocalStorage() {
    if (typeof localStorage !== "undefined") {
      let serverNames = localStorage.getItem(FAVORITE_SERVERS_STORAGE_KEY);
      if (serverNames) {
        serverNames = JSON.parse(serverNames);

        for (let i = 0; i < serverNames.length; i++) {
          const serverRegistration =
            this._app.serverRegistry.getServerRegistration(serverNames[i]);

          // The serverName may not exist in the backend configuration anymore
          // Ensure serverRegistration is defined before mutating data or considering valid
          if (serverRegistration) {
            serverRegistration.isFavorite = true;

            // Update icon since by default it is unfavorited
            document
              .getElementById(`favorite-toggle_${serverRegistration.serverId}`)
              .setAttribute(
                "class",
                this.getIconClass(serverRegistration.isFavorite)
              );
          }
        }
      }
    }
  }

  updateLocalStorage() {
    if (typeof localStorage !== "undefined") {
      // Mutate the serverIds array into server names for storage use
      const serverNames = this._app.serverRegistry
        .getServerRegistrations()
        .filter((serverRegistration) => serverRegistration.isFavorite)
        .map((serverRegistration) => serverRegistration.data.name);

      if (serverNames.length > 0) {
        // Only save if the array contains data, otherwise clear the item
        localStorage.setItem(
          FAVORITE_SERVERS_STORAGE_KEY,
          JSON.stringify(serverNames)
        );
      } else {
        localStorage.removeItem(FAVORITE_SERVERS_STORAGE_KEY);
      }
    }
  }

  handleFavoriteButtonClick = (serverRegistration) => {
    serverRegistration.isFavorite = !serverRegistration.isFavorite;

    // Update the displayed favorite icon
    document
      .getElementById(`favorite-toggle_${serverRegistration.serverId}`)
      .setAttribute("class", this.getIconClass(serverRegistration.isFavorite));

    // Request the app controller instantly re-sort the server listing
    // This handles the favorite sorting logic internally
    this._app.sortController.sortServers();

    this._app.graphDisplayManager.handleServerIsFavoriteUpdate(
      serverRegistration
    );

    // Write an updated settings payload
    this.updateLocalStorage();
  };

  getIconClass(isFavorite) {
    if (isFavorite) {
      return "icon-star server-is-favorite";
    } else {
      return "icon-star-o server-is-not-favorite";
    }
  }
}