#!/usr/bin/perl

###############################################################################
# Demonstrates Kayak API Hotel Search.
# See http://www.kayak.com/labs/api/search/spec.vtl for API details.
#
# Takes query options from command line, sends query to kayak, prints search
# results on stdout.
#
# ./hsearch.pl --city="Los Angeles" --state=CA --numresults=10
#
###############################################################################

use strict;

use Getopt::Long;
use LWP::Simple;
use URI::Escape;
use XML::DOM;

my %opts = ();

#
# See http://www.kayak.com/labs/api/search/developerkey.vtl
# Purposelly causes error at runtime so you'll have to look at this line!
#

my $g_token = INSERT YOUR TOKEN HERE

#
# Establish default values for the command line arguments.  Makes testing
# easier.
#

my $g_hostname = "http://www.kayak.com";
my $g_city = "Boston";
my $g_state = "MA";
my $g_country = "US";
my $g_guests1 = "2";
my $g_rooms = "1";
my $g_checkin = `date +%m/%d/%Y --date=\"2 days\"`;
chop($g_checkin);
my $g_checkout = `date +%m/%d/%Y --date=\"4 days\"`;
chop($g_checkout);
my $g_othercity;
my $g_numresults = 50;
my $g_filtermode = "normal";
my $g_sortdirection = "up";
my $g_sortkey = "price";

&main();
exit;

###############################################################################
# Module entrypoint.
###############################################################################
sub main() {

    GetOptions(\%opts,
               "host=s" => \$g_hostname,
               "token=s" => \$g_token,
               "city=s" => \$g_city,
               "state=s" => \$g_state,
               "country=s" => \$g_country,
               "guests1=i" => \$g_guests1,
               "rooms=i" => \$g_rooms,
               "checkin=s" => \$g_checkin,
               "checkout=s" => \$g_checkout,
               "numresults=i" => \$g_numresults,
               "filtermode=s" => \$g_filtermode,
               "sortdirection=s" => \$g_sortdirection,
               "sortkey=s" => \$g_sortkey,
               "help");

    &validateOptions();
    my $rsp = &performHotelSearch();
    print $rsp . "\n";
}

###############################################################################
# Make sure that whatever was entered on command line is within bounds.
###############################################################################
sub validateOptions() {
    my ($s) = @_;
    &usage("Usage:") if $opts{"help"};

    $g_state = uc($g_state);
    &usage("Invalid state/province") unless (2 == length($g_state));

    $g_country = uc($g_country);
    &usage("Invalid country code") unless (2 == length($g_country));

    $g_othercity = $g_city . "," . $g_state . "," . $g_country;

    &usage("Invalid checkin date [$g_checkin]") unless (isDate($g_checkin));
    &usage("Invalid checkout date [$g_checkout]") unless (isDate($g_checkout));
    &usage("Invalid guests1 [$g_guests1]") unless 
        (($g_guests1 >= 1) && ($g_guests1 <=6));
    &usage("Invalid rooms [$g_rooms]") unless 
        (($g_rooms >= 1) && ($g_rooms <=3));

    &usage("Invalid numresults [$g_numresults]") unless ($g_numresults > 1);

    $g_filtermode = lc($g_filtermode);
    &usage("Invalid filtermode [$g_filtermode]") 
        unless ((0 == index($g_filtermode, "normal")) || (0 == index($g_filtermode,"stars:")));

    $g_sortdirection = lc($g_sortdirection);
    &usage("Invalid sortdirection [$g_sortdirection]") 
        unless (($g_sortdirection eq "up") || ($g_sortdirection eq "down"));

    $g_sortkey = lc($g_sortkey);
    &usage("Invalid sortkey [$g_sortkey]") 
        unless (($g_sortkey eq "price") || ($g_sortkey eq "stars") || 
                ($g_sortkey eq "hotel") || ($g_sortkey eq "distance"));
}

###############################################################################
# Shows the command line options.
###############################################################################
sub usage() {

    my ($eMsg) = @_;
    my $msg = "
Refer to http://www.kayak.com/labs/api/search/spec.vtl for semantics

$eMsg

$0 
  --token={your developer key}
  --city={City to search within}
  --state={2 character state/province code}
  --country={2 character country code}
  --guests1={integer 1-6}
  --rooms={integer 1-3}
  --checkin={MM/DD/YYYY}
  --checkout={MM/DD/YYYY}
  --numresults={integer 1-500}
  --filtermode={normal || stars:#}
  --sortdirection=$g_sortdirection 
  --sortkey={up || down}
  --help

";
    die($msg);
}

###############################################################################
# expect MM/DD/YYYY
###############################################################################
sub isDate() {
    my($s) = @_;
    my $pattern = '([0-9]{2})/([0-9]{2})/([0-9]{4})';
    return ($s =~ m/$pattern/);
}

##############################################################################
# Assemble search URLs and initiate the search.
##############################################################################
sub performHotelSearch() {

    my $sid = getsession($g_token);
    die("Unable to get session") unless($sid);

    my $url = "/s/apisearch?basicmode=true&minstars=-1";
    $url .= "&action=dohotels&apimode=1";

    $url .= "&othercity=" . uri_escape($g_othercity);
    $url .= "&checkin_date=" . uri_escape($g_checkin);
    $url .= "&checkout_date=" . uri_escape($g_checkout);
    $url .= "&guests1=" . $g_guests1;
    $url .= "&rooms=" . $g_rooms;
    $url .= "&_sid_=" . $sid;

    my $searchId = &start_search($url);
    my ($more,$last_count,$xmlRsp) = &poll_results("h", $sid, $searchId, 
                                                   $g_numresults, 0);
    while($more) {
        sleep(5);
        ($more,$last_count,$xmlRsp) = &poll_results("h", $sid, $searchId, 
                                                    $g_numresults, 0);
    }

    # Make final poll with c set to count which'll retrieve all the results
    # at once.
    ($more,$last_count,$xmlRsp) = &poll_results("h", $sid, $searchId, 
                                                $last_count, 1);

    return $xmlRsp;
}


##############################################################################
# 
##############################################################################
sub getsession() {
    my ($token) = @_;
    die("Missing required developer token") unless ($token);
    my $sid="";
    my $response=get("$g_hostname/k/ident/apisession?token=$token");
    my $parser = XML::DOM::Parser->new();
    my $doc = $parser->parse($response);
    $sid=$doc->getElementsByTagName('sid')->item(0)->getFirstChild->getNodeValue
        if ( defined( $doc->getElementsByTagName('sid')->item(0)->getFirstChild ));
    return $sid;
}

##############################################################################
#
##############################################################################
sub start_search() {
    my ($uri) = @_;

    my $searchURL = $g_hostname . $uri;
    my $response = get($searchURL);

    my $parser = XML::DOM::Parser->new();
    my $doc = $parser->parse($response);

    my $searchid="";

    $searchid = $doc->getElementsByTagName('searchid')->item(0)->getFirstChild->getNodeValue
        if ( defined( $doc->getElementsByTagName('searchid')->item(0) ) ) ;
    return $searchid if ( $searchid ne "" ) ;

    if (defined($doc->getElementsByTagName('hotel_errors')->item(0)->getFirstChild )) {
        my $errorNode = $doc->getElementsByTagName('hotel_errors')->item(0);
        die($errorNode->toString());
    }

    die("unknown error in $0");
}

##############################################################################
#
##############################################################################
sub poll_results() {
    my($searchtype, $sid, $searchid, $maxRes, $showResults) = @_;
    my $url = "/s/apibasic/hotel?searchid=$searchid";
    $url .= "&apimode=1&_sid_=$sid&c=$maxRes";

    my $postUrl = $g_hostname . $url;
    my $response = get($postUrl);
    my ($more,$last_count,$xmlStr) = handle_results($searchtype, $response, $showResults);
    return ($more,$last_count,$xmlStr);
}

##############################################################################
# The response in this case is the set of results.
##############################################################################
sub handle_results() {
    my($searchtype, $response, $showResults) = @_;


    my $more = "";

    my $parser = XML::DOM::Parser->new();
    my $doc = $parser->parse($response);

    if ( defined($doc->getElementsByTagName('morepending')->item(0)->getFirstChild) )
    {
        $more=$doc->getElementsByTagName('morepending')->item(0)->getFirstChild->getNodeValue;
    }

    my $lastcount =
        $doc->getElementsByTagName('count')->item(0)->getFirstChild->getNodeValue;


    my $xmlStr = $doc->toString;


    return (1,$lastcount,$xmlStr) if( $more eq "true");
    return (0,$lastcount,$xmlStr);
}