!7

cmodule TopDownParsing {
  switchable S input = "Bob paid for Charlie 's college education";
  TryPatterns root;
  transient JTree tree;
  transient S selectedGrouped;
  transient SingleComponentPanel scp;
  transient ReliableSingleThread rstProcessInput = dm_rstWithPreDelay(this, 500, r processInput);
  
  replace GroupingAndPatterns with Pair<S, Set<S>>.

  // Tree has 2 types of nodes: composite and options
  abstract class Base {
    L<Base> children;
    L<Base> children() { ret children; }
    
    abstract S grouped();
    abstract LS allGroupings();
    
    // allGroupings + patterns used in each grouping
    abstract L<GroupingAndPatterns> allGroupingsWithUsedPatterns();
  }
  
  // composite node
  class AppliedPattern > Base {
    S pattern;
    LS arguments;
    
    L<Base> children() {
      if (children == null)
        children = map(arguments, a -> new TryPatterns(a));
      ret children;
    }

    toString { ret shortName(this) + "(" + quote(pattern) + ")"
      + (empty(arguments) ? "" : " with " + join(" + " , quoteAll(arguments))); }
    
    S grouped() {
      ret format3_round(pattern, toStringArray(arguments));
    }
    
    LS allGroupings() {
      LLS childGroupings = map(children(), a -> a.allGroupings());
      print(quote(grouped()) + " got child groupings: " + childGroupings);
      ItIt<LS> combinations = allCombinations(childGroupings);
      ret map(combinations, c -> format3_round(pattern, c));
    }
    
    L<GroupingAndPatterns> allGroupingsWithUsedPatterns() {
      LL<GroupingAndPatterns> childGroupings = map(children(), a -> a.allGroupingsWithUsedPatterns());
      ItIt<L<GroupingAndPatterns>> combinations = allCombinations(childGroupings);
      ret map(combinations, c -> pair(
        format3_round(pattern, pairsA(c)),
        concatListsAsCISet(itemPlusList(pattern, pairsB(c)))));
    }
  }
  
  // options node (try different patterns)
  class TryPatterns > Base {
    S input;
    
    *() {}
    *(S *input) {}
    
    L<Base> children() {
      if (children == null) {
        children = new L;
        for (S pat : patterns())
          for (LS arguments : matchesToStringLists(flexMatchIC_all(pat, input)))
            children.add(setAll(new AppliedPattern, pattern := pat, +arguments));
      }
      ret children;
    }

    toString { ret shortName(this) + "(" + quote(input) + ")"
      + (empty(children) ? "" : " [" + nMatches(children()) + "]"); }
    
    S grouped() {
      ret empty(children()) ? input : first(children).grouped();
    }
    
    LS allGroupings() {
      ret uniquifyCI(listPlusItem(concatMap(children(), a -> a.allGroupings()), input));
    }
    
    L<GroupingAndPatterns> allGroupingsWithUsedPatterns() {
      ret uniquifyByFieldCI a(listPlusItem(concatMap(children(), a -> a.allGroupingsWithUsedPatterns()), pair(input, emptySet())));
    }
  }
  
  start {
    dm_watchFieldAndNow input(rstProcessInput);
    dm_vmBus_onMessage unclearListChanged((mod, name) -> {
      if (eqic((S) name, "Patterns")) rstProcessInput.trigger();
    });
  }
  
  visual northCenterAndSouthWithMargins(
    jCenteredSection("Input", dm_centeredTextField input()),
    scp = singleComponentPanel(makeTree()),
    jCenteredSection("Grouped", dm_label selectedGrouped()));
  
  JTree makeTree() {
    tree = jDynamicTree(root, x -> x.children());
    onTreeSelectionChanged(tree, r {
      Base base = cast jtree_selectedUserObject(tree);
      setField(selectedGrouped := base == null ? null : base.grouped());
    });
    ret tree;
  }
  
  LS patterns() { ret dm_getUnclearList("patterns"); }
  
  // API
  
  void processInput {
    setField(root := parse(input));
    setSCPComponent(scp, makeTree());
  }
  
  TryPatterns parse(S s) {
    ret new TryPatterns(s);
  }
  
  Cl<S> parseToGroupings(S s) {
    ret parse(s).allGroupings();
  }
  
  TryPatterns root() { ret root; }
  
  LS allGroupings() { ret root().allGroupings(); }
  L<GroupingAndPatterns> allGroupingsWithUsedPatterns() { ret root().allGroupingsWithUsedPatterns(); }
}