#!/usr/bin/perl -i
use warnings;
use strict;
use IkiWiki;
use HTML::Entities;

my $regex = qr{
	(\\?)		# 1: escape?
	\[\[(!?)	# directive open; 2: optional prefix
	([-\w]+)	# 3: command
	(		# 4: the parameters (including initial whitespace)
	\s+
		(?:
			(?:[-\w]+=)?		# named parameter key?
			(?:
				""".*?"""	# triple-quoted value
				|
				"[^"]+"		# single-quoted value
				|
				[^\s\]]+	# unquoted value
			)
			\s*			# whitespace or end
						# of directive
		)
	*)		# 0 or more parameters
	\]\]		# directive closed
}sx;

sub handle_directive {
	my $escape = shift;
	my $prefix = shift;
	my $directive = shift;
	my $args = shift;

	if (length $escape) {
		return "${escape}[[${prefix}${directive}${args}]]"
	}
	if ($directive =~ m/^(if|more|table|template|toggleable)$/) {
		$args =~ s{$regex}{handle_directive($1, $2, $3, $4)}eg;
	}
	return "[[!${directive}${args}]]"
}

sub prefix_directives {
	$/=undef; # process whole files at once
	
	while (<>) {
		s{$regex}{handle_directive($1, $2, $3, $4)}eg;
		print;
	}
}

sub indexdb {
	$config{wikistatedir}=shift()."/.ikiwiki";

	if (! defined $config{wikistatedir}) {
		usage();		
	}

	if (! IkiWiki::oldloadindex()) {
		die "failed to load index\n";
	}
	if (! IkiWiki::saveindex()) {
		die "failed to save indexdb\n"
	}
	if (! IkiWiki::loadindex()) {
		die "transition failed, cannot load new indexdb\n";
	}
	if (! unlink("$config{wikistatedir}/index")) {
		die "unlink failed: $!\n";
	}
}

sub usage {
	print STDERR "Usage: ikiwiki-transition type ...\n";
	print STDERR "Currently supported transition subcommands:\n";
	print STDERR "	prefix_directives file\n";
	print STDERR "	indexdb srcdir\n";
	exit 1;
}

usage() unless @ARGV;

my $mode=shift;
if ($mode eq 'prefix_directives') {
	prefix_directives(@ARGV);
}
elsif ($mode eq 'indexdb') {
	indexdb(@ARGV);
}
else {
	usage();
}

package IkiWiki;

# A slightly modified version of the old loadindex function.
sub oldloadindex {
	%oldrenderedfiles=%pagectime=();
	if (! $config{rebuild}) {
		%pagesources=%pagemtime=%oldlinks=%links=%depends=
			%destsources=%renderedfiles=%pagecase=%pagestate=();
	}
	open (my $in, "<", "$config{wikistatedir}/index") || return;
	while (<$in>) {
		chomp;
		my %items;
		$items{link}=[];
		$items{dest}=[];
		foreach my $i (split(/ /, $_)) {
			my ($item, $val)=split(/=/, $i, 2);
			push @{$items{$item}}, decode_entities($val);
		}

		next unless exists $items{src}; # skip bad lines for now

		my $page=pagename($items{src}[0]);
		if (! $config{rebuild}) {
			$pagesources{$page}=$items{src}[0];
			$pagemtime{$page}=$items{mtime}[0];
			$oldlinks{$page}=[@{$items{link}}];
			$links{$page}=[@{$items{link}}];
			$depends{$page}=$items{depends}[0] if exists $items{depends};
			$destsources{$_}=$page foreach @{$items{dest}};
			$renderedfiles{$page}=[@{$items{dest}}];
			$pagecase{lc $page}=$page;
			foreach my $k (grep /_/, keys %items) {
				my ($id, $key)=split(/_/, $k, 2);
				$pagestate{$page}{decode_entities($id)}{decode_entities($key)}=$items{$k}[0];
			}
		}
		$oldrenderedfiles{$page}=[@{$items{dest}}];
		$pagectime{$page}=$items{ctime}[0];
	}

	# saveindex relies on %hooks being populated, else it won't save
	# the page state owned by a given hook. But no plugins are loaded
	# by this program, so populate %hooks with all hook ids that
	# currently have page state.
	foreach my $page (keys %pagemtime) {
		foreach my $id (keys %{$pagestate{$page}}) {
			$hooks{_dummy}{$id}=1;
		}
	}
	
	return close($in);
}