#!/usr/bin/perl -w

# index.pl:
# Main code for Neighbourhood Fix-It
#
# Copyright (c) 2006 UK Citizens Online Democracy. All rights reserved.
# Email: matthew@mysociety.org. WWW: http://www.mysociety.org
#
# $Id: index.cgi,v 1.39 2006-10-07 17:55:10 matthew Exp $

# TODO
# Nothing is done about the update checkboxes - not stored anywhere on anything!
# Nothing is done with fixed checkbox either

use strict;
require 5.8.0;

# Horrible boilerplate to set up appropriate library paths.
use FindBin;
use lib "$FindBin::Bin/../perllib";
use lib "$FindBin::Bin/../../perllib";
use Error qw(:try);
use File::Slurp;
use LWP::Simple;
use RABX;
use POSIX qw(strftime);
use CGI::Carp;

use Page;
use mySociety::AuthToken;
use mySociety::Config;
use mySociety::DBHandle qw(dbh select_all);
use mySociety::Email;
use mySociety::Util;
use mySociety::MaPit;
use mySociety::VotingArea;
use mySociety::Web qw(ent NewURL);

BEGIN {
    mySociety::Config::set_file("$FindBin::Bin/../conf/general");
    mySociety::DBHandle::configure(
        Name => mySociety::Config::get('BCI_DB_NAME'),
        User => mySociety::Config::get('BCI_DB_USER'),
        Password => mySociety::Config::get('BCI_DB_PASS'),
        Host => mySociety::Config::get('BCI_DB_HOST', undef),
        Port => mySociety::Config::get('BCI_DB_PORT', undef)
    );

    if (!dbh()->selectrow_array('select secret from secret for update of secret')) {
        local dbh()->{HandleError};
        dbh()->do('insert into secret (secret) values (?)', {}, unpack('h*', mySociety::Util::random_bytes(32)));
    }
    dbh()->commit();

    mySociety::MaPit::configure();
}

# Main code for index.cgi
sub main {
    my $q = shift;

    my $out = '';
    my $title = '';
    if ($q->param('submit_problem')) {
        $title = 'Submitting your problem';
        $out = submit_problem($q);
    } elsif ($q->param('submit_update')) {
        $title = 'Submitting your update';
        $out = submit_update($q);
    } elsif ($q->param('map')) {
        $title = 'Reporting a problem';
        $out = display_form($q);
    } elsif ($q->param('id')) {
        $title = 'Viewing a problem';
        $out = display_problem($q);
    } elsif ($q->param('pc')) {
        $title = 'Map';
        $out = display($q);
    } else {
        $out = front_page($q);
    }
    print Page::header($q, $title);
    print $out;
    print Page::footer();
}
Page::do_fastcgi(\&main);

# Display front page
sub front_page {
    my ($q, $error) = @_;
    my $pc_h = ent($q->param('pc') || '');
    my $out = <<EOF;
<p id="expl">Report, view, or discuss local problems
like graffiti, fly tipping, broken paving slabs, or street lighting</p>
EOF
    $out .= '<p id="error">' . $error . 'Please try again.</p>' if ($error);
    $out .= <<EOF;
<form action="./" method="get" id="postcodeForm">
<label for="pc">Enter a postcode:</label>
&nbsp;<input type="text" name="pc" value="$pc_h" id="pc" size="10" maxlength="10">
&nbsp;<input type="submit" value="Go">
</form>

<p>Reports are sent directly to the local council &ndash; at the moment, we only cover <em>Newham, Lewisham, and Islington</em> councils. The rest of the UK is coming soon!</p>

<p>Reporting a problem is hopefully very simple:</p>

<ol>
<li>Enter a postcode;
<li>Locate the problem on a high-scale map;
<li>Enter details of the problem;
<li>Submit to your council.
</ol>

</div>
EOF
    return $out;
}

sub submit_update {
    my $q = shift;
    my @vars = qw(id name email update updates);
    my %input = map { $_ => $q->param($_) || '' } @vars;
    my @errors;
    push(@errors, 'Please enter a message') unless $input{update};
    push(@errors, 'Please enter your name') unless $input{name};
    push(@errors, 'Please enter your email') unless $input{email};
    return display_problem($q, @errors) if (@errors);

    my $template = File::Slurp::read_file("$FindBin::Bin/../templates/emails/update-confirm");

    my $id = dbh()->selectrow_array("select nextval('comment_id_seq');");
    dbh()->do("insert into comment
        (id, problem_id, name, email, website, text, state)
        values (?, ?, ?, ?, ?, ?, 'unconfirmed')", {},
        $id, $input{id}, $input{name}, $input{email}, '', $input{update});
    my %h = ();
    $h{update} = $input{update};
    $h{name} = $input{name};
    $h{url} = mySociety::Config::get('BASE_URL') . '/C/' . mySociety::AuthToken::store('update', $id);
    dbh()->commit();

    my $email = mySociety::Email::construct_email({
        _template_ => $template,
        _parameters_ => \%h,
            From => [mySociety::Config::get('CONTACT_EMAIL'), 'Heighbourhood Fix-It'],
        To => [[$input{email}, $input{name}]],
    });
    my $result = mySociety::Util::send_email($email, mySociety::Config::get('CONTACT_EMAIL'), $input{email});
    my $out;
    if ($result == mySociety::Util::EMAIL_SUCCESS) {
        $out = <<EOF;
<h1>Nearly Done! Now check your email...</h1>
<p>The confirmation email <strong>may</strong> take a few minutes to arrive &mdash; <em>please</em> be patient.</p>
<p>If you use web-based email or have 'junk mail' filters, you may wish to check your bulk/spam mail folders: sometimes, our messages are marked that way.</p>
<p>You must now click on the link within the email we've just sent you -
<br>if you do not, your update will not be posted.</p>
<p>(Don't worry - we'll hang on to your update while you're checking your email.)</p>
EOF
    } else {
        $out = <<EOF;
<p>I'm afraid something went wrong when we tried to send your email. Please click Back, check your details, and try again.</p>
EOF
    }
    return $out;
}

sub submit_problem {
    my $q = shift;
    my @vars = qw(title detail name email pc easting northing updates);
    my %input = map { $_ => $q->param($_) || '' } @vars;
    my @errors;
    push(@errors, 'Please enter a title') unless $input{title};
    push(@errors, 'Please enter some details') unless $input{detail};
    push(@errors, 'Please enter your name') unless $input{name};
    push(@errors, 'Please enter your email') unless $input{email};
    return display_form($q, @errors) if (@errors);

    my $template = File::Slurp::read_file("$FindBin::Bin/../templates/emails/problem-confirm");

    my $id = dbh()->selectrow_array("select nextval('problem_id_seq');");
    dbh()->do("insert into problem
        (id, postcode, easting, northing, title, detail, name, email, state)
        values
        (?, ?, ?, ?, ?, ?, ?, ?, 'unconfirmed')", {},
        $id, $input{pc}, $input{easting}, $input{northing}, $input{title},
        $input{detail}, $input{name}, $input{email}
    );
    my %h = ();
    $h{title} = $input{title};
    $h{detail} = $input{detail};
    $h{name} = $input{name};
    $h{url} = mySociety::Config::get('BASE_URL') . '/P/' . mySociety::AuthToken::store('problem', $id);
    dbh()->commit();

    my $email = mySociety::Email::construct_email({
        _template_ => $template,
        _parameters_ => \%h,
            From => [mySociety::Config::get('CONTACT_EMAIL'), 'Heighbourhood Fix-It'],
        To => [[$input{email}, $input{name}]],
    });
    my $result = mySociety::Util::send_email($email, mySociety::Config::get('CONTACT_EMAIL'), $input{email});
    my $out;
    if ($result == mySociety::Util::EMAIL_SUCCESS) {
        $out = <<EOF;
<h1>Nearly Done! Now check your email...</h1>
<p>The confirmation email <strong>may</strong> take a few minutes to arrive &mdash; <em>please</em> be patient.</p>
<p>If you use web-based email or have 'junk mail' filters, you may wish to check your bulk/spam mail folders: sometimes, our messages are marked that way.</p>
<p>You must now click on the link within the email we've just sent you -
<br>if you do not, your problem will not be posted on the site.</p>
<p>(Don't worry - we'll hang on to your information while you're checking your email.)</p>
EOF
    } else {
        $out = <<EOF;
<p>I'm afraid something went wrong when we tried to send your email. Please click Back, check your details, and try again.</p>
EOF
    }
    return $out;
}

sub display_form {
    my ($q, @errors) = @_;
    my ($pin_x, $pin_y, $pin_tile_x, $pin_tile_y);
    my @vars = qw(title detail name email updates pc easting northing x y skipped);
    my %input = map { $_ => $q->param($_) || '' } @vars;
    my %input_h = map { $_ => $q->param($_) ? ent($q->param($_)) : '' } @vars;
    my @ps = $q->param;
    foreach (@ps) {
        ($pin_tile_x, $pin_tile_y, $pin_x) = ($1, $2, $q->param($_)) if /^tile_(\d+)\.(\d+)\.x$/;
        $pin_y = $q->param($_) if /\.y$/;
    }
    return display($q)
        unless $input{skipped} || ($pin_x && $pin_y)
            || ($input{easting} && $input{northing});

    my $out = '';
    if ($input{skipped}) {
        $out .= <<EOF;
<form action="./" method="post">
<input type="hidden" name="map" value="1">
<input type="hidden" name="pc" value="$input_h{pc}">
<h1>Reporting a problem</h1>
<p>Please fill in the form below with details of the problem, and
describe the location as precisely as possible in the details box.</p>
EOF
    } else {
        my ($px, $py, $easting, $northing);
        if ($pin_x && $pin_y) {
            # Map was clicked on
            $pin_x = click_to_tile($pin_tile_x, $pin_x);
            $pin_y = click_to_tile($pin_tile_y, $pin_y, 1);
            $px = tile_to_px($pin_x, $input{x});
            $py = tile_to_px($pin_y, $input{y});
            $easting = tile_to_os($pin_x);
            $northing = tile_to_os($pin_y);
        } else {
            # Normal form submission
            $px = os_to_px($input{easting}, $input{x});
            $py = os_to_px($input{northing}, $input{y});
            $easting = $input_h{easting};
            $northing = $input_h{northing};
        }
        # XXX: How to do this for not London?
	# Needs to return all council types, so passing in an array of types would be good
	# And then display choice to user
        my $council = mySociety::MaPit::get_voting_area_by_location_en($easting, $northing, 'polygon', 'LBO');
        my $areas_info = mySociety::MaPit::get_voting_areas_info($council);
	$council = join(', ', map { $areas_info->{$_}->{name} } @$council);
        my $pins = display_pin($q, $px, $py, 'yellow');
        $out .= display_map($q, $input{x}, $input{y}, 1, 0, $pins);
        $out .= '<h1>Reporting a problem</h1>';
        $out .= '<p>You have located the problem at the location marked with a yellow pin on the map, which is within '
	    . $council . '. If this is not the correct location, simply click on the map again.</p>
<p>Please fill in details of the problem below. Your council won\'t be able
to help unless you leave as much detail as you can, so please describe the
exact location of the problem (ie. on a wall or the floor), and so on.</p>';
        $out .= '<input type="hidden" name="easting" value="' . $easting . '">
<input type="hidden" name="northing" value="' . $northing . '">';
    }

    if (@errors) {
        $out .= '<ul id="error"><li>' . join('</li><li>', @errors) . '</li></ul>';
    }
    my $updates = (!defined($q->param('updates')) || $input{updates}) ? ' checked' : '';
    my $back = NewURL($q, map => undef, "tile_$pin_tile_x.$pin_tile_y.x" => undef,
        "tile_$pin_tile_x.$pin_tile_y.y" => undef);
    $out .= <<EOF;
<fieldset>
<div><label for="form_title">Title:</label>
<input type="text" value="$input_h{title}" name="title" id="form_title" size="30"> (work out from details?)</div>
<div><label for="form_detail">Details:</label>
<textarea name="detail" id="form_detail" rows="7" cols="30">$input_h{detail}</textarea></div>
<div><label for="form_name">Name:</label>
<input type="text" value="$input_h{name}" name="name" id="form_name" size="30"></div>
<div><label for="form_email">Email:</label>
<input type="text" value="$input_h{email}" name="email" id="form_email" size="30"></div>
<div class="checkbox"><input type="checkbox" name="updates" id="form_updates" value="1"$updates>
<label for="form_updates">Receive email when updates are left on this problem</label></div>
<div class="checkbox"><input type="submit" name="submit_problem" value="Submit"></div>
</fieldset>

<p align="right"><a href="$back">Back to listings</a></p>
EOF
    $out .= display_map_end(1);
    return $out;
}

sub display {
    my ($q, @errors) = @_;

    my @vars = qw(pc x y);
    my %input = map { $_ => $q->param($_) || '' } @vars;
    my %input_h = map { $_ => $q->param($_) ? ent($q->param($_)) : '' } @vars;

    my($error, $x, $y, $name);
    try {
        ($name, $x, $y) = postcode_check($input{pc}, $input{x}, $input{y});
    } catch RABX::Error with {
        my $e = shift;
        if ($e->value() == mySociety::MaPit::BAD_POSTCODE
           || $e->value() == mySociety::MaPit::POSTCODE_NOT_FOUND) {
            $error = 'That postcode was not recognised, sorry. ';
        } else {
            $error = $e;
        }
    } catch Error::Simple with {
        my $e = shift;
        $error = $e;
    };
    return front_page($q, $error) if ($error);

    my $pins = '';
    my $min_e = tile_to_os($x);
    my $min_n = tile_to_os($y);
    my $mid_e = tile_to_os($x+1);
    my $mid_n = tile_to_os($y+1);
    my $max_e = tile_to_os($x+2);
    my $max_n = tile_to_os($y+2);
    my $current_map = select_all(
        "select id,title,easting,northing from problem where state='confirmed'
         and easting>=? and easting<? and northing>=? and northing<?
         order by created desc limit 3", $min_e, $max_e, $min_n, $max_n);
    my @ids = ();
    foreach (@$current_map) {
        push(@ids, $_->{id});
        my $px = os_to_px($_->{easting}, $x);
        my $py = os_to_px($_->{northing}, $y);
        $pins .= display_pin($q, $px, $py, 'red', 1);
    }
    my $current = select_all(
        "select id, title, easting, northing, distance
            from problem_find_nearby(?, ?, 10) as nearby, problem
            where nearby.problem_id = problem.id
            and state = 'confirmed'" . (@ids ? ' and id not in (' . join(',' , @ids) . ')' : '') . "
         order by created desc limit 3", $mid_e, $mid_n);
    foreach (@$current) {
        my $px = os_to_px($_->{easting}, $x);
        my $py = os_to_px($_->{northing}, $y);
        $pins .= display_pin($q, $px, $py, 'red', 1);
    }

    my $out = '';
    $out .= display_map($q, $x, $y, 1, 1, $pins);
    $out .= '<h1>Click on the map to report a problem</h1>';
    if (@errors) {
        $out .= '<ul id="error"><li>' . join('</li><li>', @errors) . '</li></ul>';
    }
    $out .= <<EOF;
<div style="font-size: 83%">
<h2>Recent problems reported on this map</h2>
<ul id="current">
EOF
    foreach (@$current_map) {
        $out .= '<li><a href="' . NewURL($q, id=>$_->{id}, x=>undef, y=>undef) . '">';
        $out .= $_->{title};
        $out .= '</a></li>';
    }
    unless (@$current_map) {
        $out .= '<li>No problems have been reported yet.</li>';
    }
    $out .= <<EOF;
    </ul>
    <h2>Recent problems reported within 10km</h2>
    <ul id="current">
EOF
    foreach (@$current) {
        $out .= '<li><a href="' . NewURL($q, id=>$_->{id}, x=>undef, y=>undef) . '">';
        $out .= $_->{title} . ' (c. ' . int($_->{distance}/100+.5)/10 . 'km)';
        $out .= '</a></li>';
    }
    unless (@$current) {
        $out .= '<li>No problems have been reported yet.</li>';
    }
    $out .= <<EOF;
    </ul>
    <h2>Recent updates to problems?</h2>
    <h2>Recently fixed problems</h2>
    <ul>
EOF
    my $fixed = select_all(
        "select id,title from problem where state='fixed'
         order by created desc limit 3");
    foreach (@$fixed) {
        $out .= '<li><a href="' . NewURL($q, id=>$_->{id}, x=>undef, y=>undef) . '">';
        $out .= $_->{title};
        $out .= '</a></li>';
    }
    unless (@$fixed) {
        $out .= '<li>No problems have been fixed yet</li>';
    }
    my $skipurl = NewURL($q, 'map'=>1, skipped=>1);
    $out .= '</ul></div>';
    $out .= <<EOF;
<p>If you cannot see a map &ndash; if you have images turned off,
or are using a text only browser, for example &ndash; and you
wish to report a problem, please
<a href="$skipurl">skip this step</a> and we will ask you
to describe the location of your problem instead.</p>
EOF
    $out .= display_map_end(1);
    return $out;
}

sub display_pin {
    my ($q, $px, $py, $col, $id) = @_;
    $id = 0 unless $id;
    # return '' if ($px<0 || $px>508 || $py<0 || $py>508);
    my $out = '<img class="pin" src="/i/pin_'.$col.'.gif" alt="Problem" style="top:' . ($py-20) . 'px; right:' . ($px-6) . 'px; position: absolute;">';
    return $out unless $id;
    my $url = NewURL($q, id=>$_->{id}, x=>undef, y=>undef);
    $out = '<a href="' . $url . '">' . $out . '</a>';
    return $out;
}

sub display_problem {
    my ($q, @errors) = @_;

    my @vars = qw(id name email update updates x y);
    my %input = map { $_ => $q->param($_) || '' } @vars;
    my %input_h = map { $_ => $q->param($_) ? ent($q->param($_)) : '' } @vars;
    $input{x} += 0;
    $input{y} += 0;

    # Get all information from database
    my $problem = dbh()->selectrow_arrayref(
        "select easting, northing, title, detail, name, extract(epoch from created)
         from problem where id=? and state='confirmed'", {}, $input{id});
    return display($q, 'Unknown problem ID') unless $problem;
    my ($easting, $northing, $title, $desc, $name, $time) = @$problem;
    my $x = os_to_tile($easting);
    my $y = os_to_tile($northing);
    my $x_tile = $input{x} || int($x);
    my $y_tile = $input{y} || int($y);
    my $created = time();

    my $px = os_to_px($easting, $x_tile);
    my $py = os_to_px($northing, $y_tile);

    my $out = '';
    my $pins = display_pin($q, $px, $py, 'red');
    $out .= display_map($q, $x_tile, $y_tile, 0, 1, $pins);
    $out .= "<h1>$title</h1>";

    # Display information about problem
    $out .= '<p><em>Reported by ' . $name . ' at ' . prettify_epoch($time);
    $out .= '</em></p> <p>';
    $out .= ent($desc);
    $out .= '</p>';

    my $back = NewURL($q, id=>undef);
    $out .= '<p align="right"><a href="' . $back . '">Back to listings</a></p>';

    # Display updates
    my $updates = select_all(
        "select id, name, extract(epoch from whenposted) as whenposted, text
         from comment where problem_id = ? and state='confirmed'
         order by whenposted desc", $input{id});
    if (@$updates) {
        $out .= '<div id="updates"> <h2>Updates</h2>';
        foreach my $row (@$updates) {
            $out .= "<div><em>Posted by $row->{name} at " . prettify_epoch($row->{whenposted}) . '</em>';
            $out .= '<br>' . $row->{text} . '</div>';
        }
        $out .= '</div>';
    }
    $out .= '<h2>Provide an update</h2>';
    if (@errors) {
        $out .= '<ul id="error"><li>' . join('</li><li>', @errors) . '</li></ul>';
    }
    my $updates = (!defined($q->param('updates')) || $input{updates}) ? ' checked' : '';
    # XXX: Should we have website too?
    $out .= <<EOF;
<form method="post" action="./">
<fieldset>
<input type="hidden" name="submit_update" value="1">
<input type="hidden" name="id" value="$input_h{id}">
<div><label for="form_name">Name:</label>
<input type="text" name="name" id="form_name" value="$input_h{name}" size="30"></div>
<div><label for="form_email">Email:</label>
<input type="text" name="email" id="form_email" value="$input_h{email}" size="30"></div>
<div><label for="form_update">Update:</label>
<textarea name="updatet" id="form_update" rows="7" cols="30">$input_h{update}</textarea></div>
<div class="checkbox"><input type="checkbox" name="fixed" id="form_fixed" value="1">
<label for="form_fixed">Has the problem been fixed?</label></div>
<div class="checkbox"><input type="checkbox" name="updates" id="form_updates" value="1"$updates>
<label for="form_updates">Receive email when updates are left on this problem</label></div>
<div class="checkbox"><input type="submit" value="Post"></div>
</fieldset>
</form>
EOF
    $out .= display_map_end(0);
    return $out;
}

# display_map Q X Y TYPE COMPASS PINS
# X,Y is bottom left tile of 2x2 grid
# TYPE is 1 if the map is clickable, 0 if not
# COMPASS is 1 to show the compass, 0 to not
# PINS is HTML of pins to show
sub display_map {
    my ($q, $x, $y, $type, $compass, $pins) = @_;
    $pins ||= '';
    my $url = mySociety::Config::get('TILES_URL');
    my $tiles_url = $url . $x . '-' . ($x+1) . ',' . $y . '-' . ($y+1) . '/RABX';
    my $tiles = LWP::Simple::get($tiles_url);
    throw Error::Simple("Unable to get tiles from URL $tiles_url\n") if !$tiles;
    my $tileids = RABX::unserialise($tiles);
    my $tl = $x . '.' . ($y+1);
    my $tr = ($x+1) . '.' . ($y+1);
    my $bl = $x . '.' . $y;
    my $br = ($x+1) . '.' . $y;
    my $tl_src = $url . $tileids->[0][0];
    my $tr_src = $url . $tileids->[0][1];
    my $bl_src = $url . $tileids->[1][0];
    my $br_src = $url . $tileids->[1][1];

    my $out = '';
    my $img_type;
    if ($type) {
        my $pc_enc = ent($q->param('pc'));
        $out .= <<EOF;
<script type="text/javascript">
x = $x - 2; y = $y - 2;
</script>
<form action="./" method="get" id="mapForm">
<input type="hidden" name="map" value="1">
<input type="hidden" name="x" value="$x">
<input type="hidden" name="y" value="$y">
<input type="hidden" name="pc" value="$pc_enc">
EOF
        $img_type = '<input type="image"';
    } else {
        $img_type = '<img';
    }
    my $imgw = '254px';
    my $imgh = '254px';
    $out .= <<EOF;
    <div id="map"><div id="drag">
        $img_type id="t2.2" name="tile_$tl" src="$tl_src" style="top:0px; left:0px;">$img_type id="t2.3" name="tile_$tr" src="$tr_src" style="top:0px; left:$imgw;"><br>$img_type id="t3.2" name="tile_$bl" src="$bl_src" style="top:$imgh; left:0px;">$img_type id="t3.3" name="tile_$br" src="$br_src" style="top:$imgh; left:$imgw;">
	$pins
    </div></div>
EOF
    $out .= Page::compass($q, $x, $y) if $compass;
    $out .= '<div id="side">';
    return $out;
}

sub display_map_end {
    my ($type) = @_;
    my $out = '</div>';
    $out .= '</form>' if ($type);
    return $out;
}

# Checks the postcode is in one of the two London boroughs
# and sets default X/Y co-ordinates if not provided in the URI
sub postcode_check {
    my ($pc, $x, $y) = @_;
    my $areas;
    $areas = mySociety::MaPit::get_voting_areas($pc);

    my @councils_allowed = (2510, 2492, 2507);
    my @councils_no_email = (2288,2402,2390,2252,2351,2430,2375,2285,2377,2374,2330,2454,2284,2378,2294,2312,2419,2386,2363,2353,2296,2300,2291,2268,2512,2504,2495,# 2510
    2530,2516,2531,2545,2586,2554,2574,2580,2615,2596,2599,2601,2648,2563,2652,2607,2582,14287,14317,14328,2223,2225,2242,2222,2248,2246,2235,2224,2244,2236);
    my ($valid_councils, $invalid_councils);
    grep (vec($valid_councils, $_, 1) = 1, @councils_allowed);
    grep (vec($invalid_councils, $_, 1) = 1, @councils_no_email);

    # Cheltenham example: CTY=2226 DIS=2326
    # Check for covered council
    my @councils;
    my $types = $mySociety::VotingArea::council_parent_types;
    foreach my $type (@$types) {
	push(@councils, $type) if ($areas->{$type} && !vec($invalid_councils, $areas->{$type}, 1));
    }
    throw Error::Simple("I'm afraid that postcode isn't yet covered by us.\n") unless $areas && @councils;

    # XXX: Pick first council, hmm
    my $council = $areas->{$councils[0]};
    throw Error::Simple("I'm afraid that postcode isn't in our covered London boroughs.\n") if (@councils_allowed && !vec($valid_councils, $council, 1));

    my $area_info = mySociety::MaPit::get_voting_area_info($council);
    my $name = $area_info->{name};

    $x ||= 0; $x += 0;
    $y ||= 0; $y += 0;
    if (!$x && !$y) {
        my $location = mySociety::MaPit::get_location($pc);
        my $northing = $location->{northing};
        my $easting = $location->{easting};
        $x = int(os_to_tile($easting));
        $y = int(os_to_tile($northing));
    }
    return ($name, $x, $y);
}

# P is easting or northing
# BL is bottom left tile reference of displayed map
sub os_to_px {
    my ($p, $bl) = @_;
    return tile_to_px(os_to_tile($p), $bl);
}

# Convert tile co-ordinates to pixel co-ordinates from top right of map
# BL is bottom left tile reference of displayed map
sub tile_to_px {
    my ($p, $bl) = @_;
    $p = 508 - 254 * ($p - $bl);
    $p = int($p + .5 * ($p <=> 0));
    return $p;
}

# Tile co-ordinates are linear scale of OS E/N
# Will need more generalising when more zooms appear
sub os_to_tile {
    return $_[0] / (5000/31);
}
sub tile_to_os {
    return $_[0] * (5000/31);
}

sub click_to_tile {
    my ($pin_tile, $pin, $invert) = @_;
    $pin -= 254 while $pin > 254;
    $pin += 254 while $pin < 0;
    $pin = 254 - $pin if $invert; # image submits measured from top down
    return $pin_tile + $pin / 254;
}

sub prettify_epoch {
    my $s = shift;
    my @s = localtime($s);
    my $tt = strftime('%H:%M', @s);
    my @t = localtime();
    if (strftime('%Y%m%d', @s) eq strftime('%Y%m%d', @t)) {
        $tt = "$tt " . 'today';
    } elsif (strftime('%U', @s) eq strftime('%U', @t)) {
        $tt = "$tt, " . strftime('%A', @s);
    } elsif (strftime('%Y', @s) eq strftime('%Y', @t)) {
        $tt = "$tt, " . strftime('%A %e %B', @s);
    } else {
        $tt = "$tt, " . strftime('%a %e %B %Y', @s);
    }
    return $tt;
}