#!/usr/bin/perl
#
# Plot the history of a debian package from the changelog, displaying
# when each release of the package occurred, and who made each release.
# To make the graph a little more interesting, the debian revision of the
# package is used as the y axis.
#
# Pass this program the changelog(s) you wish to be plotted.
#
# Copyright 1999 by Joey Hess <joey@kitenet.net>
# Modifications copyright 2003 by Julian Gilbey <jdg@debian.org>
#
# This program 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 of the License, or
# (at your option) any later version.
#
# This program 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 should have received a copy of the GNU General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.

use 5.006;
use strict;
use FileHandle;
use File::Basename;
use File::Temp qw/ tempfile /;
use Fcntl;
use Getopt::Long qw(:config bundling permute no_getopt_compat);

BEGIN {
    pop @INC if $INC[-1] eq '.';
    eval { require Date::Parse; import Date::Parse(); };
    if ($@) {
        my $progname = basename($0);
        if ($@ =~ /^Can\'t locate Date\/Parse\.pm/) {
            die
"$progname: you must have the libtimedate-perl package installed\nto use this script\n";
        } else {
            die
"$progname: problem loading the Date::Parse module:\n  $@\nHave you installed the libtimedate-perl package?\n";
        }
    }
}

my $progname = basename($0);
my $modified_conf_msg;

sub usage {
    print <<"EOF";
Usage: plotchangelog [options] changelog ...
	-v	  --no-version	  Do not show package version information.
	-m	  --no-maint	  Do not show package maintainer information.
	-u        --urgency       Use larger points for higher urgency uploads.
	-l        --linecount     Make the Y axis be number of lines in the
	                          changelog.
	-b        --bugcount      Make the Y axis be number of bugs closed
	                          in the changelog.
        -c        --cumulative    With -l or -b, graph the cumulative number
                                  of lines or bugs closed.
	-g "commands"             Pass "commands" on to gnuplot, they will be
	--gnuplot="commands"      added to the gnuplot script that is used to
				  generate the graph.
	-s file   --save=file     Save the graph to the specified file in
	                          postscript format.
	-d        --dump          Dump gnuplot script to stdout.
	          --verbose       Outputs the gnuplot script.
                  --help          Show this message.
                  --version       Display version and copyright information.
                  --noconf        Don\'t read devscripts configuration files

  At most one of -l and -b (or their long equivalents) may be used.

Default settings modified by devscripts configuration files:
$modified_conf_msg
EOF
}

my $versioninfo = <<"EOF";
This is $progname, from the Debian devscripts package, version ###VERSION###
This code is copyright 1999 by Joey Hess <joey\@kitenet.net>.
Modifications copyright 1999-2003 by Julian Gilbey <jdg\@debian.org>
This program comes with ABSOLUTELY NO WARRANTY.
You are free to redistribute this code under the terms of the
GNU General Public License, version 2 or later.
EOF

my (
    $no_version,    $no_maintainer, $gnuplot_commands, $dump,
    $save_filename, $verbose,       $linecount,        $bugcount,
    $cumulative,    $help,          $showversion,      $show_urgency,
    $noconf
) = "";

# Handle config file unless --no-conf or --noconf is specified
# The next stuff is boilerplate
my $extra_gnuplot_commands = '';
if (@ARGV and $ARGV[0] =~ /^--no-?conf$/) {
    $modified_conf_msg = "  (no configuration files read)";
    shift;
} else {
    my @config_files = ('/etc/devscripts.conf', '~/.devscripts');
    my %config_vars = (
        'PLOTCHANGELOG_OPTIONS' => '',
        'PLOTCHANGELOG_GNUPLOT' => '',
    );
    my %config_default = %config_vars;

    my $shell_cmd;
    # Set defaults
    foreach my $var (keys %config_vars) {
        $shell_cmd .= "$var='$config_vars{$var}';\n";
    }
    $shell_cmd .= 'for file in ' . join(" ", @config_files) . "; do\n";
    $shell_cmd .= '[ -f $file ] && . $file; done;' . "\n";
    # Read back values
    foreach my $var (keys %config_vars) { $shell_cmd .= "echo \$$var;\n" }
    my $shell_out = `/bin/bash -c '$shell_cmd'`;
    @config_vars{ keys %config_vars } = split /\n/, $shell_out, -1;

    foreach my $var (sort keys %config_vars) {
        if ($config_vars{$var} ne $config_default{$var}) {
            $modified_conf_msg .= "  $var=$config_vars{$var}\n";
        }
    }
    $modified_conf_msg ||= "  (none)\n";
    chomp $modified_conf_msg;

    if ($config_vars{'PLOTCHANGELOG_OPTIONS'}) {
        unshift @ARGV, split(' ', $config_vars{'PLOTCHANGELOG_OPTIONS'});
    }
    $extra_gnuplot_commands = $config_vars{'PLOTCHANGELOG_GNUPLOT'};
}

GetOptions(
    "no-version|v", \$no_version,
    "no-maint|m",   \$no_maintainer,
    "gnuplot|g=s",  \$gnuplot_commands,
    "save|s=s",     \$save_filename,
    "dump|d",       \$dump,
    "urgency|u",    \$show_urgency,
    "verbose",      \$verbose,
    "l|linecount",  \$linecount,
    "b|bugcount",   \$bugcount,
    "c|cumulative", \$cumulative,
    "help",         \$help,
    "version",      \$showversion,
    "noconf"  => \$noconf,
    "no-conf" => \$noconf,
  )
  or die
"Usage: $progname [options] changelog ...\nRun $progname --help for more details\n";

if ($noconf) {
    die
"$progname: --no-conf is only acceptable as the first command-line option!\n";
}

if ($help) {
    usage();
    exit 0;
}

if ($showversion) {
    print $versioninfo;
    exit 0;
}

if ($bugcount && $linecount) {
    die
"$progname: can't use --bugcount and --linecount\nRun $progname --help for usage information.\n";
}

if ($cumulative && !$bugcount && !$linecount) {
    warn
"$progname: --cumulative without --bugcount or --linecount: ignoring\nRun $progname --help for usage information.\n";
}

if (!@ARGV) {
    die
"Usage: $progname [options] changelog ...\nRun $progname --help for more details\n";
}

my %data;
my ($package, $version, $maintainer, $date, $urgency) = undef;
my ($data_tmpfile, $script_tmpfile);
my ($data_fh,      $script_fh);

if (!$dump) {
    $data_fh = tempfile("plotdataXXXXXX", UNLINK => 1)
      or die "cannot create temporary file: $!";
    fcntl $data_fh, Fcntl::F_SETFD(), 0
      or die "disabling close-on-exec for temporary file: $!";
    $script_fh = tempfile("plotscriptXXXXXX", UNLINK => 1)
      or die "cannot create temporary file: $!";
    fcntl $script_fh, Fcntl::F_SETFD(), 0
      or die "disabling close-on-exec for temporary file: $!";
    $data_tmpfile   = '/dev/fd/' . fileno($data_fh);
    $script_tmpfile = '/dev/fd/' . fileno($script_fh);
} else {
    $data_tmpfile = '-';
}
my %pkgcount;
my $c;

# Changelog parsing.
foreach (@ARGV) {
    if (/\.gz$/) {
        open F, "zcat $_|" || die "$_: $!";
    } else {
        open F, $_ || die "$_: $!";
    }

    while (<F>) {
        chomp;
        # Note that some really old changelogs use priority, not urgency.
        if (/^(\w+.*?)\s+\((.*?)\)\s+.*?;\s+(?:urgency|priority)=(.*)/i) {
            $package = lc($1);
            $version = $2;
            if ($show_urgency) {
                $urgency = $3;
                if ($urgency =~ /high/i) {
                    $urgency = 2;
                } elsif ($urgency =~ /medium/i) {
                    $urgency = 1.5;
                } else {
                    $urgency = 1;
                }
            } else {
                $urgency = 1;
            }
            undef $maintainer;
            undef $date;
            $c = 0;
        } elsif (/^ -- (.*?)  (.*)/) {
            $maintainer = $1;
            $date       = str2time($2);

            # Strip email address.
            $maintainer =~ s/<.*>//;
            $maintainer =~ s/\(.*\)//;
            $maintainer =~ s/\s+$//;
        } elsif (/^(\w+.*?)\s+\((.*?)\)\s+/) {
            print STDERR qq[Parse error on "$_"\n];
        } elsif ($linecount && /^  /) {
            $c++;    # count changelog size.
        } elsif ($bugcount && /^  /) {
            # count bugs that were said to be closed.
            my @bugs = m/#\d+/g;
            $c += $#bugs + 1;
        }

        if (   defined $package
            && defined $version
            && defined $maintainer
            && defined $date
            && defined $urgency) {
            $data{$package}{ $pkgcount{$package}++ } = [
                $linecount || $bugcount ? $c : $version,
                $maintainer, $date, $urgency
            ];
            undef $package;
            undef $version;
            undef $maintainer;
            undef $date;
            undef $urgency;
        }
    }

    close F;
}

if ($cumulative) {
    # have to massage the data; based on some code from later on
    foreach $package (keys %data) {
        my $total = 0;
        # It's crucial the output is sorted by date.
        foreach my $i (
            sort { $data{$package}{$a}[2] <=> $data{$package}{$b}[2] }
            keys %{ $data{$package} }
        ) {
            $total += $data{$package}{$i}[0];
            $data{$package}{$i}[0] = $total;
        }
    }
}

my $header = q{
set key below title "key" box
set timefmt "%m/%d/%Y %H:%M"
set xdata time
set format x "%m/%y"
set yrange [0 to *]
};
if ($linecount) {
    if ($cumulative) {
        $header .= "set ylabel 'Cumulative changelog length'\n";
    } else {
        $header .= "set ylabel 'Changelog length'\n";
    }
} elsif ($bugcount) {
    if   ($cumulative) { $header .= "set ylabel 'Cumulative bugs closed'\n"; }
    else               { $header .= "set ylabel 'Bugs closed'\n"; }
} else {
    $header .= "set ylabel 'Debian version'\n";
}
if ($save_filename) {
    $header .= "set terminal postscript color solid\n";
    $header .= "set output '$save_filename'\n";
}
my $script = "plot ";
my $data   = '';
my $index  = 0;
my %maintdata;

# Note that "lines" is used if we are also showing maintainer info,
# otherwise we use "linespoints" to make sure points show up for each
# release anyway.
my $style = $no_maintainer ? "linespoints" : "lines";

foreach $package (keys %data) {
    my $oldmaintainer = "";
    my $oldversion    = "";
    # It's crucial the output is sorted by date.
    foreach my $i (
        sort { $data{$package}{$a}[2] <=> $data{$package}{$b}[2] }
        keys %{ $data{$package} }
    ) {
        my $v = $data{$package}{$i}[0];
        $maintainer = $data{$package}{$i}[1];
        $date       = $data{$package}{$i}[2];
        $urgency    = $data{$package}{$i}[3];

        $maintainer =~ s/"/\\"/g;

        my $y;

        # If it's got a debian revision, use that as the y coordinate.
        if ($v =~ m/(.*)-(.*)/) {
            $y       = $2;
            $version = $1;
        } else {
            $y = $v;
        }

      # Now make sure the version is a real number. This includes making
      # sure it has no more than one decimal point in it, and getting rid of
      # any nonnumeric stuff. Otherwise, the "set label" command below could
      # fail. Luckily, perl's string -> num conversion is perfect for this job.
        $y = $y + 0;

        if (lc($maintainer) ne lc($oldmaintainer)) {
            $oldmaintainer = $maintainer;
        }

        my ($sec, $min, $hour, $mday, $mon, $year) = localtime($date);
        my $x = ($mon + 1) . "/$mday/" . (1900 + $year) . " $hour:$min";
        $data .= "$x\t$y\n";
        $maintdata{$oldmaintainer}{$urgency} .= "$x\t$y\n";

        if ($oldversion ne $version && !$no_version) {
            # Upstream version change. Label it.
            $header .= "set label '$version' at '$x',$y left\n";
            $oldversion = $version;
        }
    }
    $data .= "\n\n";    # start new dataset
                        # Add to plot command.
    $script
      .= "'$data_tmpfile' index $index using 1:3 title '$package' with $style, ";
    $index++;
}

# Add a title.
my $title .= "set title '";
$title .=
  $#ARGV > 1
  ? "Graphing Debian changelogs"
  : "Graphing Debian changelog";
$title .= "'\n";

if (!$no_maintainer) {
    foreach $maintainer (sort keys %maintdata) {
        foreach $urgency (sort keys %{ $maintdata{$maintainer} }) {
            $data .= $maintdata{$maintainer}{$urgency} . "\n\n";
            $script
              .= "'$data_tmpfile' index $index using 1:3 title \"$maintainer\" with points pointsize "
              . (1.5 * $urgency) . ", ";
            $index++;
        }
    }
}

$script =~ s/, $/\n/;
$script = qq{
$header
$title
$extra_gnuplot_commands
$gnuplot_commands
$script
};
$script .= "pause -1 'Press Return to continue.'\n"
  unless $save_filename || $dump;

if (!$dump) {
    # Annoyingly, we have to use 2 temp files. I could just send everything to
    # gnuplot on stdin, but then the pause -1 doesn't work.
    open(DATA,   ">$data_tmpfile")   || die "$data_tmpfile: $!";
    open(SCRIPT, ">$script_tmpfile") || die "$script_tmpfile: $!";
} else {
    open(DATA,   ">&STDOUT");
    open(SCRIPT, ">&STDOUT");
}

print SCRIPT $script;
print $script if $verbose && !$dump;
print DATA $data;
close SCRIPT;
close DATA;

if (!$dump) {
    unless (system("gnuplot", $script_tmpfile) == 0) {
        die "gnuplot program failed (is the gnuplot package installed?): $!\n";
    }
}