#!/bin/sh
exec perl -w -x $0 ${1+"$@"} # -*- mode: perl; perl-indent-level: 2; -*-
#!perl -w

##############################################################
###                                                        ###
### cvs2cl.pl: produce ChangeLog(s) from `cvs log` output. ###
###                                                        ###
##############################################################

## $Revision: 1.1 $
## $Date: 2002/02/06 04:36:17 $
## $Author: seank $
##
##   (C) 1999 Karl Fogel <kfogel@red-bean.com>, under the GNU GPL.
## 
##   (Extensively hacked on by Melissa O'Neill <oneill@cs.sfu.ca>.)
##
## cvs2cl.pl is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2, or (at your option)
## any later version.
##
## cvs2cl.pl is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##
## You may have received a copy of the GNU General Public License
## along with cvs2cl.pl; see the file COPYING.  If not, write to the
## Free Software Foundation, Inc., 59 Temple Place - Suite 330,
## Boston, MA 02111-1307, USA.



use strict;
use Text::Wrap;
use Time::Local;
use File::Basename;


# The Plan:
#
# Read in the logs for multiple files, spit out a nice ChangeLog that
# mirrors the information entered during `cvs commit'.
#
# The problem presents some challenges. In an ideal world, we could
# detect files with the same author, log message, and checkin time --
# each <filelist, author, time, logmessage> would be a changelog entry.
# We'd sort them; and spit them out.  Unfortunately, CVS is *not atomic*
# so checkins can span a range of times.  Also, the directory structure
# could be hierarchical.
#
# Another question is whether we really want to have the ChangeLog
# exactly reflect commits. An author could issue two related commits,
# with different log entries, reflecting a single logical change to the
# source. GNU style ChangeLogs group these under a single author/date.
# We try to do the same.
#
# So, we parse the output of `cvs log', storing log messages in a
# multilevel hash that stores the mapping:
#   directory => author => time => message => filelist
# As we go, we notice "nearby" commit times and store them together
# (i.e., under the same timestamp), so they appear in the same log
# entry.
#
# When we've read all the logs, we twist this mapping into
# a time => author => message => filelist mapping for each directory.
#
# If we're not using the `--distributed' flag, the directory is always
# considered to be `./', even as descend into subdirectories.


############### Globals ################


# What we run to generate it:
my $Log_Source_Command = "cvs log";

# In case we have to print it out:
my $VERSION = '$Revision: 1.1 $';
$VERSION =~ s/\S+\s+(\S+)\s+\S+/$1/;

## Vars set by options:

# Print debugging messages?
my $Debug = 0;

# Just show version and exit?
my $Print_Version = 0;

# Just print usage message and exit?
my $Print_Usage = 0;

# Single top-level ChangeLog, or one per subdirectory?
my $Distributed = 0;

# What file should we generate (defaults to "ChangeLog")?
my $Log_File_Name = "ChangeLog";

# Grab most recent entry date from existing ChangeLog file, just add
# to that ChangeLog.
my $Cumulative = 0;

# Expand usernames to email addresses based on a map file?
my $User_Map_File = "";

# Output to a file or to stdout?
my $Output_To_Stdout = 0;

# Eliminate empty log messages?
my $Prune_Empty_Msgs = 0;

# Don't call Text::Wrap on the body of the message
my $No_Wrap = 0;

# Separates header from log message.  Code assumes it is either " " or
# "\n\n", so if there's ever an option to set it to something else,
# make sure to go through all conditionals that use this var.
my $After_Header = " ";

# Format more for programs than for humans.
my $XML_Output = 0;

# Do some special tweaks for log data that was written in FSF
# ChangeLog style.
my $FSF_Style = 0;

# Show times in UTC instead of local time
my $UTC_Times = 0;

# Show day of week in output?
my $Show_Day_Of_Week = 0;

# Show revision numbers in output?
my $Show_Revisions = 0;

# Show tags (symbolic names) in output?
my $Show_Tags = 0;

# Show branches by symbolic name in output?
my $Show_Branches = 0;

# Show only revisions on these branches or their ancestors.
my @Follow_Branches;

# Don't bother with files matching this regexp.
my @Ignore_Files;

# How exactly we match entries.  We definitely want "o",
# and user might add "i" by using --case-insensitive option.
my $Case_Insensitive = 0;

# Maybe only show log messages matching a certain regular expression.
my $Regexp_Gate = "";

# Pass this global option string along to cvs, to the left of `log':
my $Global_Opts = "";

# Pass this option string along to the cvs log subcommand:
my $Command_Opts = "";

# Read log output from stdin instead of invoking cvs log?
my $Input_From_Stdin = 0;

# Don't show filenames in output.
my $Hide_Filenames = 0;

# Max checkin duration. CVS checkin is not atomic, so we may have checkin
# times that span a range of time. We assume that checkins will last no
# longer than $Max_Checkin_Duration seconds, and that similarly, no
# checkins will happen from the same users with the same message less
# than $Max_Checkin_Duration seconds apart.
my $Max_Checkin_Duration = 180;

# What to put at the front of [each] ChangeLog.  
my $ChangeLog_Header = "";

## end vars set by options.

# In 'cvs log' output, one long unbroken line of equal signs separates
# files:
my $file_separator = "======================================="
                   . "======================================";

# In 'cvs log' output, a shorter line of dashes separates log messages
# within a file:
my $logmsg_separator = "----------------------------";


############### End globals ############




&parse_options ();
&derive_change_log ();



### Everything below is subroutine definitions. ###

# If accumulating, grab the boundary date from pre-existing ChangeLog.
sub maybe_grab_accumulation_date ()
{
  if (! $Cumulative) {
    return "";
  }

  # else

  open (LOG, "$Log_File_Name")
      or die ("trouble opening $Log_File_Name for reading ($!)");

  my $boundary_date;
  while (<LOG>)
  {
    if (/^(\d\d\d\d-\d\d-\d\d\s+\d\d:\d\d)/)
    {
      $boundary_date = "$1";
      last;
    }
  }

  close (LOG);
  return $boundary_date;
}


# Fills up a ChangeLog structure in the current directory.
sub derive_change_log ()
{
  # See "The Plan" above for a full explanation.
  
  my %grand_poobah;

  my $file_full_path;
  my $time;
  my $revision;
  my $author;
  my $msg_txt;
  my $detected_file_separator;

  # Might be adding to an existing ChangeLog
  my $accumulation_date = &maybe_grab_accumulation_date ();
  if ($accumulation_date) {
    $Log_Source_Command .= " -d\'>${accumulation_date}\'";
  }

  # We might be expanding usernames
  my %usermap;

  # In general, it's probably not very maintainable to use state
  # variables like this to tell the loop what it's doing at any given
  # moment, but this is only the first one, and if we never have more
  # than a few of these, it's okay.
  my $collecting_symbolic_names = 0;
  my %symbolic_names;    # Where tag names get stored.
  my %branch_names;      # We'll grab branch names while we're at it.
  my %branch_numbers;    # Save some revisions for @Follow_Branches
  my @branch_roots;      # For showing which files are branch ancestors.

  # Bleargh.  Compensate for a deficiency of custom wrapping.
  if (($After_Header ne " ") and $FSF_Style)
  {
    $After_Header .= "\t";
  }

  if (! $Input_From_Stdin) {
    open (LOG_SOURCE, "$Log_Source_Command |")
        or die "unable to run \"${Log_Source_Command}\"";
  }
  else {
    open (LOG_SOURCE, "-") or die "unable to open stdin for reading";
  }

  %usermap = &maybe_read_user_map_file ();

  while (<LOG_SOURCE>)
  {
    # If on a new file and don't see filename, skip until we find it, and
    # when we find it, grab it.
    if ((! (defined $file_full_path)) and /^Working file: (.*)/) 
    {
      $file_full_path = $1;
      if (@Ignore_Files) 
      {
        my $base;
        ($base, undef, undef) = fileparse ($file_full_path);
        # Ouch, I wish trailing operators in regexps could be
        # evaluated on the fly!
        if ($Case_Insensitive) {
          if (grep ($file_full_path =~ m|$_|i, @Ignore_Files)) {
            undef $file_full_path;
          }
        }
        elsif (grep ($file_full_path =~ m|$_|, @Ignore_Files)) {
          undef $file_full_path;
        }
      }
      next;
    }

    # Just spin wheels if no file defined yet.
    next if (! $file_full_path);

    # Collect tag names in case we're asked to print them in the output.
    if (/^symbolic names:$/) {
      $collecting_symbolic_names = 1;
      next;  # There's no more info on this line, so skip to next
    }
    if ($collecting_symbolic_names)
    {
      # All tag names are listed with whitespace in front in cvs log
      # output; so if see non-whitespace, then we're done collecting.
      if (/^\S/) {
        $collecting_symbolic_names = 0;
      }
      else    # we're looking at a tag name, so parse & store it
      {
        # According to the Cederqvist manual, in node "Tags", tag
        # names must start with an uppercase or lowercase letter and
        # can contain uppercase and lowercase letters, digits, `-',
        # and `_'.  However, it's not our place to enforce that, so
        # we'll allow anything CVS hands us to be a tag:
        /^\s+([^:]+): ([\d.]+)$/;
        my $tag_name = $1;
        my $tag_rev  = $2;

        # A branch number either has an odd number of digit sections
        # (and hence an even number of dots), or has ".0." as the
        # second-to-last digit section.  Test for these conditions.
        my $real_branch_rev = "";
        if (($tag_rev =~ /^(\d+\.\d+\.)+\d+$/)   # Even number of dots...
            and (! ($tag_rev =~ /^(1\.)+1$/)))   # ...but not "1.[1.]1"
        {
          $real_branch_rev = $tag_rev;
        }
        elsif ($tag_rev =~ /(\d+\.(\d+\.)+)0.(\d+)/)  # Has ".0."
        {
          $real_branch_rev = $1 . $3;
        }
        # If we got a branch, record its number.
        if ($real_branch_rev)
        {
          $branch_names{$real_branch_rev} = $tag_name;
          if (@Follow_Branches) {
            if (grep ($_ eq $tag_name, @Follow_Branches)) {
              $branch_numbers{$tag_name} = $real_branch_rev;
            }
          }
        }
        else {
          # Else it's just a regular (non-branch) tag.
          push (@{$symbolic_names{$tag_rev}}, $tag_name);
        }
      }
    }
    # End of code for collecting tag names.

    # If have file name, but not revision, and see revision, then grab
    # it.  (We collect unconditionally, even though we may or may not
    # ever use it.)
    if ((! (defined $revision)) and (/^revision (\d+\.[\d.]+)/))
    {
      $revision = $1;

      if (@Follow_Branches)
      {
        foreach my $branch (@Follow_Branches) 
        {
          # Special case for following trunk revisions
          if (($branch =~ /^trunk$/i) and ($revision =~ /^[0-9]+\.[0-9]+$/))
          {
            goto dengo;
          }

          my $branch_number = $branch_numbers{$branch};
          if ($branch_number) 
          {
            # Are we on one of the follow branches or an ancestor of
            # same?
            #
            # If this revision is a prefix of the branch number, or
            # possibly is less in the minormost number, OR if this
            # branch number is a prefix of the revision, then yes.
            # Otherwise, no.
            #
            # So below, we determine if any of those conditions are
            # met.
            
            # Trivial case: is this revision on the branch?
            # (Compare this way to avoid regexps that screw up Emacs
            # indentation, argh.)
            if ((substr ($revision, 0, ((length ($branch_number)) + 1)))
                eq ($branch_number . "."))
            {
              goto dengo;
            }
            # Non-trivial case: check if rev is ancestral to branch
            elsif ((length ($branch_number)) > (length ($revision)))
            {
              $revision =~ /^((?:\d+\.)+)(\d+)$/;
              my $r_left = $1;          # still has the trailing "."
              my $r_end = $2;
              
              $branch_number =~ /^((?:\d+\.)+)(\d+)\.\d+$/;
              my $b_left = $1;  # still has trailing "."
              my $b_mid  = $2;   # has no trailing "."

              if (($r_left eq $b_left)
                  && ($r_end <= $b_mid))
              {
                goto dengo;
              }
            }
          }
        }
      }
      else    # (! @Follow_Branches)
      {
        next;
      }

      # Else we are following branches, but this revision isn't on the
      # path.  So skip it.
      undef $revision;
    dengo:
      next;
    }
    
    # If we don't have a revision right now, we couldn't possibly
    # be looking at anything useful. 
    if (! (defined ($revision))) {
      $detected_file_separator = /^$file_separator$/o;
      if ($detected_file_separator) {
        # No revisions for this file; can happen, e.g. "cvs log -d DATE"
        goto CLEAR;
      }
      else {
        next;
      }
    }

    # If have file name but not date and author, and see date or
    # author, then grab them:
    unless (defined $time) 
    {
      if (/^date: .*/)
      {
        ($time, $author) = &parse_date_and_author ($_);
        if (defined ($usermap{$author}) and $usermap{$author}) {
          $author = $usermap{$author};
        }
      }
      else {
        $detected_file_separator = /^$file_separator$/o;
        if ($detected_file_separator) {
          # No revisions for this file; can happen, e.g. "cvs log -d DATE"
          goto CLEAR;
        }
      }
      # If the date/time/author hasn't been found yet, we couldn't
      # possibly care about anything we see.  So skip:
      next;
    }

    # A "branches: ..." line here indicates that one or more branches
    # are rooted at this revision.  If we're showing branches, then we
    # want to show that fact as well, so we collect all the branches
    # that this is the latest ancestor of and store them in
    # @branch_roots.  Just for reference, the format of the line we're
    # seeing at this point is:
    #
    #    branches:  1.5.2;  1.5.4;  ...;
    #
    # Okay, here goes:

    if (/^branches:\s+(.*);$/)
    {
      if ($Show_Branche