#!/usr/bin/perl

# $Id: category_engine,v 1.2 1996/01/15 22:05:20 lupus Exp lupus $

# Category engine for Xfinans.

# "calling protocol", the following variables are expected to be set 
# in the $initFile or $userInitFile:
#
# $output           determines what type of output is produced
#		    (status or a listing of a single category)
# $showNumber       the category number to be listed when listing 
#                   of a single category is selected via $output
#
# $fromDate         period in focus
# $toDate           period in focus

$categoryFile="categories";
$initFile="_engine.init";
$userInitFile="variables";
$initialBalanceCalculated=0;

&loadCategories();		 # load category definitions from file
require($initFile);	 # load and evaluate initialization code
require($userInitFile); # load and evaluate 
                                 # user initialization code

if( $output==$transactionList ) { # print header 
    printf("Date     Trans#  %-35s       Amount       Total\n", "Text");
}

&loadTransactions();		# load and process the transactions
				# when the desired output is a trans.list,
				# output is printed during &loadTransactions();

if($output == $status) {	# produce status output if required
    printf("Cat#  %-28sBalances:  Opening      Closing   Difference\n", "Category name"); # begin with a header
    foreach $catNum (sort numerically keys(%categoryName)) {
	printf("%04d  %-33s  %11.2f  %11.2f  %11.2f\n", $catNum, 
	       $categoryName{$catNum}, 
	       $initialBalance{$catNum},
	       $categoryBalance{$catNum},
	       $categoryBalance{$catNum}-$initialBalance{$catNum});
    }
}

# subroutines ----------------

sub loadTransactions {
    while($entry=<>) {		 # read transactions from STDIN
	chop($entry);
	($date, $transNum, $catNum, $text, $amount, $commit)=split(/;/, $entry);
	if(!$initialBalanceCalculated && $date>=$fromDate) {
	    $initialBalanceCalculated=1;
	    foreach $categNum (keys(%categoryName)) {
		$initialBalance{$categNum}=$categoryBalance{$categNum};
	    }
	}
	if($date>$toDate) { 
	    return;
	}

	&recursiveEnter($catNum, $date, $transNum, $text, $amount, $commit);
    }
}

sub enter {
    local($catNum, $date, $transNum, $text, $amount, $commit) = @_;
    $categoryBalance{$catNum}+=$amount;
    # print $catNum, " ", $categoryName{$catNum}, " ", $amount, " : ", $categoryBalance{$catNum}, "\n";

    &makeOutput($catNum, $date, $transNum, $text, $amount, $commit);
}			       

sub recursiveEnter {
    local($catNum, $date, $transNum, $text, $amount, $commit) = @_;
    local($warning);
    # print join(' ', ($date, $transNum, $catNum, $text, $amount, $commit)), "\n";

    if( $categoryDefinition{$catNum} ) {
	eval $categoryDefinition{$catNum};
        if( $@ ) {
	    &warn( $@ );
	    &warn("CODE CAUSING THE PROBLEM:\n");
	    &warn($categoryDefinition{$catNum});
	    &warn("\nWHICH IS FROM : category definition ".$catNum."\n----\n");
	}
    } else {
	$warning="[category not found: ".$catNum.", trans.num: ".$transNum." ".$text."]\n";
	&warn($warning);
    }
}

sub std_income {
# enter the transaction without modification
    &enter($catNum, $date, $transNum, $text, $amount, $commit);
}

sub std_expense {
# change the sign of the amount, to have positive numbers in the 
# category
    &enter($catNum, $date, $transNum, $text, -$amount, $commit);
}

sub copy_to {
    local($catN) = @_;
    &recursiveEnter($catN, $date, $transNum, $text, $amount, $commit);
}

sub makeOutput {
    local($catNum, $date, $transNum, $text, $amount, $commit) = @_;
    
    if( $output==$transactionList ) {
	if( $catNum==$showNumber && $date>=$fromDate ) {
	    printf("%d  %05d  %-35s  %11.2f %11.2f\n", $date, $transNum, 
		   $text, $amount, $categoryBalance{$catNum}-$initialBalance{$catNum});
	}			 
    }
}

sub loadCategories {
    local($num, $name, $definition, $def);
    open(CATEGORIES, $categoryFile) || die "Couldn't open categories-file";
    
    while($num=<CATEGORIES>) {	# for each entry in the categories-file"
	$name=<CATEGORIES>;
	$definition="";
	$def=<CATEGORIES>;
	while( !($def =~ m/\#enddef/) ) {
	    $definition.=$def;
	    $def=<CATEGORIES>;
	}

	chop($num); chop($name);
				# 
	# print $num, "\n", $name, "\n", $definition;
	$categoryName{$num}=$name; # 
	$categoryDefinition{$num}=$definition;
	$categoryBalance{$num}=0.0;
    }
    close CATEGORIES;
}
    
sub warn {
    local($message) = @_;

    print $message;
}

sub loadAndEvaluate {
    local($file) = @_;
    local($code, $line);
    if( !open(CODEFILE, $file) ) { 
	&warn("Couldn't open file \n".$file); 
	return; 
    }
    
    while($line=<CODEFILE>) {	
	$code.=$line;
    }
    close CODEFILE;

    # print $code;
    eval($code);
    if( $@ ) {
	&warn( $@ );
	&warn("code causing the problem:\n");
	&warn($code);
    }
}

sub numerically { $a <=> $b; }	# subroutine used for numerical sort