#!/usr/bin/perl

use strict;
use FCGI;
use JSON;
use DBI;
use Data::Dumper;
use warnings;

$Data::Dumper::Sortkeys = 1;

my $conf = load_conf("../etc/autodoc.json");
my $dbh  = sqlconnect($conf->{sql});

my %map = (
	api_v1_POST_documents		=> &api_v1_POST_documents,
	api_v1_POST_documents_id_data	=> &api_v1_POST_documents_id_data,
	api_v1_GET_documents_id_image	=> &api_v1_GET_documents_id_image,
	api_v1_GET_pages_image		=> &api_v1_GET_pages_image,
	api_v1_GET_documents		=> &api_v1_GET_documents,
	api_v1_GET_documents_id		=> &api_v1_GET_documents_id,
	api_v1_GET_pages_id		=> &api_v1_GET_pages_id,
	api_v1_PATCH_documents_id	=> &api_v1_PATCH_documents_id,
);

my $request = FCGI::Request();

while($request->Accept() >= 0) {

	my $user   = $ENV{REMOTE_USER} || 'undefined';
	my $qs     = parse_querystring($ENV{QUERY_STRING});
	my $method = $ENV{REQUEST_METHOD};

	my $path   = [ split(/\//,$ENV{SCRIPT_NAME}) ] if exists $ENV{SCRIPT_NAME};
	shift(@{$path});

	my $post   = parse_post(
		\*STDIN,
		exists $ENV{CONTENT_LENGTH} ? $ENV{CONTENT_LENGTH} : 0,
		exists $ENV{CONTENT_TYPE}   ? $ENV{CONTENT_TYPE}   : 0
	);


	my($code, $type, $data) = process_query($method, $path, $qs, $post, $user);

	if ( $type eq 'application/json' ) {
		$data = to_json($data);
	}

	printf("Status: %s\r\n", $code);
	printf("Content-type: %s\r\n", $type);
	printf("Content-length: %i\r\n", length($data));
	printf("\r\n");
	print $data;
}

sub load_conf {
	my($file) = @_;

	my $x='';

	open(F,"$file") || fatal_api_error(500,"Failed to load configuration file");
	while(<F>) { $x.=$_; }
	close(F);

	return from_json($x);
}

sub process_query {
	my($method, $path, $qs, $post, $user) = @_;

	my ($api_version, $path_main, $path_id, $path_sub) = @{$path};

	my $func = sprintf("api_%s_%s_%s",
		defined $api_version ? $api_version : "unknown",
		defined $method      ? $method      : "unknown",
		defined $path_main   ? $path_main   : "unknown"
	);

	$func .= '_id' if defined $path_id;
	$func .= '_'.$path_sub if defined $path_sub;

	return $map{$func}->($path_id, $qs, $post, $user) if exists $map{$func};
	return api_error(404);

}

sub db_get_document_object {
	my($id) = @_;

	my $document;
	my @pages;
	my @pageids;

	my $q = sqlquery($dbh, "SELECT * FROM documents WHERE id = ?", $id);
	while(my $hash = $q->fetchrow_hashref()) { $document = $hash; }

	$q = sqlquery($dbh, "SELECT * FROM pages WHERE documentId = ?", $id);
	while(my $hash = $q->fetchrow_hashref()) { push @pages, $hash; push @pageids, $hash->{id}; }

	my %lang;

	foreach my $page ( @pages ) {
		$q = sqlquery($dbh, "SELECT * FROM pages_lang WHERE pageId = ?", $page->{id});
		while(my $hash = $q->fetchrow_hashref()) {
			$lang{$hash->{language}}++;
		}
	}

	my $out = {
		id => $document->{id},
		pageId => [ @pageids ],
		name => $document->{name},
		created => $document->{created},
		owner => $document->{owner},
		status => $document->{status},
		languages => [ keys %lang ],
	};

	return (200, "application/json", $out);

}

# create an empty document object.
sub api_v1_POST_documents {
	my($id, $qs, $post, $user) = @_;

	my $q = sqlquery($dbh, "
		INSERT INTO documents
		SET
			owner = ?,
			status = 'nodata'
		", $user);
	$q = sqlquery($dbh, "SELECT LAST_INSERT_ID()");
	while(my($lastid) = $q->fetchrow_array()) {
		$id = $lastid;
	}

	return db_get_document_object($id);
}

sub api_v1_POST_documents_id_data { return api_error(501,"Not yet implemented"); }
sub api_v1_GET_documents_id_image { return api_error(501,"Not yet implemented"); }
sub api_v1_GET_pages_image        { return api_error(501,"Not yet implemented"); }

# get a list of document objects
sub api_v1_GET_documents {
	my($id, $qs, $post, $user) = @_;

	$qs->{pageSize}  = $conf->{query}{pageSize}  if !exists $qs->{pageSize};
	$qs->{pageIndex} = $conf->{query}{pageIndex} if !exists $qs->{pageIndex};

	my @out;

	my $q = sqlquery($dbh, "SELECT id FROM documents LIMIT ?,?",
		$qs->{pageSize} * $qs->{pageIndex},
		$qs->{pageSize});
	while(my ($id) = $q->fetchrow_array()) {
		my ($code, $ct, $body) = db_get_document_object($id);
		push @out, $body;
	}

	return (
		200,
		"application/json",
		\@out
	);
}

# get a single document object
sub api_v1_GET_documents_id {
	my($id, $qs, $post, $user) = @_;
	return db_get_document_object($id);
}

sub api_v1_GET_pages_id           { return api_error(501,"Not yet implemented"); }
sub api_v1_PATCH_documents_id     { return api_error(501,"Not yet implemented"); }

sub fatal_api_error {
	my($code,$type,$body)=api_error(@_);

        printf("Status: %s\r\n", $code);
        printf("Content-type: %s\r\n", $type);
        printf("Content-length: %i\r\n", length($body));
        printf("\r\n");
        print $body;
	exit;
}

sub api_error {
	my($code, $text)=@_;

	my %deftext = (
		"000" => "An error produced an internal error, cascading errors over errors",
		"404" => "No such API path"
	);

	$code = "000" if !defined $code;
	$text = $deftext{$code} if ( !defined $text || $code eq "000" );

	return ( $code, "text/plain", $text );
}

sub parse_querystring {
	my($in) = @_;

	my %out;

	if ( defined $in && length $in ) {
		foreach(split(/&/,$in)) {
			my($name,$value) = split(/=/);
			$value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
			$out{$name}=$value;
		}
	}

	return \%out;
}

sub parse_post {
	my($fd, $len, $ct) = @_;

	my $data = '';
	while ( $len > 0 ) {
		my $buf;
		my $read = read($fd, $buf, $len);
		$len -= $read;
		$data .= $buf;
	}

	if ( $ct eq 'application/json' ) {
		my $tmp = from_json($data);
		$data = $tmp;
	}

	return $data;
}

sub sqlconnect {
	my($sql) = @_;

	my $dsn = "DBI:mysql:database=$sql->{base};host=$sql->{host}";
	my $dbh = DBI->connect($dsn, $sql->{user}, $sql->{pass}) || \\
		fatal_api_error(500,"Failed to connect to database");

	return $dbh;
}

sub sqlquery {
	my $dbh   = shift;
	my $query = shift;
	my @args  = @_;

	my $sth = $dbh->prepare($query) || fatal_api_error(500,"Failed to execute SQL query");
	$sth->execute(@args) || fatal_api_error(500,"Failed to execute SQL query");
	return $sth;
}