#!/usr/bin/perl
#
# Add $DSV_HOME/bin to your PATH.
#

$DSV_HOME = $ENV{"DSV_HOME"};
$DSV_HOME = "/home/moko/dsv" unless defined $DSV_HOME;


sub mkdir
{
    mkdir($_[0]) && return;
    return if $!{EEXIST};
    die "$_[0]: $!";
}


sub mkbin
{
    local ($pgm, $file) = @_;

    open(F, ">$pgm") || die "$pgm: $!";
    print F "#!/bin/sh\n# MACHINE-GENERATED. DO NOT EDIT !\nxpdf \"$file\"\n"
	|| die "$pgm: $!";
    close(F) || die "$pgm: $!";
    chmod(0777 & ~umask, $pgm) || die "chmod $pgm: $!";
}


sub dl
{
    $bin_dir = "$DSV_HOME/bin";
    $ds_dir = "$DSV_HOME/ds/$sym";
    $url =~ /[^\/?&]*$/;
    $name = $&;

    local ($p) = "$ds_dir/$name";

    if (!-r "$p") {
	&mkdir($ds_dir);
	if (system("wget -nv -O \"$p-tmp\" \"$url\"")) {
	    print STDERR "FAILED: $sym -> $url\n";
	} else {
	    rename("$p-tmp", $p) || die "rename: $!\n";
	}
    }
    if (!-x "$bin_dir/dsv-$sym") {
	print STDERR "adding dsv-$sym\n";
	&mkbin("$bin_dir/dsv-$sym", $p);
    }
    for (@alias) {
	if (!-x "$bin_dir/dsv-$_") {
	    print STDERR "adding dsv-$_\n";
	    &mkbin("$bin_dir/dsv-$_", $p);
	}
    }
}


sub flush
{
    &dl if defined($sym) && defined($url);
    undef @alias;
    undef $url;
}


if ($ARGV[0] eq "-d") {
	print "$DSV_HOME\n";
	exit(0);
}

&mkdir("$DSV_HOME");
&mkdir("$DSV_HOME/ds");
&mkdir("$DSV_HOME/bin");

while (<>) {
    s/#.*//;
    next if /^\s*$/;
    if (/^S:\s+(\S+)\s*$/) {
	&flush if defined $sym;
	$sym = $1;
    } elsif (/^A:\s+(\S+)\s*$/) {
	push(@alias, $1);
    } elsif (/^D:\s+(.*?)\s*$/) {
	$url = $1 unless defined $url;
	die unless defined $sym;
	&flush;
    } elsif (/^M:\s+(.*?)\s*$/) {
	# ignore
    } else {
	die "bad syntax: \"$_\"";
    }
}
&flush if defined $sym;