HTML::Tested::Value - Base class for most HTML::Tested widgets.

use strict;
use warnings FATAL => 'all';

package HTML::Tested::Value;
use HTML::Entities;
use HTML::Tested::Seal;
use Carp;
use Data::Dumper;

sub setup_datetime_option {
	my ($self, $dto, $opts) = @_;
	$opts ||= $self->options;
	eval "use DateTime::Format::Strptime";
	confess "Unable to use DateTime::Format::Strptime: $@" if $@;
	$dto = { pattern => $dto } unless ref($dto);
	$opts->{is_datetime} = DateTime::Format::Strptime->new($dto);
	$self->compile;
}

sub new {
	my ($class, $parent, $name, %opts) = @_;
	my $self = bless({ name => $name, _options => \%opts
			, constraints => [], validators => [] }, $class);
	my $cs = $opts{constraints} || [];
	$self->push_constraint($_) for @$cs;

	my $dto = $self->options->{is_datetime};
	$self->setup_datetime_option($dto) if $dto;
	return $self;
}

sub _get_option {
	my ($self, $caller, $wname, $opname) = @_;
	if ($caller && ref($caller)) {
		my $n = "__ht__$wname\_$opname";
		return $caller->{$n} if exists $caller->{$n};
	}
	return $self->options->{$opname};
}

sub name { return shift()->{name}; }

sub options { return shift()->{_options}; }

sub value_to_string {
	my ($self, $name, $val) = @_;
	return $val;
}

sub encode_value {
	my ($self, $val) = @_;
	confess ref($self) . "->" . $self->name . ": Non scalar value $val\n"
		. Dumper($val) if ref($val);
	return encode_entities($val, '<>&"' . "'");
}

sub get_default_value {
	my ($self, $caller, $n) = @_;
	my $func = $caller->{"__$n\_defval"} || $self->{__defval};
	return $func->($self, $n, $caller);
}

sub get_value {
	my ($self, $caller, $id, $n) = @_;
	return $caller->{$n} // $self->get_default_value($caller, $n);
}

sub seal_value {
	my ($self, $val, $caller) = @_;
	return HTML::Tested::Seal->instance->encrypt($val);
}

sub transform_value {
	my ($self, $caller, $val, $n) = @_;
	my $func = $caller->{"__$n\_transform"} || $self->{__transform};
	return $func->($self, $val, $caller, $n);
}

sub prepare_value {
	my ($self, $caller, $id, $n) = @_;
	my $val = $self->get_value($caller, $id, $n);
	return undef unless defined($val);
	return $self->transform_value($caller, $val, $n);
}

sub _render_i {
	my ($self, $caller, $stash, $id, $n) = @_;
	my $val = $self->prepare_value($caller, $id, $n);
	return unless defined($val);
	return $self->value_to_string($id, $val, $caller, $stash);
}

sub render {
	my ($self, $caller, $stash, $id, $n) = @_;
	my $func = $caller->{"__$n\_render"} || $self->{__render};
	my $res = $func->($self, $caller, $stash, $id, $n);
	$stash->{$n} = $res if defined($res);
}

sub bless_from_tree { return $_[1]; }

sub push_constraint {
	my ($self, $c) = @_;
	my $func;
	push @{ $self->{constraints} }, $c;
	confess "Constraint should be of [ TYPE, OP ] format"
			unless ($c && ref($c) eq 'ARRAY');
	if ($c->[0] eq 'regexp') {
		my $rexp = $c->[1];
		$func = sub {
			my $v = shift;
			return defined($v) ? $v =~ /$rexp/ : undef;
		};
	} elsif ($c->[0] eq 'defined') {
		$func = sub { return defined($_[0]); };
	} elsif ($c->[1]) {
		$func = $c->[1];
	} else {
		confess "Unknown type " . $c->[0] . " found!\n";
	}
	push @{ $self->{validators} }, $func if $func;
}

sub validate {
	my ($self, $caller) = @_;
	my $n = $self->name;
	my $val = $caller->$n;
	return () if $caller->ht_get_widget_option($n, "no_validate");
	return ([ $n, 'integer' ]) if (defined($val)
			&& $caller->ht_get_widget_option($n, "is_integer")
			&& $val !~ /^\d+$/);
	my $vs = $self->{validators};
	my @res;
	for (my $i = 0; $i < @$vs; $i++) {
		next if $vs->[$i]->($val, $caller);
		push @res, [ $n, @{ $self->{constraints}->[$i] } ];
	}
	return @res;
}

sub unseal_value {
	my ($self, $val, $caller) = @_;
	return HTML::Tested::Seal->instance->decrypt($val);
}

sub merge_one_value { shift()->absorb_one_value(@_); }

sub absorb_one_value {
	my ($self, $root, $val, @path) = @_;
	return if $self->options->{is_trusted};
	$val = $self->unseal_value($val, $root)
			if $self->options->{"is_sealed"};
	my $dtfs = $self->options->{"is_datetime"};
	$val = $dtfs->parse_datetime($val) if $dtfs;
	$root->{ $self->name } = (defined($val) && $val eq ""
			&& !$self->options->{keep_empty_string}) ? undef : $val;
}

sub _set_callback {
	my ($self, $caller, $n, $what, $func) = @_;
	my $obj = ($caller && ref($caller)) ? $caller : $self;
	my $key = ($caller && ref($caller)) ? "__$n\_$what" : "__$what";
	$obj->{$key} = $func;
}

sub _trans_datetime {
	my ($self, $dtfs, $val, $caller, $n) = @_;
	return $dtfs->format_datetime($val) if $val;
}

sub compile {
	my ($self, $caller) = @_;
	my $n = $self->name;
	my $trans = $self->can('encode_value');
	my $func = $self->can('_render_i');
	my $defval = sub { return '' };
	if ($self->_get_option($caller, $n, 'is_disabled')) {
		$func = $defval;
	} elsif (my $dtfs = $self->_get_option($caller, $n, "is_datetime")) {
		$trans = sub { return shift()->_trans_datetime($dtfs, @_); };
	} elsif ($self->_get_option($caller, $n, "is_sealed")) {
		$trans = sub {
			my $this = shift;
			my $val = shift;
			$val = $this->seal_value($val, @_);
			return $this->encode_value($val, @_);
		};
	} elsif ($self->_get_option($caller, $n, "is_trusted")) {
		$trans = sub { return $_[1]; };
	}

	my $dval = $self->_get_option($caller, $n, "default_value");
	if (defined($dval)) {
		$defval = ref($dval) eq 'CODE' ? $dval : sub { return $dval; };
	} elsif ($self->_get_option($caller, $n, "skip_undef")) {
		$defval = sub { return undef; };
	}

	$self->_set_callback($caller, $n, 'render', $func);
	$self->_set_callback($caller, $n, 'transform', $trans);
	$self->_set_callback($caller, $n, 'defval', $defval);
}

1;