#!/usr/bin/env perl

use Carp;
use warnings;
use strict;

## report the program and machine
use Sys::Hostname;
my $host = hostname();
print "\n\n";
print "Starting script $0 on $host\n\n";

use vars qw( $VERSION );
$VERSION = '0.01';

use IPC::Cmd 0.36 qw( can_run run );
use PS::IPP::Metadata::Config;
use PS::IPP::Metadata::Stats;

use PS::IPP::Metadata::List qw( parse_md_list );
use Statistics::Descriptive;

use PS::IPP::Config qw($PS_EXIT_SUCCESS
		       $PS_EXIT_UNKNOWN_ERROR
		       $PS_EXIT_SYS_ERROR
		       $PS_EXIT_CONFIG_ERROR
		       $PS_EXIT_PROG_ERROR
		       $PS_EXIT_DATA_ERROR
		       $PS_EXIT_TIMEOUT_ERROR
		       caturi
		       );
my $ipprc = PS::IPP::Config->new(); # IPP configuration

use Getopt::Long qw( GetOptions :config auto_help auto_version gnu_getopt );
use Pod::Usage qw( pod2usage );

my ($det_id, $iter, $det_type, $camera, $filter, $workdir, $dbname, $no_update, $no_op);
GetOptions(
	   'det_id|d=s'        => \$det_id,
	   'iteration=s'       => \$iter,
	   'det_type|t=s'      => \$det_type,
	   'camera=s'          => \$camera,
	   'filter=s'          => \$filter,
	   'workdir|w=s'       => \$workdir, # Working directory for output files
	   'dbname|d=s'        => \$dbname, # Database name
	   'no-update'         => \$no_update,
	   'no-op'             => \$no_op,
) or pod2usage( 2 );

pod2usage( -msg => "Unknown option: @ARGV", -exitval => 2 ) if @ARGV;
pod2usage( -msg => "Required options: --det_id --iteration --det_type --camera",
	   -exitval => 3)
    unless defined $det_id
    and defined $iter
    and defined $det_type
    and defined $camera;

# values to extract from output metadata and the stats to calculate
# XXX -bg_mean_stdev should take rms of bg_mean_stdev if bg_mean_stdev != 0 (A)
# XXX -bg_mean_stdev should take stdev of bg_mean if bg_mean_stdev == 0     (B)
# XXX  (A) if imfile.Ncomp > 1, (B) if imfile.Ncomp == 1
my $STATS = 
   [   
       #          KEYWORD                 STATISTIC          CHIPTOOL FLAG
       { name => "bg",             type => "mean",  flag => "-bg",            dtype => "float" },
       { name => "bg_mean_stdev",  type => "stdev", flag => "-bg_mean_stdev", dtype => "float" },
       { name => "bg_stdev",       type => "rms",   flag => "-bg_stdev",      dtype => "float" },
   ];
my $stats = PS::IPP::Metadata::Stats->new($STATS); # Stats parser

# these stats are used it the rejections but not passed to the database
# there is some duplication with the above, but the calculation time is minimal
my $REJSTATS = 
   [   
       #          KEYWORD                 STATISTIC          CHIPTOOL FLAG
       { name => "bg",             type => "mean",  flag => "ensMeanMean",       dtype => "float" },
       { name => "bg",             type => "stdev", flag => "ensMeanStdev",      dtype => "float" },
       { name => "bg_mean_stdev",  type => "mean",  flag => "ensMeanStdevMean",  dtype => "float" },
       { name => "bg_mean_stdev",  type => "stdev", flag => "ensMeanStdevStdev", dtype => "float" },
       { name => "bg_stdev",       type => "mean",  flag => "ensStdevMean",      dtype => "float" },
       { name => "bg_stdev",       type => "stdev", flag => "ensStdevStdev",     dtype => "float" },
   ];
my $rejstats = PS::IPP::Metadata::Stats->new($REJSTATS); # Stats parser

# Look for programs we need
my $missing_tools;
my $dettool = can_run('dettool') or (warn "Can't find dettool" and $missing_tools = 1);
if ($missing_tools) { 
    warn("Can't find required tools.");
    exit($PS_EXIT_CONFIG_ERROR); 
}

# Get list of component files
my ($exposures, $command, $success, $error_code, $full_buf, $stdout_buf, $stderr_buf);
{
    # dettool command to select exp data for this det_run
    $command = "$dettool -residexp";
    $command .= " -det_id $det_id";
    $command .= " -iteration $iter";
    $command .= " -dbname $dbname" if defined $dbname;
    ( $success, $error_code, $full_buf, $stdout_buf, $stderr_buf ) =
	run(command => $command, verbose => 1);
    unless ($success) {
	$error_code = (($error_code >> 8) or $PS_EXIT_PROG_ERROR);
	&my_die("Unable to perform dettool -residexp: $error_code", $det_id, $iter, $error_code);
    }

    # Parse the stdout buffer into a metadata
    my $mdcParser = PS::IPP::Metadata::Config->new;	# Parser for metadata config files
    my $metadata = $mdcParser->parse(join "", @$stdout_buf) or
	&my_die("Unable to parse metadata config doc", $det_id, $iter, $PS_EXIT_PROG_ERROR);

    # parse the file info in the metadata
    $exposures = parse_md_list($metadata) or
	&my_die("Unable to parse metadata list", $det_id, $iter, $PS_EXIT_PROG_ERROR);

    # Parse the statistics on the residual image
    $stats->parse($metadata) or &my_die("Unable to find all values in statistics output.", $det_id, $iter, $PS_EXIT_PROG_ERROR);

    # Parse the statistics for rejections
    $rejstats->parse($metadata) or &my_die("Unable to find all values in statistics output.", $det_id, $iter, $PS_EXIT_PROG_ERROR);
}

# we use the statistics of the ensemble to accept/reject exposurs
my $ensMeanMean       = $rejstats->value_for_flag ("ensMeanMean");      
my $ensMeanStdev      = $rejstats->value_for_flag ("ensMeanStdev");     
my $ensMeanStdevMean  = $rejstats->value_for_flag ("ensMeanStdevMean"); 
my $ensMeanStdevStdev = $rejstats->value_for_flag ("ensMeanStdevStdev");
my $ensStdevMean      = $rejstats->value_for_flag ("ensStdevMean");     
my $ensStdevStdev     = $rejstats->value_for_flag ("ensStdevStdev");    

$ipprc->define_camera($camera);
# Rejection thresholds
my $reject_mean      = rejection_limit( 'ENSEMBLE.MEAN',      $det_type, $filter );
my $reject_stdev     = rejection_limit( 'ENSEMBLE.STDEV',     $det_type, $filter );
my $reject_meanstdev = rejection_limit( 'ENSEMBLE.MEANSTDEV', $det_type, $filter );

$workdir = caturi( $workdir, "$camera.$det_type.$det_id" ) if defined $workdir;

my $logName = $ipprc->file_prepare( "$camera.$det_type.$det_id.$iter.detreject.log", $workdir ); # Name for log

my $logFile;
unless ($no_op) {
    $logFile = $ipprc->file_create_append( $logName );
    print $logFile "Ensemble mean $ensMeanMean +/- $ensMeanStdevMean, stdev $ensStdevMean\n\n";
}

# Go through again to do rejection, and update the database for each exposure
my $numChanges = 0;		# Number of exposures with changed status
my $numReject = 0;		# Number of exposures rejected
my $firstElement = 1;

foreach my $exposure (@$exposures) {
    my $mean      = $exposure->{bg};	# Mean for this exposure
    my $stdev     = $exposure->{bg_stdev}; # Stdev for this exposure
    my $meanStdev = $exposure->{bg_mean_stdev}; # Stdev of Means for this exposure
    my $expID     = $exposure->{exp_id};
    my $accept    = $exposure->{accept};
    my $include   = $exposure->{include};

    &my_die("Unable to find exposure id.\n", $det_id, $iter, $PS_EXIT_SYS_ERROR) unless defined $expID;
    &my_die("Unable to find accept.\n",      $det_id, $iter, $PS_EXIT_SYS_ERROR) unless defined $accept;
    &my_die("Unable to find include.\n",     $det_id, $iter, $PS_EXIT_SYS_ERROR) unless defined $include;

    my $reject = 0;		# Reject this exposure?

    $command  = "$dettool -updateresidexp";
    $command .= " -det_id $det_id";
    $command .= " -iteration $iter";
    $command .= " -exp_id $expID";
    $command .= " -dbname $dbname" if defined $dbname;
    
    if (not $accept) {
	# Rejected this at an earlier stage
	unless ($no_op) {
	    print $logFile "Rejecting $expID based on earlier determination.\n";
	}
	$reject = 1;
	goto UPDATE;
    }

    # Cop-out if we're not doing any operations
    if ($no_op) {
	# Make sure something gets rejected (just once!), just so that
	# we can trace the full range of the workflow
	if ($firstElement and $iter == 0) {
	    $reject = 1;
	}
	goto UPDATE;
    }
    
    if ($reject_mean > 0 and $ensMeanStdev > 0) {
	my $delta = abs($mean - $ensMeanMean);
	if ($delta > ($reject_mean * $ensMeanStdev)) {
	    print $logFile "Rejecting $expID based on ensemble mean value: ";
	    $reject = 1;
	    #goto UPDATE;
	} else {
	    print $logFile "$expID OK against ensemble mean: ";
	}
	print $logFile "$mean --> $delta vs " . $reject_mean * $ensMeanStdev . "\n";
    } else {
	print $logFile "No rejection of $expID for ensemble mean\n";
    }

    if ($reject_stdev > 0 and $ensStdevStdev > 0) {
	my $delta = abs($stdev - $ensStdevMean);
	if ($delta > ($reject_stdev * $ensStdevStdev)) {
	    print $logFile "Rejecting $expID based on ensemble stdev: ";
	    $reject = 1;
	    #goto UPDATE;
	} else {
	    print $logFile "$expID OK against ensemble stdev: ";
	}
	print $logFile "$stdev --> $delta sigma vs " . $reject_stdev * $ensStdevStdev . "\n";
    } else {
	print $logFile "No rejection of $expID for ensemble stdev\n";
    }
    
    if ($reject_meanstdev > 0 and $ensMeanStdevStdev > 0) {
	my $delta = abs($meanStdev - $ensMeanStdevMean);
	if ($delta > ($reject_meanstdev * $ensMeanStdevStdev)) {
	    print $logFile "Rejecting $expID based on ensemble mean stdev: ";
	    $reject = 1;
	    #goto UPDATE;
	} else {
	    print $logFile "$expID OK against ensemble mean stdev: ";
	}
	print $logFile "$meanStdev --> $delta sigma vs " . $reject_meanstdev * $ensMeanStdevStdev. "\n";
    } else {
	print $logFile "No rejection of $expID for ensemble mean stdev\n";
    }

  UPDATE:
    if ($reject) {
	$command .= ' -reject';
	$numReject++;
    }
    
    # Check for status changes
    if ((not $include and not $reject) or ($include and $reject)) {
	unless ($no_op) {
	    print $logFile "Status of $expID has changed.\n";
	}
	$numChanges++;
    }

    unless ($no_update) {
	# Update 
	( $success, $error_code, $full_buf, $stdout_buf, $stderr_buf ) =
	    run(command => $command, verbose => 1);
	unless ($success) {
	    $error_code = (($error_code >> 8) or $PS_EXIT_PROG_ERROR);
	    &my_die("Unable to perform dettool -updateresidexp: $error_code", $det_id, $iter, $error_code);
	}
    }
}

# Decide if the current is sufficient to use as a master, and if we can stop iterating
my $master = 1;			# This is good enough for a master
my $stop = 1;			# Stop iterating

if ($numChanges > 0) {
    $master = 0;
    $stop = 0;
}

# Rejecting everything --- stop before something bad happens!
if ($numReject == scalar @$exposures) {
    $master = 0;
    $stop = 1;
}

unless ($no_op) {
    print $logFile "Master: $master\n";
    print $logFile "Stop: $stop\n";
    close $logFile;
}

## add the summary statistics, and request a new iteration if needed
$command = "$dettool -adddetrunsummary";
$command .= " -det_id $det_id";
$command .= " -iteration $iter";
$command .= " -accept" if $master;
$command .= " -dbname $dbname" if defined $dbname;
$command .= " -again" unless $stop; 
$command .= $stats->cmdflags();

# Put results into the database
unless ($no_update) {
    ( $success, $error_code, $full_buf, $stdout_buf, $stderr_buf ) =
	run(command => $command, verbose => 1);
    unless ($success) {
	$error_code = (($error_code >> 8) or $PS_EXIT_PROG_ERROR);
	warn("Unable to perform dettool -adddetrunsummary: $error_code");
	exit($error_code);
    }
} else {
    print "skipping command: $command\n";
}

END {
    my $status = $?;
    system("sync") == 0
        or die "failed to execute sync: $!" ;
    $? = $status;
}


sub my_die
{
    my $msg = shift; # Warning message on die
    my $det_id = shift;		# Detrend identifier
    my $iter = shift;		# Iteration
    my $exit_code = shift; # Exit code to add

    carp($msg);
    if ($det_id and $iter and not $no_update) {
	my $command = "$dettool -adddetrunsummary";
	$command .= " -det_id $det_id";
	$command .= " -iteration $iter";
	$command .= " -code $exit_code";
	$command .= " -dbname $dbname" if defined $dbname;
###        system ($command);
    }
    exit $exit_code;
}

# Retrieve the requested rejection limit, dying unless extant
sub rejection_limit
{
    my $name = shift;		# Rejection limit to 
    my $type = shift;		# Type of exposure
    my $filter = shift;		# Filter

    my $value = $ipprc->rejection( $name, $det_type, $filter );
    if (not defined $value) {
	$filter = "(no filter)" unless defined $filter;
	die "Unable to determine $name rejection limit for $det_type with $filter.\n";
    }

    return $value;
}

__END__
