!7

concept RewriteExample {
  S in, out;
}

cmodule RewriteDatabase {
  transient CRUD<RewriteExample> rewriteExamplesCRUD;
  transient SingleComponentPanel scpSuggestions;
  transient ReliableSingleThread rstMakeSuggestions = dm_rst(me(), r makeSuggestions);
  
  start {
    rewriteExamplesCRUD = CRUD(RewriteExample);
  }
  
  visualize {
    JComponent c = jtabs("Rewrite Examples", centerAndSouthWithMargin(
      rewriteExamplesCRUD.visualize(),
      jCenteredSection("Suggestions", jMinHeight(100, scpSuggestions = singleComponentPanel()))));
    onTableSelectionChanged(rewriteExamplesCRUD.table(), rstMakeSuggestions);
    onConceptChangeByClass RewriteExample(rstMakeSuggestions);
    ret c;
  }

  void makeSuggestions {
    RewriteExample e = rewriteExamplesCRUD.selected(), ret if null;
    new L<JComponent> buttons;
    
    S transferred = transferCurlyBracketPhrases(e.out, e.in);
    if (neq(transferred, e.in))
      buttons.add(jbutton("Change LHS to: " + transferred, r { cset(e, in := transferred) }));

    Set<S> sharedPhrases = sharedCurlyBracketPhrases(e.in, e.out);
    if (nempty(sharedPhrases)) {
      S var = firstUnusedCountingDollarVar(e.in);
      for (S phrase : sharedPhrases)
        buttons.add(jbutton("Replace " + curly(phrase) + " with " + var, r {
          cset(e, in := jreplaceIC_literal(e.in, curly(phrase), var))
        }));
    }
      
    setComponent(scpSuggestions, scrollableStackWithSpacing(buttons));
  }
}