package Padre::Document;

=head1 NAME

Padre::Document - Padre Document API

=head1 DESCRIPTION

The B<Padre::Document> class provides a base class, default implementation
and API documentation for document type support in L<Padre>.

As an API, it allows L<Padre> developers and plug-in authors to implement
extended support for various document types in Padre, while ensuring that
a naive default document implementation exists that allows Padre to provide
basic support (syntax highlighting mainly) for many document types without
the need to install extra modules unless you need the extra functionality.

=head2 Document Type Registration

Padre uses MIME types as the fundamental identifier when working with
documents. Files are typed at load-time based on file extension (with a
simple heuristic fallback when opening files with no extension).

Many of the MIME types are unofficial X-style identifiers, but in cases
without an official type, Padre will try to use the most popular
identifier (based on research into the various language communities).

Each supported mime has a mapping to a Scintilla lexer (for syntax
highlighting), and an optional mapping to the class that provides enhanced
support for that document type.

Plug-ins that implement support for a document type provide a
C<registered_documents> method that the plug-in manager will call as needed.

Plug-in authors should B<not> load the document classes in advance, they
will be automatically loaded by Padre as needed.

Padre does B<not> currently support opening non-text files.

=head2 File to MIME type mapping

Padre has a built-in hash mapping the file extensions to MIME types.
In certain cases (.t, .pl, .pm) Padre also looks in the content of the
file to determine if the file is Perl 5 or Perl 6.

MIME types are mapped to lexers that provide the syntax highlighting.

MIME types are also mapped to modules that implement
special features needed by that kind of a file type.

Plug-ins can add further mappings.

=head2 Plan

Padre has a built-in mapping of file extension to either
a single MIME type or function name. In order to determine
the actual MIME type Padre checks this hash. If the key
is a subroutine it is called and it should return the
MIME type of the file.

The user has a way in the GUI to add more file extensions
and map them to existing MIME types or functions. It is probably
better to have a commonly used name along with the MIME type
in that GUI instead of the MIME type only.

I wonder if we should allow the users (and or plug-in authors) to
change the functions or to add new functions that will map
file content to MIME type or if we should just tell them to
patch Padre. What if they need it for some internal project?

A plug-in is able to add new supported MIME types. Padre should
either check for collisions if a plug-in wants to provide
an already supported MIME type or should allow multiple support
modules with a way to select the current one. (Again I think we
probably don't need this. People can just come and add the
MIME types to Padre core.) (not yet implemented)

A plug-in can register zero or more modules that implement
special features needed by certain MIME types. Every MIME type
can have only one module that implements its features. Padre is
checking if a MIME type already has a registered module and
does not let to replace it.
(Special features such as commenting out a few lines at once,
auto-completion or refactoring tools).

Padre should check if the given MIME type is one that is
in the supported MIME type list. (TO DO)

Each MIME type is mapped to one or more lexers that provide
the syntax highlighting. Every MIME type has to be mapped to at least
one lexer but it can be mapped to several lexers as well.
The user is able to select the lexer for each MIME type.
(For this each lexer should have a reasonable name too.) (TO DO)

Every plug-in should be able to add a list of lexers to the existing
MIME types regardless if the plug-in also provides the class that
implements the features of that MIME type. By default Padre
supports the built-in syntax highlighting of Scintilla.
Perl 5 currently has two L<PPI> based syntax highlighter,
Perl 6 can use the STD.pm or Rakudo/PGE for syntax highlighting but
there are two plug-ins - Parrot and Kate - that can provide syntax
highlighting to a wide range of MIME types.

C<provided_highlighters()> returns a list of arrays like this:

    ['Module with a colorize function' => 'Human readable Name' => 'Long description']

C<highlighting_mime_types()> returns a hash where the keys are module
names listed in C<provided_highlighters>, the values are array references to MIME types:

    'Module::A' => [ mime-type-1, mime-type-2]

The user can change the MIME type mapping of individual
files and Padre should remember this choice and allow the
user to change it to another specific MIME type
or to set it to "Default by extension".

=head1 METHODS

=cut

use 5.008;
use strict;
use warnings;
use Carp ();
use File::Spec 3.2 (); # 3.21 needed for volume-safe abs2rel
use File::Temp              ();
use Params::Util            ();
use Wx::Scintilla::Constant ();
use Padre::Constant         ();
use Padre::Current          ();
use Padre::Util             ();
use Padre::Wx               ();
use Padre::MIME             ();
use Padre::File             ();
use Padre::Logger;

our $VERSION    = '1.00';
our $COMPATIBLE = '0.91';





#####################################################################
# Task Integration

sub task_functions {
	return '';
}

sub task_outline {
	return '';
}

sub task_syntax {
	return '';
}





#####################################################################
# Document Registration

# NOTE: This is probably a bad place to store this
my $UNSAVED = 0;





#####################################################################
# Constructor and Accessors

use Class::XSAccessor {
	getters => {
		unsaved      => 'unsaved',
		filename     => 'filename',    # setter is defined as normal function
		file         => 'file',        # Padre::File - object
		editor       => 'editor',
		timestamp    => 'timestamp',
		mimetype     => 'mimetype',
		encoding     => 'encoding',
		errstr       => 'errstr',
		tempfile     => 'tempfile',
		highlighter  => 'highlighter',
		outline_data => 'outline_data',
	},
	setters => {
		set_editor       => 'editor',
		set_timestamp    => 'timestamp',
		set_mimetype     => 'mimetype',
		set_encoding     => 'encoding',
		set_newline_type => 'newline_type',
		set_errstr       => 'errstr',
		set_tempfile     => 'tempfile',
		set_highlighter  => 'highlighter',
		set_outline_data => 'outline_data',
	},
};

=head2 new

  my $doc = Padre::Document->new(
      filename => $file,
  );

C<$file> is optional and if given it will be loaded in the document.
MIME type is defined by the C<guess_mimetype> function.

=cut

sub new {
	my $class = shift;
	my $self = bless {@_}, $class;

	# This sub creates the document object and is allowed to use self->filename,
	# once noone else uses it, it shout be deleted from the $self - hash before
	# leaving the sub.
	# Use document->{file}->filename instead!
	if ( $self->{filename} ) {
		$self->{file} = Padre::File->new(
			$self->{filename},
			info_handler => sub {
				$self->current->main->info( $_[1] );
			}
		);

		unless ( defined $self->{file} ) {
			$self->error( Wx::gettext('Error while opening file: no file object') );
			return;
		}

		if ( defined $self->{file}->{error} ) {
			$self->error( $self->{file}->{error} );
			return;
		}

		# The Padre::File - module knows how to format the filename to the right
		# syntax to correct (for example) .//file.pl to ./file.pl)
		$self->{filename} = $self->{file}->{filename};

		if ( $self->{file}->exists ) {

			# Test script must be able to pass an alternate config object
			# NOTE: Since when do we support per-document configuration objects?
			my $config = $self->{config} || $self->config;
			if ( defined( $self->{file}->size ) and ( $self->{file}->size > $config->editor_file_size_limit ) ) {
				my $ret = Wx::MessageBox(
					sprintf(
						Wx::gettext(
							"The file %s you are trying to open is %s bytes large. It is over the arbitrary file size limit of Padre which is currently %s. Opening this file may reduce performance. Do you still want to open the file?"
						),
						$self->{file}->{filename},
						_commafy( -s $self->{file}->{filename} ),
						_commafy( $config->editor_file_size_limit )
					),
					Wx::gettext("Warning"),
					Wx::YES_NO | Wx::CENTRE,
					$self->current->main,
				);
				if ( $ret != Wx::YES ) {
					return;
				}
			}
		}
		$self->load_file;
	} else {
		$self->{unsaved}      = ++$UNSAVED;
		$self->{newline_type} = $self->default_newline_type;
	}

	unless ( $self->mimetype ) {
		my $mimetype = $self->guess_mimetype;
		if ( defined $mimetype ) {
			$self->set_mimetype($mimetype);
		} else {
			$self->error(
				Wx::gettext(
					"Error while determining MIME type.\nThis is possibly an encoding problem.\nAre you trying to load a binary file?"
				)
			);
			return;
		}
	}

	$self->rebless;

	# NOTE: Hacky support for the Padre Popularity Contest
	unless ( defined $ENV{PADRE_IS_TEST} ) {
		my $popcon = $self->current->ide->{_popularity_contest};
		$popcon->count( 'mime.' . $self->mimetype ) if $popcon;
	}

	return $self;
}

sub rebless {
	my $self = shift;

	# Rebless as either to a subclass if there is a mime-type or
	# to the the base class,
	# This isn't exactly the most elegant way to do this, but will
	# do for a first implementation.
	my $class = $self->mime->document;
	TRACE("Reblessing to mimetype class: '$class'") if DEBUG;
	if ($class) {
		unless ( $class->VERSION ) {
			(my $source = $class.".pm") =~ s{::}{/}g;
			eval { require $source }
				or die "Failed to load $class: $@";
		}
		bless $self, $class;
	}

	require Padre::Wx::Scintilla;
	$self->set_highlighter( Padre::Wx::Scintilla->highlighter($self) );

	return;
}

sub current {
	Padre::Current->new( document => $_[0] );
}

sub config {
	$_[0]->{config} or $_[0]->current->config;
}

sub mime {
	Padre::MIME->find( $_[0]->mimetype );
}

# Abstract methods, each subclass should implement it
# TO DO: Clearly this isn't ACTUALLY abstract (since they exist)

sub scintilla_word_chars {
	return '';
}

sub scintilla_key_words {
	require Padre::Wx::Scintilla;
	Padre::Wx::Scintilla->keywords( $_[0]->mimetype );
}

sub get_calltip_keywords {
	return {};
}

sub get_function_regex {
	return '';
}





######################################################################
# Padre::Cache Integration

# The detection of VERSION allows us to make this call without having
# to load modules at document destruction time if it isn't needed.
sub DESTROY {
	if ( defined $_[0]->{filename} and $Padre::Cache::VERSION ) {
		Padre::Cache->release( $_[0]->{filename} );
	}
}





#####################################################################
# Padre::Document GUI Integration

sub colourize {
	my $self   = shift;
	my $editor = $self->editor;
	require Padre::Wx::Scintilla;
	my $lexer = Padre::Wx::Scintilla->lexer( $self->mimetype );
	$editor->SetLexer($lexer);
	TRACE("colourize called") if DEBUG;

	$editor->remove_color;
	if ( $lexer == Wx::Scintilla::Constant::SCLEX_CONTAINER ) {
		$self->colorize;
	} else {
		TRACE("Colourize is being called") if DEBUG;
		$editor->Colourise( 0, $editor->GetLength );
		TRACE("Colourize completed") if DEBUG;
	}
}

sub colorize {
	my $self   = shift;
	my $module = $self->highlighter;
	unless ($module) {

		# TO DO sometime this happens when I open Padre with several file
		# I think this can be somehow related to the quick (or slow ?) switching of
		# what is the current document while the code is still running.
		# for now I hide the warnings as this would just frighten people and the
		# actual problem seems to be only the warning or maybe late highighting
		# of a single document - szabgab
		#Carp::cluck("highlighter is set to 'stc' while colorize() is called for " . ($self->filename || '') . "\n");
		#warn "Length: " . $self->editor->GetTextLength;
		return;
	}

	# allow virtual modules if they have a colorize method
	unless ( $module->can('colorize') ) {
		eval "use $module";
		if ($@) {
			my $name = $self->{file} ? $self->{file}->filename : $self->get_title;
			Carp::cluck("Could not load module '$module' for file '$name'\n");
			return;
		}
	}
	if ( $module->can('colorize') ) {
		TRACE("Call '$module->colorize(@_)'") if DEBUG;
		$module->colorize(@_);
	} else {
		warn("Module $module does not have a colorize method\n");
	}
	return;
}

# For ts without a newline type
# TO DO: get it from config
sub default_newline_type {
	my $self = shift;

	# Very ugly hack to make the test script work
	if ( $0 =~ /t.70_document\.t/ ) {
		return Padre::Constant::NEWLINE;
	}

	$self->config->default_line_ending;
}

=head2 error

    $document->error( $msg );

Open an error dialog box with C<$msg> as main text. There's only one OK
button. No return value.

=cut

# TO DO: A globally used error/message box function may be better instead
#       of replicating the same function in many files:
sub error {
	$_[0]->current->main->message( $_[1], Wx::gettext('Error') );
}





#####################################################################
# Disk Interaction Methods

# These methods implement the interaction between the document and the
# filesystem.

sub basename {
	my $self = shift;
	if ( defined $self->{file} ) {
		return $self->{file}->basename;
	}
	return $self->{file}->{filename};
}

sub dirname {
	my $self = shift;
	if ( defined $self->{file} ) {
		return $self->{file}->dirname;
	}
	return;
}

sub is_new {
	return !!( not defined $_[0]->file );
}

sub is_modified {
	return !!( $_[0]->editor->GetModify );
}

sub is_saved {
	return !!( defined $_[0]->file and not $_[0]->is_modified );
}

sub is_unsaved {
	return !!( $_[0]->editor->GetModify and defined $_[0]->file );
}

# Returns true if this is a new document that is too insignificant to
# bother checking with the user before throwing it away.
# Usually this is because it's empty or just has a space or two in it.
sub is_unused {
	my $self = shift;
	return '' unless $self->is_new;
	return 1  unless $self->is_modified;
	return 1  unless $self->text_get =~ /\S/s;
	return '';
}

sub is_readonly {
	my $self = shift;

	my $file = $self->file;
	return 0 unless defined($file);

	# Fill the cache if it's empty and assume read-write as a default
	$self->{readonly} ||= $self->file->readonly || 0;

	return $self->{readonly};
}

# Returns true if file has changed on the disk
# since load time or the last time we saved it.
# Check if the file on the disk has changed
# 1) when document gets the focus (gvim, notepad++)
# 2) when we try to save the file (gvim)
# 3) every time we type something ????
sub has_changed_on_disk {
	my $self = shift;
	return 0 unless defined $self->file;
	return 0 unless defined $self->timestamp;

	# Caching the result for two lines saved one stat-I/O each time this sub is run
	my $timestamp_now = $self->timestamp_now;
	return 0 unless defined $timestamp_now; # there may be no mtime on remote files

	# Return -1 if file has been deleted from disk
	return -1 unless $timestamp_now;

	# Return 1 if the file has changed on disk, otherwise 0
	return $self->timestamp < $timestamp_now ? 1 : 0;
}

sub timestamp_now {
	my $self = shift;
	my $file = $self->file;
	return 0 unless defined $file;

	# It's important to return undef if there is no ->mtime for this filetype
	return undef unless $file->can('mtime');
	return $file->mtime;
}

=head2 load_file

    $doc->load_file;

Loads the current file.

Sets the B<Encoding> bit using L<Encode::Guess> and tries to figure
out what kind of newlines are in the file. Defaults to C<utf-8> if it
could not figure out the encoding.

Returns true on success false on failure. Sets C<< $doc->errstr >>.

=cut

sub load_file {
	my $self = shift;
	my $file = $self->file;

	if (DEBUG) {
		my $name = $file->{filename} || '';
		TRACE("Loading file '$name'");
	}

	# Show the file-changed-dialog again after the file was (re)loaded:
	delete $self->{_already_popup_file_changed};

	# check if file exists
	if ( !$file->exists ) {

		# file doesn't exist, try to create an empty one
		if ( !$file->write('') ) {

			# oops, error creating file. abort operation
			$self->set_errstr( $file->error );
			return;
		}
	}

	# load file
	$self->set_errstr('');
	my $content = $file->read;
	if ( !defined($content) ) {
		$self->set_errstr( $file->error );
		return;
	}
	$self->{timestamp} = $self->timestamp_now;

	# if guess encoding fails then use 'utf-8'
	require Padre::Locale;
	require Encode;
	$self->{encoding} = Padre::Locale::encoding_from_string($content);
	$content = Encode::decode( $self->{encoding}, $content );

	# Determine new line type using file content.
	$self->{newline_type} = Padre::Util::newline_type($content);

	# Cache the original value of various things so we can do
	# smart things at save time later.
	$self->{original_content} = $content;
	$self->{original_newline} = $self->{newline_type};

	return 1;
}

# New line type acan be one of these values:
# WIN, MAC (for classic Mac) or UNIX (for Mac OS X and Linux/*BSD)
# Special cases:
# 'Mixed' for mixed end of lines,
# 'None' for one-liners (no EOL)
sub newline_type {
	$_[0]->{newline_type} or $_[0]->default_newline_type;
}

# Get the newline char(s) for this document.
# TO DO: This solution is really terrible - it should be {newline} or at least a caching of the value
#       because of speed issues:
sub newline {
	my $self = shift;
	if ( $self->newline_type eq 'WIN' ) {
		return "\r\n";
	} elsif ( $self->newline_type eq 'MAC' ) {
		return "\r";
	}
	return "\n";
}

=head2 autocomplete_matching_char

The first argument needs to be a reference to the editor this method should
work on.

The second argument is expected to be a event reference to the event object
which is the reason why the method was launched.

This method expects a hash as the third argument. If the last key typed by the
user is a key in this hash, the value is automatically added and the cursor is
set between key and value. Both key and value are expected to be ASCII codes.

Usually used for brackets and text signs like:

  $self->autocomplete_matching_char(
      $editor,
      $event,
      39  => 39,  # ' '
      40  => 41,  # ( )
  );

Returns 1 if something was added or 0 otherwise (if anybody cares about this).

=cut

sub autocomplete_matching_char {
	my $self   = shift;
	my $editor = shift;
	my $event  = shift;
	my %table  = @_;
	my $key    = $event->GetUnicodeKey;
	unless ( $table{$key} ) {
		return 0;
	}

	# Is autocomplete enabled
	my $current = $self->current;
	my $config  = $current->config;
	unless ( $config->autocomplete_brackets ) {
		return 0;
	}

	# Is something selected?
	my $pos  = $editor->GetCurrentPos;
	my $text = $editor->GetSelectedText;
	if ( defined $text and length $text ) {
		my $start = $editor->GetSelectionStart;
		my $end   = $editor->GetSelectionEnd;
		$editor->GotoPos($end);
		$editor->AddText( chr( $table{$key} ) );
		$editor->GotoPos($start);

	} else {
		my $nextChar;
		if ( $editor->GetTextLength > $pos ) {
			$nextChar = $editor->GetTextRange( $pos, $pos + 1 );
		}
		unless ( defined($nextChar) && ord($nextChar) == $table{$key}
			and ( !$config->autocomplete_multiclosebracket ) )
		{
			$editor->AddText( chr( $table{$key} ) );
			$editor->CharLeft;
		}
	}

	return 1;
}

sub set_filename {
	my $self     = shift;
	my $filename = shift;

	unless ( defined $filename ) {
		warn 'Request to set filename to undef from ' . join( ',', caller );
		return 0;
	}

	# Shortcut if no change in file name
	if ( defined $self->{filename} and $self->{filename} eq $filename ) {
		return 1;
	}

	# Flush out old state information, primarily the file object.
	# Additionally, whenever we change the name of the file we can no
	# longer trust that we are in the same project, so flush that as well.
	delete $self->{filename};
	delete $self->{file};
	delete $self->{project_dir};

	# Save the new filename
	$self->{file} = Padre::File->new($filename);

	# Padre::File reformats filenames to the protocol/OS specific format, so use this:
	$self->{filename} = $self->{file}->{filename};
}

# Only a dummy for documents which don't support this
sub autoclean {
	my $self = shift;

	return 1;
}

sub save_file {
	my $self    = shift;
	my $current = $self->current;
	my $manager = $current->ide->plugin_manager;
	unless ( $manager->hook( 'before_save', $self ) ) {
		return;
	}

	# Show the file-changed-dialog again after the file was saved:
	delete $self->{_already_popup_file_changed};

	# If padre is run on files that have no project
	# I.E Padre foo.pl &
	# The assumption of $self->project as defined will cause a fail
	my $config;
	$config = $self->project->config if $self->project;
	$self->set_errstr('');

	if ( $config and $config->save_autoclean ) {
		$self->autoclean;
	}

	my $content = $self->text_get;
	my $file    = $self->file;
	unless ( defined $file ) {

		# NOTE: Now we have ->set_filename, should this situation ever occur?
		$file = Padre::File->new( $self->filename );
		$self->{file} = $file;
	}

	# This is just temporary for security and should prevend data loss:
	if ( $self->{filename} ne $file->{filename} ) {
		my $ret = Wx::MessageBox(
			sprintf(
				Wx::gettext('Visual filename %s does not match the internal filename %s, do you want to abort saving?'),
				$self->{filename},
				$file->{filename}
			),
			Wx::gettext("Save Warning"),
			Wx::YES_NO | Wx::CENTRE,
			$current->main,
		);

		return 0 if $ret == Wx::YES;
	}

	# Not set when first time to save
	# Allow the upgrade from ascii to utf-8 if there were unicode characters added
	unless ( $self->{encoding} and $self->{encoding} ne 'ascii' ) {
		require Padre::Locale;
		$self->{encoding} = Padre::Locale::encoding_from_string($content);
	}

	my $encode = '';
	if ( defined $self->{encoding} ) {
		$encode = ":raw:encoding($self->{encoding})";
	} else {
		warn "encoding is not set, (couldn't get from contents) when saving file $file->{filename}\n";
	}

	unless ( $file->write( $content, $encode ) ) {
		$self->set_errstr( $file->error );
		return;
	}

	# File must be closed at this time, slow fs/userspace-fs may not
	# return the correct result otherwise!
	$self->{timestamp} = $self->timestamp_now;

	# Determine new line type using file content.
	$self->{newline_type} = Padre::Util::newline_type($content);

	# Update read-only-cache
	$self->{readonly} = $self->file->readonly;

	$manager->hook( 'after_save', $self );

	return 1;
}

=head2 write

Writes the document to an arbitrary local file using the same semantics
as when we do a full file save.

=cut

sub write {
	my $self = shift;
	my $file = shift;          # File object, not just path
	my $text = $self->text_get;

	# Get the locale, but don't save it.
	# This could fire when only one of two characters have been
	# typed, and we may not know the encoding yet.
	# Not set when first time to save
	# Allow the upgrade from ascii to utf-8 if there were unicode characters added
	my $encoding = $self->{encoding};
	unless ( $encoding and $encoding ne 'ascii' ) {
		require Padre::Locale;
		$encoding = Padre::Locale::encoding_from_string($text);
	}
	if ( defined $encoding ) {
		$encoding = ":raw:encoding($encoding)";
	}

	# Write the file
	$file->write( $text, $encoding );
}

=head2 reload

Reload the current file discarding changes in the editor.

Returns true on success false on failure. Error message will be in C<< $doc->errstr >>.

TO DO: In the future it should backup the changes in case the user regrets the action.

=cut

sub reload {
	my $self = shift;
	my $file = $self->file or return;
	return $self->load_file;
}

# Copies document content to a temporary file.
# Returns temporary file name.
sub store_in_tempfile {
	my $self = shift;

	$self->create_tempfile unless $self->tempfile;

	open my $FH, ">", $self->tempfile;
	print $FH $self->text_get;
	close $FH;

	return $self->tempfile;
}

sub create_tempfile {
	my $tempfile = File::Temp->new( UNLINK => 0 );
	$_[0]->set_tempfile( $tempfile->filename );
	close $tempfile;

	return;
}

sub remove_tempfile {
	unlink $_[0]->tempfile;
	return;
}





#####################################################################
# Basic Content Manipulation

=head2 text_get

  my $string = $document->text_get;

The C<text_get> method returns the content of the document as a simple
plain scalar string.

=cut

sub text_get {
	$_[0]->editor->GetText;
}

=head2 text_length

  my $chars = $document->GetLength;

The C<text_length> method returns the size of the document in characters.

Note that this is the character length of the document and not the byte
size of the document. The byte size of the file when saved is likely to
differ from the character size.

=cut

sub text_length {
	$_[0]->editor->GetLength;
}

=head2 text_like

  my $cool = $document->text_like( qr/(?:robot|ninja|pirate)/i );

The C<text_like> method takes a regular expression and tests the document
to see if it matches.

Returns true if the document matches the regular express, or false if not.

=cut

sub text_like {
	my $self = shift;
	return !!( $self->text_get =~ /$_[0]/m );
}

sub text_with_one_nl {
	my $self   = shift;
	my $text   = $self->text_get or return;
	my $nlchar = "\n";
	if ( $self->newline_type eq 'WIN' ) {
		$nlchar = "\r\n";
	} elsif ( $self->newline_type eq 'MAC' ) {
		$nlchar = "\r";
	}
	$text =~ s/$nlchar/\n/g;
	return $text;
}

=head2 text_set

  $document->text_set("This is an\nentirely new document");

The C<text_set> method takes a content string and does a complete atomic
replacement of the document with new and entirely different content.

It uses a simple and direct approach which is fast but is not aware of
context such as the current cursor position and the undo buffer.

As a result, it is only appropriate for use when a document is being
changed for new content that is completely and utterly different.

To change a document to a new version that is similar to the old one
(such as when you are doing refactoring tasks) the alternative
L</text_replace> or ideally L</text_delta> should be used instead.

=cut

sub text_set {
	my $self = shift;
	my $editor = $self->editor or return;
	$editor->SetText(shift);
	$editor->refresh_notebook;
	return 1;
}

=head2 text_replace

  $document->text_replace("This is a\nmodified document");

The C<text_replace> method takes content as a string and incrementally
modifies the current document to look like the new content.

The logic for this process is done with a L<Padre::Delta> object created
using L<Algorithm::Diff> and is run in the foreground. Because this blocks
the entire IDE it is considered relatively slow and expensive, and is
particularly bad for large documents.

But because it is by the most simple way of applying changes to a document
and does not require locks or background tasks, this method has a role to
play in early implementations of new logic.

Once functionality using C<text_replace> has matured, you should consider
moving it into a background task which emits a L<Padre::Delta> and then
use C<text_delta> to apply the change to the editor in the foreground.

Returns true if changes were made to the current document, or false if the
new document is identical to the existing one and no change was needed.

=cut

sub text_replace {
	my $self = shift;
	my $to   = shift;
	my $from = $self->text_get;
	return 0 if $to eq $from;

	# Generate a delta and apply it
	require Padre::Delta;
	my $delta = Padre::Delta->from_scalars( \$from => \$to );
	return $self->text_delta($delta);
}

=head2 text_delta

The C<text_delta> method takes a single L<Padre::Delta> object as a
parameter and applies it to the current document.

Returns true if the document was changed, false if passed the null delta
and no changes were needed, or C<undef> if not passed a L<Padre::Delta>.

=cut

sub text_delta {
	my $self = shift;
	my $delta = Params::Util::_INSTANCE( shift, 'Padre::Delta' ) or return;
	return 0 if $delta->null;

	my $editor = $self->editor;
	$delta->to_editor($editor);
	$editor->refresh_notebook;
	return 1;
}





#####################################################################
# GUI Integration Methods

# What should be shown in the notebook tab
sub get_title {
	my $self = shift;
	if ( defined( $self->{file} ) and defined( $self->{file}->filename ) and ( $self->{file}->filename ne '' ) ) {
		return $self->basename;
	} else {
		$self->{unsaved} ||= ++$UNSAVED;
		my $str = sprintf(
			Wx::gettext("Unsaved %d"),
			$self->{unsaved},
		);

		# A bug in Wx requires a space at the front of the title
		# (For reasons I don't understand yet)
		return ' ' . $str;
	}
}

# TO DO: experimental
sub get_indentation_style {
	my $self   = shift;
	my $config = $self->config;

	# TO DO: (document >) project > config

	my $style;
	if ( $config->editor_indent_auto ) {

		# TO DO: This should be cached? What's with newish documents then?
		$style = $self->guess_indentation_style;
	} else {
		$style = {
			use_tabs    => $config->editor_indent_tab,
			tabwidth    => $config->editor_indent_tab_width,
			indentwidth => $config->editor_indent_width,
		};
	}

	return $style;
}

=head2 get_indentation_level_string

Calculates the string that should be used to indent a given
number of levels for this document.

Takes the indentation level as an integer argument which
defaults to one. Note that indenting to level 2 may be different
from just concatenating the indentation string to level one twice
due to tab compression.

=cut

sub get_indentation_level_string {
	my $self  = shift;
	my $level = shift;
	$level = 1 if not defined $level;
	my $style        = $self->get_indentation_style;
	my $indent_width = $style->{indentwidth};
	my $tab_width    = $style->{tabwidth};
	my $indent;

	if ( $style->{use_tabs} and $indent_width != $tab_width ) {

		# do tab compression if necessary
		# - First, convert all to spaces (aka columns)
		# - Then, add an indentation level
		# - Then, convert to tabs as necessary
		my $tab_equivalent = " " x $tab_width;
		$indent = ( " " x $indent_width ) x $level;
		$indent =~ s/$tab_equivalent/\t/g;
	} elsif ( $style->{use_tabs} ) {
		$indent = "\t" x $level;
	} else {
		$indent = ( " " x $indent_width ) x $level;
	}
	return $indent;
}

=head2 event_on_char

NOT IMPLEMENTED IN THE BASE CLASS

This method - if implemented - is called after any addition of a character
to the current document. This enables document classes to aid the user
in the editing process in various ways, e.g. by auto-pairing of brackets
or by suggesting usable method names when method-call syntax is detected.

Parameters retrieved are the objects for the document, the editor, and the
wxWidgets event.

Returns nothing.

Cf. C<Padre::Document::Perl> for an example.

=head2 event_on_context_menu

NOT IMPLEMENTED IN THE BASE CLASS

This method - if implemented - is called when a user triggers the context menu
(either by right-click or the context menu key or Shift+F10) in an editor after
the standard context menu was created and populated in the C<Padre::Wx::Editor>
class.
By manipulating the menu document classes may provide the user with
additional options.

Parameters retrieved are the objects for the document, the editor, the
context menu (C<Wx::Menu>) and the event.

Returns nothing.

=head2 event_on_left_up

NOT IMPLEMENTED IN THE BASE CLASS

This method - if implemented - is called when a user left-clicks in an
editor. This can be used to implement context-sensitive actions if
the user presses modifier keys while clicking.

Parameters retrieved are the objects for the document, the editor,
and the event.

Returns nothing.

=cut





#####################################################################
# Project Integration Methods

=pod

=head2 project

  my $project = $document->project;

The C<project> method is used to discover which project a document is part
of. It uses a variety of methods to discover, scanning the file system if
needed to "intuit" the location and type of project.

Returns a L<Padre::Project> object for the project, or C<undef> if the
document is unsaved, anonymous, or not part of any type of project for
some other reason.

=cut

sub project {
	my $self    = shift;
	my $manager = $self->current->ide->project_manager;

	# If we have a cached project_dir return the object based on that
	if ( defined $self->{project_dir} ) {
		return $manager->project( $self->{project_dir} );
	}

	# Anonymous files don't have a project
	my $file = $self->file or return;

	# Currently no project support for remote files
	return unless $file->{protocol} eq 'local';

	# Find the project for this document's filename
	my $project = $manager->from_file( $file->{filename} );
	return undef unless defined $project;

	# To prevent the creation of tons of references to the project object,
	# cache the project by it's root directory.
	$self->{project_dir} = $project->root;

	return $project;
}

=pod

=head2 project_dir

  my $path = $document->project_dir;

The C<project_dir> method behaves similarly to C<project>, but instead it
returns a path to the root directory of the project for this document.

Returns a directory as a string, or C<''> if the document is unsaved,
anonymous, or not part of any type of project for some other reason.

=cut

sub project_dir {
	my $self = shift;
	unless ( defined $self->{project_dir} ) {

		# Find the project, which slightly bizarely caches the
		# location of the project via it's root.
		# NOTE: Yes this looks weird, but it is significantly
		# less weird than the code it replaced.
		$self->project;
	}
	return $self->{project_dir};
}

# Find the project-relative file name
sub filename_relative {
	File::Spec->abs2rel( $_[0]->filename, $_[0]->project_dir );
}





#####################################################################
# Document Analysis Methods

# Unreliable methods that provide heuristic best-attempts at automatically
# determining various document properties.

# Left here as it is used in many places.
# Maybe we need to remove this sub.
sub guess_mimetype {
	my $self = shift;
	Padre::MIME->detect(
		text  => $self->{original_content},
		file  => $self->file,
		perl6 => $self->config->lang_perl6_auto_detection,
	);
}

=head2 guess_indentation_style

Automatically infer the indentation style of the document using
L<Text::FindIndent>.

Returns a hash reference containing the keys C<use_tabs>,
C<tabwidth>, and C<indentwidth>. It is suitable for passing
to C<set_indendentation_style>.

=cut

sub guess_indentation_style {
	my $self = shift;
	my $text = $self->text_get;

	# Hand off to the standalone module
	my $indentation = 'u'; # Unknown
	if ( length $text ) {

		# Allow for the delayed loading of Text::FindIndent if we startup
		# with no file or a completely empty file.
		require Text::FindIndent;
		$indentation = Text::FindIndent->parse(
			\$text,
			skip_pod => $self->isa('Padre::Document::Perl'),
		);
	}

	my $style;
	my $config = $self->config;
	if ( $indentation =~ /^t\d+/ ) { # we only do ONE tab
		$style = {
			use_tabs    => 1,
			tabwidth    => $config->editor_indent_tab_width || 8,
			indentwidth => 8,
		};
	} elsif ( $indentation =~ /^s(\d+)/ ) {
		$style = {
			use_tabs    => 0,
			tabwidth    => $config->editor_indent_tab_width || 8,
			indentwidth => $1,
		};
	} elsif ( $indentation =~ /^m(\d+)/ ) {
		$style = {
			use_tabs    => 1,
			tabwidth    => $config->editor_indent_tab_width || 8,
			indentwidth => $1,
		};
	} else {

		# fallback
		$style = {
			use_tabs    => $config->editor_indent_tab,
			tabwidth    => $config->editor_indent_tab_width,
			indentwidth => $config->editor_indent_width,
		};
	}

	return $style;
}

=head2 guess_filename

  my $name = $document->guess_filename

When creating new code, one job that the editor should really be able to do
for you without needing to be told is to work out where to save the file.

When called on a new unsaved file, this method attempts to guess what the
name of the file should be based purely on the content of the file.

In the base implementation, this returns C<undef> to indicate that the
method cannot make a reasonable guess at the name of the file.

Your MIME type specific document subclass should implement any file name
detection as it sees fit, returning the file name as a string.

=cut

sub guess_filename {
	my $self = shift;

	# If the file already has an existing name, guess that
	my $filename = $self->filename;
	if ( defined $filename ) {
		return ( File::Spec->splitpath($filename) )[2];
	}

	return undef;
}

=head2 guess_subpath

  my $subpath = $document->guess_subpath;

When called on a new unsaved file, this method attempts to guess what the
sub-path of the file should be inside of the current project, based purely
on the content of the file.

In the base implementation, this returns a null list to indicate that the
method cannot make a reasonable guess at the name of the file.

Your MIME type specific document subclass should implement any file name
detection as it sees fit, returning the project-rooted sub-path as a list
of directory names.

These directory names do not need to exist, they only represent intent.

=cut

sub guess_subpath {
	my $self = shift;

	# For an unknown document type, we cannot make any reasonable guess
	return ();
}

sub functions {
	my $self = shift;
	my $task = Params::Util::_DRIVER( $self->task_functions, 'Padre::Task' ) or return;
	$task->find( $self->text_get );
}

sub pre_process {
	return 1;
}

sub selection_stats {
	my $self    = shift;
	my $text    = $self->editor->GetSelectedText;
	my $words   = 0;
	my $newline = $self->newline;
	my $lines   = 1;
	$lines++ while ( $text =~ /$newline/g );
	$words++ while ( $text =~ /\s+/g );

	my $chars_with_space    = length $text;
	my $whitespace          = "\n\r\t ";
	my $chars_without_space = $chars_with_space - ( $text =~ tr/$whitespace// );

	return ( $lines, $chars_with_space, $chars_without_space, $words );
}

sub stats {
	my $self                = shift;
	my $chars_without_space = 0;
	my $words               = 0;
	my $editor              = $self->editor;
	my $text                = $self->text_get;
	my $lines               = $editor->GetLineCount;
	my $chars_with_space    = $editor->GetTextLength;

	# TODO: Remove this limit? Right now, it is greater than the default file size limit.
	if ( length $text < 2_500_000 ) {
		$words++ while ( $text =~ /\s+/g );

		my $whitespace = "\n\r\t ";

		# TODO: make this depend on the current character set
		#       see http://en.wikipedia.org/wiki/Whitespace_character
		$chars_without_space = $chars_with_space - ( $text =~ tr/$whitespace// );
	} else {
		$words               = Wx::gettext('Skipped for large files');
		$chars_without_space = Wx::gettext('Skipped for large files');
	}

	# not set when first time to save
	# allow the upgread of ascii to utf-8
	require Padre::Locale;
	if ( not $self->{encoding} or $self->{encoding} eq 'ascii' ) {
		$self->{encoding} = Padre::Locale::encoding_from_string($text);
	}
	return (
		$lines, $chars_with_space, $chars_without_space, $words, $self->{newline_type},
		$self->{encoding}
	);
}





#####################################################################
# Document Manipulation Methods

# Apply an arbitrary transform
sub transform {
	my $self   = shift;
	my %args   = @_;
	my $driver = Params::Util::_DRIVER( delete $args{class}, 'Padre::Transform' ) or return;
	my $editor = $self->editor;
	my $input  = $editor->GetText;
	my $delta  = $driver->new(%args)->scalar_delta( \$input );
	$delta->to_editor($editor);
	return 1;
}

# Delete all leading spaces.
# Passes through to the editor by default, and is only defined in the
# document class so that document classes can overload and do special stuff.
sub delete_leading_spaces {
	my $self = shift;
	my $editor = $self->editor or return;
	return $editor->delete_leading_spaces;
}

# Delete all trailing spaces.
# Passes through to the editor by default, and is only defined in the
# document class so that document classes can overload and do special stuff.
sub delete_trailing_spaces {
	my $self = shift;
	my $editor = $self->editor or return;
	return $editor->delete_trailing_spaces;
}





#####################################################################
# Unknown Methods
# Dumped here because it's not clear which section they belong in

# should return ($length, @words)
# where $length is the length of the prefix to be replaced by one of the words
# or
# return ($error_message)
# in case of some error
sub autocomplete {
	my $self   = shift;
	my $editor = $self->editor;
	my $pos    = $editor->GetCurrentPos;
	my $line   = $editor->LineFromPosition($pos);
	my $first  = $editor->PositionFromLine($line);

	# line from beginning to current position
	my $prefix = $editor->GetTextRange( $first, $pos );
	$prefix =~ s{^.*?(\w+)$}{$1};
	my $last = $editor->GetLength;
	my $text = $editor->GetTextRange( 0, $last );
	my $pre  = $editor->GetTextRange( 0, $first + length($prefix) );
	my $post = $editor->GetTextRange( $first, $last );

	my $regex = eval {qr{\b(\Q$prefix\E\w+)\b}};
	return ("Cannot build regular expression for '$prefix'.") if $@;

	my %seen;
	my @words;
	push @words, grep { !$seen{$_}++ } reverse( $pre =~ /$regex/g );
	push @words, grep { !$seen{$_}++ } ( $post =~ /$regex/g );

	if ( @words > 20 ) {
		@words = @words[ 0 .. 19 ];
	}

	return ( length($prefix), @words );
}

# Individual document classes should override this method.
# It gets a string (the current selection) and it should
# return a list of files that are possible matches to that file.
# In Perl for example A::B  would be mapped to A/B.pm in various places on
# the filesystem.
sub guess_filename_to_open {
	return;
}

# Individual document classes should override this method.
# It needs to return the document specific help topic string.
# In Perl this is using PPI to find the correct token
sub find_help_topic {
	return;
}

# Individual document classes should override this method.
# see L<Padre::Help>
sub get_help_provider {
	return;
}

sub _commafy {
	my $number = reverse shift;
	$number =~ s/(\d{3})(?=\d)/$1,/g;
	return scalar reverse $number;
}

1;

# Copyright 2008-2013 The Padre development team as listed in Padre.pm.
# LICENSE
# This program is free software; you can redistribute it and/or
# modify it under the same terms as Perl 5 itself.
