#!/usr/bin/perl

# Companion script:

# #!/bin/bash
# cd
#while true; do
#  tput civis;
#  clear; tput smul;
#  printf "%+50s" "(every 5 mins)";
#  tput cub 99; date; tput sgr0; echo;
#  perl df-highlight.pl -c 3 -p;
#  echo; uptime | cut -d, -f4- | awk '{$1=$1};1' # https://unix.stackexchange.com/a/205854
#  tput cnorm; sleep 300;
#done

use warnings;
use strict;
use Term::ANSIColor;
use Time::HiRes qw(usleep nanosleep);
use Time::localtime;

# "User modifiable" data
my $DFCMD="/usr/bin/df";
my $TPUT="/usr/bin/tput";
my $DFARGS="-h";
my $CLEAR_SCREEN=`/usr/bin/clear`;

# Arguments
my ($CLS, $RBG, $ARGDEX, $MY_COL) = (0,0,0,3);
for (@ARGV) {
  if ($_ eq "-p") {$RBG=1;}
  elsif ($_ eq "-c") {$MY_COL=$ARGV[$ARGDEX+1];}
  elsif ($_ eq "--help" or $_ eq "-h" ) {get_help();}
  $ARGDEX++;
}

# Static data
my $ROW_START=`$TPUT cub 120`; # If this doesn't work on your terminal, make the value more than 120 lol
my $UP_ONE_ROW=`$TPUT cuu1`;
my $CLEAR_TO_END=`$TPUT el`;
my @HEADERS=qw(MT Filesystem Size Used Avail 'Use%' 'Mounted on');
my @COLORS=qw(MT bright_red bright_yellow bright_green bright_cyan bright_blue bright_magenta);
my @COLWIDTHS=qw(0 28 6 6 7 6 10);
my $COLOR_OFFSET=9;

# Helper functions
# https://stackoverflow.com/a/5047362
sub clean {my $text = shift; $text=~s/\n//g; $text=~s/\r//g;return $text;}
sub randcol {return int(rand(6)+1);}
sub cachemath {my $lcache=(localtime->min*60)+localtime->sec;return $lcache;}
sub get_help {
  my ($underline,$undereset)=(`tput smul`,`tput sgr0`);
  my @help_columns=qw(12);
  printf("\n%s%s%s\n\n","$underline","DF Highlight Script Usage","$undereset");
  printf("");
  printf(" %-$help_columns[0]s %s\n","-h, --help","Displays this help and exits");
  printf(" %-$help_columns[0]s %s\n","-c #","Highlights the specified column (default: 3)");
  printf(" %-$help_columns[0]s %s\n","-p","Enables a pinball-esque color mode before highlighting the chosen column");
  exit 0;
}

# Runtime data
my @linedata=();
my $line="";
my @dfdata=();
my $dfcache=0;
my $current_column=1;
my @colored_cols=qw'0';
my $rows=0;

sub dfboi {
  my $colored_column = $_[0];
  my $COLOR = $COLORS[$colored_column];
  if ($dfcache == 0 or cachemath()-$dfcache > 60) {
    # REFRESH DF DATA
    @dfdata=(); # Clear the array to avoid duplicating data
    open my $cmd, '-|', "$DFCMD $DFARGS";
    while (my $line = <$cmd>) {
      push(@dfdata,$line); # P O P U L A T E
    }
    close $cmd;
    $dfcache=cachemath();
    $rows=scalar @dfdata;
  }
  for (@dfdata) {
    $line=$_;
    $current_column=1;
    #             Filesystem            Size             Used             Avail            Use%        Mounted
    if ($line =~ /([a-zA-Z0-9\/\-_]+)\s+([0-9GMKT\.]+)\s+([0-9GMKT\.]+)\s+([0-9GMKT\.]+)\s+([0-9%]+)\s+([\/a-z\-0-9A-Z]+)/ or $line =~ /^(Filesystem)\s+(Size)\s+(Used)\s+(Avail)\s+(Use%)\s+(Mounted on)/) {
      @linedata=("MT", "$1", "$2", "$3", "$4", "$5", "$6");
      while ($current_column <= 6) {
        if ($current_column == $colored_column) {
          $colored_cols[0]=$COLWIDTHS[$current_column]+$COLOR_OFFSET;
          printf("%-$colored_cols[0]s",clean(colored("$linedata[$current_column]", $COLOR)));
        } else {
          printf("%-$COLWIDTHS[$current_column]s",clean("$linedata[$current_column]"));
        }
        $current_column=$current_column+1;
      }
    }
    printf("\n");
  }
}

if ($RBG) {
  my $blinky=10;
  my $undoline=0;
  while ($blinky--) {
    dfboi(randcol());
    select()->flush();
    usleep($blinky < 2 ? 600000 : $blinky < 4 ? 300000 : 150000);
    $undoline=0;
    while ($undoline < $rows) {printf("%s",$UP_ONE_ROW);$undoline++;}
  }
}
dfboi($MY_COL);