sclass G22DatabasesPanel {
  G22Utils g22utils;
  Concepts concepts;
  JObjectTable<GazelleDB> table;
  FileWatchService dirWatcher;
  ReliableSingleThread rstUpdate = new(r _updateTable);
  
  *(G22Utils *g22utils, Concepts *concepts) {}
  
  record GazelleDB(S name, File dir) {
    simplyCached bool loaded() {
      ret sameFile(dir, concepts.conceptsDir());
    }
  }

  visualize {
    table = swing(-> new JObjectTable);
    table.defaultAction(runnableToIVF1(rThread switchDB));
    table.itemToMap = db -> litorderedmap(
      "Name" := db.name,
      "Directory" := f2s(db.dir),
      "Loaded" := db.loaded() ? "Yes" : "No"
    );

    var tbl = table.visualize();
    
    //updateTable();
    bindToComponent(tbl, -> {
      dirWatcher = new FileWatchService;
      dirWatcher.addNonRecursiveListener(g22utils.databasesMotherDir(), dir ->
        rstUpdate!);
      rstUpdate!;
    }, -> { dispose dirWatcher; });

    ret withTopAndBottomMargin(jCenteredRaisedSection("Gazelle Databases",
      northAndCenterWithMargins(
        jline(
          toolTip("Create a new Gazelle database", jbutton("New Gazelle database...", rThread newDatabase))
        ),
        centerAndEastWithMargins(
          tbl,
          vstackWithSpacing_fixed(
            tableDependentButton(table.table, "Switch to database", rThread switchDB),
            tableDependentButton(table.table, "Delete database (TODO)"),
            tableDependentButton(table.table, "Browse files", rThread browse)
          ))));
  }
  
  void newDatabase {
    temp g22utils.enter();
    
    var tf = jtextfield();
    var lblDir = jlabel(" ");
    var lblStatus = jlabel(" ");
    var button = jbutton("Create database", r {
      temp g22utils.enter();
      
      S name = trim(tf.getText());
      File dir = newFile(g22utils.databasesMotherDir(), name);
      createEmptyConceptsFileInDir(dir);
      disposeFrame(tf);
      
      //updateTable();
    });
    disableButton(button);
    onEnter(tf, button);
    
    onChange(tf, r {
      S name = trim(tf.getText());
      bool ok;
      S status = " ", path = " ";
      if (isValidFileName(name)) {
        File dir = newFile(g22utils.databasesMotherDir(), name);
        path = f2s(dir);
        if (dirExists(dir))
          status = "A database with that name exists";
        else
          ok = true;
      } else if (!empty(name))
        status = "Database name must be a valid file name";
      setEnabled(button, ok);
      setText(lblStatus, status);
      setText(lblDir, path);
    });
    
    showForm_makeFrame("New Gazelle Database",
      vstackWithSpacing(
        withLabel("Name for new database", tf),
        lblDir,
        lblStatus,
        button);
  }

  void _updateTable {  
    new L<GazelleDB> dbs;
    dbs.add(new GazelleDB("Legacy DB", programDir()));
    for (File dir : listDirsContainingFileNamed(g22utils.databasesMotherDir(),
      "concepts.structure.gz"))
      dbs.add(new GazelleDB(fileName(dir), dir));
        
    table.setList(dbs);
  }
  
  void browse {
    desktopOpen(table.selected().dir);
  }
  
  void switchDB {
    g22utils.masterStuff().switchDatabase(table.selected().dir);
  }
}