#!/usr/bin/perl -w

use XML::Parser;
use Getopt::Long;
use Date::Parse;
use Date::Format;
use YAML;

=head1 SYNOPSIS

gasInfo.pl - extract fuel-use statistics from a GNUcash account

=cut

$gasAcctGuid = '251ece66fd136c8f1c212f84392cc9ef' ;

GetOptions("out|o=s" => \$out,
	   "accountGuid|acctGuid|guid|g=s" => \$gasAcctGuid );

$file = shift @ARGV if scalar @ARGV == 1;
$file = "household.xac" if !defined $file;

open FILE, "gunzip <$file |" or die "Couldn't open '$file'";
if (defined $out) {
    open STDOUT, ">$out" or die "Couldn't open '$out' for writing";
} 



sub handle_init;
sub handle_start;
sub handle_char;
sub handle_end;
sub handle_final;

$tranData = { isGas => 0 };
$splitData = {};

$parser = new XML::Parser(Handlers => { Init => \&handle_init,
					Start =>\&handle_start,
					Char => \&handle_char,
					End =>  \&handle_end,
					Final =>\&handle_final } );
$parser->parse(*FILE);

exit 0;

sub handle_init {
    print "date,gallons,miles,cost\n";
}

sub handle_start {
    my ($expat,$element,%attrs) = @_;
    
    if ($element eq 'gnc:transaction') {
	$tranData = { isGas => 0 };
    }
    elsif ($element eq 'trn:split') {
	$splitData = {};
    }
}


sub handle_char {
    my ($expat, $text) = @_;

    if ($expat->current_element eq 'trn:description') {
	$tranData->{description} = $text;
    } elsif ($expat->current_element eq 'split:account') {
	$splitData->{account} = $text;
    } elsif ($expat->current_element eq 'split:value') {
	$splitData->{value} = eval( $text . '.0' );
    } elsif ($expat->current_element eq 'ts:date'
	     and ($expat->context)[-2] eq 'trn:date-posted') {
	$tranData->{date} = $text;
    }
}

sub handle_end {
    my ($expat, $element) = @_;

    if ($element eq 'gnc:transaction' and
	$tranData->{isGas}) {
	
	my $FIXP = "\\d+[.]\\d*|\\d*[.]\\d+";

	if ($tranData->{description} 
	    =~ /Gas.*-.*?($FIXP) *gal.*-.*?($FIXP) mi/) {

	    my $gallons = 0.0+$1;
	    my $miles = 0.0+$2;
     
	    print join(",",
		       substr($tranData->{date},0,10), 
		       sprintf("%.3f",$gallons),
		       sprintf("%.1f",$miles),
		       sprintf("%.2f",$tranData->{value})
		       ),  "\n";
	}
	$tranData = { isGas => 0 };
    }
    elsif ($element eq 'trn:split' and 
	   $splitData->{account} eq $gasAcctGuid) {
	$tranData->{isGas} = 1;
	$tranData->{value} = $splitData->{value};
	$splitData = {};
    }
}

sub handle_final {
    ;
}