/*
 *  Copyright (c) 2012 Sam Harwell, Tunnel Vision Laboratories LLC
 *  All rights reserved.
 *
 *  The source code of this document is proprietary work, and is not licensed for
 *  distribution. For information about licensing, contact Sam Harwell at:
 *      sam@tunnelvisionlabs.com
 */
package org.tvl.goworks.editor.go.semantics;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.logging.Level;
import org.antlr.v4.runtime.tree.TerminalNode;
import org.antlr.works.editor.antlr4.classification.DocumentSnapshotToken;
import org.tvl.goworks.editor.go.codemodel.CodeElementModel;
import org.tvl.goworks.editor.go.codemodel.CodeElementPositionRegion;
import org.tvl.goworks.editor.go.codemodel.PackageModel;
import org.tvl.goworks.editor.go.codemodel.impl.TypeModelImpl;
import org.tvl.goworks.editor.go.codemodel.impl.TypePointerModelImpl;

/**
 *
 * @author Sam Harwell
 */
public class ReceiverTypeReference extends CodeElementReference {

    private final TerminalNode name;
    private final boolean pointer;

    public ReceiverTypeReference(TerminalNode name, boolean pointer) {
        this.name = name;
        this.pointer = pointer;
    }

    @Override
    public Collection<? extends CodeElementModel> resolve(GoAnnotatedParseTree annotatedParseTree, PackageModel currentPackage, Map<String, Collection<PackageModel>> resolvedPackages) {
        TerminalNode localTarget = annotatedParseTree.getTreeDecorator().getProperty(name, GoAnnotations.LOCAL_TARGET);

        Collection<? extends CodeElementModel> types = currentPackage.getTypes(name.getText());
        if (localTarget == null) {
            return types;
        }

        if (localTarget.getSymbol() instanceof DocumentSnapshotToken) {
            DocumentSnapshotToken snapshotToken = (DocumentSnapshotToken)localTarget.getSymbol();
            boolean foundCurrentDefinition = false;
            boolean foundCurrentFile = false;
            for (CodeElementModel model : types) {
                CodeElementPositionRegion seek = model.getSeek();
                if (seek == null) {
                    continue;
                }

                if (!seek.getFileObject().equals(snapshotToken.getSnapshot().getVersionedDocument().getFileObject())) {
                    continue;
                }

                foundCurrentFile = true;
                foundCurrentDefinition |= seek.getOffsetRegion().getStart() == localTarget.getSymbol().getStartIndex();
                if (foundCurrentDefinition) {
                    break;
                }
            }

            if (!foundCurrentDefinition) {
                String reason;
                if (foundCurrentFile) {
                    reason = "Cached type appears to be out-of-date.";
                } else {
                    reason = "Type not found in cache.";
                }

                LOGGER.log(Level.WARNING, "Unable to verify receiver type for local target type '{0}'. {1}", new Object[] { localTarget.getText(), reason });
            }
        } else if (localTarget != null) {
            LOGGER.log(Level.WARNING, "Unable to verify receiver type for local target from token class {0}.", localTarget.getClass());
        }

        if (!pointer) {
            return types;
        }

        List<CodeElementModel> pointerTypes = new ArrayList<>();
        for (CodeElementModel model : types) {
            if (!(model instanceof TypeModelImpl)) {
                continue;
            }

            TypeModelImpl typeModel = (TypeModelImpl)model;
            pointerTypes.add(new TypePointerModelImpl(typeModel));
        }

        return pointerTypes;
    }

}