#!/usr/bin/python
# -*- coding: utf-8 -*-

# Copyright (c) 2009 Alejandro R. Sedeño <asedeno@mit.edu>

# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation files
# (the "Software"), to deal in the Software without restriction,
# including without limitation the rights to use, copy, modify, merge,
# publish, distribute, sublicense, and/or sell copies of the Software,
# and to permit persons to whom the Software is furnished to do so,
# subject to the following conditions:

# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

# git svn keyword parsing, populating, and clearing.

from __future__ import with_statement
import errno, os, re, urllib
from ConfigParser import ConfigParser
from optparse import OptionParser
import git

VERSION = "0.9"

# Where we keep data in the repo.
def gsk(g):
    return os.path.join(g.path, 'svn_keywords')

#Configuration Data
CONFIG = ConfigParser()
FILES = ConfigParser()
FILEINFO = ConfigParser()

CONFIG_PATH = ''
FILES_PATH = ''
FILEINFO_PATH = ''


# Valid keywords:
svn_keywords = {'Date': ['Date', 'LastDateChanged'],
                'Revision': ['Revision', 'LastChangedRevision', 'Rev'],
                'Author': ['Author','LastChangedBy'],
                'URL': ['HeadURL', 'URL'],
                'Id': ['Id']
                }

# Regular expressions we'll be using to smudge/clean; created as
# needed and cached.
svn_keywords_re = {}
def get_svn_keyword_re(s):
    if not s in svn_keywords:
        raise 'Invalid SVN Keyword'
    if not s in svn_keywords_re:
        svn_keywords_re[s] = re.compile('\$(' + ('|'.join(svn_keywords[s])) + ')[^$]*\$')
    return svn_keywords_re[s]

# Parse the unhandled log.
def parse_svn_unhandled(g):
    try:
        os.mkdir(gsk(g))
    except os.error, e:
        if e.errno != errno.EEXIST:
            raise

    ver = -1
    if CONFIG.has_option('core', 'version'):
        ver = CONFIG.get('core', 'version')

    lastrev = None
    if ver == VERSION:
        FILES.read(FILES_PATH)
        if CONFIG.has_option('core', 'lastrev'):
            lastrev = CONFIG.getint('core', 'lastrev')

    with open(g.path + '/svn/git-svn/unhandled.log', 'r') as f:
        # Compile the regular expressions we'll be using here.
        re_rev = re.compile("^r(\d+)$")
        re_keywords = re.compile("^\s+[-+]file_prop: (\S+) svn:keywords ?(\S*)$")

        rev = None
        for line in f:
            m = re_rev.match(line)
            if m:
                rev = m.group(1)
                continue

            if (lastrev >= int(rev)):
                continue

            m = re_keywords.match(line)
            if m:
                path = urllib.unquote(m.group(1))
                keywords = set(urllib.unquote(m.group(2)).split(' '))
                if not FILES.has_section(path):
                    FILES.add_section(path)
                FILES.set(path, rev, keywords)

        lastrev = max(int(rev), lastrev)
        CONFIG.set('core', 'lastrev', lastrev)
        CONFIG.set('core', 'version', VERSION)

    with open(FILES_PATH, 'wb') as f:
        FILES.write(f)

    with open(CONFIG_PATH, 'wb') as f:
        CONFIG.write(f)

def get_path_info(g, path):
    write_config = False

    # parse ls-tree output and get a blob id for path
    blob = g.git.ls_tree('HEAD', path).split(' ')[2].split("\t")[0]

    # translate that to a commit id
    if not CONFIG.has_option('BlobToCommit', blob):
        CONFIG.set('BlobToCommit', blob, g.commits('HEAD', path, 1)[0].id)
        write_config = True
    commit = CONFIG.get('BlobToCommit', blob)

    # tranlsate that into an svn revision id
    if not CONFIG.has_option('CommitToRev', commit):
        CONFIG.set('CommitToRev',commit,g.git.svn('find-rev', commit))
        write_config = True
    file_rev = CONFIG.get('CommitToRev', commit)

    # get information about that revision
    info_dict = {}
    if not CONFIG.has_option('RevInfo', file_rev):
        for line in g.git.svn('info', path).split("\n"):
            k, v = line.split(": ", 1)
            if k == 'Last Changed Date':
                info_dict['Date'] = v
            elif k == 'Last Changed Author':
                info_dict['Author'] = v
        CONFIG.set('RevInfo', file_rev, info_dict)
        write_config = True
    else:
        info = CONFIG.get('RevInfo', file_rev)
        info_dict.update(info if type(info) is dict else eval(info))

    if write_config:
        with open(CONFIG_PATH, 'wb') as f:
            CONFIG.write(f)

    info_dict['Revision'] = file_rev
    return info_dict

# Do the work.
def smudge(g, options):
    parse_svn_unhandled(g)
    rev_head = int(g.git.svn('find-rev', 'HEAD'))
    url_base = g.git.svn('info', '--url')

    FILES.read(FILES_PATH)
    FILEINFO.read(FILEINFO_PATH)

    paths = FILES.sections()
    paths.sort()
    for path in paths:
        if not os.path.exists(path):
            continue

        kw_rev = max(filter(lambda x: x <= rev_head, map(int, FILES.options(path))))

        info_dict = {}
        if not options.clean:
            info_dict.update(get_path_info(g, path))
            info_dict['URL'] = '/'.join([url_base, path])
            info_dict['Name'] = os.path.basename(path)
            info_dict['Revision'] = str(max(kw_rev, info_dict['Revision']))

        buf = ''
        with open(os.path.join(g.wd, path), 'r') as f:
            buf = f.read()

        keywords = eval(FILES.get(path, str(kw_rev)))
        for k in keywords:
            for sk in svn_keywords:
                if k in svn_keywords[sk]:
                    if options.clean:
                        buf = re.sub(get_svn_keyword_re(sk), '$\\1$', buf)
                    elif sk == 'Id':
                        id_str = ' '.join([info_dict['Name'],
                                           info_dict['Revision'],
                                           info_dict['Date'],
                                           info_dict['Author']])
                        buf = re.sub(get_svn_keyword_re(sk), '$\\1: ' + id_str + ' $', buf)
                    else:
                        buf = re.sub(get_svn_keyword_re(sk), '$\\1: ' + info_dict[sk] + ' $', buf)

        with open(os.path.join(g.wd, path), 'w') as f:
            f.write(buf)
        if options.verbose:
            print path + ' [' + ', '.join(keywords) + '] [len: ' + str(len(buf)) +']'

if __name__ == '__main__':

    parser = OptionParser(version="%prog "+str(VERSION))
    parser.set_defaults(clean=None)
    parser.add_option("-s", "--smudge",
                      action="store_false", dest="clean",
                      help="Populate svn:keywords.")
    parser.add_option("-c", "--clean",
                      action="store_true", dest="clean",
                      help="Return svn:keywords to pristene state.")
    parser.add_option("-v", "--verbose",
                      action="store_true", dest="verbose", default=False)
    (options, args) = parser.parse_args()

    if (options.clean is None):
        parser.print_help()
        exit(0)
    else:
        try:
            g = git.Repo()
        except git.errors.InvalidGitRepositoryError:
            print "You are not in a git repository or working directory."
            exit(1)

        CONFIG_PATH = os.path.join(gsk(g), 'conf.ini')
        FILES_PATH = os.path.join(gsk(g), 'files.ini')
        FILEINFO_PATH = os.path.join(gsk(g), 'fileinfo.ini')

        CONFIG.read(CONFIG_PATH)
        for section in ['core','CommitToRev','BlobToCommit', 'RevInfo']:
            if not CONFIG.has_section(section):
                CONFIG.add_section(section)

        smudge(g, options)