#!/usr/local/bin/perl -w
# Program: filmstat.pl
# Author: Spencer Shimko
# Purpose: Display top films based on user input
# Usage: ./filmstat.pl <datafile> [year] [numoffilms]
# Created: 3/30/04
# Modified: 4/01/04 

############################
#    sub parse cmd line    #
############################
sub getcmdline{
   
   # parse command line and assign to some vars
   while ( defined $ARGV[0] ){
      $arg = shift @ARGV;
      if ( $arg =~ /^\d{1,3}$/ ){
         $num2show = $arg unless defined $num2show;
      } elsif ($arg =~ /^\d{4}$/ ){
         $year2show = $arg unless defined $year2show;
      } else {
         $filename = $arg unless defined $filename;
      }
   }
   
   # if we don't have a filename die
   if ( ! defined $filename ){
      die "$0: require a filename"; 
   }    
} 
#############################
# end sub parse cmd line    #
#############################

#############################
# start sub by_score_votes  #
#############################
sub by_score_votes{
   # return higher hash by score then votes
   if ( $$a{'score'} > $$b{'score'} ){
      return -1;
   } elsif ( $$a{'score'} < $$b{'score'} ){
      return 1;
   } else {
      # if we reach this point scores are equal so sort on # votes
      return ( $$b{'votes'} <=> $$a{'votes'} );
   }
}
#############################
# end sub by_score_votes    #
#############################

#############################
# start sub display_results # 
#############################
sub display_results{
   print "\nTop ";
 
   # if max num requested show
   if ( defined $num2show ){
      # make sure requested number is smaller then total 
      if ( $num2show > ( $#sorted + 1) ){
          $num2show = $#sorted + 1;
      }
      print "$num2show "; 
   }
   print "Films ";
   
   # if year requested
   if ( defined $year2show ){
      print "from Year $year2show ";
      # this is to correct the num2show for the year requested
      $yrcnt = 0;
      foreach (@sorted){
        if ( $$_{'year'} == $year2show ){
           $yrcnt++;
        }
      }
      if ( defined $num2show ){
         if ( $num2show > $yrcnt ){
           $num2show  = $yrcnt;
         }
      } else {
        $num2show = $yrcnt;
      }
   }
   print "(source: $filename)\n\n";
      
   # i need an index for my for loop control
   $num2show = $#sorted + 1 unless defined $num2show;

   for ( $index=0, $cnt=0; $cnt < $num2show; $index++,$cnt++ ){
      if ( defined $year2show ){
         if ( $sorted[$index]{'year'} == $year2show ){
            print "$sorted[$index]{'score'}: $sorted[$index]{'name'} ($sorted[$index]{'year'}) [$sorted[$index]{'votes'} votes]\n";
         } else{
           $cnt--;
         }
      } else {
            print "$sorted[$index]{'score'}: $sorted[$index]{'name'} ($sorted[$index]{'year'}) [$sorted[$index]{'votes'} votes]\n";
      }
   }
}
#############################
# end sub display_results   #
#############################

#############################
#         start main        #
#############################
getcmdline(); # read/parse cmd line

# open file
open (FILE, $filename) or die "$0: cannot open $filename, $!";

while ( <FILE> ){
   chomp;
   # remove blanklines and comments
   s/^\s*$//;
   s/\s*\#.*$//;
   s/^(\s+)(.*)/$2/;
   s/(.*)(\s+)$/$1/;

   if ( /^$/ ){
      next;
   }
   
   if ( /^\d*\.\s+(\d+\.\d+)\/.*?\s+(.*)\s+\((\d+)\)\s+(\d{4})$/ ){
      $score = $1;
      $name = $2;
      $votes = $3;
      $year = $4;
   } 
   push @list,  ({'name' => $name, 'score' => $score, 'votes' => $votes, 'year' => $year});

}
close (FILE);
# sort list of movies
@sorted = sort by_score_votes @list;
display_results();