#!/usr/bin/env perl
use strict;
#use warnings;
use Getopt::Long qw(:config no_ignore_case);
use Data::Dumper;

#
# Code released under GPLv3: http://www.gnu.org/licenses/gpl.html
# v0.3 - Adrian Popa (2016.03.11) 
#

#we get our data mainly from /sys/devices/system/cpu

my %options = ();

my $cls = "\033[2J\033[0;0H"; #fancy ANSI escape string

GetOptions(\%options, 'help|h', 'quiet|q', 'list|l', 'set|s', 'governor|g:s', 'cpu|c=s', 'min|m:s', 'max|M:s', 'frequency|f', 'interactive|i=f', 'temperature|t');
#print Dumper(\%options);

if(defined $options{'help'}){
    usage();
    exit(0);
}

if(defined $options{'set'}){
    #interpret the parameters as a set command
    
    #user must be root
    die "The script must be run as root in order to apply changes!" if($> != 0);
    
    #see on which cpus you need to set things
    my @cpu = getCPUs();
    my %before;
    if(! exists $options{'quiet'}){
        %before = getListing(@cpu);
    }
    
    #set the data
    foreach my $core (@cpu){
        if(defined $options{'governor'}){
            open FILE, ">/sys/devices/system/cpu/cpu${core}/cpufreq/scaling_governor" or die "$!";
            print FILE $options{'governor'};
            close FILE;
        }
        if(defined $options{'min'}){
            open FILE, ">/sys/devices/system/cpu/cpu${core}/cpufreq/scaling_min_freq" or die "$!";
            my $number = $options{'min'};
            if($options{'min'}=~/([0-9\.]+)(M|G)?/){
                $number = $1;
                my $scale = $2;
                $number = $number * 1000 if($scale eq 'M');
                $number = $number * 1000_000 if($scale eq 'G');
            }
            print FILE $number;
            close FILE;
        }
        if(exists $options{'max'}){
            open FILE, ">/sys/devices/system/cpu/cpu${core}/cpufreq/scaling_max_freq" or die "$!";
            my $number = $options{'max'};
            if($options{'max'}=~/([0-9\.]+)(M|G)?/){
                $number = $1;
                my $scale = $2;
                #print "DBG: $options{'max'}\n";
                $number = $number * 1000 if(defined $scale && $scale eq 'M');
                $number = $number * 1000_000 if(defined $scale && $scale eq 'G');
            }
            print FILE $number;
            close FILE;
        }
        if(exists $options{'frequency'}){
            #can't set current frequency
        }
    }
    
    #display results (if any)
    if(! exists $options{'quiet'}){
        my %after = getListing(@cpu);
#        print "DBG: ".Dumper(\%after);
        foreach my $core (@cpu){
            
            if(defined $after{$core}{'governor'}){
                print "CPU$core: governor $before{$core}{'governor'} -> $after{$core}{'governor'}\n";
            }
            if(defined $after{$core}{'scale_min'}){
                print "CPU$core: min ".humanReadable($before{$core}{'scale_min'})." [".humanReadable($before{$core}{'cpuinfo_min'}) ."] -> ".humanReadable($after{$core}{'scale_min'})." [".humanReadable($after{$core}{'cpuinfo_min'}) ."]\n";
            }
            if(defined $after{$core}{'scale_max'}){
                print "CPU$core: max ".humanReadable($before{$core}{'scale_max'})." [".humanReadable($before{$core}{'cpuinfo_max'}) ."] -> ".humanReadable($after{$core}{'scale_max'})." [".humanReadable($after{$core}{'cpuinfo_max'}) ."]\n";
            }
        }
    }
    
}
elsif(defined $options{'list'}){
    #select all things to display if none is specified
    if(! exists $options{'governor'} && ! exists $options{'min'} && ! exists $options{'max'} && ! exists $options{'frequency'} && ! exists $options{'temperature'}){
        $options{'governor'} = undef;
        $options{'min'} = undef;
        $options{'max'} = undef;
        $options{'frequency'} = undef;
	$options{'temperature'} = undef;
    }
    #start an infinte loop in case we're in interactive mode
    while(1){
    	my @cpu = getCPUs();
	
        #make output buffered
        $|=0;
	
	if(defined $options{'interactive'}){
		print $cls;
		print "Type CTRL+C to exit.\n";
	}
        
	my $temp = 0;
	if(defined $options{'temperature'}){
	    $temp = getTemperature();
	}

	#print Dumper(\%results);
	if(exists $options{'governor'} || exists $options{'frequency'} || exists $options{'min'} || exists $options{'max'}){
	    my %results = getListing(@cpu);
        #display the data -- redundant for, but we might expand/decouple the display later
	foreach my $core (@cpu){
        
	    my $output.= "CPU$core: ";
    	    $output.="governor $results{$core}{'governor'}\t" if (exists $results{$core}{'governor'});
    	    $output.="current ".humanReadable($results{$core}{'cur'})."\t" if (exists $results{$core}{'cur'});
    	    $output.="min ".humanReadable($results{$core}{'scale_min'})." [".humanReadable($results{$core}{'cpuinfo_min'}) ."]\t" if (exists $results{$core}{'scale_min'});
    	    $output.="max ".humanReadable($results{$core}{'scale_max'})." [".humanReadable($results{$core}{'cpuinfo_max'}) ."] \t" if (exists $results{$core}{'scale_max'});
        
        
    	    print $output."\n";
	}
	}
	if(defined $options{'temperature'}){
	    print "TEMP: ${temp}C\n";
	}

	if(defined $options{'interactive'}){
	    #sleep($options{'interactive'});
	    #sleep fractional seconds without the need of Time::HiRes
	    select(undef, undef, undef, $options{'interactive'});
	}
	else{
	    last; #break the infinite while
	}
    $|=1;
    }
}
else{
    usage();
    exit(1);
}

sub humanReadable{
    my $value = shift;
    my %scaleMapping = (
        '3' => 'MHz',
        '6' => 'GHz',
        '9' => 'THz'
    );
    
    my $result = $value;
    my $scale = 0;
    my $break = 0;
    while($result >= 1000){
        $result = $result/1000;
        $scale+=3;
    }
    return sprintf("%.2f", $result) . $scaleMapping{$scale};
}

sub usage{
    my $governors = getData("/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors");
    print "Usage:
$0 [options]

Options:
 -l, --list\t\t\t List a parameter
 -s, --set\t\t\t Set a parameter
 -g, --governor <governor>\t Select a governor
 \t\t\t\t ($governors)
 -c, --cpu <number|range>\t The CPU to edit/query. Leave blank for all CPUs. Valid syntax:
 \t\t\t\t 0; 0,4; 0,4,5-7; 0-7
 -m, --min <number>\t\t The minimum CPU frequency (must be supported by governor and CPU)
 -M, --max <number>\t\t The maximum CPU frequency (must be supported by governor and CPU)
 -f, --frequency\t\t The current CPU frequency
 -t, --temperature\t\t The current CPU temperature
 -q, --quiet\t\t\t Don't display much output when setting a parameter
 -i, --interactive <number>\t Keep running the list command every number seconds
 -h, --help\t\t\t Show this help screen
 
Examples:
 $0 -l\t\t\t\tLists current frequency/governor for all cores
 $0 -l -g -f\t\t\t\tLists just governor and current frequency for all cores
 $0 -l -c 0,4\t\t\t\tLists all information only for cores 0 and 4
 $0 -l -c 0-4\t\t\t\tLists all information for cores 0 to 4
 $0 -s -g powersave -m 300M -M 600M\tSets governor, minimum and maximum frequency for all cores
 $0 -s -M 1.2G -c 0,4\t\t\tSets maximum frequency on cores 0 and 4
"
}

sub getCPUs{
    my @cpu = ();
    #see if the user specified a CPU
    if(defined $options{'cpu'}){
        #parse the CPU option. Could be a number or a sequence
        # -c 1
        # -c 1,4
        # -c 1,4,5-8
        my @commas = split(/,/, $options{'cpu'});
        foreach my $comma (@commas){
            #see if there are any ranges
            if($comma=~/([0-9]+)-([0-9]+)/){
                my $start = $1;
                my $stop = $2;
                for($start..$stop){
                    push @cpu, $_;
                }
            }
            else{
                push @cpu, $comma;
            }
        }
        #push @cpu, $options{'cpu'};
    }
    else{
        #get all cpus from the system
        my $content = getData("/sys/devices/system/cpu/online");
        if($content=~/([0-9]+)(?:-([0-9]+))?/){
            my $minCPU = $1;
	    my $maxCPU = $minCPU;
	    $maxCPU = $2 if(defined $2);
            for($minCPU..$maxCPU){
                push @cpu, $_;
            }
        }
        else{
            die "Unable to get the list of CPUs";
        }
    }
    return @cpu;
}

sub getData{
    my $filename = shift;
    my $line = 'N/A';
    if(open FILE, "$filename"){
    	$line = <FILE>;
    	$line=~s/\r|\n//g;
    	close FILE;
    }
    return $line;
}

sub getTemperature{
    my $temperatureFile = '/sys/devices/virtual/thermal/thermal_zone0/temp';
    my $temp = 0;
    if(-f "$temperatureFile"){
	$temp = getData($temperatureFile);
	$temp = $temp/1000;
    }
    return $temp;
}

sub getListing{
    my %results;
    my @cpu = @_;
    
    #get the data
    foreach my $core (@cpu){
        if(exists $options{'governor'}){
            $results{$core}{'governor'} = getData("/sys/devices/system/cpu/cpu${core}/cpufreq/scaling_governor");
        }
        if(exists $options{'min'}){
            $results{$core}{'scale_min'} = getData("/sys/devices/system/cpu/cpu${core}/cpufreq/scaling_min_freq");
            $results{$core}{'cpuinfo_min'} = getData("/sys/devices/system/cpu/cpu${core}/cpufreq/cpuinfo_min_freq");
        }
        if(exists $options{'max'}){
            $results{$core}{'scale_max'} = getData("/sys/devices/system/cpu/cpu${core}/cpufreq/scaling_max_freq");
            $results{$core}{'cpuinfo_max'} = getData("/sys/devices/system/cpu/cpu${core}/cpufreq/cpuinfo_max_freq");
        }
        if(exists $options{'frequency'}){
            $results{$core}{'cur'} = getData("/sys/devices/system/cpu/cpu${core}/cpufreq/scaling_cur_freq");
        }
    }
    
    return %results;
}