#!/usr/bin/perl -w

# written by andrewt@cse.unsw.edu.au September 2016
# as a starting point for COMP2041/9041 assignment 2
# http://cgi.cse.unsw.edu.au/~cs2041/assignments/matelook/

use CGI qw/:all/;
use CGI::Carp qw/fatalsToBrowser warningsToBrowser/;

sub main() {
    # print start of HTML ASAP to assist debugging if there is an error in the script
    print page_header();

    # Now tell CGI::Carp to embed any warning in HTML
    warningsToBrowser(1);

    # define some global variables
    $debug = 1;
    $users_dir = "dataset-medium";

    verify_user();
}

# Verifies username and password
sub verify_user {
    $username = param('username') || '';
    $password = param('password') || '';
    $current_user = param('current_user');

    #sanitise username
    $username = substr $username, 0, 256;
    $username =~ s/\W//g;

    if ($username && $password) {
        $details_file = "$users_dir/$username/user.txt";
        open my $p, "$details_file";
        my $correct_password = "";
        while ($line = <$p>) {
            if ($line =~ /password=/) {
                $line =~ s/password=//;
                $correct_password = $line;
            }
            if ($line =~ /zid=/) {
                $line =~ s/zid=//;
                $username = $line;
            }
        }
        close $p;
        chomp $correct_password;
        if ($password eq $correct_password) {
            print "Welcome to Matelook, $username! :)";
            $current_user = $username;
            print user_search($username);
            print user_page($username);
            print page_trailer();
        } else {
            print "Incorrect password/username!\n";
        }
    } else {
        if ($current_user ne '') { #already someone logged in
            print <<eof;
<form method="post" action="">
<input type="hidden" name="current_user" value="$username">
</form>

eof
            print "Welcome to Matelook, $current_user! :)";
            print user_search($current_user);
            print user_page($current_user);
            print page_trailer();
        } else {
            print start_form, "\n";
            if ($username) {
                print hidden('username'), "\n";
            } else {
                print "Username:\n", textfield('username'), "\n";
            }
            if ($password) {
                print hidden('password');
#               <input type="hidden" name="current_user" value="$current_user">
            } else {
                print "Password:\n", textfield('password'), "\n";
            }
            print submit(value => Login), "\n";
            print end_form;
        }
    }


}


sub user_search {
    my $username = param('username');
    my $search_name = param('search_name');
    my @users = sort(glob("$users_dir/*"));

    if (defined $search_name) {
        foreach $user_details(@users) {
            $user_details = $user_details."/user.txt";
            open my $p, "$user_details";
            while ($line = <$p>) {
                chomp $line;
                if ($line =~ /full_name=/) {
                    $line =~ s/full_name=//;
                    if ($line =~ m/$search_name/g) {
                        if ($line =~ /zid=/) {
                            $line =~ s/zid=//;
                            $username = $line;
                            print user_page($username);
                        }
                    }
                }
            }
        }
    }

    print <<eof
<form method="post">
Search Name: <input type="text" name="search_name">
<input type="hidden" name="current_user" value="$username">
<input type="submit" class="btn btn-link" value="Search user">

</form>

eof

}



#
# Show unformatted details for user "n".
# Increment parameter n and store it as a hidden variable
#
sub user_page {
    chomp $username;
    my $user_to_show = shift;
    my $details_filename = "$users_dir/$user_to_show/user.txt";
    my $dp_filename = "$users_dir/$user_to_show/profile.jpg";
    my $posts_filename = "$users_dir/$user_to_show/posts/0/post.txt";

    open my $p, "$details_filename" or die "can not open $details_filename: $!";
    while ($line = <$p>) {
        $line =~ s/\n//g;
        if ($line =~ /email=/ || $line =~ /password=/ || $line =~ /courses=/ || $line =~ /home_latitude=/ || $line =~ /home_longitude=/) {
            next;
        } elsif ($line =~ /mates=/) {
            $line =~ s/mates=\[//;
            $line =~ s/\]//;
            $line =~ s/, /\n/g;
            $mates = $line;
            next;
        } elsif ($line =~ /birthday=/) {
            $line =~ s/birthday=//;
            $birthday = $line;
            next;
        } elsif ($line =~ /program=/) {
            $line =~ s/program=//;
            $program = $line;
            next;
        } elsif ($line =~ /full_name=/) {
            $line =~ s/full_name=//;
            $name = $line;
            next;
        } elsif ($line =~ /zid=/) {
            $line =~ s/zid=//;
            next;
        } elsif ($line =~ /home_suburb=/) {
            $line =~ s/home_suburb=//;
            $suburb = $line;
            next;
        }
    }
    close $p;

    open my $p, "$posts_filename" or die "cannot open $posts_filename: $!";
    my @posts_indexes = ();
    my %posts_hash = ();
    my @posts= ();
    while ($line = <$p>) {
        if ($line =~ /\d{10}/) {
            push @posts_indexes, $line;
        }
    }
    close $p;

    foreach $posts_index(@posts_indexes) {
        $post_address = "dataset-medium/posts/$post_index/[0-9]";
        open my $p, "$post_address" or die "dcannot open $post_address: $!";
        my $time = 0;
        my $post = " ";
        while ($line = <$p>) {
            if ($line =~ /message=/) {
                $line =~ s/message=//;
                $post = $line;
            }
            if ($line =~ /time=/) {
                $line =~ s/time=//;
                $time = $line;
            }
        }
        close $p;
        $posts_hash{$post} = $time;
    }

    @posts = sort {$posts_hash{$b}<=>$posts_hash{$a}} keys %posts_hash;
    my $post_print = join('', @posts);

    return <<eof
<div class="matelook_user_details">
<img src="$dp_filename" class="img-thumbnail">
<h3>$name</h3>ZID: $zid
Program: $program
Birthday: $birthday
Lives in: $suburb

Posts:

$post_print
</div>
<p>
<form method="POST" action="">
    <input type="submit" value="Log Out :(" class="matelook_button">
</form>
eof

}


#
# HTML placed at the top of every page
#
sub page_header {
    return <<eof
Content-Type: text/html;charset=utf-8

<!DOCTYPE html>
<html lang="en">
<head>
<title>matelook</title>
<link href="matelook.css" rel="stylesheet">
</head>
<body>
<div class="matelook_heading">
matelook
</div>
eof
}


#
# HTML placed at the bottom of every page
# It includes all supplied parameter values as a HTML comment
# if global variable $debug is set
#
sub page_trailer {
    my $html = "";
    $html .= join("", map("<!-- $_=".param($_)." -->\n", param())) if $debug;
    $html .= end_html;
    return $html;
}

main();