<?php

/*
 * Copyright 2011 Facebook, Inc.
 *
 * 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.
 */

class ArcanistAmendWorkflow extends ArcanistBaseWorkflow {

  public function getCommandHelp() {
    return phutil_console_format(<<<EOTEXT
      **amend** [--revision __revision_id__] [--show]
          Supports: git
          Amend the working copy after a revision has been accepted, so commits
          can be marked 'committed' and pushed upstream.
EOTEXT
      );
  }

  public function requiresWorkingCopy() {
    return true;
  }

  public function requiresConduit() {
    return true;
  }

  public function requiresAuthentication() {
    return true;
  }

  public function requiresRepositoryAPI() {
    return true;
  }

  public function getArguments() {
    return array(
      'show' => array(
        'help' =>
          "Show the amended commit message."
      ),
      'revision' => array(
        'param' => 'revision_id',
        'help' =>
          "Amend a specific revision. If you do not specify a revision, ".
          "arc will look in the commit message at HEAD.",
      ),
    );
  }

  public function run() {
    $repository_api = $this->getRepositoryAPI();
    if (!($repository_api instanceof ArcanistGitAPI)) {
      throw new ArcanistUsageException(
        "You may only run 'arc amend' in a git working copy.");
    }

    if ($repository_api->getUncommittedChanges()) {
      throw new ArcanistUsageException(
        "You have uncommitted changes in this branch. Stage and commit (or ".
        "revert) them before proceeding.");
    }

    if ($this->getArgument('revision')) {
      $revision_id = $this->getArgument('revision');
    } else {
      $log = $repository_api->getGitCommitLog();
      $parser = new ArcanistDiffParser();
      $changes = $parser->parseDiff($log);
      if (count($changes) != 1) {
        throw new Exception("Expected one log.");
      }
      $change = reset($changes);
      if ($change->getType() != ArcanistDiffChangeType::TYPE_MESSAGE) {
        throw new Exception("Expected message change.");
      }
      $message = ArcanistDifferentialCommitMessage::newFromRawCorpus(
        $change->getMetadata('message'));
      $revision_id = $message->getRevisionID();
      if (!$revision_id) {
        throw new ArcanistUsageException(
          "No revision specified with '--revision', and no Differential ".
          "revision marker in HEAD.");
      }
    }

    // TODO: The old 'arc amend' had a check here to see if you were running
    // 'arc amend' with an explicit revision but HEAD already had another
    // revision in it. Maybe this is worth restoring?

    $conduit = $this->getConduit();
    $message = $conduit->callMethodSynchronous(
      'differential.getcommitmessage',
      array(
        'revision_id' => $revision_id,
      ));

    if ($this->getArgument('show')) {
      echo $message."\n";
    } else {
      $repository_api->amendGitHeadCommit($message);
      echo "Amended commit message.\n";

      $working_copy = $this->getWorkingCopy();
      $remote_hooks = $working_copy->getConfig('remote_hooks_installed', false);
      if (!$remote_hooks) {
        echo "According to .arcconfig, remote commit hooks are not installed ".
             "for this project, so the revision will be marked committed now. ".
             "Consult the documentation for instructions on installing hooks.".
             "\n\n";
        $mark_workflow = $this->buildChildWorkflow(
          'mark-committed',
          array($revision_id));
        $mark_workflow->run();
      }
    }

    echo phutil_console_wrap(
      "You may now push this commit upstream, as appropriate (e.g. with ".
      "'git push', or 'git svn dcommit', or by printing and faxing it).\n");

    return 0;
  }

  protected function getSupportedRevisionControlSystems() {
    return array('git');
  }

}