import_to_git

#!/usr/bin/env python
import re, subprocess

def get_svn_log():
    return subprocess.check_output(['svn', 'log']).split('\n')

def parse_svn_log_data(svn_log):
    revisions = []
    rev, author, timestamp, message = None, None, None, ''
    for line in svn_log:
        if line.startswith('----------------'):
            if rev:
                revisions.append((rev, author, timestamp, message.strip()))
            rev, author, timestamp, message = None, None, None, ''
        elif line.startswith('r') and rev == None:
            tokens =  [token.strip() for token in line.split('|')]
            rev, author, timestamp, nlines = tokens
        else:
            message += line + '\n'
    revisions.reverse()
    return revisions

def svn_checkout(revision):
    subprocess.call(['svn', 'update', '-r', revision])

def git_commit(message, author=None, date=None):
    if message == "":
	    message = "No message."
    git_call = ['git', 'commit', '-a', '-m', message]
    if author:
        if '<' not in author:
            author = '%s <%s>' % (author, author)
        git_call.extend(['--author', author])
    if date:
        git_call.extend(['--date', date])
    subprocess.call(['git', 'add', '.'])
    subprocess.call(git_call)

def git_tag(revision):
    subprocess.call(['git', 'tag', revision])

def git_revision_tags():
    tags = []
    for tag in subprocess.check_output(['git', 'tag']).split('\n'):
        tag = tag.strip()
        if re.match(r'r\d+', tag):
            tags.append(tag)
    return tags

def get_latest_local_revision():
    try:
        i = 0
        while True:
            tags = subprocess.check_output(['git', 'tag', '--points-at', 'HEAD~%i' % i]).strip().split()
            revisions = [int(tag[1:]) for tag in tags if tag.startswith('r') and tag[1:].isdigit()]
            if revisions:
                return 'r%d' % max(revisions)
            i += 1
    except:
        pass

def add_changes_to_git(revisions):
    for revision, author, date, message in revisions:
        svn_checkout(revision)
        git_commit(message, author, date)
        git_tag(revision)

def git_fetch(revisions):
    max_local_revision = get_latest_local_revision()
    if max_local_revision:
        rev_iter = iter(revisions)
        for rev in rev_iter:
            if rev[0] == max_local_revision:
                break
        remote_revisions = list(rev_iter)
    else:
        remote_revisions = revisions
    if remote_revisions:
        add_changes_to_git(remote_revisions)
    else:
        print "Already up to date."


if __name__ == '__main__':
    svn_log = get_svn_log()
    revision_data = parse_svn_log_data(svn_log)
    git_fetch(revision_data)