#!/usr/bin/env python
# -*- Mode: python -*-
#
# Copyright (C) 2004 James Henstridge
#
# By using this file, you agree to the terms and conditions set forth in
# the LICENSE.html file which can be found at the top level of the ViewCVS
# distribution or at http://www.lyra.org/viewcvs/license-1.html.
#
# -----------------------------------------------------------------------
#
# administrative program for loading Subversion revision information
# into the checkin database.  It can be used to add a single revision
# to the database, or rebuild/update all revisions.
#
# To add all the checkins from a Subversion repository to the checkin
# database, run the following:
#    /path/to/svndbadmin rebuild /path/to/repo
#
# This script can also be called from the Subversion post-commit hook,
# something like this:
#    REPOS="$1"
#    REV="$2"
#    /path/to/svndbadmin update "$REPOS" "$REV"
#
# If you allow changes to revision properties in your repository, you
# might also want to set up something similar in the
# post-revprop-change hook using "rebuild" instead of "update" to keep
# the checkin database consistent with the repository.
#
# -----------------------------------------------------------------------
#

#########################################################################
#
# INSTALL-TIME CONFIGURATION
#
# These values will be set during the installation process. During
# development, they will remain None.
#

LIBRARY_DIR = None
CONF_PATHNAME = None

# Adjust sys.path to include our library directory
import sys

if LIBRARY_DIR:
  sys.path.insert(0, LIBRARY_DIR)
else:
  sys.path[:0] = ['../lib']     # any other places to look?

#########################################################################

import os
import string
import re

import svn.core
import svn.repos
import svn.fs
import svn.delta

import cvsdb

class SvnRepo:
    """Class used to manage a connection to a SVN repository."""
    pool = None
    def __init__(self, path, pool):
        self.pool = pool
        self.scratch_pool = svn.core.svn_pool_create(self.pool)
        self.path = path
        self.repo = svn.repos.svn_repos_open(path, self.pool)
        self.fs = svn.repos.svn_repos_fs(self.repo)
        # youngest revision of base of file system is highest revision number
        self.rev_max = svn.fs.youngest_rev(self.fs, self.pool)
    def __del__(self):
        if self.pool:
            svn.core.svn_pool_destroy(self.pool)
    def __getitem__(self, rev):
        if rev is None:
            rev = self.rev_max
        elif rev < 0:
            rev = rev + self.rev_max + 1
        assert 0 <= rev <= self.rev_max

        rev = SvnRev(self, rev, self.scratch_pool)
        svn.core.svn_pool_clear(self.scratch_pool)
        return rev

_re_diff_change_command = re.compile('(\d+)(?:,(\d+))?([acd])(\d+)(?:,(\d+))?')

def _get_diff_counts(last_fsroot, fsroot, path1, path2, pool):
    """Calculate the plus/minus counts by parsing the output of a
    normal diff.  The reasons for choosing Normal diff format are:
      - the output is short, so should be quicker to parse.
      - only the change commands need be parsed to calculate the counts.
      - All file data is prefixed, so won't be mistaken for a change
        command.
    This code is based on the description of the format found in the
    GNU diff manual."""
    diffobj = svn.fs.FileDiff(last_fsroot, path1,
                              fsroot, path2, pool, [])
    fp = diffobj.get_pipe()

    plus, minus = 0, 0
    line = fp.readline()
    while line:
        match = re.match(_re_diff_change_command, line)
        if match:
            # size of first range
            if match.group(2):
                count1 = int(match.group(2)) - int(match.group(1)) + 1
            else:
                count1 = 1
            cmd = match.group(3)
            # size of second range
            if match.group(5):
                count2 = int(match.group(5)) - int(match.group(4)) + 1
            else:
                count2 = 1

            if cmd == 'a':
                # LaR - insert after line L of file1 range R of file2
                plus = plus + count2
            elif cmd == 'c':
                # FcT - replace range F of file1 with range T of file2
                minus = minus + count1
                plus = plus + count2
            elif cmd == 'd':
                # RdL - remove range R of file1, which would have been
                #       at line L of file2
                minus = minus + count1
        line = fp.readline()
    return plus, minus

class SvnRev:
    """Class used to hold information about a particular revision of
    the repository."""
    def __init__(self, repo, rev, pool):
        self.repo = repo
        self.rev = rev

        # revision properties ...
        properties = svn.fs.revision_proplist(repo.fs, rev, pool)
        self.author = str(properties.get(svn.core.SVN_PROP_REVISION_AUTHOR,''))
        self.date = str(properties.get(svn.core.SVN_PROP_REVISION_DATE, ''))
        self.log = str(properties.get(svn.core.SVN_PROP_REVISION_LOG, ''))

        # convert the date string to seconds since epoch ...
        self.date = svn.core.secs_from_timestr(self.date, pool)

        fsroot = svn.fs.revision_root(repo.fs, rev, pool)
        if rev > 0:
            last_fsroot = svn.fs.revision_root(repo.fs, rev-1, pool)
        else:
            last_fsroot = None
        
        # find changes in the revision
        editor = svn.repos.RevisionChangeCollector(repo.fs, rev, pool)
        e_ptr, e_baton = svn.delta.make_editor(editor, pool)
        svn.repos.svn_repos_replay(fsroot, e_ptr, e_baton, pool)

        self.changes = []
        for path, change in editor.changes.items():
            if change.item_kind != svn.core.svn_node_file: continue

            # we handle 
            if not change.path:
                oldpath, newpath, action = path, None, 'remove'
            elif change.added:
                oldpath, newpath, action = None, path, 'add'
            else:
                oldpath, newpath, action = path, path, 'change'
            plus, minus = _get_diff_counts(last_fsroot, fsroot,
                                           oldpath, newpath, pool)
            self.changes.append((path, action, plus, minus))


def handle_revision(db, command, repo, rev):
    """Adds a particular revision of the repository to the checkin database."""
    revision = repo[rev]
    for (path, action, plus, minus) in revision.changes:
        directory, file = os.path.split(path)
        commit = cvsdb.CreateCommit()
        commit.SetRepository(repo.path)
        commit.SetDirectory(directory)
        commit.SetFile(file)
        commit.SetRevision(str(rev))
        commit.SetAuthor(revision.author)
        commit.SetDescription(revision.log)
        commit.SetTime(revision.date)
        commit.SetPlusCount(plus)
        commit.SetMinusCount(minus)
        commit.SetBranch(None)

        if action == 'add':
            commit.SetTypeAdd()
        elif action == 'remove':
            commit.SetTypeRemove()
        elif action == 'change':
            commit.SetTypeChange()

        if command == 'update':
            result = db.CheckCommit(commit)
            if result: continue # already recorded

        # commit to database
        db.AddCommit(commit)
    pass

def main(pool, command, repository, rev=None):
    db = cvsdb.ConnectDatabase()

    repo = SvnRepo(repository, pool)
    if rev:
        handle_revision(db, command, repo, rev)
    else:
        for rev in range(repo.rev_max+1):
            handle_revision(db, command, repo, rev)

def usage():
    sys.stderr.write('Usage: %s {rebuild | update} <repository> [<revision>]\n'
                     % os.basename(sys.argv[0]))
    sys.exit(1)

if __name__ == '__main__':
    if len(sys.argv) < 3:
        usage()

    command = string.lower(sys.argv[1])
    if command not in ('rebuild', 'update'):
        sys.stderr.write('ERROR: unknown command %s\n' % command)
        usage()

    repository = sys.argv[2]
    if not os.path.exists(repository):
        sys.stderr.write('ERROR: could not find repository %s\n' % repository)
        usage()

    if len(sys.argv) > 3:
        rev = sys.argv[3]
        try:
            rev = int(rev)
        except ValueError:
            sys.stderr.write('ERROR: revision "%s" is not numeric\n' % rev)
            usage()
    else:
        rev = None

    svn.core.run_app(main, command, repository, rev)