package TAP::Parser::Source;

use strict;
use vars qw($VERSION @ISA);

use TAP::Object ();
use File::Basename qw( fileparse );

use constant BLK_SIZE => 512;

@ISA = qw(TAP::Object);

=head1 NAME

TAP::Parser::Source - a TAP source & meta data about it

=head1 VERSION

Version 3.26

=cut

$VERSION = '3.26';

=head1 SYNOPSIS

use TAP::Parser::Source;
my $source = TAP::Parser::Source->new;
$source->raw( \'reference to raw TAP source' )
->config( \%config )
->merge( $boolean )
->switches( \@switches )
->test_args( \@args )
->assemble_meta;

do { ... } if $source->meta->{is_file};
# see assemble_meta for a full list of data available

=head1 DESCRIPTION

A TAP I<source> is something that produces a stream of TAP for the parser to
consume, such as an executable file, a text file, an archive, an IO handle, a
database, etc. C<TAP::Parser::Source>s encapsulate these I<raw> sources, and
provide some useful meta data about them. They are used by
L<TAP::Parser::SourceHandler>s, which do whatever is required to produce &
capture a stream of TAP from the I<raw> source, and package it up in a
L<TAP::Parser::Iterator> for the parser to consume.

Unless you're writing a new L<TAP::Parser::SourceHandler>, a plugin or
subclassing L<TAP::Parser>, you probably won't need to use this module directly.

=head1 METHODS

=head2 Class Methods

=head3 C<new>

my $source = TAP::Parser::Source->new;

Returns a new C<TAP::Parser::Source> object.

=cut

# new() implementation supplied by TAP::Object

sub _initialize {
my ($self) = @_;
$self->meta( {} );
$self->config( {} );
return $self;
}

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

=head2 Instance Methods

=head3 C<raw>

my $raw = $source->raw;
$source->raw( $some_value );

Chaining getter/setter for the raw TAP source. This is a reference, as it may
contain large amounts of data (eg: raw TAP).

=head3 C<meta>

my $meta = $source->meta;
$source->meta({ %some_value });

Chaining getter/setter for meta data about the source. This defaults to an
empty hashref. See L</assemble_meta> for more info.

=head3 C<has_meta>

True if the source has meta data.

=head3 C<config>

my $config = $source->config;
$source->config({ %some_value });

Chaining getter/setter for the source's configuration, if any has been provided
by the user. How it's used is up to you. This defaults to an empty hashref.
See L</config_for> for more info.

=head3 C<merge>

my $merge = $source->merge;
$source->config( $bool );

Chaining getter/setter for the flag that dictates whether STDOUT and STDERR
should be merged (where appropriate). Defaults to undef.

=head3 C<switches>

my $switches = $source->switches;
$source->config([ @switches ]);

Chaining getter/setter for the list of command-line switches that should be
passed to the source (where appropriate). Defaults to undef.

=head3 C<test_args>

my $test_args = $source->test_args;
$source->config([ @test_args ]);

Chaining getter/setter for the list of command-line arguments that should be
passed to the source (where appropriate). Defaults to undef.

=cut

sub raw {
my $self = shift;
return $self->{raw} unless @_;
$self->{raw} = shift;
return $self;
}

sub meta {
my $self = shift;
return $self->{meta} unless @_;
$self->{meta} = shift;
return $self;
}

sub has_meta {
return scalar %{ shift->meta } ? 1 : 0;
}

sub config {
my $self = shift;
return $self->{config} unless @_;
$self->{config} = shift;
return $self;
}

sub merge {
my $self = shift;
return $self->{merge} unless @_;
$self->{merge} = shift;
return $self;
}

sub switches {
my $self = shift;
return $self->{switches} unless @_;
$self->{switches} = shift;
return $self;
}

sub test_args {
my $self = shift;
return $self->{test_args} unless @_;
$self->{test_args} = shift;
return $self;
}

=head3 C<assemble_meta>

my $meta = $source->assemble_meta;

Gathers meta data about the L</raw> source, stashes it in L</meta> and returns
it as a hashref. This is done so that the L<TAP::Parser::SourceHandler>s don't
have to repeat common checks. Currently this includes:

is_scalar => $bool,
is_hash => $bool,
is_array => $bool,

# for scalars:
length => $n
has_newlines => $bool

# only done if the scalar looks like a filename
is_file => $bool,
is_dir => $bool,
is_symlink => $bool,
file => {
# only done if the scalar looks like a filename
basename => $string, # including ext
dir => $string,
ext => $string,
lc_ext => $string,
# system checks
exists => $bool,
stat => [ ... ], # perldoc -f stat
empty => $bool,
size => $n,
text => $bool,
binary => $bool,
read => $bool,
write => $bool,
execute => $bool,
setuid => $bool,
setgid => $bool,
sticky => $bool,
is_file => $bool,
is_dir => $bool,
is_symlink => $bool,
# only done if the file's a symlink
lstat => [ ... ], # perldoc -f lstat
# only done if the file's a readable text file
shebang => $first_line,
}

# for arrays:
size => $n,

=cut

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

return $self->meta if $self->has_meta;

my $meta = $self->meta;
my $raw = $self->raw;

# rudimentary is object test - if it's blessed it'll
# inherit from UNIVERSAL
$meta->{is_object} = UNIVERSAL::isa( $raw, 'UNIVERSAL' ) ? 1 : 0;

if ( $meta->{is_object} ) {
$meta->{class} = ref($raw);
}
else {
my $ref = lc( ref($raw) );
$meta->{"is_$ref"} = 1;
}

if ( $meta->{is_scalar} ) {
my $source = $$raw;
$meta->{length} = length($$raw);
$meta->{has_newlines} = $$raw =~ /\n/ ? 1 : 0;

# only do file checks if it looks like a filename
if ( !$meta->{has_newlines} and $meta->{length} < 1024 ) {
my $file = {};
$file->{exists} = -e $source ? 1 : 0;
if ( $file->{exists} ) {
$meta->{file} = $file;

# avoid extra system calls (see `perldoc -f -X`)
$file->{stat} = [ stat(_) ];
$file->{empty} = -z _ ? 1 : 0;
$file->{size} = -s _;
$file->{text} = -T _ ? 1 : 0;
$file->{binary} = -B _ ? 1 : 0;
$file->{read} = -r _ ? 1 : 0;
$file->{write} = -w _ ? 1 : 0;
$file->{execute} = -x _ ? 1 : 0;
$file->{setuid} = -u _ ? 1 : 0;
$file->{setgid} = -g _ ? 1 : 0;
$file->{sticky} = -k _ ? 1 : 0;

$meta->{is_file} = $file->{is_file} = -f _ ? 1 : 0;
$meta->{is_dir} = $file->{is_dir} = -d _ ? 1 : 0;

# symlink check requires another system call
$meta->{is_symlink} = $file->{is_symlink}
= -l $source ? 1 : 0;
if ( $file->{is_symlink} ) {
$file->{lstat} = [ lstat(_) ];
}

# put together some common info about the file
( $file->{basename}, $file->{dir}, $file->{ext} )
= map { defined $_ ? $_ : '' }
fileparse( $source, qr/\.[^.]*/ );
$file->{lc_ext} = lc( $file->{ext} );
$file->{basename} .= $file->{ext} if $file->{ext};

if ( !$file->{is_dir} && $file->{read} ) {
eval { $file->{shebang} = $self->shebang($$raw); };
if ( my $e = $@ ) {
warn $e;
}
}
}
}
}
elsif ( $meta->{is_array} ) {
$meta->{size} = $#$raw + 1;
}
elsif ( $meta->{is_hash} ) {
; # do nothing
}

return $meta;
}

=head3 C<shebang>

Get the shebang line for a script file.

my $shebang = TAP::Parser::Source->shebang( $some_script );

May be called as a class method

=cut

{

# Global shebang cache.
my %shebang_for;

sub _read_shebang {
my ( $class, $file ) = @_;
open my $fh, '<', $file or die "Can't read $file: $!\n";

# Might be a binary file - so read a fixed number of bytes.
my $got = read $fh, my $buf, BLK_SIZE;
defined $got or die "I/O error: $!\n";
return $1 if $buf =~ /(.*)/;
return;
}

sub shebang {
my ( $class, $file ) = @_;
$shebang_for{$file} = $class->_read_shebang($file)
unless exists $shebang_for{$file};
return $shebang_for{$file};
}
}

=head3 C<config_for>

my $config = $source->config_for( $class );

Returns L</config> for the $class given. Class names may be fully qualified
or abbreviated, eg:

# these are equivalent
$source->config_for( 'Perl' );
$source->config_for( 'TAP::Parser::SourceHandler::Perl' );

If a fully qualified $class is given, its abbreviated version is checked first.

=cut

sub config_for {
my ( $self, $class ) = @_;
my ($abbrv_class) = ( $class =~ /(?:\:\:)?(\w+)$/ );
my $config = $self->config->{$abbrv_class} || $self->config->{$class};
return $config;
}

1;

__END__

=head1 AUTHORS

Steve Purkis.

=head1 SEE ALSO

L<TAP::Object>,
L<TAP::Parser>,
L<TAP::Parser::IteratorFactory>,
L<TAP::Parser::SourceHandler>

=cut