/*
 * Copyright 2013-2016 Netherlands Forensic Institute
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package io.parsingdata.metal.data.selection;

import static io.parsingdata.metal.Util.checkNotNull;

import io.parsingdata.metal.data.ParseGraph;
import io.parsingdata.metal.data.ParseItem;
import io.parsingdata.metal.data.ParseItemList;
import io.parsingdata.metal.data.ParseValueList;
import io.parsingdata.metal.token.Token;

public final class ByToken {

    private ByToken() {}

    public static ParseItem get(final ParseGraph graph, final Token definition) {
        checkNotNull(graph, "graph");
        checkNotNull(definition, "definition");
        if (graph.definition == definition) { return graph; }
        if (graph.isEmpty()) { return null; }
        final ParseItem head = graph.head;
        if (head.isValue() && head.asValue().definition == definition) { return head; }
        if (head.isGraph()) {
            final ParseItem item = get(head.asGraph(), definition);
            if (item != null) { return item; }
        }
        return get(graph.tail, definition);
    }

    public static ParseItemList getAll(final ParseGraph graph, final Token definition) {
        checkNotNull(graph, "graph");
        checkNotNull(definition, "definition");
        return getAllRecursive(graph, definition);
    }

    private static ParseItemList getAllRecursive(final ParseGraph graph, final Token definition) {
        if (graph.isEmpty()) { return ParseItemList.EMPTY; }
        final ParseItemList tailResults = getAllRecursive(graph.tail, definition);
        final ParseItemList results = graph.definition == definition ? tailResults.add(graph) : tailResults;
        final ParseItem head = graph.head;
        if (head.isValue() && head.asValue().definition == definition) { return results.add(head); }
        if (head.isRef() && head.asRef().definition == definition) { return results.add(head); }
        if (head.isGraph()) { return results.add(getAllRecursive(head.asGraph(), definition)); }
        return results;
    }

    public static ParseValueList getAllValues(final ParseGraph graph, final Token definition) {
        checkNotNull(graph, "graph");
        checkNotNull(definition, "definition");
        return getAllValuesRecursive(graph, definition);
    }

    private static ParseValueList getAllValuesRecursive(final ParseGraph graph, final Token definition) {
        if (graph.isEmpty()) { return ParseValueList.EMPTY; }
        final ParseValueList tailResults = getAllValuesRecursive(graph.tail, definition);
        final ParseItem head = graph.head;
        if (head.isValue() && head.asValue().definition == definition) { return tailResults.add(head.asValue()); }
        if (head.isGraph()) { return tailResults.add(getAllValuesRecursive(head.asGraph(), definition)); }
        return tailResults;
    }

    public static ParseItemList getAllRoots(final ParseGraph graph, final Token definition) {
        checkNotNull(graph, "graph");
        checkNotNull(definition, "definition");

        final ParseItemList result = graph.getDefinition() == definition ? ParseItemList.create(graph) : ParseItemList.EMPTY;
        if (!graph.isEmpty()) {
            return getAllRootsRecursive(graph.tail, graph, definition)
                    .add(getAllRootsRecursive(graph.head, graph, definition))
                    .add(result);
        }
        return result;
    }

    private static ParseItemList getAllRootsRecursive(final ParseItem item, final ParseGraph parent, final Token definition) {
        final ParseItemList result = (item.getDefinition() == definition && parent.getDefinition() != definition ? ParseItemList.create(item) : ParseItemList.EMPTY);
        if (item.isGraph() && !item.asGraph().isEmpty()) {
            return getAllRootsRecursive(item.asGraph().tail, item.asGraph(), definition)
                    .add(getAllRootsRecursive(item.asGraph().head, item.asGraph(), definition))
                    .add(result);
        }
        return result;
    }

}

@@ -3553,381 +3553,68 @@
 %22);%0A
-%0A        final ParseItemList result = graph.getDefinition() == definition ? ParseItemList.create(graph) : ParseItemList.EMPTY;%0A        if (!graph.isEmpty()) %7B%0A            return getAllRootsRecursive(graph.tail, graph, definition)%0A                    .add(getAllRootsRecursive(graph.head, graph, definition))%0A                    .add(result);%0A        %7D%0A        return result
+        return getAllRootsRecursive(graph, null, definition)
 ;%0A  
@@ -3782,17 +3782,16 @@
 esult = 
-(
 item.get
@@ -3819,16 +3819,35 @@
 ition &&
+ (parent == null %7C%7C
  parent.
@@ -3875,16 +3875,33 @@
 finition
+)%0A               
  ? Parse
@@ -3921,16 +3921,32 @@
 te(item)
+%0A               
  : Parse
@@ -3959,17 +3959,16 @@
 st.EMPTY
-)
 ;%0A      

Simplify getAllRoots().