package Font::TTF::Mort::Ligature;

=head1 NAME

Font::TTF::Mort::Ligature - Ligature Mort subtable for AAT

=head1 METHODS

=cut

use strict;

use vars qw(@ISA);

use Font::TTF::Utils;

use Font::TTF::AATutils;

use IO::File;

@ISA = qw(Font::TTF::Mort::Subtable);

sub new

{

    my ($class, $direction, $orientation, $subFeatureFlags) = @_;

    my ($self) = {

                    'direction'            => $direction,

                    'orientation'        => $orientation,

                    'subFeatureFlags'    => $subFeatureFlags

                };

    $class = ref($class) || $class;

    bless $self, $class;

}

=head2 $t->read

Reads the table into memory

=cut

sub read

{

    my ($self, $fh) = @_;

    my ($dat);

    my $stateTableStart = $fh->tell();

    my ($classes, $states, $entries) = AAT_read_state_table($fh, 0);

    $fh->seek($stateTableStart, IO::File::SEEK_SET);

    $fh->read($dat, 14);

    my ($stateSize, $classTable, $stateArray, $entryTable,

        $ligActionTable, $componentTable, $ligatureTable) = unpack("nnnnnnn", $dat);

    my $limits = [$classTable, $stateArray, $entryTable, $ligActionTable, $componentTable, $ligatureTable, $self->{'length'} - 8];

    my %actions;

    my $actionLists;

    foreach (@$entries) {

        my $offset = $_->{'flags'} & 0x3fff;

        $_->{'flags'} &= ~0x3fff;

        if ($offset != 0) {

            if (not defined $actions{$offset}) {

                $fh->seek($stateTableStart + $offset, IO::File::SEEK_SET);

                my $actionList;

                while (1) {

                    $fh->read($dat, 4);

                    my $action = unpack("N", $dat);

                    my ($last, $store, $component) = (($action & 0x80000000) != 0, ($action & 0xC0000000) != 0, ($action & 0x3fffffff));

                    $component -= 0x40000000 if $component > 0x1fffffff;

                    $component -= $componentTable / 2;

                    push @$actionList, { 'store' => $store, 'component' => $component };

                    last if $last;

                }

                push @$actionLists, $actionList;

                $actions{$offset} = $#$actionLists;

            }

            $_->{'actions'} = $actions{$offset};

        }

    }

    $self->{'componentTable'} = $componentTable;

    my $components = [unpack("n*", AAT_read_subtable($fh, $stateTableStart, $componentTable, $limits))];

    foreach (@$components) {

        $_ = ($_ - $ligatureTable) . " +" if $_ >= $ligatureTable;

    }

    $self->{'components'} = $components;

    $self->{'ligatureTable'} = $ligatureTable;

    $self->{'ligatures'} = [unpack("n*", AAT_read_subtable($fh, $stateTableStart, $ligatureTable, $limits))];

    $self->{'classes'} = $classes;

    $self->{'states'} = $states;

    $self->{'actionLists'} = $actionLists;

    $self;

}

=head2 $t->pack_sub($fh)

=cut

sub pack_sub

{

    my ($self) = @_;

    my ($dat);

    $dat .= pack("nnnnnnn", (0) x 7);    # placeholders for stateSize, classTable, stateArray, entryTable, actionLists, components, ligatures

    my $classTable = length($dat);

    my $classes = $self->{'classes'};

    $dat .= AAT_pack_classes($classes);

    my $stateArray = length($dat);

    my $states = $self->{'states'};

    my ($dat1, $stateSize, $entries) = AAT_pack_states($classes, $stateArray, $states,

            sub {

                ( $_->{'flags'} & 0xc000, $_->{'actions'} )

            }

        );

    $dat .= $dat1;

    my $actionLists = $self->{'actionLists'};

    my %actionListOffset;

    my $actionListDataLength = 0;

    my @actionListEntries;

    foreach (0 .. $#$entries) {

        my ($nextState, $flags, $offset) = split(/,/, $entries->[$_]);

        if ($offset eq "") {

            $offset = undef;

        }

        else {

            if (defined $actionListOffset{$offset}) {

                $offset = $actionListOffset{$offset};

            }

            else {

                $actionListOffset{$offset} = $actionListDataLength;

                my $list = $actionLists->[$offset];

                $actionListDataLength += 4 * @$list;

                push @actionListEntries, $list;

                $offset = $actionListOffset{$offset};

            }

        }

        $entries->[$_] = [ $nextState, $flags, $offset ];

    }

    my $entryTable = length($dat);

    my $ligActionLists = ($entryTable + @$entries * 4 + 3) & ~3;

    foreach (@$entries) {

        $_->[2] += $ligActionLists if defined $_->[2];

        $dat .= pack("nn", $_->[0], $_->[1] + $_->[2]);

    }

    $dat .= pack("C*", (0) x ($ligActionLists - $entryTable - @$entries * 4));

    die "internal error" unless length($dat) == $ligActionLists;

    my $componentTable = length($dat) + $actionListDataLength;

    my $actionList;

    foreach $actionList (@actionListEntries) {

        foreach (0 .. $#$actionList) {

            my $action = $actionList->[$_];

            my $val = $action->{'component'} + $componentTable / 2;

            $val += 0x40000000 if $val < 0;

            $val &= 0x3fffffff;

            $val |= 0x40000000 if $action->{'store'};

            $val |= 0x80000000 if $_ == $#$actionList;

            $dat .= pack("N", $val);

        }

    }

    die "internal error" unless length($dat) == $componentTable;

    my $components = $self->{'components'};

    my $ligatureTable = $componentTable + @$components * 2;

    $dat .= pack("n*", map { (index($_, '+') >= 0 ? $ligatureTable : 0) + $_ } @$components);

    my $ligatures = $self->{'ligatures'};

    $dat .= pack("n*", @$ligatures);

    $dat1 = pack("nnnnnnn", $stateSize, $classTable, $stateArray, $entryTable, $ligActionLists, $componentTable, $ligatureTable);

    substr($dat, 0, length($dat1)) = $dat1;

    return $dat;

}

=head2 $t->print($fh)

Prints a human-readable representation of the table

=cut

sub print

{

    my ($self, $fh) = @_;

    my $post = $self->post();

    $fh = 'STDOUT' unless defined $fh;

    $self->print_classes($fh);

    $fh->print("\n");

    my $states = $self->{'states'};

    foreach (0 .. $#$states) {

        $fh->printf("\t\tState %d:", $_);

        my $state = $states->[$_];

        foreach (@$state) {

            my $flags;

            $flags .= "!" if ($_->{'flags'} & 0x4000);

            $flags .= "*" if ($_->{'flags'} & 0x8000);

            $fh->printf("\t(%s%d,%s)", $flags, $_->{'nextState'}, defined $_->{'actions'} ? $_->{'actions'} : "=");

        }

        $fh->print("\n");

    }

    $fh->print("\n");

    my $actionLists = $self->{'actionLists'};

    foreach (0 .. $#$actionLists) {

        $fh->printf("\t\tList %d:\t", $_);

        my $actionList = $actionLists->[$_];

        $fh->printf("%s\n", join(", ", map { ($_->{'component'} . ($_->{'store'} ? "*" : "") ) } @$actionList));

    }

    my $ligatureTable = $self->{'ligatureTable'};

    $fh->print("\n");

    my $components = $self->{'components'};

    foreach (0 .. $#$components) {

        $fh->printf("\t\tComponent %d: %s\n", $_, $components->[$_]);

    }

    $fh->print("\n");

    my $ligatures = $self->{'ligatures'};

    foreach (0 .. $#$ligatures) {

        $fh->printf("\t\tLigature %d: %d [%s]\n", $_, $ligatures->[$_], $post->{'VAL'}[$ligatures->[$_]]);

    }

}

1;

=head1 BUGS

None known

=head1 AUTHOR

Jonathan Kew L<http://scripts.sil.org/FontUtils>. 

=head1 LICENSING

Copyright (c) 1998-2016, SIL International (http://www.sil.org) 

This module is released under the terms of the Artistic License 2.0. 

For details, see the full text of the license in the file LICENSE.

=cut