#!/usr/bin/perl -w
# generate_random_line_edits.pl - Don Yang (uguu.org)
#
# Generate event log with focus on inserting/deleting lines.
#
# 06/28/11

use strict;
use constant FILE_SIZE => 128;

my @lines = ();

for(my $frame = 0; $frame < 1000; $frame++)
{
   # Apply edits
   my $current_size = scalar @lines;
   if( $current_size == 0 )
   {
      # Append lines if file is currently empty
      my $target_size = int(rand(FILE_SIZE) + FILE_SIZE / 2);
      print "Init $target_size\n";
      for(my $i = 0; $i < $target_size; $i++)
      {
         push @lines, int(rand(2));
      }
   }
   elsif( $current_size < FILE_SIZE )
   {
      # Insert lines if current file is too small
      for(my $insert_size = int(rand(FILE_SIZE * 1.5 - $current_size + 1) + 2);
          $insert_size > 0; $insert_size--)
      {
         my $offset = int(rand(scalar @lines));
         print "Insert $offset\n";
         my @tail = splice @lines, $offset;
         push @lines, int(rand(2)), @tail;
      }
   }
   else
   {
      # Delete lines if current file is too large
      do
      {
         my $length = int(rand($current_size)) + 1;
         my $offset = int(rand($current_size - $length));
         print "Delete $offset, $length\n";
         splice @lines, $offset, $length;
         $current_size -= $length;
      } while( $current_size > FILE_SIZE );
   }

   # Output snapshot
   print "Y1X1F${frame}T${frame}\n";
   for(my $i = 0; $i <= $#lines; $i++)
   {
      print "L", $i + 1, "E", (scalar @lines), "=", $lines[$i], "\n";
   }
}