/* Copyright (c) 2012-2014 Boundless and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Distribution License v1.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/org/documents/edl-v10.html
 *
 * Contributors:
 * Johnathan Garrett (LMN Solutions) - initial implementation
 */
package org.locationtech.geogig.cli.porcelain;

import java.io.IOException;
import java.util.List;

import jline.console.ConsoleReader;

import org.locationtech.geogig.api.porcelain.FetchOp;
import org.locationtech.geogig.api.porcelain.TransferSummary;
import org.locationtech.geogig.api.porcelain.SynchronizationException;
import org.locationtech.geogig.cli.AbstractCommand;
import org.locationtech.geogig.cli.CLICommand;
import org.locationtech.geogig.cli.CommandFailedException;
import org.locationtech.geogig.cli.GeogigCLI;
import org.locationtech.geogig.cli.annotation.RemotesReadOnly;
import org.locationtech.geogig.cli.annotation.StagingDatabaseReadOnly;

import com.beust.jcommander.Parameter;
import com.beust.jcommander.Parameters;

/**
 * Fetches named heads or tags from one or more other repositories, along with the objects necessary
 * to complete them.
 * <p>
 * {@code geogig fetch} can fetch from either a single named repository, or from several
 * repositories at once.
 * <p>
 * CLI proxy for {@link FetchOp}
 * <p>
 * Usage:
 * <ul>
 * <li> {@code geogig fetch [<options>] [<repository>...]}
 * </ul>
 * 
 * @see FetchOp
 */
@StagingDatabaseReadOnly
@RemotesReadOnly
@Parameters(commandNames = "fetch", commandDescription = "Download objects and refs from another repository")
public class Fetch extends AbstractCommand implements CLICommand {

    @Parameter(names = "--all", description = "Fetch from all remotes.")
    private boolean all = false;

    @Parameter(names = { "-p", "--prune" }, description = "After fetching, remove any remote-tracking branches which no longer exist on the remote.")
    private boolean prune = false;

    @Parameter(names = { "--depth" }, description = "Depth of the fetch.")
    private int depth = 0;

    @Parameter(names = { "--fulldepth" }, description = "Fetch the full history from the repository.")
    private boolean fulldepth = false;

    @Parameter(description = "[<repository>...]")
    private List<String> args;

    /**
     * Executes the fetch command using the provided options.
     */
    @Override
    public void runInternal(GeogigCLI cli) throws IOException {
        checkParameter(depth > 0 ? !fulldepth : true,
                "Cannot specify a depth and full depth.  Use --depth <depth> or --fulldepth.");

        if (depth > 0 || fulldepth) {
            checkParameter(cli.getGeogig().getRepository().getDepth().isPresent(),
                    "Depth operations can only be used on a shallow clone.");
        }

        TransferSummary result;
        try {
            FetchOp fetch = cli.getGeogig().command(FetchOp.class);
            fetch.setProgressListener(cli.getProgressListener());
            fetch.setAll(all).setPrune(prune).setFullDepth(fulldepth);
            fetch.setDepth(depth);

            if (args != null) {
                for (String repo : args) {
                    fetch.addRemote(repo);
                }
            }

            result = fetch.call();
        } catch (SynchronizationException e) {
            switch (e.statusCode) {
            case HISTORY_TOO_SHALLOW:
            default:
                throw new CommandFailedException("Unable to fetch, the remote history is shallow.",
                        e);
            }
        } catch (IllegalArgumentException iae) {
            throw new CommandFailedException(iae.getMessage(), iae);
        } catch (IllegalStateException ise) {
            throw new CommandFailedException(ise.getMessage(), ise);
        }

        ConsoleReader console = cli.getConsole();
        if (result.getChangedRefs().isEmpty()) {
            console.println("Already up to date.");
        } else {
            FetchResultPrinter.print(result, console);
        }
    }
}