/brz/remove-bazaar

# Copyright (C) 2010 Canonical Ltd

#

# This program 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 2 of the License, or

# (at your option) any later version.

#

# This program 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, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

"""Logic to create commit templates."""

from __future__ import absolute_import

import patiencediff

from ... import bugtracker, osutils

import re

_BUG_MATCH = re.compile(r'lp:(\d+)')

class CommitTemplate(object):

    def __init__(self, commit, message, filespec):

        """Create a commit template for commit with initial message message.

        :param commit: A Commit object for the in progress commit.

        :param message: The current message (which may be None).

        :param filespec: List of files to match

        """

        self.commit = commit

        self.message = message

        self.filespec = filespec

    def make(self):

        """Make the template.

        If NEWS is missing or not not modified, the original template is

        returned unaltered. Otherwise the changes from NEWS are concatenated

        with whatever message was provided to __init__.

        """

        delta = self.commit.builder.get_basis_delta()

        found_old_path = None

        found_entry = None

        for old_path, new_path, fileid, entry in delta:

            if new_path in self.filespec:

                found_entry = entry

                found_old_path = old_path

                break

        if not found_entry:

            return self.message

        if found_old_path is None:

            # New file

            _, new_chunks = list(

                self.commit.builder.repository.iter_files_bytes(

                    [(found_entry.file_id, found_entry.revision, None)]))[0]

            content = b''.join(new_chunks).decode('utf-8')

            return self.merge_message(content)

        else:

            # Get a diff. XXX Is this hookable? I thought it was, can't find it

            # though.... add DiffTree.diff_factories. Sadly thats not at the

            # right level: we want to identify the changed lines, not have the

            # final diff: because we want to grab the sections for regions

            # changed in new version of the file. So for now a direct diff

            # using patiencediff is done.

            old_revision = self.commit.basis_tree.get_file_revision(old_path)

            needed = [(found_entry.file_id, found_entry.revision, 'new'),

                      (found_entry.file_id, old_revision, 'old')]

            contents = self.commit.builder.repository.iter_files_bytes(needed)

            lines = {}

            for name, chunks in contents:

                lines[name] = osutils.chunks_to_lines(chunks)

            new = lines['new']

            sequence_matcher = patiencediff.PatienceSequenceMatcher(

                None, lines['old'], new)

            new_lines = []

            for group in sequence_matcher.get_opcodes():

                tag, i1, i2, j1, j2 = group

                if tag == 'equal':

                    continue

                if tag == 'delete':

                    continue

                new_lines.extend([l.decode('utf-8') for l in new[j1:j2]])

            if not self.commit.revprops.get('bugs'):

                # TODO: Allow the user to configure the bug tracker to use

                # rather than hardcoding Launchpad.

                bt = bugtracker.tracker_registry.get('launchpad')

                bugids = []

                for line in new_lines:

                    bugids.extend(_BUG_MATCH.findall(line))

                self.commit.revprops['bugs'] = \

                    bugtracker.encode_fixes_bug_urls(

                        [(bt.get_bug_url(bugid), bugtracker.FIXED)

                         for bugid in bugids])

            return self.merge_message(''.join(new_lines))

    def merge_message(self, new_message):

        """Merge new_message with self.message.

        :param new_message: A string message to merge with self.message.

        :return: A string with the merged messages.

        """

        if self.message is None:

            return new_message

        return self.message + new_message