package TAP::Parser::Iterator::Process;

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

use TAP::Parser::Iterator ();
use Config;
use IO::Handle;

@ISA = 'TAP::Parser::Iterator';

my $IS_WIN32 = ( $^O =~ /^(MS)?Win32$/ );

=head1 NAME

TAP::Parser::Iterator::Process - Iterator for process-based TAP sources

=head1 VERSION

Version 3.26

=cut

$VERSION = '3.26';

=head1 SYNOPSIS

use TAP::Parser::Iterator::Process;
my %args = (
command => ['python', 'setup.py', 'test'],
merge => 1,
setup => sub { ... },
teardown => sub { ... },
);
my $it = TAP::Parser::Iterator::Process->new(\%args);
my $line = $it->next;

=head1 DESCRIPTION

This is a simple iterator wrapper for executing external processes, used by
L<TAP::Parser>. Unless you're writing a plugin or subclassing, you probably
won't need to use this module directly.

=head1 METHODS

=head2 Class Methods

=head3 C<new>

Create an iterator. Expects one argument containing a hashref of the form:

command => \@command_to_execute
merge => $attempt_merge_stderr_and_stdout?
setup => $callback_to_setup_command
teardown => $callback_to_teardown_command

Tries to uses L<IPC::Open3> & L<IO::Select> to communicate with the spawned
process if they are available. Falls back onto C<open()>.

=head2 Instance Methods

=head3 C<next>

Iterate through the process output, of course.

=head3 C<next_raw>

Iterate raw input without applying any fixes for quirky input syntax.

=head3 C<wait>

Get the wait status for this iterator's process.

=head3 C<exit>

Get the exit status for this iterator's process.

=cut

{

local $^W; # no warnings
# get around a catch22 in the test suite that causes failures on Win32:
local $SIG{__DIE__} = undef;
eval { require POSIX; &POSIX::WEXITSTATUS(0) };
if ($@) {
*_wait2exit = sub { $_[1] >> 8 };
}
else {
*_wait2exit = sub { POSIX::WEXITSTATUS( $_[1] ) }
}
}

sub _use_open3 {
my $self = shift;
return unless $Config{d_fork} || $IS_WIN32;
for my $module (qw( IPC::Open3 IO::Select )) {
eval "use $module";
return if $@;
}
return 1;
}

{
my $got_unicode;

sub _get_unicode {
return $got_unicode if defined $got_unicode;
eval 'use Encode qw(decode_utf8);';
$got_unicode = $@ ? 0 : 1;

}
}

# new() implementation supplied by TAP::Object

sub _initialize {
my ( $self, $args ) = @_;

my @command = @{ delete $args->{command} || [] }
or die "Must supply a command to execute";

$self->{command} = [@command];

# Private. Used to frig with chunk size during testing.
my $chunk_size = delete $args->{_chunk_size} || 65536;

my $merge = delete $args->{merge};
my ( $pid, $err, $sel );

if ( my $setup = delete $args->{setup} ) {
$setup->(@command);
}

my $out = IO::Handle->new;

if ( $self->_use_open3 ) {

# HOTPATCH {{{
my $xclose = \&IPC::Open3::xclose;
local $^W; # no warnings
local *IPC::Open3::xclose = sub {
my $fh = shift;
no strict 'refs';
return if ( fileno($fh) == fileno(STDIN) );
$xclose->($fh);
};

# }}}

if ($IS_WIN32) {
$err = $merge ? '' : '>&STDERR';
eval {
$pid = open3(
'<&STDIN', $out, $merge ? '' : $err,
@command
);
};
die "Could not execute (@command): $@" if $@;
if ( $] >= 5.006 ) {

# Kludge to avoid warning under 5.5
eval 'binmode($out, ":crlf")';
}
}
else {
$err = $merge ? '' : IO::Handle->new;
eval { $pid = open3( '<&STDIN', $out, $err, @command ); };
die "Could not execute (@command): $@" if $@;
$sel = $merge ? undef : IO::Select->new( $out, $err );
}
}
else {
$err = '';
my $command
= join( ' ', map { $_ =~ /\s/ ? qq{"$_"} : $_ } @command );
open( $out, "$command|" )
or die "Could not execute ($command): $!";
}

$self->{out} = $out;
$self->{err} = $err;
$self->{sel} = $sel;
$self->{pid} = $pid;
$self->{exit} = undef;
$self->{chunk_size} = $chunk_size;

if ( my $teardown = delete $args->{teardown} ) {
$self->{teardown} = sub {
$teardown->(@command);
};
}

return $self;
}

=head3 C<handle_unicode>

Upgrade the input stream to handle UTF8.

=cut

sub handle_unicode {
my $self = shift;

if ( $self->{sel} ) {
if ( _get_unicode() ) {

# Make sure our iterator has been constructed and...
my $next = $self->{_next} ||= $self->_next;

# ...wrap it to do UTF8 casting
$self->{_next} = sub {
my $line = $next->();
return decode_utf8($line) if defined $line;
return;
};
}
}
else {
if ( $] >= 5.008 ) {
eval 'binmode($self->{out}, ":utf8")';
}
}

}

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

sub wait { shift->{wait} }
sub exit { shift->{exit} }

sub _next {
my $self = shift;

if ( my $out = $self->{out} ) {
if ( my $sel = $self->{sel} ) {
my $err = $self->{err};
my @buf = ();
my $partial = ''; # Partial line
my $chunk_size = $self->{chunk_size};
return sub {
return shift @buf if @buf;

READ:
while ( my @ready = $sel->can_read ) {
for my $fh (@ready) {
my $got = sysread $fh, my ($chunk), $chunk_size;

if ( $got == 0 ) {
$sel->remove($fh);
}
elsif ( $fh == $err ) {
print STDERR $chunk; # echo STDERR
}
else {
$chunk = $partial . $chunk;
$partial = '';

# Make sure we have a complete line
unless ( substr( $chunk, -1, 1 ) eq "\n" ) {
my $nl = rindex $chunk, "\n";
if ( $nl == -1 ) {
$partial = $chunk;
redo READ;
}
else {
$partial = substr( $chunk, $nl + 1 );
$chunk = substr( $chunk, 0, $nl );
}
}

push @buf, split /\n/, $chunk;
return shift @buf if @buf;
}
}
}

# Return partial last line
if ( length $partial ) {
my $last = $partial;
$partial = '';
return $last;
}

$self->_finish;
return;
};
}
else {
return sub {
if ( defined( my $line = <$out> ) ) {
chomp $line;
return $line;
}
$self->_finish;
return;
};
}
}
else {
return sub {
$self->_finish;
return;
};
}
}

sub next_raw {
my $self = shift;
return ( $self->{_next} ||= $self->_next )->();
}

sub _finish {
my $self = shift;

my $status = $?;

# Avoid circular refs
$self->{_next} = sub {return}
if $] >= 5.006;

# If we have a subprocess we need to wait for it to terminate
if ( defined $self->{pid} ) {
if ( $self->{pid} == waitpid( $self->{pid}, 0 ) ) {
$status = $?;
}
}

( delete $self->{out} )->close if $self->{out};

# If we have an IO::Select we also have an error handle to close.
if ( $self->{sel} ) {
( delete $self->{err} )->close;
delete $self->{sel};
}
else {
$status = $?;
}

# Sometimes we get -1 on Windows. Presumably that means status not
# available.
$status = 0 if $IS_WIN32 && $status == -1;

$self->{wait} = $status;
$self->{exit} = $self->_wait2exit($status);

if ( my $teardown = $self->{teardown} ) {
$teardown->();
}

return $self;
}

=head3 C<get_select_handles>

Return a list of filehandles that may be used upstream in a select()
call to signal that this Iterator is ready. Iterators that are not
handle based should return an empty list.

=cut

sub get_select_handles {
my $self = shift;
return grep $_, ( $self->{out}, $self->{err} );
}

1;

=head1 ATTRIBUTION

Originally ripped off from L<Test::Harness>.

=head1 SEE ALSO

L<TAP::Object>,
L<TAP::Parser>,
L<TAP::Parser::Iterator>,

=cut