package XMLTV::ValidateGrabber;

use strict;

BEGIN {
    use Exporter   ();
    our (@ISA, @EXPORT, @EXPORT_OK, %EXPORT_TAGS);
    
    @ISA         = qw(Exporter);
    @EXPORT      = qw( );
    %EXPORT_TAGS = ( );     # eg: TAG => [ qw!name1 name2! ],
    @EXPORT_OK   = qw/ConfigureGrabber ValidateGrabber/;
}
our @EXPORT_OK;

my $CMD_TIMEOUT = 600;

=head1 NAME

XMLTV::ValidateGrabber - Validates an XMLTV grabber

=head1 DESCRIPTION

Utility library that validates that a grabber properly implements the
capabilities described at

http://wiki.xmltv.org/index.php/XmltvCapabilities

The ValidateGrabber call first asks the grabber which capabilities it
claims to support and then validates that it actually does support
these capabilities.

=head1 EXPORTED FUNCTIONS

All these functions are exported on demand.

=over 4

=cut

use XMLTV::ValidateFile qw/ValidateFile/;

use File::Slurp qw/read_file/;
use File::Spec::Functions qw/devnull/;
use List::Util qw(min);

my $runfh;

sub w;
sub run;
sub run_capture;

=item ConfigureGrabber

    ConfigureGrabber( "./tv_grab_new", "./tv_grab_new.conf" )

=cut

sub ConfigureGrabber {
    my( $exe, $conf ) = @_;

    if ( run( "$exe --configure --config-file $conf" ) ) {
	w "Error returned from grabber during configure.";
	return 1;
    }
    
    return 1;
}

=item ValidateGrabber

Run the validation for a grabber.

    ValidateGrabber( "tv_grab_new", "./tv_grab_new", "./tv_grab_new.conf", 
		     "/tmp/new_", "./blib/share", 0 )

ValidateGrabber takes the following parameters:

=over

=item *

a short name for the grabber. This is only used when printing error messages.

=item *

the command to run the grabber.

=item *

the name of a configuration-file for the grabber.

=item *

a file-prefix that is added to all output-files.

=item *

a path to a directory with metadata for the grabber. This path
is passed to the grabber via the --share option if the grabber
supports the capability 'share'. undef if no --share parameter shall
be used.

=item *

a boolean specifying if the --cache parameter shall be used for grabbers
that support the 'cache' capability.

=back

ValidateGrabber returns a list of errors that it found with the grabber. Each
error takes the form of a keyword:  

=over

=item noparamcheck

The grabber accepts any parameter without returning an error-code.

=item noversion

The grabber returns an error when run with --version.

=item nodescription

The grabber returns an error when run with --description.

=item nocapabilities

The grabber returns an error when run with --capabilities.

=item nobaseline

The grabber does not list 'baseline' as one of its supported capabilities.

=item nomanualconfig

The grabber does not list 'manualconfig' as one of its supported capabilities.

=item noconfigurationfile

The specified configuration-file does not exist.

=item graberror

The grabber returned with an error-code when asked to grab data.
 
=item notquiet

The grabber printed something to STDERR even though the --quiet option 
was used.

=item outputdiffers

The grabber produced different output when called with different combinations
of --output and --quiet.

=item caterror

tv_cat returned an error-code when we asked it to process the output from
the grabber.

=item sorterror

tv_sort found errors in the data generated by the grabber. Probably overlapping
programmes.

=item notadditive

grabbing data for tomorrow first and then for the day after tomorrow and
concatenating them does not yield the same result as grabbing the data
for tomorrow and the day after tomorrow at once.

=back

Additionally, the list of errors will contain error keywords from 
XMLTV::ValidateFile if the xmltv-file generated by the grabber was not
valid. 

If no errors are found, an empty list is returned.

=cut

sub ValidateGrabber {
    my( $shortname, $exe, $conf, $op, $sharedir, $usecache ) = @_;

    # if sharedir contains 'blib' we should prepend the relevant development paths!
    if( defined $sharedir && $sharedir =~ m|/blib/share/$| ) {
      my( $blib )=( $sharedir =~ m|^(.*/blib)/share/$| );

      use Env qw(@PATH @PERL5LIB);
      unshift( @PATH, $blib . '/script' );
      unshift( @PERL5LIB, $blib . '/lib' );
    }

    my @errors;
    open( $runfh, ">${op}commands.log" )
	or die "Failed to write to ${op}commands.log";

    if (not run( "$exe --ahdmegkeja > " . devnull() . " 2>&1" )) {
      w "$shortname with --ahdmegkeja did not fail. The grabber seems to "
	  . "accept any command-line parameter without returning an error.";
      push @errors, "noparamcheck";
    }

    if (run( "$exe --version > " . devnull() . " 2>&1" )) {
      w "$shortname with --version failed: $?, $!";
      push @errors, "noversion";
    }

    if (run( "$exe --description > " . devnull() . " 2>&1" )) {
      w "$shortname with --description failed: $?, $!";
      push @errors, "nodescription";
    }

    my $cap = run_capture( "$exe --capabilities 2> " . devnull() );
    if (not defined $cap) {
      w "$shortname with --capabilities failed: $?, $!";
      push @errors, "nocapabilities";
    }

    my @capabilities = split( /\s+/, $cap );
    my %capability;
    foreach my $c (@capabilities) {
	$capability{$c} = 1;
    }

    if (not defined( $capability{baseline} )) {
	w "The grabber does not claim to support the 'baseline' capability.";
	push @errors, "nobaseline";
    }

    if (not defined( $capability{manualconfig} )) {
	w "The grabber does not claim to support the 'manualconfig' capability.";
	push @errors, "nomanualconfig";
    }

    my $extraop = "";
    $extraop .= "--cache  ${op}cache " 
	if $capability{cache} and $usecache;
    $extraop .= "--share $sharedir "
	if $capability{share} and defined( $sharedir );

    if (not -f $conf) {
	w "Configuration file $conf does not exist. Aborting.";
	close( $runfh );
	push @errors, "noconfigurationfile";
	goto bailout;
    }

    # Should we test for --list-channels?

    my $cmd = "$exe --config-file $conf --offset 1 --days 2 $extraop";

    my $output = "${op}1_2";
    
    if (run "$cmd > $output.xml --quiet 2>${op}1.log") {
	w "$shortname failed: See ${op}1.log";
	push @errors, "graberror";
	goto bailout;
    }
    else {
	if ( -s "${op}1.log" ) {
	    w "$shortname with --quiet produced output to STDERR when it " .
		"shouldn't have. See ${op}1.log";
	    push @errors, "notquiet";
	}
	else {
	    unlink( "${op}1.log" );
	}

	# Okay, it ran, and we have the result in $output.xml.  Validate.
	my @xmlerr = ValidateFile( "$output.xml" );
	if (scalar(@xmlerr) > 0) {
	    w "Errors found in $output.xml";
	    close( $runfh );
	    push @errors, @xmlerr;
	    goto bailout;
	}
	w "$output.xml validates ok";
	
	# Run through tv_cat, which makes sure the data looks like XMLTV.
	# What kind of errors does this catch that ValidateFile misses?
	if (not cat_file( "$output.xml", devnull(), "${op}6.log" )) {
	    w "$output.xml makes tv_cat choke, see ${op}6.log";
	    push @errors, "caterror";
	    goto bailout;
	}
	
	# Do tv_sort sanity checks.  One day it would be better to put
	# this stuff in a Perl library.
	my $sort_errors = "$output.sort.log";
	if (not sort_file( "$output.xml", "$output.sorted.xml",
			   $sort_errors )) {
	    w "tv_sort failed on $output.xml, probably because of strange " .
		"start or stop times. See $sort_errors";
	    push @errors, "sorterror";
	}
	
    }

    # Run again to see that --output and --quiet works and to see that
    # --offset 1 --days 2 equals --offset 1 days 1 plus --offset 2 --days 1.
    my $output2 = "${op}1_1.xml";
    my $cmd2 = "$exe --config-file $conf --offset 1 --days 1 $extraop"
	. " --output $output2  2>${op}2.log";
    
    if (run $cmd2) {
	w "$shortname with --output failed: See ${op}2.log";
	push @errors, "graberror";
    }
    
    my $output3 = "${op}2_1.xml";
    my $cmd3 = "$exe --config-file $conf --offset 2 --days 1 $extraop"
	. " > $output3 2>${op}3.log";

    if (run $cmd3 ) {
	w "$shortname with --quiet failed: See ${op}3.log";
	push @errors, "graberror";
    }
    else {
	unlink( "${op}3.log" );
    }
    
    my $output4 = "${op}4.xml";
    my $cmd4 = "$cmd --quiet --output $output4 2>${op}4.log";

    if (run $cmd4 ) {
	w "$shortname with --quiet and --output failed: See ${op}4.log";
	push @errors, "graberror";
    }
    else {
	if ( -s "${op}4.log" ) {
	    w "$shortname with --quiet and --output produced output " .
		"to STDERR when it shouldn't have. See ${op}4.log";
	    push @errors, "notquiet";
	}
	else {
	    unlink( "${op}4.log" );
	}
    }
	
    if (not cat_files( $output2, $output3, "${op}1_2-2.xml", "${op}5.log" )) {
	w "tv_cat failed to concatenate the data. See ${op}5.log";
	push @errors, "caterror";
    }
    
    if (not sort_file( "${op}1_2-2.xml", "${op}1_2-2.sorted.xml", 
		       "${op}7.log" )) {
	w "tv_sort failed on the concatenated data. Probably due " .
	    "to overlapping data between days. See ${op}7.log";
	push @errors, "notadditive";
    }
    
    if( !compare_files( "$output.sorted.xml", "${op}1_2-2.sorted.xml",
			"${op}_1_2.diff" ) ) {
	w "The data is not additive. See ${op}_1_2.diff";
	push @errors, "notadditive";
    }
    
  bailout:
    close( $runfh );
    $runfh = undef;

    # Remove duplicate entries.
    my $lasterror = "nosucherror";
    my @ferrors;
    foreach my $err (@errors) {
	push( @ferrors, $err ) if $err ne $lasterror;
	$lasterror = $err;
    }

    if (scalar( @ferrors )) {
	w "$shortname did not validate ok. See ${op}commands.log for a " 
	    . "list of the commands that were used";
    }
    else {
	w "$shortname validated ok.";
    }

    return @ferrors;
}

sub w {
    print "$_[0]\n";
}

# Run an external command. Exit if the command is interrupted with ctrl-c.
sub run {
    my( $cmd ) = @_;

    print $runfh "$cmd\n"
	if defined $runfh;

    my $killed = 0;

    # Set a timer and run the real command.
    eval {
	local $SIG{ALRM} =
            sub {
		# ignore SIGHUP here so the kill only affects children.
		local $SIG{HUP} = 'IGNORE';
		kill 1,(-$$);
		$killed = 1;
	    };
	alarm $CMD_TIMEOUT;
	system ( $cmd );
	alarm 0;
    };
    $SIG{HUP} = 'DEFAULT';    

    if ($killed) {
	w "Timeout";
	return 1;
    }

    if ($? == -1) {
	w "Failed to execute $cmd: $!";
	return 1;
    }
    elsif ($? & 127) {
	w "Terminated by signal " . ($? & 127);
	exit 1;
    }

    return $? >> 8;
}

# Run an external command and return the output. Exit if the command is 
# interrupted with ctrl-c.
sub run_capture {
    my( $cmd ) = @_;

#    print "Running $cmd\n";

    my $killed = 0;
    my $result;

    # Set a timer and run the real command.
    eval {
	local $SIG{ALRM} =
            sub {
		# ignore SIGHUP here so the kill only affects children.
		local $SIG{HUP} = 'IGNORE';
		kill 1,(-$$);
		$killed = 1;
	    };
	alarm $CMD_TIMEOUT;
	$result = qx/$cmd/;
	alarm 0;
    };
    $SIG{HUP} = 'DEFAULT';    

    if ($killed) {
	w "Timeout";
	return undef;
    }

    if ($? == -1) {
	w "Failed to execute $cmd: $!";
	return undef;
    }
    elsif ($? & 127) {
	w "Terminated by signal " . ($? & 127);
	exit 1;
    }

    if ($? >> 8) {
	return undef;
    }
    else {
	return $result;
    }
}

# Compare two files. Return true if they have the same contents.
sub compare_files {
    my( $file1, $file2, $output ) = @_;

    $output = devnull() unless defined $output;
    run("diff $file1 $file2 > $output");
    return $? ? 0 : 1;
}

# Run an xmltv-file through tv_cat. Return true on success.
sub cat_file {
    my( $file1, $outfile, $logfile ) = @_;

    my $ret = run( "tv_cat $file1 > $outfile 2>$logfile" );
    
    return $ret ? 0 : 1;
}

# Concatenate two xmltv-files. Return true on success.
sub cat_files {
    my( $file1, $file2, $outfile, $logfile ) = @_;

    my $ret = run( "tv_cat $file1 $file2 > $outfile 2>$logfile" );
    
    return $ret ? 0 : 1;
}

# Sort an xmltv-file. Return true on success
sub sort_file {
    my( $file1, $outfile, $logfile ) = @_;

    my $ret = run( "tv_sort --duplicate-error $file1 > $outfile 2>$logfile" );
    
    return 0 if -s $logfile > 0;
    return $ret ? 0 : 1;
}
    
1;


=back 
   
=head1 COPYRIGHT

Copyright (C) 2006 Mattias Holmlund.

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

=cut

### Setup indentation in Emacs
## Local Variables:
## perl-indent-level: 4
## perl-continued-statement-offset: 4
## perl-continued-brace-offset: 0
## perl-brace-offset: -4
## perl-brace-imaginary-offset: 0
## perl-label-offset: -2
## cperl-indent-level: 4
## cperl-brace-offset: 0
## cperl-continued-brace-offset: 0
## cperl-label-offset: -2
## cperl-extra-newline-before-brace: t
## cperl-merge-trailing-else: nil
## cperl-continued-statement-offset: 2
## indent-tabs-mode: t
## End:
