package VladimirBot::ScheduleII;

# This is supposed to parse and process complex scheduling stuff
#
# History / Notes
#   2003.12.25
#     - Added history

use strict;
use Carp;
use Parse::Earley;
use Data::Dumper;
$Data::Dumper::Deparse = 1;

# Here I push myself onto the module call stack
push @VladimirBot::vladimir_module, 'ScheduleII';

sub parse {
  my $sentence = shift;
  my $grammar = <<'END';

# Sentences which must be parsed:
#   "What am I doing today?"
#   "What am I doing tomorrow?"
#   "What am I doing on Wednesday?"
#   "What am I doing on April 9th?"
#   "What's going on today?"
#   "What was I doing last week?"
#   "I have an appointment with Chris tomorrow."
#   "There is an AzEIP meeting tomorrow which I must attend."
#   "I am going to the concert on july 5th"
#   "I went to the concert today."
#   "When is that concert?"

schedule: question_word subject schedule_verb timespan punctuation
  {{
      query => 'schedule',
      %{$_[1]},
      %{$_[3]}
  }}

question_word:
    'what' 'am'
  | 'what' 'are'

subject:
    'i' | 'me' | 'my' { return {who => 'brock'} }
  | 'you'
    {{who => 'vladimir'}}

schedule_verb: 'doing' 'on' | 'doing'

nothing:

punctuation: '.' | '?' | nothing

timespan: timespan_day { $_[0] }

timespan_day: 
  /today|tomorrow|sunday|monday|tuesday|wednesday|thursday|friday|saturday|((\s|\w|,)+)/
  {{
    start_time => "$_[0] at 00:00:00",
    end_time => "$_[0] at 23:59:59"
  }}

END

  my $parser = new Parse::Earley;
  $parser->grammar($grammar);
  $parser->start('schedule');

  do {
    $parser->advance($sentence)
  } until(
      $parser->fails($sentence, 'schedule')
      or $parser->matches($sentence, 'schedule'));

  if ($parser->matches($sentence, 'schedule'))
  {
    my $out;
    my $graph;
    ($graph) = $parser->matches($sentence, 'schedule');
    my $e = $parser->eval_production($graph);
    $out = "result: " . Dumper($e) . "\n";
    return $out;
  }
  
  return 0; # Nope, we couldn't figure it out.
}



1;