#! /usr/bin/env python

"""Consolidate a bunch of CVS or RCS logs read from stdin.

Input should be the output of a CVS or RCS logging command, e.g.

    cvs log -rrelease14:

which dumps all log messages from release1.4 upwards (assuming that
release 1.4 was tagged with tag 'release14').  Note the trailing
colon!

This collects all the revision records and outputs them sorted by date
rather than by file, collapsing duplicate revision record, i.e.,
records with the same message for different files.

The -t option causes it to truncate (discard) the last revision log
entry; this is useful when using something like the above cvs log
command, which shows the revisions including the given tag, while you
probably want everything *since* that tag.

XXX This code was created by reverse engineering CVS 1.9 and RCS 5.7
from their output.

"""

import os, sys, getopt, string, re

sep1 = '='*77 + '\n'                    # file separator
sep2 = '-'*28 + '\n'                    # revision separator

def main():
    """Main program"""
    truncate_last = 0
    reverse = 0
    opts, args = getopt.getopt(sys.argv[1:], "tr")
    for o, a in opts:
        if o == '-t':
            truncate_last = 1
        elif o == '-r':
            reverse = 1
    database = []
    while 1:
        chunk = read_chunk(sys.stdin)
        if not chunk:
            break
        records = digest_chunk(chunk)
        if truncate_last:
            del records[-1]
        database[len(database):] = records
    database.sort()
    if not reverse:
        database.reverse()
    format_output(database)

def read_chunk(fp):
    """Read a chunk -- data for one file, ending with sep1.

    Split the chunk in parts separated by sep2.

    """
    chunk = []
    lines = []
    while 1:
        line = fp.readline()
        if not line:
            break
        if line == sep1:
            if lines:
                chunk.append(lines)
            break
        if line == sep2:
            if lines:
                chunk.append(lines)
                lines = []
        else:
            lines.append(line)
    return chunk

def digest_chunk(chunk):
    """Digest a chunk -- extrach working file name and revisions"""
    lines = chunk[0]
    key = 'Working file:'
    keylen = len(key)
    for line in lines:
        if line[:keylen] == key:
            working_file = string.strip(line[keylen:])
            break
    else:
        working_file = None
    records = []
    for lines in chunk[1:]:
        revline = lines[0]
        dateline = lines[1]
        text = lines[2:]
        words = string.split(dateline)
        author = None
        if len(words) >= 3 and words[0] == 'date:':
            dateword = words[1]
            timeword = words[2]
            if timeword[-1:] == ';':
                timeword = timeword[:-1]
            date = dateword + ' ' + timeword
            if len(words) >= 5 and words[3] == 'author:':
                author = words[4]
                if author[-1:] == ';':
                    author = author[:-1]
        else:
            date = None
            text.insert(0, revline)
        words = string.split(revline)
        if len(words) >= 2 and words[0] == 'revision':
            rev = words[1]
        else:
            rev = None
            text.insert(0, revline)
        records.append((date, working_file, rev, author, text))
    return records

def format_output(database):
    prevtext = None
    prev = []
    database.append((None, None, None, None, None)) # Sentinel
    for (date, working_file, rev, author, text) in database:
        if text != prevtext:
            if prev:
                print sep2,
                for (p_date, p_working_file, p_rev, p_author) in prev:
                    print p_date, p_author, p_working_file, p_rev
                sys.stdout.writelines(prevtext)
            prev = []
        prev.append((date, working_file, rev, author))
        prevtext = text

main()
