#!/usr/bin/perl

use strict;
use warnings;

package PHPFina;
our $VERSION = '1.00';

use POSIX 'strftime';
#use Getopt::Long;

#my $directory = 'data/phpfina';
#my $clean;
#my $binout_filename;
#
#GetOptions('dir=s'    => \$directory,
#           'binary=s' => \$binout_filename,
#            clean     => \$clean,
#          );
#
#die "usage: $0 [ -d data-directory ] [ -b binary-output-filename ] [ -clean ] data-file-number output-filename\n"
#    unless scalar @ARGV == 2;
#
#get_phpfina($directory, $ARGV[0], $ARGV[1]);
#
#if ($clean)
#{
#	x
#}
#
#exit;
#
#################

sub isnan {!($_[0]<=0||$_[0]>=0)}

#################

=head2

  ($start_time, $first_value, $self) =
      PHPFina->new(
          [ directory => data/phpfina, ]
            id => file id number,
          [ fill_NaN => 0 / 1, ]
          [ fix_notches => 0 / 1, ]
      );

=cut

sub new
{
    my ($class, %args) = @_;

    my $self = bless({}, $class);

    my $d = $args{directory};
    $d = 'data/phpfina' unless defined $d;
    $self->{directory} = $d;
    my $id = $args{id};
    die "No file id number supplied" unless defined $id;
    $self->{id} = $id;

    my $path = $d;
    $path .= '/' unless $path =~ '/$';

    $self->{fill_NaN} = 1 if $args{fill_NaN};
    $self->{fix_notches} = 1 if $args{fix_notches};

    # Open the metadata file and read its contents
    open my $fh_meta, '<:raw', $path . $id . '.meta'
      or die "Can't open $path${id}.meta: $!\n";
    local $/ = \16;	# set record size
    my $raw_metadata = <$fh_meta>;
    close $fh_meta;

    my ($id_dummy, $npoints, $interval, $start_time) =
        unpack 'LLLL', $raw_metadata;

    $self->{interval}   = $interval;
    $self->{start_time} = $start_time;
    $self->{epoch}      = $start_time+$interval;
    $self->{prev_value} = 0;

print "$path$id metadata\n";
print "id:\t$id\n";
print "interval:\t$interval\n";
print "start_time:\t$start_time\t"
    . POSIX::strftime('%F %H:%M:%S', localtime $start_time) . "\n\n";

    # Open the data file and prepare to read the values
    open my $fh, '<:raw', $path . $id . '.dat'
        or die "Can't open $path${id}.dat: $!\n";

    local $/ = \4;	# set record size

    my $data  = <$fh>;
    return undef unless defined $data;
    my $value = unpack 'f', $data;
    $self->{fh} = $fh;

    return ($start_time, $value, $self);
}


sub get_next
{
    my ($self) = @_;

    local $/ = \4;	# set record size

    my $fh = $self->{fh};
    my $data  = <$fh>;
#    my $data  = <$self->{fh}>;
    return undef unless defined $data;
    my $value = unpack 'f', $data;

    # ignore NaN and replace if required
    $value = $self->{prev_value} if isnan($value) and $self->{fill_NaN};

    my $epoch = $self->{epoch};
    $self->{epoch} += $self->{interval};
    $self->{prev_value} = $value;

    return ($epoch, $value);
}

=pod

#sub get_phpfina
#{
#    my ($path, $id, $output_filename) = @_;
#
#    $path .= '/' unless $path =~ '/$';
#
#    warn "($path, $id, $output_filename)\n";
#
#    open STDOUT, '>', $output_filename
#      or die "Can't open output file $output_filename: $!\n";
#
#    open my $fh_meta, '<:raw', $path . $id . '.meta'
#      or die "Can't open $path${id}.meta: $!\n";
#    $/ = \16;	# set record size
#    my $raw_metadata = <$fh_meta>;
#    close $fh_meta;
#
#    my ($id_dummy, $npoints, $interval, $start_time) =
#        unpack 'LLLL', $raw_metadata;
#
#    print "$path$id metadata\n";
#    print "id:\t$id\n";
#    print "npoints:\t$npoints\n";
#    print "interval:\t$interval\n";
#    print "start_time:\t$start_time\t"
#        . POSIX::strftime('%F %H:%M:%S', localtime $start_time) . "\n";
#
#
#    open my $fh, '<:raw', $path . $id . '.dat'
#        or die "Can't open $path${id}.dat: $!\n";
#
#    local $/ = \4;	# set record size
#
    my $bofh;
    if ($binout_filename)
    {
        open $bofh, '>:raw', $binout_filename
	    or die "Can't create binary output file '$binout_filename': $!\n";
    }

    local $/ = \4;	# set record size

    print "\n$path$id\n";

    my $epoch = $start_time;
    my $prev_value = 0;
    my $moving_average = 0;
    my $alpha = 2/(5+1);
#    while (my $data = <$fh>)
#    # for (my $i = 0; $i < 10; $i++)
#    {
#        # my $data = <$fh>;
#        my ($value) = unpack 'f', $data;
        my $timestamp = POSIX::strftime('%F %H:%M:%S', localtime $epoch);

#	    if (isnan($value))
#	    {
#	        # ignore NaN and replace if required
#            warn "$timestamp\tNaN\n";
#	        $value = $prev_value if $clean;
#	    }	
#	    else
	    {
	        # fudge an initial value for moving average
            $moving_average = $value if $moving_average == 0;

	        if ($clean)
	        {
	            # look for spikes and replace if required
                if (abs($value - $moving_average) > 0.3)
                {
                    my $spike = sprintf '%.1f %.2f', $value, $moving_average;
                    warn "$timestamp\tspike\t$spike\n";
                    $value = $prev_value; # if $clean;
                }
                else
                {
                    $moving_average = 
                      $alpha * ($value - $moving_average) + $moving_average;
                }
            }
	    }

        print $timestamp, "\t";
        printf '%f', $value;
    	print "\t", $value - $prev_value;
        print "\n";

	    print $bofh pack('f', $value)
	      if $bofh;

        $epoch += $interval;
	    $prev_value = $value;
    }

    close $bofh if $bofh;
}

=cut

1;

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