<?php

/*
 * Copyright 2012 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.
 */

/**
 * Applies changes from Differential or a file to the working copy.
 *
 * @group workflow
 */
final class ArcanistPatchWorkflow extends ArcanistBaseWorkflow {

  const SOURCE_BUNDLE         = 'bundle';
  const SOURCE_PATCH          = 'patch';
  const SOURCE_REVISION       = 'revision';
  const SOURCE_DIFF           = 'diff';

  private $source;
  private $sourceParam;

  public function getCommandSynopses() {
    return phutil_console_format(<<<EOTEXT
      **patch** __D12345__
      **patch** __--revision__ __revision_id__
      **patch** __--diff__ __diff_id__
      **patch** __--patch__ __file__
      **patch** __--arcbundle__ __bundlefile__
EOTEXT
      );
  }

  public function getCommandHelp() {
    return phutil_console_format(<<<EOTEXT
          Supports: git, svn, hg
          Apply the changes in a Differential revision, patchfile, or arc
          bundle to the working copy.
EOTEXT
      );
  }

  public function getArguments() {
    return array(
      'revision' => array(
        'param' => 'revision_id',
        'paramtype' => 'complete',
        'help' =>
          "Apply changes from a Differential revision, using the most recent ".
          "diff that has been attached to it. You can run 'arc patch D12345' ".
          "as a shorthand for this.",
      ),
      'diff' => array(
        'param' => 'diff_id',
        'help' =>
          "Apply changes from a Differential diff. Normally you want to use ".
          "--revision to get the most recent changes, but you can ".
          "specifically apply an out-of-date diff or a diff which was never ".
          "attached to a revision by using this flag.",
      ),
      'arcbundle' => array(
        'param' => 'bundlefile',
        'paramtype' => 'file',
        'help' =>
          "Apply changes from an arc bundle generated with 'arc export'.",
      ),
      'patch' => array(
        'param' => 'patchfile',
        'paramtype' => 'file',
        'help' =>
          "Apply changes from a git patchfile or unified patchfile.",
      ),
      'encoding' => array(
        'param' => 'encoding',
        'help' =>
          "Attempt to convert non UTF-8 patch into specified encoding.",
      ),
      'update' => array(
        'supports' => array(
          'git', 'svn', 'hg'
        ),
        'help' =>
          "Update the local working copy before applying the patch.",
        'conflicts' => array(
          'nobranch' => true,
        ),
      ),
      'nocommit' => array(
        'supports' => array(
          'git'
        ),
        'help' =>
          "Normally under git if the patch is successful the changes are ".
          "committed to the working copy. This flag prevents the commit.",
      ),
      'nobranch' => array(
        'supports' => array(
          'git'
        ),
        'help' =>
          "Normally under git a new branch is created and then the patch ".
          "is applied and committed in the branch.  This flag skips the ".
          "branch creation step and applies and commits the patch to the ".
          "current branch.",
        'conflicts' => array(
          'update' => true,
        ),
      ),
      'force' => array(
        'help' =>
          "Do not run any sanity checks.",
      ),
      '*' => 'name',
    );
  }

  protected function didParseArguments() {
    $source = null;
    $requested = 0;
    if ($this->getArgument('revision')) {
      $source = self::SOURCE_REVISION;
      $requested++;
    }
    if ($this->getArgument('diff')) {
      $source = self::SOURCE_DIFF;
      $requested++;
    }
    if ($this->getArgument('arcbundle')) {
      $source = self::SOURCE_BUNDLE;
      $requested++;
    }
    if ($this->getArgument('patch')) {
      $source = self::SOURCE_PATCH;
      $requested++;
    }

    $use_revision_id = null;
    if ($this->getArgument('name')) {
      $namev = $this->getArgument('name');
      if (count($namev) > 1) {
        throw new ArcanistUsageException("Specify at most one revision name.");
      }
      $source = self::SOURCE_REVISION;
      $requested++;

      $use_revision_id = $this->normalizeRevisionID(head($namev));
    }

    if ($requested === 0) {
      throw new ArcanistUsageException(
        "Specify one of 'D12345', '--revision <revision_id>' (to select the ".
        "current changes attached to a Differential revision), ".
        "'--diff <diff_id>' (to select a specific, out-of-date diff or a ".
        "diff which is not attached to a revision), '--arcbundle <file>' ".
        "or '--patch <file>' to choose a patch source.");
    } else if ($requested > 1) {
      throw new ArcanistUsageException(
        "Options 'D12345', '--revision', '--diff', '--arcbundle' and ".
        "'--patch' are not compatible. Choose exactly one patch source.");
    }

    $this->source = $source;
    $this->sourceParam = nonempty(
      $use_revision_id,
      $this->getArgument($source));
  }

  public function requiresConduit() {
    return ($this->getSource() != self::SOURCE_PATCH);
  }

  public function requiresRepositoryAPI() {
    return true;
  }

  public function requiresWorkingCopy() {
    return true;
  }

  private function getSource() {
    return $this->source;
  }

  private function getSourceParam() {
    return $this->sourceParam;
  }

  private function shouldCommit() {
    $no_commit = $this->getArgument('nocommit', false);
    if ($no_commit) {
      return false;
    }

    return true;
  }

  private function shouldBranch() {
    // git only for now
    $repository_api = $this->getRepositoryAPI();
    if (!($repository_api instanceof ArcanistGitAPI)) {
      return false;
    }

    $no_branch = $this->getArgument('nobranch', false);
    if ($no_branch) {
      return false;
    }

    return true;
  }

  private function getBranchName(ArcanistBundle $bundle) {
    $branch_name    = null;
    $repository_api = $this->getRepositoryAPI();
    $revision_id    = $bundle->getRevisionID();
    $base_name      = "arcpatch";
    if ($revision_id) {
      $base_name .= "-D{$revision_id}";
    }

    $suffixes = array(null, '-1', '-2', '-3');
    foreach ($suffixes as $suffix) {
      $proposed_name = $base_name.$suffix;

      list($err) = $repository_api->execManualLocal(
        'rev-parse --verify %s',
        $proposed_name);

      // no error means git rev-parse found a branch
      if (!$err) {
        echo phutil_console_format(
          "Branch name {$proposed_name} already exists; trying a new name.\n"
        );
        continue;
      } else {
        $branch_name = $proposed_name;
        break;
      }
    }

    if (!$branch_name) {
      throw new Exception(
        "Arc was unable to automagically make a name for this patch.  ".
        "Please clean up your working copy and try again."
      );
    }

    return $branch_name;
  }

  private function createBranch(ArcanistBundle $bundle) {
    $branch_name    = $this->getBranchName($bundle);
    $repository_api = $this->getRepositoryAPI();
    $base_revision  = $bundle->getBaseRevision();

    // verify the base revision is valid
    // in a working copy that uses the git-svn bridge, the base revision might
    // be a svn uri instead of a git ref

    // NOTE: Use 'cat-file', not 'rev-parse --verify', because 'rev-parse'
    // always "verifies" any properly-formatted commit even if it does not
    // exist.
    list($err) = $repository_api->execManualLocal(
      'cat-file -t %s',
      $base_revision);

    if ($base_revision && !$err) {
      $repository_api->execxLocal(
        'checkout -b %s %s',
        $branch_name,
        $base_revision);
    } else {
      $repository_api->execxLocal(
        'checkout -b %s',
        $branch_name);
    }

    echo phutil_console_format(
      "Created and checked out branch %s.\n",
      $branch_name);
  }

  private function shouldUpdateWorkingCopy() {
    return $this->getArgument('update', false);
  }

  private function updateWorkingCopy() {
    echo "Updating working copy...\n";
    $this->getRepositoryAPI()->updateWorkingCopy();
    echo "Done.\n";
  }

  public function run() {

    $source = $this->getSource();
    $param = $this->getSourceParam();
    try {
      switch ($source) {
        case self::SOURCE_PATCH:
          if ($param == '-') {
            $patch = @file_get_contents('php://stdin');
            if (!strlen($patch)) {
              throw new ArcanistUsageException(
                "Failed to read patch from stdin!");
            }
          } else {
            $patch = Filesystem::readFile($param);
          }
          $bundle = ArcanistBundle::newFromDiff($patch);
          break;
        case self::SOURCE_BUNDLE:
          $path = $this->getArgument('arcbundle');
          $bundle = ArcanistBundle::newFromArcBundle($path);
          break;
        case self::SOURCE_REVISION:
          $bundle = $this->loadRevisionBundleFromConduit(
            $this->getConduit(),
            $param);
          break;
        case self::SOURCE_DIFF:
          $bundle = $this->loadDiffBundleFromConduit(
            $this->getConduit(),
            $param);
          break;
      }
    } catch (ConduitClientException $ex) {
      if ($ex->getErrorCode() == 'ERR-INVALID-SESSION') {
        // Phabricator is not configured to allow anonymous access to
        // Differential.
        $this->authenticateConduit();
        return $this->run();
      } else {
        throw $ex;
      }
    }

    $try_encoding = nonempty($this->getArgument('encoding'), null);
    if (!$try_encoding) {
      if ($this->requiresConduit()) {
        try {
          $try_encoding = $this->getRepositoryEncoding();
        } catch (ConduitClientException $e) {
          $try_encoding = null;
        }
      }
    }

    if ($try_encoding) {
      $bundle->setEncoding($try_encoding);
    }

    $force = $this->getArgument('force', false);
    if ($force) {
      // force means don't do any sanity checks about the patch
    } else {
      $this->sanityCheck($bundle);
    }

    // we should update the working copy before we do ANYTHING else
    if ($this->shouldUpdateWorkingCopy()) {
      $this->updateWorkingCopy();
    }

    if ($this->shouldBranch()) {
      $this->createBranch($bundle);
    }

    $repository_api = $this->getRepositoryAPI();
    if ($repository_api instanceof ArcanistSubversionAPI) {
      $patch_err = 0;

      $copies = array();
      $deletes = array();
      $patches = array();
      $propset = array();
      $adds = array();
      $symlinks = array();

      $changes = $bundle->getChanges();
      foreach ($changes as $change) {
        $type = $change->getType();
        $should_patch = true;

        $filetype = $change->getFileType();
        switch ($filetype) {
          case ArcanistDiffChangeType::FILE_SYMLINK:
            $should_patch = false;
            $symlinks[] = $change;
            break;
        }

        switch ($type) {
          case ArcanistDiffChangeType::TYPE_MOVE_AWAY:
          case ArcanistDiffChangeType::TYPE_MULTICOPY:
          case ArcanistDiffChangeType::TYPE_DELETE:
            $path = $change->getCurrentPath();
            $fpath = $repository_api->getPath($path);
            if (!@file_exists($fpath)) {
              $ok = phutil_console_confirm(
                "Patch deletes file '{$path}', but the file does not exist in ".
                "the working copy. Continue anyway?");
              if (!$ok) {
                throw new ArcanistUserAbortException();
              }
            } else {
              $deletes[] = $change->getCurrentPath();
            }
            $should_patch = false;
            break;
          case ArcanistDiffChangeType::TYPE_COPY_HERE:
          case ArcanistDiffChangeType::TYPE_MOVE_HERE:
            $path = $change->getOldPath();
            $fpath = $repository_api->getPath($path);
            if (!@file_exists($fpath)) {
              $cpath = $change->getCurrentPath();
              if ($type == ArcanistDiffChangeType::TYPE_COPY_HERE) {
                $verbs = 'copies';
              } else {
                $verbs = 'moves';
              }
              $ok = phutil_console_confirm(
                "Patch {$verbs} '{$path}' to '{$cpath}', but source path ".
                "does not exist in the working copy. Continue anyway?");
              if (!$ok) {
                throw new ArcanistUserAbortException();
              }
            } else {
              $copies[] = array(
                $change->getOldPath(),
                $change->getCurrentPath());
            }
            break;
          case ArcanistDiffChangeType::TYPE_ADD:
            $adds[] = $change->getCurrentPath();
            break;
        }
        if ($should_patch) {
          if ($change->getHunks()) {
            $cbundle = ArcanistBundle::newFromChanges(array($change));
            $patches[$change->getCurrentPath()] = $cbundle->toUnifiedDiff();
          }
          $prop_old = $change->getOldProperties();
          $prop_new = $change->getNewProperties();
          $props = $prop_old + $prop_new;
          foreach ($props as $key => $ignored) {
            if (idx($prop_old, $key) !== idx($prop_new, $key)) {
              $propset[$change->getCurrentPath()][$key] = idx($prop_new, $key);
            }
          }
        }
      }

      // Before we start doing anything, create all the directories we're going
      // to add files to if they don't already exist.
      foreach ($copies as $copy) {
        list($src, $dst) = $copy;
        $this->createParentDirectoryOf($dst);
      }

      foreach ($patches as $path => $patch) {
        $this->createParentDirectoryOf($path);
      }

      foreach ($adds as $add) {
        $this->createParentDirectoryOf($add);
      }

      // TODO: The SVN patch workflow likely does not work on windows because
      // of the (cd ...) stuff.

      foreach ($copies as $copy) {
        list($src, $dst) = $copy;
        passthru(
          csprintf(
            '(cd %s; svn cp %s %s)',
            $repository_api->getPath(),
            $src,
            $dst));
      }

      foreach ($deletes as $delete) {
        passthru(
          csprintf(
            '(cd %s; svn rm %s)',
            $repository_api->getPath(),
            $delete));
      }

      foreach ($symlinks as $symlink) {
        $link_target = $symlink->getSymlinkTarget();
        $link_path = $symlink->getCurrentPath();
        switch ($symlink->getType()) {
          case ArcanistDiffChangeType::TYPE_ADD:
          case ArcanistDiffChangeType::TYPE_MODIFY:
          case ArcanistDiffChangeType::TYPE_MOVE_HERE:
          case ArcanistDiffChangeType::TYPE_COPY_HERE:
            execx(
              '(cd %s && ln -sf %s %s)',
              $repository_api->getPath(),
              $link_target,
              $link_path);
            break;
        }
      }

      foreach ($patches as $path => $patch) {
        $tmp = new TempFile();
        Filesystem::writeFile($tmp, $patch);
        $err = null;
        passthru(
          csprintf(
            '(cd %s; patch -p0 < %s)',
            $repository_api->getPath(),
            $tmp),
          $err);
        if ($err) {
          $patch_err = max($patch_err, $err);
        }
      }

      foreach ($adds as $add) {
        passthru(
          csprintf(
            '(cd %s; svn add %s)',
            $repository_api->getPath(),
            $add));
      }

      foreach ($propset as $path => $changes) {
        foreach ($change as $prop => $value) {
          // TODO: Probably need to handle svn:executable specially here by
          // doing chmod +x or -x.
          if ($value === null) {
            passthru(
              csprintf(
                '(cd %s; svn propdel %s %s)',
                $repository_api->getPath(),
                $prop,
                $path));
          } else {
            passthru(
              csprintf(
                '(cd %s; svn propset %s %s %s)',
                $repository_api->getPath(),
                $prop,
                $value,
                $path));
          }
        }
      }

      if ($patch_err == 0) {
        echo phutil_console_format(
          "<bg:green>** OKAY **</bg> Successfully applied patch ".
          "to the working copy.\n");
      } else {
        echo phutil_console_format(
          "\n\n<bg:yellow>** WARNING **</bg> Some hunks could not be applied ".
          "cleanly by the unix 'patch' utility. Your working copy may be ".
          "different from the revision's base, or you may be in the wrong ".
          "subdirectory. You can export the raw patch file using ".
          "'arc export --unified', and then try to apply it by fiddling with ".
          "options to 'patch' (particularly, -p), or manually. The output ".
          "above, from 'patch', may be helpful in figuring out what went ".
          "wrong.\n");
      }

      return $patch_err;
    } else if ($repository_api instanceof ArcanistGitAPI) {
      $future = $repository_api->execFutureLocal(
        'apply --index --reject');
      $future->write($bundle->toGitPatch());

      try {
        $future->resolvex();
      } catch (CommandException $ex) {
        echo phutil_console_format(
          "\n<bg:red>** Patch Failed! **</bg>\n");
        $stderr = $ex->getStdErr();
        if (preg_match('/already exists in working directory/', $stderr)) {
          echo phutil_console_wrap(
            phutil_console_format(
              "\n<bg:yellow>** WARNING **</bg> This patch may have failed ".
              "because it attempts to change the case of a filename (for ".
              "instance, from 'example.c' to 'Example.c'). Git can not apply ".
              "patches like this on case-insensitive filesystems. You must ".
              "apply this patch manually.\n"));
        }
        throw $ex;
      }

      if ($this->shouldCommit()) {
        $commit_message = $this->getCommitMessage($bundle);
        $future = $repository_api->execFutureLocal(
          'commit -a -F -');
        $future->write($commit_message);
        $future->resolvex();
        $verb = 'committed';
      } else {
        $verb = 'applied';
      }
      echo phutil_console_format(
        "<bg:green>** OKAY **</bg> Successfully {$verb} patch.\n");
    } else if ($repository_api instanceof ArcanistMercurialAPI) {
      $future = $repository_api->execFutureLocal(
        'import --no-commit -');
      $future->write($bundle->toGitPatch());
      $future->resolvex();

      echo phutil_console_format(
        "<bg:green>** OKAY **</bg> Successfully applied patch.\n");
    } else {
      throw new Exception('Unknown version control system.');
    }

    return 0;
  }

  private function getCommitMessage(ArcanistBundle $bundle) {
    $revision_id    = $bundle->getRevisionID();
    $commit_message = null;
    $prompt_message = null;

    // if we have a revision id the commit message is in differential

    // TODO: See T848 for the authenticated stuff.
    if ($revision_id && $this->isConduitAuthenticated()) {

      $conduit        = $this->getConduit();
      $commit_message = $conduit->callMethodSynchronous(
        'differential.getcommitmessage',
        array(
          'revision_id' => $revision_id,
        ));
      $prompt_message = "  Note arcanist failed to load the commit message ".
                        "from differential for revision D{$revision_id}.";
    }

    // no revision id or failed to fetch commit message so get it from the
    // user on the command line
    if (!$commit_message) {
      $template =
        "\n\n".
        "# Enter a commit message for this patch.  If you just want to apply ".
        "the patch to the working copy without committing, re-run arc patch ".
        "with the --nocommit flag.".
        $prompt_message.
        "\n";

      $commit_message = id(new PhutilInteractiveEditor($template))
        ->setName('arcanist-patch-commit-message')
        ->editInteractively();

      $commit_message = ArcanistCommentRemover::removeComments($commit_message);
      if (!strlen(trim($commit_message))) {
        throw new ArcanistUserAbortException();
      }
    }

    return $commit_message;
  }

  public function getShellCompletions(array $argv) {
    // TODO: Pull open diffs from 'arc list'?
    return array('ARGUMENT');
  }

  /**
   * Do the best we can to prevent PEBKAC and id10t issues.
   */
  private function sanityCheck(ArcanistBundle $bundle) {

    // Require clean working copy
    $this->requireCleanWorkingCopy();

    // Check to see if the bundle's project id matches the working copy
    // project id
    $bundle_project_id = $bundle->getProjectID();
    $working_copy_project_id = $this->getWorkingCopy()->getProjectID();
    if (empty($bundle_project_id)) {
      // this means $source is SOURCE_PATCH || SOURCE_BUNDLE w/ $version = 0
      // they don't come with a project id so just do nothing
    } else if ($bundle_project_id != $working_copy_project_id) {
      $ok = phutil_console_confirm(
        "This diff is for the '{$bundle_project_id}' project but the working ".
        "copy belongs to the '{$working_copy_project_id}' project. ".
        "Still try to apply it?",
        $default_no = false
      );
      if (!$ok) {
        throw new ArcanistUserAbortException();
      }
    }

    // Check to see if the bundle's base revision matches the working copy
    // base revision
    $repository_api = $this->getRepositoryAPI();
    if ($repository_api->supportsRelativeLocalCommits()) {
      $bundle_base_rev = $bundle->getBaseRevision();
      if (empty($bundle_base_rev)) {
        // this means $source is SOURCE_PATCH || SOURCE_BUNDLE w/ $version < 2
        // they don't have a base rev so just do nothing
        $commit_exists = true;
      } else {
        $commit_exists =
          $repository_api->hasLocalCommit($bundle_base_rev);
      }
      if (!$commit_exists) {
        // we have a problem...! lots of work because we need to ask
        // differential for revision information for these base revisions
        // to improve our error message.
        $bundle_base_rev_str = null;
        $source_base_rev     = $repository_api->getWorkingCopyRevision();
        $source_base_rev_str = null;

        if ($repository_api instanceof ArcanistGitAPI) {
          $hash_type = ArcanistDifferentialRevisionHash::HASH_GIT_COMMIT;
        } else if ($repository_api instanceof ArcanistMercurialAPI) {
          $hash_type = ArcanistDifferentialRevisionHash::HASH_MERCURIAL_COMMIT;
        } else {
          $hash_type = null;
        }

        if ($hash_type) {
          // 2 round trips because even though we could send off one query
          // we wouldn't be able to tell which revisions were for which hash
          $hash = array($hash_type, $bundle_base_rev);
          $bundle_revision = $this->loadRevisionFromHash($hash);
          $hash = array($hash_type, $source_base_rev);
          $source_revision = $this->loadRevisionFromHash($hash);

          if ($bundle_revision) {
            $bundle_base_rev_str = $bundle_base_rev .
                                   ' \ D' . $bundle_revision['id'];
          }
          if ($source_revision) {
            $source_base_rev_str = $source_base_rev .
                                   ' \ D' . $source_revision['id'];
          }
        }
        $bundle_base_rev_str = nonempty($bundle_base_rev_str,
                                        $bundle_base_rev);
        $source_base_rev_str = nonempty($source_base_rev_str,
                                        $source_base_rev);

        $ok = phutil_console_confirm(
          "This diff is against commit {$bundle_base_rev_str}, but the ".
          "commit is nowhere in the working copy. Try to apply it against ".
          "the current working copy state? ({$source_base_rev_str})",
          $default_no = false
        );
        if (!$ok) {
          throw new ArcanistUserAbortException();
        }
      }
    }

    // TODO -- more sanity checks here
  }

  /**
   * Create parent directories one at a time, since we need to "svn add" each
   * one. (Technically we could "svn add" just the topmost new directory.)
   */
  private function createParentDirectoryOf($path) {
    $repository_api = $this->getRepositoryAPI();
    $dir = dirname($path);
    if (Filesystem::pathExists($dir)) {
      return;
    } else {
      // Make sure the parent directory exists before we make this one.
      $this->createParentDirectoryOf($dir);
      execx(
        '(cd %s && mkdir %s)',
        $repository_api->getPath(),
        $dir);
      passthru(
        csprintf(
          '(cd %s && svn add %s)',
          $repository_api->getPath(),
          $dir));
    }
  }

  private function loadRevisionFromHash($hash) {
    // TODO -- de-hack this as permissions become more clear with things
    // like T848 (add scope to OAuth)
    if (!$this->isConduitAuthenticated()) {
      return null;
    }

    $conduit = $this->getConduit();

    $revisions = $conduit->callMethodSynchronous(
      'differential.query',
      array(
        'commitHashes' => array($hash),
      )
    );


    // grab the latest committed revision only
    $found_revision = null;
    $revisions = isort($revisions, 'dateModified');
    foreach ($revisions as $revision) {
      if ($revision['status'] ==
          ArcanistDifferentialRevisionStatus::COMMITTED) {
        $found_revision = $revision;
      }
    }
    return $found_revision;
  }
}