#!/usr/bin/perl

use LWP::Simple;
use LWP::UserAgent;
use HTTP::Request;
use HTTP::Response;
use HTML::LinkExtor; # allows you to extract the links off of an HTML page.

# tag filename with datestamp
my $tag;
# where to dump saved files
my $savedir="/usr/weather";
my $debug ="";

# Get the all the values for current time
($Second, $Minute, $Hour, $Day, $Month, $Year, $WeekDay, $DayOfYear, $IsDST) = localtime(time);
$Year =~s/^10/200/;
$Month++;

$Minute = &prettify ($Minute);
$Hour = &prettify ($Hour);
$Day = &prettify ($Day);
$Month = &prettify ($Month);

$tag="$Year.$Month.$Day.$Hour.$Minute";
$savedir = $savedir."/$Year.$Month.$Day";

mkdir ($savedir);

my $savefile = "$savedir/$tag.hfxradar.gif";
&dprint ("Saving page to $savefile");
getpage ("http://weatheroffice.ec.gc.ca/radar/index_e.html?id=XGO", "XGO_CAPPI.*GIF", $savefile);

$savefile = "$savedir/$tag.atlradar.gif";
&dprint ("Saving page to $savefile");
getpage ("http://weatheroffice.ec.gc.ca/radar/index_e.html?id=ERN", "COMPOSITE_ERN.*GIF", $savefile);

$savefile = "$savedir/$tag.natradar.gif";
&dprint ("Saving page to $savefile");
getpage ("http://weatheroffice.ec.gc.ca/radar/index_e.html", "COMPOSITE_NAT.*GIF", $savefile);



sub prettify {
  # $number = prettify ($number)
  # Add a leading 0 if required
  local ($number) = pop(@_);
  if ($number < 10) {
    $number = "0$number";
  }
  return ($number);
}

sub getpage {
  # getpage (urltoget, patternmatch, filetosave)
  # Does the grunt work pulling down the page
  local ($filesave) = pop(@_);
  local ($pat) = pop(@_);
  local ($URL) = pop(@_);
  
  &dprint ("filesave $filesave, pat $pat, url $URL");

  my $linkfound = "";
  
  $browser = LWP::UserAgent->new();
  $browser->timeout(10);

  local ($request) = HTTP::Request->new(GET => $URL);
  local ($response) = $browser->request($request);
  if ($response->is_error()) {printf "%s\n", $response->status_line;}

  $contents = $response->content();
  
  local ($page_parser) = HTML::LinkExtor->new(undef, $URL);
  $page_parser->parse($contents)->eof;
  @links = $page_parser->links;

  foreach $link (@links) {
    if ($$link[2] =~ m/$pat/ && !$linkfound) {
      $linkfound = $$link[2];
      &dprint ("Found link $linkfound");
    }
  }

  $content = get($linkfound);
  if ($content) {
    open IMAGE, ">$filesave" || die ("Could not save to $filesave: $!");
    print IMAGE $content;
    close IMAGE;
  } else {
    &dprint ("Not writing empty file to $filesave");
  }
}

sub dprint {
# prints out a debug message if debug enabled
  if ($debug) {  
    local ($message) = pop(@_);
    print $message."\n";
  }
}