package Slic3r;

# Copyright holder: Alessandro Ranellucci
# This application is licensed under the GNU Affero General Public License, version 3

use strict;
use warnings;
require v5.10;

our $VERSION = VERSION();

our $debug = 0;
sub debugf {
    printf @_ if $debug;
}

# load threads before Moo as required by it
our $have_threads;
BEGIN {
    use Config;
    $have_threads = $Config{useithreads} && eval "use threads; use threads::shared; use Thread::Queue; 1";
    warn "threads.pm >= 1.96 is required, please update\n" if $have_threads && $threads::VERSION < 1.96;
    
    ### temporarily disable threads if using the broken Moo version
    use Moo;
    $have_threads = 0 if $Moo::VERSION == 1.003000;
}

warn "Running Slic3r under Perl 5.16 is not supported nor recommended\n"
    if $^V == v5.16;

use FindBin;
our $var = "$FindBin::Bin/var";

use Encode;
use Encode::Locale;
use Moo 1.003001;

use Slic3r::XS;   # import all symbols (constants etc.) before they get parsed
use Slic3r::Config;
use Slic3r::ExPolygon;
use Slic3r::ExtrusionLoop;
use Slic3r::ExtrusionPath;
use Slic3r::Fill;
use Slic3r::Flow;
use Slic3r::Format::AMF;
use Slic3r::Format::OBJ;
use Slic3r::Format::STL;
use Slic3r::GCode;
use Slic3r::GCode::ArcFitting;
use Slic3r::GCode::CoolingBuffer;
use Slic3r::GCode::MotionPlanner;
use Slic3r::GCode::PlaceholderParser;
use Slic3r::GCode::PressureRegulator;
use Slic3r::GCode::Reader;
use Slic3r::GCode::SpiralVase;
use Slic3r::GCode::VibrationLimit;
use Slic3r::Geometry qw(PI);
use Slic3r::Geometry::Clipper;
use Slic3r::Layer;
use Slic3r::Layer::PerimeterGenerator;
use Slic3r::Layer::Region;
use Slic3r::Line;
use Slic3r::Model;
use Slic3r::Point;
use Slic3r::Polygon;
use Slic3r::Polyline;
use Slic3r::Print;
use Slic3r::Print::GCode;
use Slic3r::Print::Object;
use Slic3r::Print::Simple;
use Slic3r::Print::SupportMaterial;
use Slic3r::Surface;
our $build = eval "use Slic3r::Build; 1";
use Thread::Semaphore;

use constant SCALING_FACTOR         => 0.000001;
use constant RESOLUTION             => 0.0125;
use constant SCALED_RESOLUTION      => RESOLUTION / SCALING_FACTOR;
use constant SMALL_PERIMETER_LENGTH => (6.5 / SCALING_FACTOR) * 2 * PI;
use constant LOOP_CLIPPING_LENGTH_OVER_NOZZLE_DIAMETER => 0.15;
use constant INFILL_OVERLAP_OVER_SPACING  => 0.3;
use constant EXTERNAL_INFILL_MARGIN => 3;
use constant INSET_OVERLAP_TOLERANCE => 0.4;

# keep track of threads we created
my @my_threads = ();
my @threads : shared = ();
my $pause_sema = Thread::Semaphore->new;
my $parallel_sema;
my $paused = 0;

sub spawn_thread {
    my ($cb) = @_;
    
    my $parent_tid = threads->tid;
    lock @threads;
    
    @_ = ();
    my $thread = threads->create(sub {
        @my_threads = ();
        
        Slic3r::debugf "Starting thread %d (parent: %d)...\n", threads->tid, $parent_tid;
        local $SIG{'KILL'} = sub {
            Slic3r::debugf "Exiting thread %d...\n", threads->tid;
            $parallel_sema->up if $parallel_sema;
            kill_all_threads();
            Slic3r::thread_cleanup();
            threads->exit();
        };
        local $SIG{'STOP'} = sub {
            $pause_sema->down;
            $pause_sema->up;
        };
        $cb->();
    });
    push @my_threads, $thread->tid;
    push @threads, $thread->tid;
    return $thread;
}

sub parallelize {
    my %params = @_;
    
    lock @threads;
    if (!$params{disable} && $Slic3r::have_threads && $params{threads} > 1) {
        my @items = (ref $params{items} eq 'CODE') ? $params{items}->() : @{$params{items}};
        my $q = Thread::Queue->new;
        $q->enqueue(@items, (map undef, 1..$params{threads}));
        
        $parallel_sema = Thread::Semaphore->new(-$params{threads});
        $parallel_sema->up;
        my $thread_cb = sub {
            # execute thread callback
            $params{thread_cb}->($q);
            
            # signal the parent thread that we're done
            $parallel_sema->up;
            
            # cleanup before terminating thread
            Slic3r::thread_cleanup();
            
            # This explicit exit avoids an untrappable 
            # "Attempt to free unreferenced scalar" error
            # triggered on Ubuntu 12.04 32-bit when we're running 
            # from the Wx plater and
            # we're reusing the same plater object more than once.
            # The downside to using this exit is that we can't return
            # any value to the main thread but we're not doing that
            # anymore anyway.
            threads->exit;
        };
            
        @_ = ();
        my @my_threads = map spawn_thread($thread_cb), 1..$params{threads};
        
        # We use a semaphore instead of $th->join because joined threads are
        # not listed by threads->list or threads->object anymore, thus can't
        # be signalled.
        $parallel_sema->down;
        $_->detach for @my_threads;
    } else {
        $params{no_threads_cb}->();
    }
}

# call this at the very end of each thread (except the main one)
# so that it does not try to free existing objects.
# at that stage, existing objects are only those that we 
# inherited at the thread creation (thus shared) and those 
# that we are returning: destruction will be handled by the
# main thread in both cases.
# reminder: do not destroy inherited objects in other threads,
# as the main thread will still try to destroy them when they
# go out of scope; in other words, if you're undef()'ing an 
# object in a thread, make sure the main thread still holds a
# reference so that it won't be destroyed in thread.
sub thread_cleanup {
    return if !$Slic3r::have_threads;
    
    # prevent destruction of shared objects
    no warnings 'redefine';
    *Slic3r::BridgeDetector::DESTROY        = sub {};
    *Slic3r::Config::DESTROY                = sub {};
    *Slic3r::Config::Full::DESTROY          = sub {};
    *Slic3r::Config::GCode::DESTROY         = sub {};
    *Slic3r::Config::Print::DESTROY         = sub {};
    *Slic3r::Config::PrintObject::DESTROY   = sub {};
    *Slic3r::Config::PrintRegion::DESTROY   = sub {};
    *Slic3r::ExPolygon::DESTROY             = sub {};
    *Slic3r::ExPolygon::Collection::DESTROY = sub {};
    *Slic3r::Extruder::DESTROY              = sub {};
    *Slic3r::ExtrusionLoop::DESTROY         = sub {};
    *Slic3r::ExtrusionPath::DESTROY         = sub {};
    *Slic3r::ExtrusionPath::Collection::DESTROY = sub {};
    *Slic3r::Flow::DESTROY                  = sub {};
    *Slic3r::GCode::PlaceholderParser::DESTROY = sub {};
    *Slic3r::GCode::Writer::DESTROY         = sub {};
    *Slic3r::Geometry::BoundingBox::DESTROY = sub {};
    *Slic3r::Geometry::BoundingBoxf::DESTROY = sub {};
    *Slic3r::Geometry::BoundingBoxf3::DESTROY = sub {};
    *Slic3r::Line::DESTROY                  = sub {};
    *Slic3r::Linef3::DESTROY                = sub {};
    *Slic3r::Model::DESTROY                 = sub {};
    *Slic3r::Model::Object::DESTROY         = sub {};
    *Slic3r::Point::DESTROY                 = sub {};
    *Slic3r::Pointf::DESTROY                = sub {};
    *Slic3r::Pointf3::DESTROY               = sub {};
    *Slic3r::Polygon::DESTROY               = sub {};
    *Slic3r::Polyline::DESTROY              = sub {};
    *Slic3r::Polyline::Collection::DESTROY  = sub {};
    *Slic3r::Print::DESTROY                 = sub {};
    *Slic3r::Print::Object::DESTROY         = sub {};
    *Slic3r::Print::Region::DESTROY         = sub {};
    *Slic3r::Surface::DESTROY               = sub {};
    *Slic3r::Surface::Collection::DESTROY   = sub {};
    *Slic3r::TriangleMesh::DESTROY          = sub {};
    return undef;  # this prevents a "Scalars leaked" warning
}

sub get_running_threads {
    return grep defined($_), map threads->object($_), @_;
}

sub kill_all_threads {
    # if we're the main thread, we send SIGKILL to all the running threads
    if (threads->tid == 0) {
        lock @threads;
        foreach my $thread (get_running_threads(@threads)) {
            Slic3r::debugf "Thread %d killing %d...\n", threads->tid, $thread->tid;
            $thread->kill('KILL');
        }
        
        # unlock semaphore before we block on wait
        # otherwise we'd get a deadlock if threads were paused
        resume_all_threads();
    }
    
    # in any thread we wait for our children
    foreach my $thread (get_running_threads(@my_threads)) {
        Slic3r::debugf "  Thread %d waiting for %d...\n", threads->tid, $thread->tid;
        $thread->join;  # block until threads are killed
        Slic3r::debugf "    Thread %d finished waiting for %d...\n", threads->tid, $thread->tid;
    }
    @my_threads = ();
}

sub pause_all_threads {
    return if $paused;
    lock @threads;
    $paused = 1;
    $pause_sema->down;
    $_->kill('STOP') for get_running_threads(@threads);
}

sub resume_all_threads {
    return unless $paused;
    lock @threads;
    $paused = 0;
    $pause_sema->up;
}

sub encode_path {
    my ($filename) = @_;
    return encode('locale_fs', $filename);
}

sub decode_path {
    my ($filename) = @_;
    return decode('locale_fs', $filename);
}

sub open {
    my ($fh, $mode, $filename) = @_;
    return CORE::open $$fh, $mode, encode_path($filename);
}

# this package declaration prevents an ugly fatal warning to be emitted when
# spawning a new thread
package GLUquadricObjPtr;

1;
