package Mojo::DOM;

use Mojo::Base -strict;

use overload

  '%{}'    => sub { shift->attr },

  bool     => sub {1},

  '""'     => sub { shift->to_xml },

  fallback => 1;

# "Fry: This snow is beautiful. I'm glad global warming never happened.

#  Leela: Actually, it did. But thank God nuclear winter canceled it out."

use Carp 'croak';

use Mojo::Collection;

use Mojo::DOM::CSS;

use Mojo::DOM::HTML;

use Mojo::Util 'squish';

use Scalar::Util qw(blessed weaken);

sub AUTOLOAD {

  my $self = shift;

  my ($package, $method) = our $AUTOLOAD =~ /^([\w:]+)::(\w+)$/;

  croak "Undefined subroutine &${package}::$method called"

    unless blessed $self && $self->isa(__PACKAGE__);

  # Search children of current element

  my $children = $self->children($method);

  return @$children > 1 ? $children : $children->[0] if @$children;

  croak qq{Can't locate object method "$method" via package "$package"};

}

sub DESTROY { }

sub new {

  my $class = shift;

  my $self = bless [Mojo::DOM::HTML->new], ref $class || $class;

  return @_ ? $self->parse(@_) : $self;

}

sub all_text { shift->_content(1, @_) }

sub ancestors { _select($_[0]->_collect(_ancestors($_[0]->tree)), $_[1]) }

sub append { shift->_add(1, @_) }

sub append_content {

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

  my $tree = $self->tree;

  push @$tree, _link($self->_parse("$new"), $tree);

  return $self;

}

sub at { shift->find(@_)->[0] }

sub attr {

  my $self = shift;

  # Hash

  my $tree = $self->tree;

  my $attrs = $tree->[0] eq 'root' ? {} : $tree->[2];

  return $attrs unless @_;

  # Get

  return $attrs->{$_[0]} // '' unless @_ > 1 || ref $_[0];

  # Set

  %$attrs = (%$attrs, %{ref $_[0] ? $_[0] : {@_}});

  return $self;

}

sub children {

  my $self = shift;

  return _select(

    $self->_collect(grep { $_->[0] eq 'tag' } _nodes($self->tree)), @_);

}

sub content_xml {

  my $self = shift;

  my $xml  = $self->xml;

  return join '', map { _render($_, $xml) } _nodes($self->tree);

}

sub find {

  my $self = shift;

  my $results = Mojo::DOM::CSS->new(tree => $self->tree)->select(@_);

  return $self->_collect(@$results);

}

sub match {

  my $self = shift;

  return undef unless Mojo::DOM::CSS->new(tree => $self->tree)->match(@_);

  return $self;

}

sub namespace {

  my $self = shift;

  return '' if (my $current = $self->tree)->[0] eq 'root';

  # Extract namespace prefix and search parents

  my $ns = $current->[1] =~ /^(.*?):/ ? "xmlns:$1" : undef;

  while ($current->[0] ne 'root') {

    # Namespace for prefix

    my $attrs = $current->[2];

    if ($ns) { /^\Q$ns\E$/ and return $attrs->{$_} for keys %$attrs }

    # Namespace attribute

    elsif (defined $attrs->{xmlns}) { return $attrs->{xmlns} }

    $current = $current->[3];

  }

  return '';

}

sub next { shift->_siblings->[1][0] }

sub parent {

  my $self = shift;

  return undef if (my $tree = $self->tree)->[0] eq 'root';

  return $self->new->tree($tree->[3])->xml($self->xml);

}

sub parse { shift->_delegate(parse => shift) }

sub prepend { shift->_add(0, @_) }

sub prepend_content {

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

  my $tree = $self->tree;

  splice @$tree, _offset($tree), 0, _link($self->_parse("$new"), $tree);

  return $self;

}

sub previous { shift->_siblings->[0][-1] }

sub remove { shift->replace('') }

sub replace {

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

  my $tree = $self->tree;

  return $self->xml(undef)->parse($new) if $tree->[0] eq 'root';

  return $self->_replace($tree, $self->_parse("$new"));

}

sub replace_content {

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

  my $tree = $self->tree;

  splice @$tree, _offset($tree), $#$tree, _link($self->_parse("$new"), $tree);

  return $self;

}

sub root {

  my $self = shift;

  return $self unless my $tree = _ancestors($self->tree, 1);

  return $self->new->tree($tree)->xml($self->xml);

}

sub siblings { _select(Mojo::Collection->new(@{_siblings($_[0], 1)}), $_[1]) }

sub strip {

  my $self = shift;

  my $tree = $self->tree;

  return $self if $tree->[0] eq 'root';

  return $self->_replace($tree, ['root', _nodes($tree)]);

}

sub tap { shift->Mojo::Base::tap(@_) }

sub text { shift->_content(0, @_) }

sub text_after {

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

  return '' if (my $tree = $self->tree)->[0] eq 'root';

  my (@nodes, $started);

  for my $n (_nodes($tree->[3])) {

    ++$started and next if $n eq $tree;

    next unless $started;

    last if $n->[0] eq 'tag';

    push @nodes, $n;

  }

  return _text(\@nodes, 0, _trim($tree->[3], $trim));

}

sub text_before {

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

  return '' if (my $tree = $self->tree)->[0] eq 'root';

  my @nodes;

  for my $n (_nodes($tree->[3])) {

    last if $n eq $tree;

    push @nodes, $n;

    @nodes = () if $n->[0] eq 'tag';

  }

  return _text(\@nodes, 0, _trim($tree->[3], $trim));

}

sub to_xml { shift->[0]->render }

sub tree { shift->_delegate(tree => @_) }

sub type {

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

  return '' if (my $tree = $self->tree)->[0] eq 'root';

  return $tree->[1] unless $type;

  $tree->[1] = $type;

  return $self;

}

sub xml { shift->_delegate(xml => @_) }

sub _add {

  my ($self, $offset, $new) = @_;

  return $self if (my $tree = $self->tree)->[0] eq 'root';

  my $parent = $tree->[3];

  splice @$parent, _parent($parent, $tree) + $offset, 0,

    _link($self->_parse("$new"), $parent);

  return $self;

}

sub _ancestors {

  my ($tree, $root) = @_;

  my @ancestors;

  push @ancestors, $tree while ($tree->[0] eq 'tag') && ($tree = $tree->[3]);

  return $root ? $ancestors[-1] : @ancestors[0 .. $#ancestors - 1];

}

sub _collect {

  my $self = shift;

  my $xml  = $self->xml;

  return Mojo::Collection->new(@_)

    ->map(sub { $self->new->tree($_)->xml($xml) });

}

sub _content {

  my $tree = shift->tree;

  return _text([_nodes($tree)], shift, _trim($tree, @_));

}

sub _delegate {

  my ($self, $method) = (shift, shift);

  return $self->[0]->$method unless @_;

  $self->[0]->$method(@_);

  return $self;

}

sub _link {

  my ($children, $parent) = @_;

  # Link parent to children

  my @new;

  for my $n (@$children[1 .. $#$children]) {

    push @new, $n;

    next unless $n->[0] eq 'tag';

    $n->[3] = $parent;

    weaken $n->[3];

  }

  return @new;

}

sub _nodes {

  return unless my $n = shift;

  return @$n[_offset($n) .. $#$n];

}

sub _offset { $_[0][0] eq 'root' ? 1 : 4 }

sub _parent {

  my ($parent, $child) = @_;

  # Find parent offset for child

  my $i = _offset($parent);

  for my $n (@$parent[$i .. $#$parent]) {

    last if $n == $child;

    $i++;

  }

  return $i;

}

sub _parse { Mojo::DOM::HTML->new(xml => shift->xml)->parse(shift)->tree }

sub _render { Mojo::DOM::HTML->new(tree => shift, xml => shift)->render }

sub _replace {

  my ($self, $tree, $new) = @_;

  my $parent = $tree->[3];

  splice @$parent, _parent($parent, $tree), 1, _link($new, $parent);

  return $self->parent;

}

sub _select {

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

  return defined $selector ? $self->grep(sub { $_->match($selector) }) : $self;

}

sub _siblings {

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

  return $merge ? [] : [[], []] unless my $parent = $self->parent;

  my $tree = $self->tree;

  my (@before, @after, $match);

  for my $child ($parent->children->each) {

    ++$match and next if $child->tree eq $tree;

    $match ? push @after, $child : push @before, $child;

  }

  return $merge ? [@before, @after] : [\@before, \@after];

}

sub _text {

  my ($nodes, $recurse, $trim) = @_;

  # Merge successive text nodes

  my $i = 0;

  while (my $next = $nodes->[$i + 1]) {

    ++$i and next unless $nodes->[$i][0] eq 'text' && $next->[0] eq 'text';

    splice @$nodes, $i, 2, ['text', $nodes->[$i][1] . $next->[1]];

  }

  my $text = '';

  for my $n (@$nodes) {

    my $type = $n->[0];

    # Nested tag

    my $content = '';

    if ($type eq 'tag' && $recurse) {

      $content = _text([_nodes($n)], 1, _trim($n, $trim));

    }

    # Text

    elsif ($type eq 'text') { $content = $trim ? squish($n->[1]) : $n->[1] }

    # CDATA or raw text

    elsif ($type eq 'cdata' || $type eq 'raw') { $content = $n->[1] }

    # Add leading whitespace if punctuation allows it

    $content = " $content" if $text =~ /\S\z/ && $content =~ /^[^.!?,;:\s]+/;

    # Trim whitespace blocks

    $text .= $content if $content =~ /\S+/ || !$trim;

  }

  return $text;

}

sub _trim {

  my ($e, $trim) = @_;

  # Disabled

  return 0 unless $e && ($trim = defined $trim ? $trim : 1);

  # Detect "pre" tag

  while ($e->[0] eq 'tag') {

    return 0 if $e->[1] eq 'pre';

    last unless $e = $e->[3];

  }

  return 1;

}

1;

=encoding utf8

=head1 NAME

Mojo::DOM - Minimalistic HTML/XML DOM parser with CSS selectors

=head1 SYNOPSIS

  use Mojo::DOM;

  # Parse

  my $dom = Mojo::DOM->new('<div><p id="a">A</p><p id="b">B</p></div>');

  # Find

  say $dom->at('#b')->text;

  say $dom->find('p')->text;

  say $dom->find('[id]')->attr('id');

  # Walk

  say $dom->div->p->[0]->text;

  say $dom->div->children('p')->first->{id};

  # Iterate

  $dom->find('p[id]')->each(sub { say shift->{id} });

  # Loop

  for my $e ($dom->find('p[id]')->each) {

    say $e->text;

  }

  # Modify

  $dom->div->p->[1]->append('<p id="c">C</p>');

  $dom->find(':not(p)')->strip;

  # Render

  say "$dom";

=head1 DESCRIPTION

L<Mojo::DOM> is a minimalistic and relaxed HTML/XML DOM parser with CSS

selector support. It will even try to interpret broken XML, so you should not

use it for validation.

=head1 CASE SENSITIVITY

L<Mojo::DOM> defaults to HTML semantics, that means all tags and attributes

are lowercased and selectors need to be lowercase as well.

  my $dom = Mojo::DOM->new('<P ID="greeting">Hi!</P>');

  say $dom->at('p')->text;

  say $dom->p->{id};

If XML processing instructions are found, the parser will automatically switch

into XML mode and everything becomes case sensitive.

  my $dom = Mojo::DOM->new('<?xml version="1.0"?><P ID="greeting">Hi!</P>');

  say $dom->at('P')->text;

  say $dom->P->{ID};

XML detection can also be disabled with the L</"xml"> method.

  # Force XML semantics

  $dom->xml(1);

  # Force HTML semantics

  $dom->xml(0);

=head1 METHODS

L<Mojo::DOM> implements the following methods.

=head2 new

  my $dom = Mojo::DOM->new;

  my $dom = Mojo::DOM->new('<foo bar="baz">test</foo>');

Construct a new array-based L<Mojo::DOM> object and L</"parse"> HTML/XML

fragment if necessary.

=head2 all_text

  my $trimmed   = $dom->all_text;

  my $untrimmed = $dom->all_text(0);

Extract all text content from DOM structure, smart whitespace trimming is

enabled by default.

  # "foo bar baz"

  $dom->parse("<div>foo\n<p>bar</p>baz\n</div>")->div->all_text;

  # "foo\nbarbaz\n"

  $dom->parse("<div>foo\n<p>bar</p>baz\n</div>")->div->all_text(0);

=head2 ancestors

  my $collection = $dom->ancestors;

  my $collection = $dom->ancestors('div');

Find all ancestors of this element matching the CSS selector and return a

L<Mojo::Collection> object containing these elements as L<Mojo::DOM> objects.

All selectors from L<Mojo::DOM::CSS> are supported.

  # List types of ancestor elements

  say $dom->ancestors->type;

=head2 append

  $dom = $dom->append('<p>Hi!</p>');

Append HTML/XML fragment to element.

  # "<div><h1>A</h1><h2>B</h2></div>"

  $dom->parse('<div><h1>A</h1></div>')->at('h1')->append('<h2>B</h2>')->root;

=head2 append_content

  $dom = $dom->append_content('<p>Hi!</p>');

Append HTML/XML fragment to element content.

  # "<div><h1>AB</h1></div>"

  $dom->parse('<div><h1>A</h1></div>')->at('h1')->append_content('B')->root;

=head2 at

  my $result = $dom->at('html title');

Find first element matching the CSS selector and return it as a L<Mojo::DOM>

object or return C<undef> if none could be found. All selectors from

L<Mojo::DOM::CSS> are supported.

  # Find first element with "svg" namespace definition

  my $namespace = $dom->at('[xmlns\:svg]')->{'xmlns:svg'};

=head2 attr

  my $attrs = $dom->attr;

  my $foo   = $dom->attr('foo');

  $dom      = $dom->attr({foo => 'bar'});

  $dom      = $dom->attr(foo => 'bar');

Element attributes.

  # List id attributes

  say $dom->find('*')->attr('id')->compact;

=head2 children

  my $collection = $dom->children;

  my $collection = $dom->children('div');

Find all children of this element matching the CSS selector and return a

L<Mojo::Collection> object containing these elements as L<Mojo::DOM> objects.

All selectors from L<Mojo::DOM::CSS> are supported.

  # Show type of random child element

  say $dom->children->shuffle->first->type;

=head2 content_xml

  my $xml = $dom->content_xml;

Render content of this element to XML.

  # "<b>test</b>"

  $dom->parse('<div><b>test</b></div>')->div->content_xml;

=head2 find

  my $collection = $dom->find('html title');

Find all elements matching the CSS selector and return a L<Mojo::Collection>

object containing these elements as L<Mojo::DOM> objects. All selectors from

L<Mojo::DOM::CSS> are supported.

  # Find a specific element and extract information

  my $id = $dom->find('div')->[23]{id};

  # Extract information from multiple elements

  my @headers = $dom->find('h1, h2, h3')->text->each;

  my @links   = $dom->find('a[href]')->attr('href')->each;

=head2 match

  my $result = $dom->match('html title');

Match the CSS selector against this element and return it as a L<Mojo::DOM>

object or return C<undef> if it didn't match. All selectors from

L<Mojo::DOM::CSS> are supported.

=head2 namespace

  my $namespace = $dom->namespace;

Find element namespace.

  # Find namespace for an element with namespace prefix

  my $namespace = $dom->at('svg > svg\:circle')->namespace;

  # Find namespace for an element that may or may not have a namespace prefix

  my $namespace = $dom->at('svg > circle')->namespace;

=head2 next

  my $sibling = $dom->next;

Return L<Mojo::DOM> object for next sibling of element or C<undef> if there

are no more siblings.

  # "<h2>B</h2>"

  $dom->parse('<div><h1>A</h1><h2>B</h2></div>')->at('h1')->next;

=head2 parent

  my $parent = $dom->parent;

Return L<Mojo::DOM> object for parent of element or C<undef> if this element

has no parent.

=head2 parse

  $dom = $dom->parse('<foo bar="baz">test</foo>');

Parse HTML/XML fragment with L<Mojo::DOM::HTML>.

  # Parse XML

  my $dom = Mojo::DOM->new->xml(1)->parse($xml);

=head2 prepend

  $dom = $dom->prepend('<p>Hi!</p>');

Prepend HTML/XML fragment to element.

  # "<div><h1>A</h1><h2>B</h2></div>"

  $dom->parse('<div><h2>B</h2></div>')->at('h2')->prepend('<h1>A</h1>')->root;

=head2 prepend_content

  $dom = $dom->prepend_content('<p>Hi!</p>');

Prepend HTML/XML fragment to element content.

  # "<div><h2>AB</h2></div>"

  $dom->parse('<div><h2>B</h2></div>')->at('h2')->prepend_content('A')->root;

=head2 previous

  my $sibling = $dom->previous;

Return L<Mojo::DOM> object for previous sibling of element or C<undef> if

there are no more siblings.

  # "<h1>A</h1>"

  $dom->parse('<div><h1>A</h1><h2>B</h2></div>')->at('h2')->previous;

=head2 remove

  my $parent = $dom->remove;

Remove element and return L<Mojo::DOM> object for parent of element.

  # "<div></div>"

  $dom->parse('<div><h1>A</h1></div>')->at('h1')->remove;

=head2 replace

  my $parent = $dom->replace('<div>test</div>');

Replace element with HTML/XML fragment and return L<Mojo::DOM> object for

parent of element.

  # "<div><h2>B</h2></div>"

  $dom->parse('<div><h1>A</h1></div>')->at('h1')->replace('<h2>B</h2>');

  # "<div></div>"

  $dom->parse('<div><h1>A</h1></div>')->at('h1')->replace('');

=head2 replace_content

  $dom = $dom->replace_content('<p>test</p>');

Replace element content with HTML/XML fragment.

  # "<div><h1>B</h1></div>"

  $dom->parse('<div><h1>A</h1></div>')->at('h1')->replace_content('B')->root;

  # "<div><h1></h1></div>"

  $dom->parse('<div><h1>A</h1></div>')->at('h1')->replace_content('')->root;

=head2 root

  my $root = $dom->root;

Return L<Mojo::DOM> object for root node.

=head2 siblings

  my $collection = $dom->siblings;

  my $collection = $dom->siblings('div');

Find all siblings of this element matching the CSS selector and return a

L<Mojo::Collection> object containing these elements as L<Mojo::DOM> objects.

All selectors from L<Mojo::DOM::CSS> are supported.

  # List types of sibling elements

  say $dom->siblings->type;

=head2 strip

  my $parent = $dom->strip;

Remove element while preserving its content and return L<Mojo::DOM> object for

parent of element.

  # "<div>A</div>"

  $dom->parse('<div><h1>A</h1></div>')->at('h1')->strip;

=head2 tap

  $dom = $dom->tap(sub {...});

Alias for L<Mojo::Base/"tap">.

=head2 text

  my $trimmed   = $dom->text;

  my $untrimmed = $dom->text(0);

Extract text content from element only (not including child elements), smart

whitespace trimming is enabled by default.

  # "foo baz"

  $dom->parse("<div>foo\n<p>bar</p>baz\n</div>")->div->text;

  # "foo\nbaz\n"

  $dom->parse("<div>foo\n<p>bar</p>baz\n</div>")->div->text(0);

=head2 text_after

  my $trimmed   = $dom->text_after;

  my $untrimmed = $dom->text_after(0);

Extract text content immediately following element, smart whitespace trimming

is enabled by default.

  # "baz"

  $dom->parse("<div>foo\n<p>bar</p>baz\n</div>")->div->p->text_after;

  # "baz\n"

  $dom->parse("<div>foo\n<p>bar</p>baz\n</div>")->div->p->text_after(0);

=head2 text_before

  my $trimmed   = $dom->text_before;

  my $untrimmed = $dom->text_before(0);

Extract text content immediately preceding element, smart whitespace trimming

is enabled by default.

  # "foo"

  $dom->parse("<div>foo\n<p>bar</p>baz\n</div>")->div->p->text_before;

  # "foo\n"

  $dom->parse("<div>foo\n<p>bar</p>baz\n</div>")->div->p->text_before(0);

=head2 to_xml

  my $xml = $dom->to_xml;

  my $xml = "$dom";

Render this element and its content to XML.

  # "<b>test</b>"

  $dom->parse('<div><b>test</b></div>')->div->b->to_xml;

=head2 tree

  my $tree = $dom->tree;

  $dom     = $dom->tree(['root', ['text', 'foo']]);

Document Object Model. Note that this structure should only be used very

carefully since it is very dynamic.

=head2 type

  my $type = $dom->type;

  $dom     = $dom->type('div');

Element type.

  # List types of child elements

  say $dom->children->type;

=head2 xml

  my $bool = $dom->xml;

  $dom     = $dom->xml($bool);

Disable HTML semantics in parser and activate case sensitivity, defaults to

auto detection based on processing instructions.

=head1 CHILD ELEMENTS

In addition to the methods above, many child elements are also automatically

available as object methods, which return a L<Mojo::DOM> or

L<Mojo::Collection> object, depending on number of children.

  say $dom->p->text;

  say $dom->div->[23]->text;

  say $dom->div->text;

=head1 ELEMENT ATTRIBUTES

Direct hash reference access to element attributes is also possible.

  say $dom->{foo};

  say $dom->div->{id};

=head1 SEE ALSO

L<Mojolicious>, L<Mojolicious::Guides>, L<http://mojolicio.us>.

=cut