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# WebKit's Python module for parsing and modifying ChangeLog files

import codecs
import fileinput # inplace file editing for set_reviewer_in_changelog
import logging
import re
import textwrap

from webkitpy.common.config.committers import CommitterList
from webkitpy.common.config.committers import Account
import webkitpy.common.config.urls as config_urls

_log = logging.getLogger(__name__)


# FIXME: parse_bug_id_from_changelog should not be a free function.
# Parse the bug ID out of a Changelog message based on the format that is
# used by prepare-ChangeLog
def parse_bug_id_from_changelog(message):
    if not message:
        return None
    match = re.search("^\s*" + config_urls.bug_url_short + "$", message, re.MULTILINE)
    if match:
        return int(match.group('bug_id'))
    match = re.search("^\s*" + config_urls.bug_url_long + "$", message, re.MULTILINE)
    if match:
        return int(match.group('bug_id'))
    # We weren't able to find a bug URL in the format used by prepare-ChangeLog. Fall back to the
    # first bug URL found anywhere in the message.
    return config_urls.parse_bug_id(message)


class ChangeLogEntry(object):
    # e.g. 2009-06-03  Eric Seidel  <eric@webkit.org>
    date_line_regexp = r'^(?P<date>\d{4}-\d{2}-\d{2})\s+(?P<authors>(?P<name>[^<]+?)\s+<(?P<email>[^<>]+)>.*?)$'

    # e.g. * Source/WebCore/page/EventHandler.cpp: Implement FooBarQuux.
    touched_files_regexp = r'^\s*\*\s*(?P<file>[A-Za-z0-9_\-\./\\]+)\s*\:'

    # e.g. Reviewed by Darin Adler.
    # (Discard everything after the first period to match more invalid lines.)
    reviewed_by_regexp = r'^\s*((\w+\s+)+and\s+)?(Review|Rubber(\s*|-)stamp)(s|ed)?\s+([a-z]+\s+)*?by\s+(?P<reviewer>.*?)[\.,]?\s*$'

    reviewed_byless_regexp = r'^\s*((Review|Rubber(\s*|-)stamp)(s|ed)?|RS)(\s+|\s*=\s*)(?P<reviewer>([A-Z]\w+\s*)+)[\.,]?\s*$'

    reviewer_name_noise_regexp = re.compile(r"""
    (\s+((tweaked\s+)?and\s+)?(landed|committed|okayed)\s+by.+) # "landed by", "commented by", etc...
    |(^(Reviewed\s+)?by\s+) # extra "Reviewed by" or "by"
    |([(<]\s*[\w_\-\.]+@[\w_\-\.]+[>)]) # email addresses
    |([(<](https?://?bugs.)webkit.org[^>)]+[>)]) # bug url
    |("[^"]+") # wresler names like 'Sean/Shawn/Shaun' in 'Geoffrey "Sean/Shawn/Shaun" Garen'
    |('[^']+') # wresler names like "The Belly" in "Sam 'The Belly' Weinig"
    |((Mr|Ms|Dr|Mrs|Prof)\.(\s+|$))
    """, re.IGNORECASE | re.VERBOSE)

    reviewer_name_casesensitive_noise_regexp = re.compile(r"""
    ((\s+|^)(and\s+)?([a-z-]+\s+){5,}by\s+) # e.g. "and given a good once-over by"
    |(\(\s*(?!(and|[A-Z])).+\)) # any parenthesis that doesn't start with "and" or a capital letter
    |(with(\s+[a-z-]+)+) # phrases with "with no hesitation" in "Sam Weinig with no hesitation"
    """, re.VERBOSE)

    reviewer_name_noise_needing_a_backreference_regexp = re.compile(r"""
    (\S\S)\.(?:(\s.+|$)) # Text after the two word characters (don't match initials) and a period followed by a space.
    """, re.IGNORECASE | re.VERBOSE)

    nobody_regexp = re.compile(r"""(\s+|^)nobody(
    ((,|\s+-)?\s+(\w+\s+)+fix.*) # e.g. nobody, build fix...
    |(\s*\([^)]+\).*) # NOBODY (..)...
    |$)""", re.IGNORECASE | re.VERBOSE)

    # e.g. == Rolled over to ChangeLog-2011-02-16 ==
    rolled_over_regexp = r'^== Rolled over to ChangeLog-\d{4}-\d{2}-\d{2} ==$'

    # e.g. git-svn-id: http://svn.webkit.org/repository/webkit/trunk@96161 268f45cc-cd09-0410-ab3c-d52691b4dbfc
    svn_id_regexp = r'git-svn-id: http://svn.webkit.org/repository/webkit/trunk@(?P<svnid>\d+) '

    def __init__(self, contents, committer_list=CommitterList(), revision=None):
        self._contents = contents
        self._committer_list = committer_list
        self._revision = revision
        self._parse_entry()

    @staticmethod
    def _parse_reviewer_text(text):
        match = re.search(ChangeLogEntry.reviewed_by_regexp, text, re.MULTILINE | re.IGNORECASE)
        if not match:
            # There are cases where people omit "by". We match it only if reviewer part looked nice
            # in order to avoid matching random lines that start with Reviewed
            match = re.search(ChangeLogEntry.reviewed_byless_regexp, text, re.MULTILINE | re.IGNORECASE)
        if not match:
            return None, None

        reviewer_text = match.group("reviewer")

        reviewer_text = ChangeLogEntry.nobody_regexp.sub('', reviewer_text)
        reviewer_text = ChangeLogEntry.reviewer_name_noise_regexp.sub('', reviewer_text)
        reviewer_text = ChangeLogEntry.reviewer_name_casesensitive_noise_regexp.sub('', reviewer_text)
        reviewer_text = ChangeLogEntry.reviewer_name_noise_needing_a_backreference_regexp.sub(r'\1', reviewer_text)
        reviewer_text = reviewer_text.replace('(', '').replace(')', '')
        reviewer_text = re.sub(r'\s\s+|[,.]\s*$', ' ', reviewer_text).strip()
        if not len(reviewer_text):
            return None, None

        reviewer_list = ChangeLogEntry._split_contributor_names(reviewer_text)

        # Get rid of "reviewers" like "even though this is just a..." in "Reviewed by Sam Weinig, even though this is just a..."
        # and "who wrote the original code" in "Noam Rosenthal, who wrote the original code"
        reviewer_list = [reviewer for reviewer in reviewer_list if not re.match('^who\s|^([a-z]+(\s+|\.|$)){6,}$', reviewer)]

        return reviewer_text, reviewer_list

    @staticmethod
    def _split_contributor_names(text):
        return re.split(r'\s*(?:,(?:\s+and\s+|&)?|(?:^|\s+)and\s+|&&|[/+&])\s*', text)

    def _fuzz_match_reviewers(self, reviewers_text_list):
        if not reviewers_text_list:
            return []
        list_of_reviewers = [self._committer_list.contributors_by_fuzzy_match(reviewer)[0] for reviewer in reviewers_text_list]
        # Flatten lists and get rid of any reviewers with more than one candidate.
        return [reviewers[0] for reviewers in list_of_reviewers if len(reviewers) == 1]

    @staticmethod
    def _parse_author_name_and_email(author_name_and_email):
        match = re.match(r'(?P<name>.+?)\s+<(?P<email>[^>]+)>', author_name_and_email)
        return {'name': match.group("name"), 'email': match.group("email")}

    @staticmethod
    def _parse_author_text(text):
        if not text:
            return []
        authors = ChangeLogEntry._split_contributor_names(text)
        assert(authors and len(authors) >= 1)
        return [ChangeLogEntry._parse_author_name_and_email(author) for author in authors]

    def _parse_entry(self):
        match = re.match(self.date_line_regexp, self._contents, re.MULTILINE)
        if not match:
            _log.warning("Creating invalid ChangeLogEntry:\n%s" % self._contents)

        # FIXME: group("name") does not seem to be Unicode?  Probably due to self._contents not being unicode.
        self._author_text = match.group("authors") if match else None
        self._authors = ChangeLogEntry._parse_author_text(self._author_text)

        self._reviewer_text, self._reviewers_text_list = ChangeLogEntry._parse_reviewer_text(self._contents)
        self._reviewers = self._fuzz_match_reviewers(self._reviewers_text_list)
        self._author = self._committer_list.contributor_by_email(self.author_email()) or self._committer_list.contributor_by_name(self.author_name())

        self._touched_files = re.findall(self.touched_files_regexp, self._contents, re.MULTILINE)

    def author_text(self):
        return self._author_text

    def revision(self):
        return self._revision

    def author_name(self):
        return self._authors[0]['name']

    def author_email(self):
        return self._authors[0]['email']

    def author(self):
        return self._author  # Might be None

    def authors(self):
        return self._authors

    # FIXME: Eventually we would like to map reviwer names to reviewer objects.
    # See https://bugs.webkit.org/show_bug.cgi?id=26533
    def reviewer_text(self):
        return self._reviewer_text

    # Might be None, might also not be a Reviewer!
    def reviewer(self):
        return self._reviewers[0] if len(self._reviewers) > 0 else None

    def reviewers(self):
        return self._reviewers

    def has_valid_reviewer(self):
        if self._reviewers_text_list:
            for reviewer in self._reviewers_text_list:
                reviewer = self._committer_list.committer_by_name(reviewer)
                if reviewer:
                    return True
        return bool(re.search("unreviewed", self._contents, re.IGNORECASE))

    def contents(self):
        return self._contents

    def bug_id(self):
        return parse_bug_id_from_changelog(self._contents)

    def touched_files(self):
        return self._touched_files


# FIXME: Various methods on ChangeLog should move into ChangeLogEntry instead.
class ChangeLog(object):

    def __init__(self, path):
        self.path = path

    _changelog_indent = " " * 8

    @staticmethod
    def parse_latest_entry_from_file(changelog_file):
        """changelog_file must be a file-like object which returns
        unicode strings.  Use codecs.open or StringIO(unicode())
        to pass file objects to this class."""
        date_line_regexp = re.compile(ChangeLogEntry.date_line_regexp)
        rolled_over_regexp = re.compile(ChangeLogEntry.rolled_over_regexp)
        entry_lines = []
        # The first line should be a date line.
        first_line = changelog_file.readline()
        assert(isinstance(first_line, unicode))
        if not date_line_regexp.match(first_line):
            return None
        entry_lines.append(first_line)

        for line in changelog_file:
            # If we've hit the next entry, return.
            if date_line_regexp.match(line) or rolled_over_regexp.match(line):
                # Remove the extra newline at the end
                return ChangeLogEntry(''.join(entry_lines[:-1]))
            entry_lines.append(line)
        return None # We never found a date line!

    svn_blame_regexp = re.compile(r'^(\s*(?P<revision>\d+) [^ ]+)\s*(?P<line>.*?\n)')

    @staticmethod
    def _separate_revision_and_line(line):
        match = ChangeLog.svn_blame_regexp.match(line)
        if not match:
            return None, line
        return int(match.group('revision')), match.group('line')

    @staticmethod
    def parse_entries_from_file(changelog_file):
        """changelog_file must be a file-like object which returns
        unicode strings.  Use codecs.open or StringIO(unicode())
        to pass file objects to this class."""
        date_line_regexp = re.compile(ChangeLogEntry.date_line_regexp)
        rolled_over_regexp = re.compile(ChangeLogEntry.rolled_over_regexp)

        # The first line should be a date line.
        revision, first_line = ChangeLog._separate_revision_and_line(changelog_file.readline())
        assert(isinstance(first_line, unicode))
        if not date_line_regexp.match(ChangeLog.svn_blame_regexp.sub('', first_line)):
            raise StopIteration

        entry_lines = [first_line]
        revisions_in_entry = {revision: 1} if revision != None else None
        for line in changelog_file:
            if revisions_in_entry:
                revision, line = ChangeLog._separate_revision_and_line(line)

            if rolled_over_regexp.match(line):
                break

            if date_line_regexp.match(line):
                most_probable_revision = max(revisions_in_entry, key=revisions_in_entry.__getitem__) if revisions_in_entry else None
                # Remove the extra newline at the end
                yield ChangeLogEntry(''.join(entry_lines[:-1]), revision=most_probable_revision)
                entry_lines = []
                revisions_in_entry = {revision: 0}

            entry_lines.append(line)
            if revisions_in_entry:
                revisions_in_entry[revision] = revisions_in_entry.get(revision, 0) + 1

        most_probable_revision = max(revisions_in_entry, key=revisions_in_entry.__getitem__) if revisions_in_entry else None
        yield ChangeLogEntry(''.join(entry_lines[:-1]), revision=most_probable_revision)

    def latest_entry(self):
        # ChangeLog files are always UTF-8, we read them in as such to support Reviewers with unicode in their names.
        changelog_file = codecs.open(self.path, "r", "utf-8")
        try:
            return self.parse_latest_entry_from_file(changelog_file)
        finally:
            changelog_file.close()

    # _wrap_line and _wrap_lines exist to work around
    # http://bugs.python.org/issue1859

    def _wrap_line(self, line):
        return textwrap.fill(line,
                             width=70,
                             initial_indent=self._changelog_indent,
                             # Don't break urls which may be longer than width.
                             break_long_words=False,
                             subsequent_indent=self._changelog_indent)

    # Workaround as suggested by guido in
    # http://bugs.python.org/issue1859#msg60040

    def _wrap_lines(self, message):
        lines = [self._wrap_line(line) for line in message.splitlines()]
        return "\n".join(lines)

    def update_with_unreviewed_message(self, message):
        first_boilerplate_line_regexp = re.compile(
                "%sNeed a short description \(OOPS!\)\." % self._changelog_indent)
        removing_boilerplate = False
        # inplace=1 creates a backup file and re-directs stdout to the file
        for line in fileinput.FileInput(self.path, inplace=1):
            if first_boilerplate_line_regexp.search(line):
                message_lines = self._wrap_lines(message)
                print first_boilerplate_line_regexp.sub(message_lines, line),
                # Remove all the ChangeLog boilerplate before the first changed
                # file.
                removing_boilerplate = True
            elif removing_boilerplate:
                if line.find('*') >= 0: # each changed file is preceded by a *
                    removing_boilerplate = False

            if not removing_boilerplate:
                print line,

    def set_reviewer(self, reviewer):
        latest_entry = self.latest_entry()
        latest_entry_contents = latest_entry.contents()
        reviewer_text = latest_entry.reviewer()
        found_nobody = re.search("NOBODY\s*\(OOPS!\)", latest_entry_contents, re.MULTILINE)

        if not found_nobody and not reviewer_text:
            bug_url_number_of_items = len(re.findall(config_urls.bug_url_long, latest_entry_contents, re.MULTILINE))
            bug_url_number_of_items += len(re.findall(config_urls.bug_url_short, latest_entry_contents, re.MULTILINE))
            for line in fileinput.FileInput(self.path, inplace=1):
                found_bug_url = re.search(config_urls.bug_url_long, line)
                if not found_bug_url:
                    found_bug_url = re.search(config_urls.bug_url_short, line)
                print line,
                if found_bug_url:
                    if bug_url_number_of_items == 1:
                        print "\n        Reviewed by %s." % (reviewer.encode("utf-8"))
                    bug_url_number_of_items -= 1
        else:
            # inplace=1 creates a backup file and re-directs stdout to the file
            for line in fileinput.FileInput(self.path, inplace=1):
                # Trailing comma suppresses printing newline
                print line.replace("NOBODY (OOPS!)", reviewer.encode("utf-8")),

    def set_short_description_and_bug_url(self, short_description, bug_url):
        message = "%s\n%s%s" % (short_description, self._changelog_indent, bug_url)
        bug_boilerplate = "%sNeed the bug URL (OOPS!).\n" % self._changelog_indent
        for line in fileinput.FileInput(self.path, inplace=1):
            line = line.replace("Need a short description (OOPS!).", message.encode("utf-8"))
            if line != bug_boilerplate:
                print line,