#!/usr/bin/perl -w
use strict qw(vars);
use IO::Handle;
use POSIX;

my $usage = <<END
usage:
  .../ypp-restock-rum [<information> ...]

where <information> is

  have  [<swill> <grog>] <fine> [<hold_shot>+<loaded_shot>]
  want  [<swill> <grog>] <fine> [<shot>]
  price  <swill> <grog>  <fine> [<shot>]

Each of which may appear only once, except \`have' which may appear
more than once which case we calculate the differences and the profit
for each one.

If <shot> is not specified at all, relevant information about shot is
not reported.  For have and want, missing entries count as zero.

In price, \`x' means the commodity is unavailable.
END
;

our (@kinds) = qw(Swill Grog Fine Shot);
our (@proofs) = qw(40 60 100);

sub parse_info ($$$\@$) {
    my ($omitswgok,$default,$multishot, $storeary, $what) = @_;
    @ARGV or badusage("missing value for information argument \`$_'");
    badusage("$what: specified more than once")
	if defined $storeary->[2];
    my (@v) = ();
    while (@ARGV and $ARGV[0] =~ m/^\d|^x$/) {
	$_ = shift @ARGV;
	push @v, $_;
    }
    if (@v==1 or @v==2) {
	badusage("$what: swill and grog amounts must be specified")
	    unless $omitswgok;
	@v=($default,$default,@v);
    }
    if ($multishot and @v==4 and length $v[3]) {
	$v[3] =~ m/^0*(\d+)\+0*(\d+)$/ or
	    badusage("$what: shot must be specified as <hold>+<loaded>");
	$v[3] = $1 + $2;
    }
    if (@v==3) {
	push @v, $default;
    }
    if (@v != 4) {
	badusage("$what: invalid syntax (wrong number of parameters)");
    }
    my $i=0;
    foreach $_ (@v) {
	if ($default>0 and m/^x$/) {
	    $_ = $default;
	} elsif (m/^0*(\d+)$/) {
	    $_= $1;
	} else {
	    badusage("$what: $kinds[$i] \`$_': bad syntax");
	}
	$i++;
    }
    @$storeary = @v;
}

our (@have,@want,@price);

sub parse_args () {
    @ARGV or badusage("need some information to go on");
    while (@ARGV) {
	$_ = shift @ARGV;
	if (m/^have$/) {
	    parse_info(1,0,1, @{ $have[@have] }, 'have');
	} elsif (m/^want$/) {
	    parse_info(1,0,0, @want, 'want');
	} elsif (m/^price$/) {
	    parse_info(0,1e7,0, @price, 'price');
	} else {
	    badusage("unknown information argument \`$_'");
	}
    }
}

sub badusage ($) {
    my ($m) = @_;
    print STDERR "\nbad usage: $m\n\n$usage\n";
    exit 16;
}

our $ff = '%6.1f';

sub valid ($) {
    my ($x) = @_;
    defined $x and $x and $x<1e5;
}    

sub prvff ($$\@$) {
    my ($what, $format, $ary, $unit) = @_;
    printf("%-25s", "$what:");
    for my $i (qw(0 1 2 3)) {
	my $x= $ary->[$i];
	my $y= valid($x) ? sprintf $format, $x : '    ';
	printf " %-9s", $y;
    }
    printf "  %s\n", $unit;
}

sub pr ($\@$) {
    my ($what, $ary, $unit) = @_;
    prvff($what, '%4d  ', @$ary, $unit);
}

sub prf ($\@$) {
    my ($what, $ary, $unit) = @_;
    prvff($what, $ff, @$ary, $unit);
}

sub pr1 ($$) {
    my ($k,$v) = @_;
    printf "%-20s %s\n", "$k:", $v;
}
sub fmt_stock_index ($) {
    my ($si) = @_;
    @have==1 ? '' : ' #'.$si;
}

sub rum_total (\@) {
    my ($rums) = @_;
    my $total= 0;
    foreach my $i (qw(0 1 2)) {
	$total += $rums->[$i] * $proofs[$i] / 100;
    }
    return $total;
}

our @norm_price;
our ($best, $best_norm_price);

sub print_inputs () {
    printf("%25s",'');
    map { printf " %5s    ", $_ } @kinds;
    print "\n\n";
    pr('prices', @price, 'poe ea.') if valid(@price);
    pr('target stocks', @want, 'units') if valid(@want);
    my $si=0; for my $stocks (@have) {
	pr('actual stocks'.fmt_stock_index(++$si),
	   @$stocks, 'units');
    }
    print "\n";
}

sub compute_cheapest_rum() {
    return unless @price;

    my (@perorder) = map { $_*10 } @price;
    prf('equiv. ordering price', @perorder, 'poe/order');

    $best= undef;
    $best_norm_price= 1e6;
    for my $i (qw(0 1 2)) {
	next unless $price[$i];
	$norm_price[$i] = $price[$i] * 100 / $proofs[$i];
	if ($norm_price[$i] <= $best_norm_price) {
	    $best= $i;
	    $best_norm_price= $norm_price[$i];
	}
    };
    prf('normalised prices', @norm_price, 'poe/fine');

    if (defined $best) {
	printf "best is %-10s%*s^^\n",
	    $kinds[$best],
	    $best*10+10, '';
	my (@bestperorder) = map {
	    $best_norm_price * $proofs[$_] / 100 * 10;
	} qw(0 1 2);
	#push @bestperorder, $perorder[3];
	prf('best is equiv. ordering', @bestperorder, 'poe/order');
    }
    print "\n";
}

sub pr1s ($) {
    my ($x) = @_;
    if (valid($x)) {
	printf ' %9.1f', $x;
    } else {
	printf "          ";
    }
}

sub compute_stock_values() {
    return unless @have;
    print @have>1 ? <<END

                _____Rum_____      ___Shot___      total      _____Profit___
             fine equiv.  value   qty    value     value     per leg     total
END
: <<END
                             Rum      Rum             Shot    Shot     total
                            equiv.   value           stocks   value    value
END
;

    my $initial_value;
    my $last_value;
    my $si=0; for my $stocks (@have) {
	my $stock_rum = rum_total(@$stocks);
	my $rum_value= defined($best) ? $stock_rum * $best_norm_price : 0;
	my $shot_value= valid($price[3]) ? $stocks->[3] * $price[3] : 0;
	my $total_value= $rum_value + $shot_value;

	printf "%-10s ", 'stocks'.fmt_stock_index(++$si).':';
	print '            ' if @have==1;
	pr1s($stock_rum);
	pr1s($rum_value);
	print '        ' if @have==1;
	printf "%6s", $stocks->[3] ? $stocks->[3] : '';
	pr1s($shot_value);
	pr1s($total_value);
	
	if (defined $last_value) {
	    printf(" %10.1f %10.1f",
		   $total_value - $last_value,
		   $total_value - $initial_value);
	}
	$initial_value= $total_value unless defined $initial_value;
	$last_value= $total_value;
	print "\n";
    }
    print "\n" if @have>1;
    print "\n";
}

sub pr2 ($$$) {
    my ($k,$v1,$v2) = @_;
    printf "%-25s %-23s %s\n", "$k:", $v1, $v2;
}

sub pr2rs ($$$) {
    my ($k,$rum,$shot) = @_;
    pr2($k,
	valid($rum) ? sprintf("%12.1f fine equiv", $rum) : '',
	valid($shot) ? sprintf("%10d shot", $shot) : '');
}

sub compute_restock_requirements () {
    return unless @want;
    
    my $rum_want= rum_total(@want);

    my $stocks= @have ? $have[-1] : [qw(0 0 0 0)];
    my $rum_have= rum_total(@$stocks);
    
    pr2rs('desired stock level', $rum_want, $want[3]);

    my $rum_need = $rum_want - $rum_have;
    my $shot_need = $want[3] - $stocks->[3];

    if (@have) {
	pr2rs('current stock', $rum_have, $stocks->[3]);
	pr2rs('restock requirement', $rum_need, $shot_need);
	print "\n";
    }

    if (@price) {
	my ($rum_buy,$shot_buy) = ('','');
	my ($rum_bill,$shot_bill) = qw(0 0);
	my $ok=1;
	if ($rum_need > 0) {
	    if (defined $best) {
		my $rum_qty= $rum_need * 100 / $proofs[$best];
		$rum_qty= ceil($rum_qty);
		$rum_buy= sprintf('%12s %-11s  ',
				  "** $rum_qty","$kinds[$best] **");
		$rum_bill= $rum_qty * $price[$best];
	    } else {
		$rum_buy= '   (rum unavailable)';
		$ok= 0;
	    }
	}
	if ($shot_need > 0) {
	    if (valid($price[3])) {
		$shot_buy= sprintf('%7s shot **', "** $shot_need");
		$shot_bill= $shot_need * $price[3];
	    } else {
		$shot_buy= '  (shot unavailable)';
		$ok= 0;
	    }
	}
	if (length($rum_buy) or length($shot_buy)) {
	    pr2($ok
		? sprintf('for a total of %d poe', $rum_bill + $shot_bill)
		: 'for',
		$rum_bill ? sprintf("%12d poe       ", $rum_bill) : '',
		$shot_bill ? sprintf("%10d poe", $shot_bill) : '');
	    pr2('BUY', $rum_buy, $shot_buy);
	} else {
	    print "stocks are sufficient.\n";
	}
	print "\n";
    }
}

parse_args();
print_inputs();
compute_cheapest_rum();
compute_stock_values();
compute_restock_requirements();

STDOUT->error and die $!;
close STDOUT or die $!;