#!/usr/bin/perl
package IkiWiki::Plugin::remove;

use warnings;
use strict;
use IkiWiki 3.00;

sub import {
	hook(type => "getsetup", id => "remove", call => \&getsetup);
	hook(type => "formbuilder_setup", id => "remove", call => \&formbuilder_setup);
	hook(type => "formbuilder", id => "remove", call => \&formbuilder);
	hook(type => "sessioncgi", id => "remove", call => \&sessioncgi);

}

sub getsetup () {
	return 
		plugin => {
			safe => 1,
			rebuild => 0,
			section => "web",
		},
}

sub check_canremove ($$$) {
	my $page=shift;
	my $q=shift;
	my $session=shift;

	# Must be a known source file.
	if (! exists $pagesources{$page}) {
		error(sprintf(gettext("%s does not exist"),
			htmllink("", "", $page, noimageinline => 1)));
	}

	# Must exist on disk, and be a regular file.
	my $file=$pagesources{$page};
	if (! -e "$config{srcdir}/$file") {
		error(sprintf(gettext("%s is not in the srcdir, so it cannot be deleted"), $file));
	}
	elsif (-l "$config{srcdir}/$file" && ! -f _) {
		error(sprintf(gettext("%s is not a file"), $file));
	}
	
	# If a user can't upload an attachment, don't let them delete it.
	# This is sorta overkill, but better safe than sorry.
	if (! defined pagetype($pagesources{$page})) {
		if (IkiWiki::Plugin::attachment->can("check_canattach")) {
			IkiWiki::Plugin::attachment::check_canattach($session, $page, "$config{srcdir}/$file");
		}
		else {
			error("removal of attachments is not allowed");
		}
	}

	my $canremove;
	IkiWiki::run_hooks(canremove => sub {
		return if defined $canremove;
		my $ret=shift->(page => $page, cgi => $q, session => $session);
		if (defined $ret) {
			if ($ret eq "") {
				$canremove=1;
			}
			elsif (ref $ret eq 'CODE') {
				$ret->();
				$canremove=0;
			}
			elsif (defined $ret) {
				error($ret);
				$canremove=0;
			}
		}
	});
	return defined $canremove ? $canremove : 1;
}

sub formbuilder_setup (@) {
	my %params=@_;
	my $form=$params{form};
	my $q=$params{cgi};

	if (defined $form->field("do") && ($form->field("do") eq "edit" ||
	    $form->field("do") eq "create")) {
		# Removal button for the page, and also for attachments.
		push @{$params{buttons}}, "Remove" if $form->field("do") eq "edit";
		$form->tmpl_param("field-remove" => '<input name="_submit" type="submit" value="Remove Attachments" />');
	}
}

sub confirmation_form ($$) {
	my $q=shift;
	my $session=shift;

	eval q{use CGI::FormBuilder};
	error($@) if $@;
	my $f = CGI::FormBuilder->new(
		name => "remove",
		header => 0,
		charset => "utf-8",
		method => 'POST',
		javascript => 0,
		params => $q,
		action => IkiWiki::cgiurl(),
		stylesheet => 1,
		fields => [qw{do page}],
	);
	
	$f->field(name => "sid", type => "hidden", value => $session->id,
		force => 1);
	$f->field(name => "do", type => "hidden", value => "remove", force => 1);

	return $f, ["Remove", "Cancel"];
}

sub removal_confirm ($$@) {
	my $q=shift;
	my $session=shift;
	my $attachment=shift;
	my @pages=@_;
		
	# Special case for unsaved attachments.
	@pages=grep {
		! (IkiWiki::Plugin::attachment->can("remove_held_attachment") &&
		   IkiWiki::Plugin::attachment::remove_held_attachment($_))
	} @pages;
	return unless @pages;

	foreach my $page (@pages) {
		IkiWiki::check_canedit($page, $q, $session);
		check_canremove($page, $q, $session);
	}

	# Save current form state to allow returning to it later
	# without losing any edits.
	# (But don't save what button was submitted, to avoid
	# looping back to here.)
	# Note: "_submit" is CGI::FormBuilder internals.
	$q->param(-name => "_submit", -value => "");
	$session->param(postremove => scalar $q->Vars);
	IkiWiki::cgi_savesession($session);
	
	my ($f, $buttons)=confirmation_form($q, $session);
	$f->title(sprintf(gettext("confirm removal of %s"),
		join(", ", map { pagetitle($_) } @pages)));
	$f->field(name => "page", type => "hidden", value => \@pages, force => 1);
	if (defined $attachment) {
		$f->field(name => "attachment", type => "hidden",
			value => $attachment, force => 1);
	}

	IkiWiki::showform($f, $buttons, $session, $q);
	exit 0;
}

sub postremove ($) {
	my $session=shift;

	# Load saved form state and return to edit form.
	my $postremove=CGI->new($session->param("postremove"));
	$session->clear("postremove");
	IkiWiki::cgi_savesession($session);
	IkiWiki::cgi($postremove, $session);
}

sub formbuilder (@) {
	my %params=@_;
	my $form=$params{form};

	if (defined $form->field("do") && ($form->field("do") eq "edit" ||
	    $form->field("do") eq "create")) {
		my $q=$params{cgi};
		my $session=$params{session};

		if ($form->submitted eq "Remove" && $form->field("do") eq "edit") {
			removal_confirm($q, $session, 0, $form->field("page"));
		}
		elsif ($form->submitted eq "Remove Attachments") {
			my @selected=map { Encode::decode_utf8($_) } $q->param("attachment_select");
			if (! @selected) {
				error(gettext("Please select the attachments to remove."));
			}
			removal_confirm($q, $session, 1, @selected);
		}
	}
}

sub sessioncgi ($$) {
	my $q=shift;

	if ($q->param("do") eq 'remove') {
		my $session=shift;
		my ($form, $buttons)=confirmation_form($q, $session);
		IkiWiki::decode_form_utf8($form);

		if ($form->submitted eq 'Cancel') {
			postremove($session);
		}
		elsif ($form->submitted eq 'Remove' && $form->validate) {
			IkiWiki::checksessionexpiry($q, $session, $q->param('sid'));

			my @pages=$form->field("page");
			
			# Validate removal by checking that the page exists,
			# and that the user is allowed to edit(/remove) it.
			my @files;
			foreach my $page (@pages) {
				IkiWiki::check_canedit($page, $q, $session);
				check_canremove($page, $q, $session);
				
				# This untaint is safe because of the
				# checks performed above, which verify the
				# page is a normal file, etc.
				push @files, IkiWiki::possibly_foolish_untaint($pagesources{$page});
			}

			# Do removal, and update the wiki.
			require IkiWiki::Render;
			if ($config{rcs}) {
				IkiWiki::disable_commit_hook();
				foreach my $file (@files) {
					IkiWiki::rcs_remove($file);
				}
				IkiWiki::rcs_commit_staged(
					message => gettext("removed"),
					session => $session,
				);
				IkiWiki::enable_commit_hook();
				IkiWiki::rcs_update();
			}
			else {
				foreach my $file (@files) {
					IkiWiki::prune("$config{srcdir}/$file");
				}
			}
			IkiWiki::refresh();
			IkiWiki::saveindex();

			if ($q->param("attachment")) {
				# Attachments were deleted, so redirect
				# back to the edit form.
				postremove($session);
			}
			else {
				# The page is gone, so redirect to parent
				# of the page.
				my $parent=IkiWiki::dirname($pages[0]);
				if (! exists $pagesources{$parent}) {
					$parent="index";
				}
				IkiWiki::redirect($q, urlto($parent));
			}
		}
		else {
			removal_confirm($q, $session, 0, $form->field("page"));
		}

		exit 0;
	}
}

1