#!/usr/bin/env perl

=head1 Select and display job vacancies

This is a "proof of concept" demo of a system for
display and management of job opportunities stored
in a text file.

User is initially given the option of selecting a
summary of all jobs, a listing of places at which
jobs are available, and an edit screen.

The summary of all jobs, if requested, produces the
report and repeats the initial form.

The request for all jobs at a location displays a
list of location and when one is selected moves on
to display all appropriate vacancies in detail.

The edit screen asks the user to enter a refernce
of a job for edit, which is then called up for
alteration as appropriate. When the data is called
up in this way, the separate options for delete and
insert allow for jobs to be removed, and for a new
job to be added rather than a current one replaced.

A password is required in order to call up a job for
edit, and a confirmation must be entered if a job is
to be deleted or a new one inserted.

The script is "secure" as far as viewers are concerned -
in other words, they can only select from pulldown
menus and can do no harm to the underlying data. Data
editors, however, need to be careful as checking is
minimal in this "proof of concept".

=cut

sub collect_form {

if ($ENV{"REQUEST_METHOD"} eq "POST") {
        read(STDIN,$buffer,$ENV{"CONTENT_LENGTH"});
        $form{"method"} = "POST";
} else {
        $buffer = $ENV{QUERY_STRING};
        $form{"method"} = "GET";
}

@fof = split(/&/,$buffer);
foreach $field(@fof) {
        ($name,$value) = split(/=/,$field);
        $value =~ tr/+/ /;
        $value =~ s/%([a-fA-F0-9]{2})/pack("C",hex($1))/eg;
        if ($form{$name}) {
                $form{$name} .= "\n$value";
        } else {
                $form{$name} = $value;
                }
        }
}

collect_form();

$topform = <<"NF";
Please select action<br>
<input name=dowhat type=radio value=display> Choose Jobs<br>
<input name=dowhat type=radio value=summary> Summarise Jobs<br>
<input name=dowhat type=radio value=edit> Edit Jobs - authorised users only<br>
<input name=pageno type=hidden value=1>
NF

if ($form{pageno} < 1) {
        $stuff = "Your results will appear here";
        $nextform = $topform;
} elsif ($form{pageno} == 1 and $form{dowhat} eq "summary") {
        $stuff = "Here is your summary";
        open (FH,"jobs.txt");
        $stuff .= "<table border=1>";
        foreach $hlines (grep (/^\*/,<FH>)) {
                $hlines =~ s/.*?\t//;
                $hlines =~ s/\t/<\/td><td>/g;
                $stuff .= "<tr><td>$hlines</td></tr>\n";
                }
        $stuff .= "</table>";
        $nextform = $topform;
} elsif ($form{pageno} == 1 and $form{dowhat} eq "display") {
        $stuff = "Here is a list of places";
        $nextform = "<input name=pageno type=hidden value=2>";
        open (FH,"jobs.txt");
        foreach $hlines (grep (/^\*/,<FH>)) {
                ($star,$place) = split(/\t/,$hlines);
                $plcount{$place}++;
                }
        foreach $venue(sort (keys(%plcount))) {
                $what = ($plcount{$venue} == 1) ? "job" : "jobs";
                $nextform .= "<input name=venue type=radio value=$venue> at $venue ".
                        "($plcount{$venue} $what listed)<br>";
                }
} elsif ($form{pageno} == 1 and $form{dowhat} eq "edit") {
        $stuff = "Select job reference for this";
        $nextform = "<input name=pageno type=hidden value=100>";
        $nextform .= "<input name=refcode size=4> Job Code<br>";
        $nextform .= "<input name=arthur size=8 type=password> password<br>";
} elsif ($form{pageno} == 1 ) {
        $stuff = "YOU GOTTA PICK AN OPTION, BOYO!";
        $nextform = $topform;
} elsif ($form{pageno} == 2) {
        $stuff = "Details of jobs on offer at $form{venue}";
        open (FH,"jobs.txt");
        foreach $hlines (<FH>) {
                ($star,$place,$rest) = split(/\t/,$hlines,3);
                if ($star eq "*") {
                        if ($place eq $form{venue}) {
                                $stuff .= "<hr><b>$rest</b><br>";
                                $inthejob = 1;
                        } else {
                                $inthejob = 0;
                        }
                } else {
                        if ($inthejob) {
                                $stuff .= "$hlines\n";
                        }
                }
        }
} elsif ($form{pageno} == 100) {
        if ($form{arthur} ne "abc123") {
                $stuff = "Bad password - your IP reported";
                $nextform = $topform;
        } else {

=head1 data looks like this

* Hemel Bottle Washer 20000 EH18
All about the job which is going to be
a number of lines long and so on

=cut

        $stuff = "Please make your changes";
        open (FH,"jobs.txt");
        foreach $hlines (<FH>) {
                chop ($hlines);
                ($star,$place,$role,$salary,$ref) = split(/\t/,$hlines);
                if ($star eq "*") {
                        if ($form{refcode} eq $ref) {
                        # At this point, make up an edit form!
                        $nextform = "<input name=pageno type=hidden value=101>";
                        $nextform .= "<input name=ref type=hidden value=$ref> Ref $ref<br>";
                        $nextform .= "<input name=newjob> Type new no. for INSERT<br>";
                        $nextform .= "<input name=remove> Type REMOVE to delete<br>";
                        $nextform .= "<input name=confirm> Type YES to confirm insert or delete<br>";
                        $nextform .= "<br><input name=salary value='$salary'> Salary<br>";
                        $nextform .= "<input name=role value='$role'> Role<br>";
                        $nextform .= "<input name=place value='$place'> Place<br>";
                        $nextform .= "<textarea name=descript rows=10 cols=40>";
                        $inthejob = 1;
                        $open = 1;
                        } else {
                                $inthejob = 0;
                                if ($open == 1) {
                                        $nextform .= "</textarea>";
                                }
                                $open = 0;
                        }
                } else {
                        if ($inthejob) {
                                $nextform .= "$hlines\n";
                        }
                }

                }
                if ($open == 1) {
                        $nextform .= "</textarea>";
                        }
                $nextform .= "<br>";
        }

} elsif ($form{pageno} == 101) {

        $action = "";
        if ($form{confirm} eq "YES" and $form{remove} eq "REMOVE") {
                $action = "del"; }
        if ($form{confirm} eq "YES" and $form{newjob} ne "") {
                $action = "ins"; }

        # add validation code!!
        if ($action ne "ins") {
        open (FHO,">newjobs.txt");
        open (FH,"jobs.txt");
        foreach $hlines (<FH>) {
                chop ($hlines);
                ($star,$place,$role,$salary,$ref) = split(/\t/,$hlines);
                if ($star eq "*") {
                        if ($form{ref} eq $ref) {
                                if ($action ne "del") {
                                print FHO "*\t$form{place}\t$form{role}\t$form{salary}\t".
                                        "$form{ref}\n";
                                $form{descript} =~ s/\n+$//;
                                print FHO "$form{descript}\n\n";
                                        }
                                $indesk = 1;
                        } else {
                                print FHO "$hlines\n";
                                $indesk = 0;
                        }
                } else {
                        # To add - save new description
                        if ($indesk == 0) {print FHO "$hlines\n"};
                }
        }
        close FHO;
        close FH;
        rename("newjobs.txt","jobs.txt");
        $stuff = "I've done that to $form{ref}!";
        } else {
                $stuff = "Inserted $form{newjob}!";
                open (FHO,">>jobs.txt");
                print FHO "*\t$form{place}\t$form{role}\t$form{salary}\t".
                        "$form{newjob}\n";
                $form{descript} =~ s/\n+$//;
                print FHO "$form{descript}\n\n";
        }
        $nextform = $topform;

} else {

}

$debug = join(", ",keys(%form));

print <<"DONE";
Content-type: text/html

<html>
<body>
<h1>Title</h1>
$stuff
<hr>
<form method=POST>
$nextform
<input type=submit>
</form>
<hr>
$debug
</body>
</html>

DONE

=head1

Following stages / actions on this script in the short(er) term ...

1. Check that jobs called up for edit really do exist
2. Deal with special characters such as < " and ' in any field
3. Deal with data lines in the description starting with "*"
4. Switch to using a MySQL or other database
5. Use a separate file for the template
6. Use cookies / shopping cart to carry more data through
7. Structure code to place data handlers in subs in
   a separate business logic file.

Follow up stages on project might include ...

a. add more fields
b. add date dependent information / code
c. provide ability to do muliple edits without re-login

=cut