use XML::Parser;

my $file = shift;

my $parser = new XML::Parser(Style=>'Subs', Pkg=>'SubHandlers', ErrorContext => 2);
$parser->setHandlers(Char  => \&char_handler);

$parser->parsefile($file);

# ---------------------------------------------

sub char_handler {
    my ($p, $data) = @_;
    if ($::state::store_contents) {
      $::state::storage{$::state::store_contents} .= $data;
    } else {
      # print $data;
    }
}

# ---------------------------------------------

package SubHandlers;

# 
# This function would perform the given action (eg. buy or sell)
# on the given stock. In this case it's simply a stub.

sub take_action {
  my ($symbol, $action) = @_;
  
  print "Taking action \"$action\" on stock \"$symbol\" .\n";
}


sub stock_quotes {
  # Open connection to database
  use DBI;

  $dsn = "DBI:mysql:database=test;";
  $::state::dbh = DBI->connect($dsn);
}

sub stock_quotes_ {
  # Close connection to database
  $::state::dbh->disconnect();
}


sub stock_quote {
  undef %::state::storage;
}

sub  stock_quote_ {
  # The values have been stored in the hash %state::storage

  my $symbol = $::state::storage{'symbol'};

  # Grab the rules for the given stock from the rules table
  my $sth = $::state::dbh->prepare("select * from rules where symbol='$symbol'");
  $sth->execute();

  while (my $ref = $sth->fetchrow_hashref()) {
    my $field   = $ref->{'field'};
    my $value   = $ref->{'value'};
    
    if ($::state::storage{$field} > $::state::storage{$value}) {
      # This rule applies
      print "Rule \"$field > $value\" applies for $symbol\n";
      take_action($symbol, $ref->{'action'});
    }
  }
  $sth->finish();

  undef %::state::storage;
}


sub symbol {
  $::state::store_contents = "symbol";
}

sub symbol_ {
  undef $::state::store_contents;
}

sub date {
  $::state::store_contents = "date";
}

sub date_ {
  undef $::state::store_contents;
}

sub time {
  $::state::store_contents = "time";
}

sub time_ {
  undef $::state::store_contents;
}

sub price {
  my $expat = shift; my $element = shift;

  # Read the attributes
  while (@_) {
    my $att = shift;
    my $val = shift;
    $attr{$att} = $val;
  }

  if ($attr{'type'} eq "ask") {
    $::state::storage{'price'} = $attr{'value'};
  }
}

sub price_ {
}

sub volume {
  $::state::store_contents = "volume";
}

sub volume_ {
  undef $::state::store_contents;
}