#! /usr/bin/perl
# * * * * * nice -n20 /root/bin/heat -s
use strict;
use warnings;
my $schedulefile="/root/heat.schedule";
my $statefile="/root/heat.state";
my $resetfile="/root/heat.reset";
my $usbrelay="/root/bin/usbrelay";
my $logfile="/var/log/heat.log";
require POSIX;
$|=1;
sub readfile($) {
  my($fname)=@_;
  local *F;
  if (!open F,$fname) {
    warn "$fname: $!";
    return undef;
  }
  my $F=do { local $/; <F>; };
  defined $F or die "read $fname: $!";
  close F or die "read-close $fname: $!";
  return $F;
}
sub writefile($$;$) {
  my($fname,$content,$mode)=@_;
  local *F;
  open F,($mode||">").$fname or die "$fname: $!";
  print F $content or die "write $fname: $!";
  close F or die "write-close $fname: $!";
}
sub logmsg($) {
  my($s)=@_;
  chomp $s;
  writefile $logfile,POSIX::strftime("%Y-%m-%dT%H:%M:%S",localtime)." $s\n",">>";
}
sub spawn($) {
  my($cmd)=@_;
  $cmd.=" >&2";
  system $cmd and die "$cmd: $!";
}
my($trash,$min,$hour)=localtime;
my $minutes=$hour*60+$min;
if (($ARGV[0]||"")=~/^[@]0?(\d+):0?(\d+)$/) {
  $minutes=$1*60+$2;
  shift;
}
my $finishline;
my %schedule;
my $schedule;
if (-e $schedulefile) {
  $schedule=readfile $schedulefile;
  while ($schedule=~s/^(0?(\d+):0?(\d+)) ([01s])\n//) {
    my $tm=$2*60+$3;
    warn "$schedulefile set twice for: $1" if defined $schedule{$tm};
    $schedule{$tm-24*60}="$1 $4\n";
    $schedule{$tm      }="$1 $4\n";
    $schedule{$tm+24*60}="$1 $4\n";
  }
  warn "$schedulefile garbage: $schedule" if $schedule ne "";
  warn "Empty $schedulefile" if !%schedule;
}
sub schedulenext($) {
  return undef if !%schedule;
  my($now)=@_;
  my($bestprev,$prev,$bestnext,$next);
  for my $found (keys(%schedule)) {
    if ($found<=$now) {
      next if defined $bestprev&&$bestprev>$found;
      $bestprev=$found;
      $prev=$schedule{$found};
    } else {
      next if defined $bestnext&&$bestnext<$found;
      $bestnext=$found;
      $next=$schedule{$found};
    }
  }
  die "No bestprev" if !defined $bestprev;
  die "No bestnext" if !defined $bestnext;
  return [$prev,$next];
}
$finishline=schedulenext($minutes);
$finishline=[$finishline->[1]] if $finishline;
my $silent=shift if ($ARGV[0]||"") eq "-s";
logmsg "command: ".join(" ",@ARGV) if !$silent&&@ARGV;
sub info($) {
  my($s)=@_;
  print $s if !$silent;
}
sub finish() {
  info join("",@$finishline) if defined $finishline;
  exit 0;
}
my $reset=readfile $resetfile if -e $resetfile;
my($resetminutes,$resetstate);
sub resetread() {
  $reset=~/^0?(\d+)[:.]0?(\d+) ([01s]|reset)\n$/ or warn "Invalid $resetfile: $reset";
  $resetminutes=$1*60+$2;
  $resetstate=($3 eq "reset"?undef:$3);
}
sub unlink_resetfile() {
  unlink $resetfile or die "$resetfile: $!";
  logmsg "remove reset: $reset";
  $reset=$resetminutes=undef;
}
if (defined $reset) {
  resetread;
  unlink_resetfile if $resetminutes==$minutes;
}
sub finishlinereset() {
  $finishline=schedulenext $resetminutes;
  if ($finishline) {
    $finishline=[$reset,$finishline->[1]];
  } else {
    $finishline=[$reset];
  }
}
finishlinereset if defined $reset;
my $state=readfile $statefile;
chomp $state;
info $state;
my $newstate=shift;
if (!defined $newstate&&defined $resetstate&&!defined $resetminutes) {
  $newstate=$resetstate;
  logmsg "reset: $newstate";
}
sub printminutes($) {
  my($m)=@_;
  return sprintf "%02d:%02d",int($m/60),$m%60;
}
if ($silent) {
  if (!defined $newstate&&!defined $reset&&%schedule) {
    my $prev=schedulenext($minutes);
    if ($prev) {
      my $prev=$prev->[0];
      if ($prev=~m{ (.)\n$}) {
	$newstate=$1;
	logmsg "scheduled: $prev";
      }
    }
  }
  $newstate=$state if !defined $newstate;
}
if (!defined $newstate) {
  info "\n";
  finish;
}
die "state!={s|0|1}" if $newstate!~/^[s01]$/;
sub setstate() {
  info "->$newstate";
  writefile $statefile,"$newstate\n" if $state ne $newstate;
  logmsg "$state->$newstate" if $state ne $newstate;
  if ($newstate ne "s") {
    my $pid=readfile "pidof -x dnf;true|";
    die "\n".printminutes($minutes)." change $state".($state eq $newstate?"":"->$newstate")." refused: dnf running: $pid" if $pid;
  }
  my $both={"s"=>[0,0],"0"=>[1,0],"1"=>[1,1]}->{$newstate};
  spawn "$usbrelay 1 ".$both->[0];
  spawn "$usbrelay 2 ".$both->[1];
  info "\n";
}
my $newreset=shift;
die "Excessive args: ".join(" ",@ARGV) if @ARGV;
if (!defined $newreset) {
  setstate;
  if (!$silent&&defined $reset) {
    unlink_resetfile;
    $finishline=schedulenext($minutes);
    $finishline=[$finishline->[1]] if $finishline;
  }
  finish;
}
$reset=$newreset;
if ($reset=~/^\d+$/) {
  $resetminutes=($reset+$minutes)%(24*60);
  $reset=printminutes($resetminutes)." reset\n";
  setstate;
} else {
  $reset.=" reset\n";
  resetread;
  $reset=printminutes($resetminutes)." $newstate\n";
  info "\n";
}
writefile $resetfile,$reset;
logmsg "new reset: $reset";
finishlinereset;
finish;