/*
 * Copyright (c) 2011, 2012 Roberto Tyley
 *
 * This file is part of 'Agit' - an Android Git client.
 *
 * Agit is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Agit is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see http://www.gnu.org/licenses/ .
 */

package com.madgag.agit;

import static com.google.common.collect.Lists.newArrayList;
import static com.madgag.agit.GitIntents.COMMIT;
import static com.madgag.agit.GitIntents.UNTIL_REVS;
import static org.eclipse.jgit.lib.Constants.R_REMOTES;

import android.util.Log;

import com.google.common.base.Function;
import com.google.inject.Inject;

import javax.annotation.Nullable;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;

import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevWalk;

import roboguice.inject.InjectExtra;

public class LogStartProvider {

    private static final String TAG = "LSP";

    public static final Function<Ref, ObjectId> OBJECT_IDS_FOR_REFS = new Function<Ref, ObjectId>() {
        public ObjectId apply(Ref ref) {
            return ref.getObjectId();
        }
    };

    private @Inject Repository repository;

    /**
     * The revs that specify the starts of the 'log'
     */
    private @InjectExtra(value=UNTIL_REVS, optional = true) ArrayList<String> untilRevs;

    /**
     * A specific commit that has been selected (possibly from a list of commits in a log)
     */
    private @InjectExtra(value=COMMIT, optional = true) String commitId;

    public String getCurrentRef() {
        return untilRevs == null ? null : untilRevs.get(0);
    }

    public void markStartsOn(RevWalk revWalk) {
        List<RevCommit> commits = newArrayList();

        try {
            if (commitId != null) {
                Log.d(TAG, "Including specific commit : " + commitId);
                commits.add(revWalk.parseCommit(ObjectId.fromString(commitId)));
            }
            if (untilRevs != null) {
                Log.d(TAG, "Including start revs : " + untilRevs);
                for (String untilRev : untilRevs) {
                    RevCommit commit = revWalk.parseCommit(repository.resolve(untilRev));
                    Log.d(TAG, "untilRev=" + untilRev + " commit=" + commit);
                    commits.add(commit);
                }
            }

            revWalk.markStart(commits);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}