#!/usr/bin/perl -T
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
#
# This Source Code Form is "Incompatible With Secondary Licenses", as
# defined by the Mozilla Public License, v. 2.0.

use 5.10.1;
use strict;
use warnings;

use lib qw(. lib);

use File::Temp;

use Bugzilla;
use Bugzilla::Constants;
use Bugzilla::Install::Filesystem;
use Bugzilla::Util;
use Bugzilla::Error;
use Bugzilla::Bug;
use Bugzilla::Status;

my $user = Bugzilla->login();

my $cgi = Bugzilla->cgi;
my $template = Bugzilla->template;
my $vars = {};
# Connect to the shadow database if this installation is using one to improve
# performance.
my $dbh = Bugzilla->switch_to_shadow_db();

our (%seen, %edgesdone, %bugtitles);
our $bug_count = 0;

# CreateImagemap: This sub grabs a local filename as a parameter, reads the 
# dot-generated image map datafile residing in that file and turns it into
# an HTML map element. THIS SUB IS ONLY USED FOR LOCAL DOT INSTALLATIONS.
# The map datafile won't necessarily contain the bug summaries, so we'll
# pull possible HTML titles from the %bugtitles hash (filled elsewhere
# in the code)

# The dot mapdata lines have the following format (\nsummary is optional):
# rectangle (LEFTX,TOPY) (RIGHTX,BOTTOMY) URLBASE/show_bug.cgi?id=BUGNUM BUGNUM[\nSUMMARY]

sub CreateImagemap {
    my $mapfilename = shift;
    my $map = "<map name=\"imagemap\">\n";
    my $default = "";

    open MAP, "<", $mapfilename;
    while(my $line = <MAP>) {
        if($line =~ /^default ([^ ]*)(.*)$/) {
            $default = qq{<area alt="" shape="default" href="$1">\n};
        }

        if ($line =~ /^rectangle \((\d+),(\d+)\) \((\d+),(\d+)\) (http[^ ]*) (\d+)(?:\\n.*)?$/) {
            my ($leftx, $rightx, $topy, $bottomy, $url, $bugid) = ($1, $3, $2, $4, $5, $6);

            # Pick up bugid from the mapdata label field. Getting the title from
            # bugtitle hash instead of mapdata allows us to get the summary even
            # when showsummary is off, and also gives us status and resolution.
            # This text is safe; it has already been escaped.
            my $bugtitle = $bugtitles{$bugid};

            # The URL is supposed to be safe, because it's built manually.
            # But in case someone manages to inject code, it's safer to escape it.
            $url = html_quote($url);

            $map .= qq{<area alt="bug $bugid" name="bug$bugid" shape="rect" } .
                    qq{title="$bugtitle" href="$url" } .
                    qq{coords="$leftx,$topy,$rightx,$bottomy">\n};
        }
    }
    close MAP;

    $map .= "$default</map>";
    return $map;
}

sub AddLink {
    my ($blocked, $dependson, $fh) = (@_);
    my $key = "$blocked,$dependson";
    if (!exists $edgesdone{$key}) {
        $edgesdone{$key} = 1;
        print $fh "$dependson -> $blocked\n";
        $bug_count++;
        $seen{$blocked} = 1;
        $seen{$dependson} = 1;
    }
}

ThrowUserError("missing_bug_id") unless $cgi->param('id');

# The list of valid directions. Some are not proposed in the dropdrown
# menu despite the fact that they are valid.
my @valid_rankdirs = ('LR', 'RL', 'TB', 'BT');

my $rankdir = $cgi->param('rankdir') || 'TB';
# Make sure the submitted 'rankdir' value is valid.
if (!grep { $_ eq $rankdir } @valid_rankdirs) {
    $rankdir = 'TB';
}

my $display = $cgi->param('display') || 'tree';
my $webdotdir = bz_locations()->{'webdotdir'};

my ($fh, $filename) = File::Temp::tempfile("XXXXXXXXXX",
                                           SUFFIX => '.dot',
                                           DIR => $webdotdir,
                                           UNLINK => 1);

chmod Bugzilla::Install::Filesystem::CGI_WRITE, $filename
    or warn install_string('chmod_failed', { path => $filename,
                                             error => $! });

my $urlbase = correct_urlbase();

print $fh "digraph G {";
print $fh qq(
graph [URL="${urlbase}query.cgi", rankdir=$rankdir]
node [URL="${urlbase}show_bug.cgi?id=\\N", style=filled, color=lightgrey]
);

my %baselist;

foreach my $i (split('[\s,]+', $cgi->param('id'))) {
    my $bug = Bugzilla::Bug->check($i);
    $baselist{$bug->id} = 1;
}

my @stack = keys(%baselist);

if ($display eq 'web') {
    my $sth = $dbh->prepare(q{SELECT blocked, dependson
                                FROM dependencies
                               WHERE blocked = ? OR dependson = ?});

    foreach my $id (@stack) {
        my $dependencies = $dbh->selectall_arrayref($sth, undef, ($id, $id));
        foreach my $dependency (@$dependencies) {
            my ($blocked, $dependson) = @$dependency;
            if ($blocked != $id && !exists $seen{$blocked}) {
                push @stack, $blocked;
            }
            if ($dependson != $id && !exists $seen{$dependson}) {
                push @stack, $dependson;
            }
            AddLink($blocked, $dependson, $fh);
        }
    }
}
# This is the default: a tree instead of a spider web.
else {
    my @blocker_stack = @stack;
    foreach my $id (@blocker_stack) {
        my $blocker_ids = Bugzilla::Bug::EmitDependList('blocked', 'dependson', $id);
        foreach my $blocker_id (@$blocker_ids) {
            push(@blocker_stack, $blocker_id) unless $seen{$blocker_id};
            AddLink($id, $blocker_id, $fh);
        }
    }
    my @dependent_stack = @stack;
    foreach my $id (@dependent_stack) {
        my $dep_bug_ids = Bugzilla::Bug::EmitDependList('dependson', 'blocked', $id);
        foreach my $dep_bug_id (@$dep_bug_ids) {
            push(@dependent_stack, $dep_bug_id) unless $seen{$dep_bug_id};
            AddLink($dep_bug_id, $id, $fh);
        }
    }
}

foreach my $k (keys(%baselist)) {
    $seen{$k} = 1;
}

my $sth = $dbh->prepare(
              q{SELECT bug_status, resolution, short_desc
                  FROM bugs
                 WHERE bugs.bug_id = ?});

my @bug_ids = keys %seen;
$user->visible_bugs(\@bug_ids);
foreach my $k (@bug_ids) {
    # Retrieve bug information from the database
    my ($stat, $resolution, $summary) = $dbh->selectrow_array($sth, undef, $k);

    $vars->{'short_desc'} = $summary if ($k eq $cgi->param('id'));

    # The bug summary is shown only if the user can see the bug.
    if ($user->can_see_bug($k)) {
        $summary = html_quote(clean_text($summary));
    }
    else {
        $summary = '';
    }

    my @params;

    if ($summary ne "" && $cgi->param('showsummary')) {
        # Wide characters cause GraphViz to die.
        if (Bugzilla->params->{'utf8'}) {
            utf8::encode($summary) if utf8::is_utf8($summary);
        }
        $summary =~ s/([\\\"])/\\$1/g;
        # Newlines must be escaped too, to not break the .map file
        # and to prevent code injection.
        $summary =~ s/\n/\\n/g;
        push(@params, qq{label="$k\\n$summary"});
    }

    if (exists $baselist{$k}) {
        push(@params, "shape=box");
    }

    if (is_open_state($stat)) {
        push(@params, "color=green");
    }

    if (@params) {
        print $fh "$k [" . join(',', @params) . "]\n";
    } else {
        print $fh "$k\n";
    }

    # Push the bug tooltip texts into a global hash so that 
    # CreateImagemap sub (used with local dot installations) can
    # use them later on.
    my $stat_display       = display_value('bug_status', $stat);
    my $resolution_display = display_value('resolution', $resolution);
    $bugtitles{$k} = trim("$stat_display $resolution_display");

    # Show the bug summary in tooltips only if not shown on 
    # the graph and it is non-empty (the user can see the bug)
    if (!$cgi->param('showsummary') && $summary ne "") {
        $bugtitles{$k} .= " - $summary";
    }
}


print $fh "}\n";
close $fh;

if ($bug_count > MAX_WEBDOT_BUGS) {
    unlink($filename);
    ThrowUserError("webdot_too_large");
}

my $webdotbase = Bugzilla->params->{'webdotbase'};

if ($webdotbase =~ /^https?:/) {
     # Remote dot server. We don't hardcode 'urlbase' here in case
     # 'sslbase' is in use.
     $webdotbase =~ s/%([a-z]*)%/Bugzilla->params->{$1}/eg;
     my $url = $webdotbase . $filename;
     $vars->{'image_url'} = $url . ".gif";
     $vars->{'map_url'} = $url . ".map";
} else {
    # Local dot installation

    # First, generate the png image file from the .dot source

    my ($pngfh, $pngfilename) = File::Temp::tempfile("XXXXXXXXXX",
                                                     SUFFIX => '.png',
                                                     DIR => $webdotdir);

    chmod Bugzilla::Install::Filesystem::WS_SERVE, $pngfilename
        or warn install_string('chmod_failed', { path => $pngfilename,
                                                 error => $! });

    binmode $pngfh;
    open(DOT, '-|', "\"$webdotbase\" -Tpng $filename");
    binmode DOT;
    print $pngfh $_ while <DOT>;
    close DOT;
    close $pngfh;

    # On Windows $pngfilename will contain \ instead of /
    $pngfilename =~ s|\\|/|g if ON_WINDOWS;

    # Under mod_perl, pngfilename will have an absolute path, and we
    # need to make that into a relative path.
    my $cgi_root = bz_locations()->{cgi_path};
    $pngfilename =~ s#^\Q$cgi_root\E/?##;
    
    $vars->{'image_url'} = $pngfilename;

    # Then, generate a imagemap datafile that contains the corner data
    # for drawn bug objects. Pass it on to CreateImagemap that
    # turns this monster into html.

    my ($mapfh, $mapfilename) = File::Temp::tempfile("XXXXXXXXXX",
                                                     SUFFIX => '.map',
                                                     DIR => $webdotdir);

    chmod Bugzilla::Install::Filesystem::WS_SERVE, $mapfilename
        or warn install_string('chmod_failed', { path => $mapfilename,
                                                 error => $! });

    binmode $mapfh;
    open(DOT, '-|', "\"$webdotbase\" -Tismap $filename");
    binmode DOT;
    print $mapfh $_ while <DOT>;
    close DOT;
    close $mapfh;

    $vars->{'image_map'} = CreateImagemap($mapfilename);
}

# Cleanup any old .dot files created from previous runs.
my $since = time() - 24 * 60 * 60;
# Can't use glob, since even calling that fails taint checks for perl < 5.6
opendir(DIR, $webdotdir);
my @files = grep { /\.dot$|\.png$|\.map$/ && -f "$webdotdir/$_" } readdir(DIR);
closedir DIR;
foreach my $f (@files)
{
    $f = "$webdotdir/$f";
    # Here we are deleting all old files. All entries are from the
    # $webdot directory. Since we're deleting the file (not following
    # symlinks), this can't escape to delete anything it shouldn't
    # (unless someone moves the location of $webdotdir, of course)
    trick_taint($f);
    my $mtime = (stat($f))[9];
    if ($mtime && $mtime < $since) {
        unlink $f;
    }
}

# Make sure we only include valid integers (protects us from XSS attacks).
my @bugs = grep(detaint_natural($_), split(/[\s,]+/, $cgi->param('id')));
$vars->{'bug_id'} = join(', ', @bugs);
$vars->{'multiple_bugs'} = ($cgi->param('id') =~ /[ ,]/);
$vars->{'display'} = $display;
$vars->{'rankdir'} = $rankdir;
$vars->{'showsummary'} = $cgi->param('showsummary');

# Generate and return the UI (HTML page) from the appropriate template.
print $cgi->header();
$template->process("bug/dependency-graph.html.tmpl", $vars)
  || ThrowTemplateError($template->error());