#!/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, specifying an empty string means
zero.  Entirely Missing <swill>/<grog>/ is taken as if both were
specified and zero.

In price, missing entries mean the commodity is unavailable.
END
;

our (@vals) = 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/) {
	$_ = 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 /s)");
    }
    my $i=0;
    foreach $_ (@v) {
	$_ = $default if !length;
	m/^0*(\d+)$/ or badusage("$what: $vals[$i] \`$_': bad syntax");
	$_= $1;
	$i++;
    }
    @$storeary = @v;
}

our (@haves,@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, @{ $haves[@haves] }, 'BUG');
	} elsif (m/^want$/) {
	    parse_info(1,0,0, @want, 'want');
	} elsif (m/^price$/) {
	    parse_info(0,1e6,0, @price, 'price');
	} else {
	    badusage("unknown information argument \`$_'");
	}
    }
}

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

parse_args();
use Data::Dumper;
print Dumper({ Have => \@haves, Want => \@want, Price => \@price });

our @norm_price;
our $best;

sub compute_cheapest_rum() {
    return unless @price;

    $best= undef;
    my $best_norm_price= 1e5;
    for my $i (qw(0 1 2)) {
	next unless $price[$i];
	$norm_price[$i] = $price[$i] * $proof[$i] / $proof[$i];
	if ($norm_price[$i] <= $best_norm_price) {
	    $best= $i;
	}
    };
    prf('normalised prices', @norm_price, 'poe/fine');
    if (defined $best) {
	printf "best is %s\n\n", $best;
    } else {
	die "no rum available ?\n";
    }
}



__DATA__

our $ff = '%6.1f';

sub prvff ($$\%$) {
    my ($what, $format, $ary, $unit) = @_;
    printf("%-40s", "$what:");
    map {
	my $x= $ary->{$_};
	my $y= defined $x ? sprintf $format, $x : '   x';
	printf " %-10s", $y;
    } @rums;
    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;
}

our ($best);

our $have_proof;

sub print_inputs () {
    printf("%40s",'');
    map { printf " %5s     ", $_ } @rums;
    print "\n\n";
    if (defined $price{Swill}) {
	map { $price{$_}= undef if $price{$_} eq 'x' } @rums;
	pr('prices', %price, 'poe ea.');
    }
    if (defined $have{Swill}) {
	$have_proof= 0;
	map { $have_proof += $have{$_} * $proof{$_} } @rums;
	pr('stock on board', %have, 'rum');
    }
}

our ($need_proof, %need, %buy);

sub compute_restock_requirements () {
    if ($ship =~ m/^\d+/) {
	$need{Fine} = $ship;
    } else {
	$ship =~ y/_/ /;
	open F, "/home/ian/private/puzzle-pirates" or die $!;
	my $this_ship= 0;
	my $the_ship;
	while (<F>) {
	    if (!m/\S/ || m/^\s*\#/) {
		$this_ship= 0;
		next;
	    }
	    if (!m/^\@/) {
		next;
	    }
	    if (m/^\@(( [A-Z][-a-z]+){2,})\s*$/) {
		$this_ship= (uc $1 eq uc " $ship" or
			     uc $+ eq uc " $ship");
		$the_ship= $1;
		next;
	    }
	    next unless $this_ship;
	    if (m/^\@\s+(\d+)\s+fine\s*/) {
		$need{Fine} = $1;
		last;
	    }
	}
	die $! if F->error;
	die "unknown ship $ship" unless defined $need{Fine};
	if (defined $ship) {
	    pr1("vessel",$the_ship);
	}
    }
    pr1('desired stock level', sprintf("%4d fine rum", $need{Fine}));
    $need_proof= $need{Fine} * $proof{Fine} - $have_proof;
    map {
	$buy{$_} = $need_proof / $proof{$_};
    } @rums;
    pr1("stock equivalent", sprintf "$ff fine rum", $have_proof / $proof{Fine});
    pr1("restock equivalent", sprintf "$ff fine rum", $need_proof / $proof{Fine});
    prf('would need', %buy, 'rum');
}

sub compute_restock_cheapest_rum() {
    my %bill;
    map {
	$bill{$_} = $buy{$_} * $price{$_} if defined $price{$_};
    } @rums;
    prf('nominal bill', %bill, 'poe');
    print "\n";
    if ($need_proof < 0) {
	printf "stocks are sufficient";
    } else {
	my $buy= ceil($buy{$best});
	printf "buy %d %s at %d poe each for %d poe",
	    $buy, $best, $price{$best}, $buy * $price{$best};
    }
    print "\n\n";
}

main();