#!/usr/bin/perl
#
# Print menu lines with commands to enable some popular monitor
# configurations or activate the selected combo.
#
# Copyright (c) 2017-2022 Eduard Bloch
# License: Simplified BSD License
#

use strict;
use warnings;

use Getopt::Long qw(:config no_ignore_case bundling auto_help);

#print("# WHAT: ".join(" ", @ARGV));

# helper: (h, v, rate)
my $prim;
my @connected;
my %active;
my @postcmd;

# development switches. Debug value of 1 is creating output with
# commented hints, 2 and above dump unformatted extra stuff into output
my $debug=0;
# Testing the --activate option without actually executing it
my $dry_run;

my $xrandr = "xrandr";

# monitor name mapping, either from cache or built from EDID info later
my %realname;

# main calculation collection
my @actionMap;

my $activate;
my $auto_num = 0;

sub parse_arguments
{
    my $bad_max;
    GetOptions("xrandr=s" => \$xrandr,
            "max"   => \$bad_max,
            "debug:i"  => \$debug,
            "activate=s" => \$activate,
            "dry-run" => \$dry_run,
            "auto-number" => \$auto_num)
        or die("Error in command line arguments\n");

    print "# Deprecated option --max, see --help or the manual page for alternatives.\n" if $bad_max;

    if($debug)
    {
        eval "use Data::Dumper";
        eval "use Diagnostics";
        eval "use warnings FATAL => 'all'";
    }
}

sub get_contents
{
    my $filename = shift;
    open my $fh, '<', $filename or return "";
    my $data = do { local $/; <$fh> };
    return $data;
}

print "Running $0\n" if $debug > 1;

my @cfiledata;

$xrandr.=" --verbose";

# Input: blob, start of the string data
sub strip_tfield
{
    my $name = substr($_[0], $_[1], 13);
    print "# Raw name: $name\n" if $debug > 4;
    $name=~s/^\W.*//;
    $name=~s/(\r|\n|\0).*//;
    $name=~s/\W$//;
    print "# Decoded: $name\n" if $debug > 2;
    return $name;
}

sub load_ini
{
    my $cfname = "xrandr_menu";
    foreach ($ENV{XDG_CONFIG_HOME} ? "$ENV{XDG_CONFIG_HOME}/icewm/$cfname" : undef, "$ENV{HOME}/.icewm/$cfname")
    {
        next if !$_;
        print ("# Ini-Check: $_\n") if $debug;
        next if ! -r $_;
        my $fd;
        my %cfg;

        {
            my %cfg=( "sectype" => "main");
            push(@cfiledata, \%cfg);
        }

        if (open($fd, "<$_"))
        {
            for (<$fd>)
            {
                s/^\s+//;
                next if /^\s*#/;
                s/#.*//;
                s/\s+$//;
                chomp;
                print "# C: $_\n" if $debug > 3;
                if (/^\[\s*(\w+)(\s+(\w+))?/)
                {
                    my %cfg=();
                    push(@cfiledata, \%cfg);
                    $cfg{sectype} = $1;
                    $cfg{"match-name"} = $3 if $3;
                }
                elsif(/^(\w\S+)\s*=\s*(\S.*)/)
                {
                    my $key = $1;
                    my $val = $2;
                    $val=~s/^"(.*)"$/$1/;
                    my $xr = $cfiledata[-1];
                    $$xr{$key} = $val;
                }
            }
        }
        print Dumper(@cfiledata) if $debug > 1;
        # config was found
        last;
    }
}

sub parse_edid
{
    my ($hexblob, $curmon) = @_;
    my $name = "";
    my $blob=pack("H*", $hexblob);
    print "Parsing monitor data for $curmon from $hexblob\n" if $debug > 2;
  	if ($debug > 4) { my $foo; open($foo,"|hexdump -C"); print $foo $blob; }
    foreach my $fpos (0..3)
    {
        $fpos = 57+$fpos*18;
        my $cv = substr($blob, $fpos,1);
        $cv = ord($cv);
        print "tcode at $fpos: $cv\n" if $debug > 3;
        if ($cv == 252) # full user description, prefer this
        {
            $name = strip_tfield($blob, $fpos + 2);
            last;
        }
  		# the alternative to Display Name descriptor is a set of
  		# description words (Vendor, Type name, etc.)
        if ($cv == 254)
        {
            my $word = strip_tfield($blob, $fpos + 2);
            if (length($name) + length($word) < 31)
            {
                $name.=" " if $name;
                $name.=$word;
            }
        }
    }
    if ($name)
    {
        $name.="%PRIMFLAG";
        $realname{$curmon} = $name.'~'.$curmon;
        print "Found: $name\n" if $debug > 2;
    }
}

sub match_output
{
    my $output = shift;
    my @ret = ();
    #print Dumper("# cfiledata:", @cfiledata) if $debug > 4;

    if (! scalar @cfiledata)
    {
        return @ret;
    }

    for my $xr (@cfiledata)
    {
        #print "# What is this?".Dumper("# $xr -> ", $xr) if $debug > 5;
        my $st = $$xr{"sectype"};
        next if !defined($st);
        next unless ($st eq "main" || $st eq "output");

        my $fil = $$xr{"match-name"};
        if (defined($fil))
        {
            if ($fil =~ /^\/(.*)\/$/)
            {
                next unless $output =~ /$1/;
            }
            else
            {
                next unless $fil eq $output;
            }
        }
        $fil = $$xr{"match-label"};
        if (defined($fil))
        {
            my $label = $realname{$output};
            if ($fil =~ /^\/(.*)\/$/)
            {
                next unless $label =~ /$1/;
            }
            else
            {
                next unless $fil eq $label;
            }
        }
        push(@ret, $xr);
    }
    return @ret;
}

sub pick_for_output
{
    my ($iface, $key) = @_;
    my $ret;
    for my $xr (match_output($iface))
    {
        my $xro = $$xr{$key};
        next unless defined($xro);
        $ret = $xro;
    }
    return $ret;
}

#
# Select a specified assignment for all combos which match the specified
# label.
#
sub pick_for_combo
{
    my $combo = shift;
    my $key = shift;
    my $val;
    for my $xr (@cfiledata)
    {
        my $st = $$xr{"sectype"};
        next if ! defined($st);
        next unless ($st eq "main" || $st eq "combo");
        my $fil = ($$xr{"match-name"} or $$xr{"match-label"});
        if (defined($fil))
        {
            if ($fil =~ /^\/(.*)\/$/)
            {
                next unless $combo =~ /$1/;
            }
            else
            {
                next unless $fil eq $combo;
            }
        }
        $val = ($$xr{$key} or $val);
    }
    return $val;
}

sub fmtMode
{
    return (pick_for_output(shift, "options") or "--auto");
}

sub fmtOutputMode
{
    my $iface = shift;
    return "--output $iface ".fmtMode($iface);
}

sub read_xrandr
{
    my @curres;
    my $currentEdid;
    my $curmon;
    my $disabled;
    for(@_)
    {
        print "# DBG: $_" if $debug > 4;
        my $resFound =/(\d+x\d+\++\d)/;
        # compressed, non-verbose output
        if(/^(\w\S*)\s+(connected|disconnected)\s+(primary)?/)
        {
# parse state helper var
            $curmon = $1;
            $prim = $curmon if $3;
            print "# curmon hit? $1 - $2 - ".(defined($3) ? $3 : "")."\n" if $debug > 4;
# disconnected and also no active resolution set!
            $disabled = ($2 eq "disconnected") && !$resFound;
            if($disabled)
            {
                print "# marked as disabled: $curmon\n" if $debug > 4;
#$turnRestOff.=" --display $curmon --off";
            }
            else
            {
                print "# add as connected: $curmon" if $debug > 4;
                push(@connected, $curmon);
            }
        }

        # consider active only when there is a flag in the resolution list...
        $active{$curmon} = (/^\s.*\*current/ && !$disabled) if $curmon;

        # print "# consider: $curmon" if $debug > 4;
        if (defined($currentEdid))
        {
            if (/:/) # now analyze and stop merging
            {
                parse_edid($currentEdid, $curmon);
                undef $currentEdid;
            }
            else
            {
                /(\w+)/;
                $currentEdid .= $1;
            }
        }
        elsif (/EDID:/)
        {
            $currentEdid = "";
        }
    }

    parse_edid($currentEdid, $curmon) if $currentEdid;
}

sub relabel_outputs
{
    for my $output (@connected)
    {
        my $newLabel = pick_for_output($output, "label");
        next unless $newLabel;
        $newLabel=~s/%OUTPUT/$output/g;
        my $oldLabel = $realname{$output};
        $newLabel=~s/%LABEL/$oldLabel/g if defined($oldLabel);
        $realname{$output} = $newLabel;
    }
}

sub eval_output
{
    my $l = shift;
    my $r = shift;
# that is always first and there is only one primary
    return -333 if ($l eq $prim);
    return 333 if ($r eq $prim);
    my $ar = $active{$r} or 0;
    my $al = $active{$l} or 0;
    return $ar <=> $al if $al != $ar;
# both are equally active or not active, then use output name
    return ($l cmp $r);
}

sub sort_monitors
{
# order the connected list, so that it starts with the active monitors,
# and among those the primary should be on the first place
	@connected = sort { eval_output($a, $b) } @connected;
}

sub ajoin { return join(' ', grep {length($_)} @_); }

sub format_last_off
{
    my $start = shift;
    my $xlast = $#connected;
    return "" if $start > $xlast;
    return ajoin(map { "--output '$_' --off" } @connected[$start..$xlast]);
}

sub nameOf
{
    my $id = shift;
    my $getsPrimary = shift;

    if(exists $realname{$id})
    {
        $id = $realname{$id};
    }
    else
    {
# old workaround for sysfs <-> xrandr mapping
#        # uber-clever xrandr hides the bustype prefix if the name is unambiguous but the kernel doesn't, so try to find the real name there
#        foreach ("A", "D", "I") {
#            my $altName = $id;
#            return $realname{$altName} if ($altName =~ s/-(\d)/-A-$1/ && exists $realname{$altName});
#        }
    }
    my $flag = $getsPrimary ? "*" : "";
    $id =~ s/%PRIMFLAG/$flag/g;
    return $id;
}

sub loc
{
    my $forced = pick_for_output(shift, "posopt");
    return defined($forced) ? ($forced) : @_;
}

sub add_conf
{
    my ($showname, $icon, $cmd, $postCmdHint) = @_;
    #	push(@actionMap, [ mini_hash($cmd), $showname, $icon, $cmd ]);
    my @cmdHints = $postCmdHint ? @{$postCmdHint} : ($prim);
    my $newPrim = $cmdHints[0];
    my %dedup;
    my @xcmds;

    print "add_conf: $showname, $icon, $cmd, $postCmdHint" if $debug > 4;

    for my $involved (@cmdHints)
    {
        print "# affected: $involved\n" if $debug;
        my $mocmd = pick_for_output($involved, "postcmd");
        next unless defined($mocmd);
        $mocmd=~s/%OUTPUT/$involved/g;
        next if $dedup{$mocmd}++;
        push(@xcmds, $mocmd);
    }
    my $cocmd = pick_for_combo($showname, "postcmd");
    push(@xcmds, $cocmd) if ($cocmd && 0 == $dedup{$cocmd});
    push(@xcmds, "icesh restart") if ($cfiledata[0]{"restart-on-primary-change"} && $newPrim && $newPrim ne $prim);

    if (@xcmds)
    {
        $cmd = "sh -c '$xrandr ".join(" ; ", ($cmd, @xcmds))."'";
    }
    else
    {
        $cmd = "$xrandr $cmd";
    }

    push(@actionMap, [
        #reserved
        undef,
        $showname, $icon, $cmd ]);
}

sub run
{
    my $rof = "--right-of";
    my $lof = "--left-of";
    my $priFlag = "--primary";

    parse_arguments;
    read_xrandr `$xrandr`;
    sort_monitors;
    load_ini;
    relabel_outputs;

    # XXX: the handling of future parameters is a mess, redundant flag passing for primary, multiple lookups from
    # config for the same target. It should better be calculated in objects.

    foreach my $mon (@connected)
    {
        my @parms = map { "--output $_ ".($_ eq $mon ?  fmtMode($mon)." $priFlag" : "--off") } @connected;
        add_conf(nameOf($mon), "setscreen".(1+int(@actionMap)), ajoin( @parms), [$mon]);
    }

    if (@connected > 1)
    {
        my $killRest = format_last_off(2);
        my $sec = $connected[1];
        add_conf(nameOf($prim, 1)." + ".nameOf($sec), "setscreen12",
            ajoin(fmtOutputMode($prim), $priFlag, loc($prim), fmtOutputMode($sec), loc($sec, $rof, $prim), $killRest),
            [$prim, $sec]
        );
        add_conf(nameOf($sec)." + ".nameOf($prim, 1), "setscreen21",
            ajoin(fmtOutputMode($sec), loc($sec), fmtOutputMode($prim), $priFlag, loc($prim, $rof, $sec), $killRest),
            [$prim, $sec]);
        add_conf(nameOf($prim)." + ".nameOf($sec, 1), "setscreen12x",
            ajoin(fmtOutputMode($prim), loc($prim), fmtOutputMode($sec), $priFlag, loc($sec, $rof, $prim), $killRest),
            [$sec, $prim]
        );
        add_conf(nameOf($sec, 1)." + ".nameOf($prim), "setscreen21x",
            ajoin(fmtOutputMode($prim), loc($prim), fmtOutputMode($sec), $priFlag, loc($sec, $lof, $prim), $killRest),
            [$sec, $prim]);
        add_conf(join(" / ", map { nameOf($_) } @connected), "display",
            ajoin(map { fmtOutputMode($_)." --pos 0x0" } @connected));
        # one pair is covered above, for 3 and more, let's find something creative
        if (@connected > 2)
        {
            my $cmd;
            my $last;
            foreach(@connected)
            {
                $cmd .= ' ' if $cmd;
                $cmd .= fmtOutputMode($_).($last ? " $rof $last" : "");
                $last = $_;
            }
            add_conf(join(" ++ ", map { nameOf($_) } @connected), "display", $cmd, [undef, @connected]);
        }
    }

    print Dumper(@actionMap) if $debug > 1;

    if ($activate)
    {
        for my $p (@actionMap)
        {
            my @el = @{$p};
            next if $activate ne $el[1];
            my $cmd = "$xrandr $el[3]";
            print "# Would run: $cmd\n" if $dry_run;
            exit($dry_run ? 0 : system("sh", "-c", $cmd));
        }
        print STDERR "Unknown selection: $activate\n";
        exit(42);
    }
    else
    {
        for my $p (@actionMap)
        {
            my @el = @{$p};
            my $name = $el[1];
            my $icon = $el[2];
            $name = $auto_num++ .": ".$name if $auto_num;
            print "prog '$name' $icon $el[3]\n";
        }
    }
}

run;

# vim: set ai sw=4 ts=4 tw=72 et nocin spell spelllang=en_ca:
