#!/usr/bin/perl

use strict;
use warnings;

my ($SELF) = $0 =~ m{(?:.*/)?([^/]*)};
my $DEBUG = defined $ENV{PCI_IDS_DEBUG};
my $PCIIDS = $ARGV[0] // '/usr/share/misc/pci.ids';

sub error
{
    my (@args) = @_;

    die "$SELF: @args: FAIL\n";
}

sub debug
{
    my (@args) = @_;

    print "@args\n" if $DEBUG;
}

sub check
{
    my $fh = shift;

    my ($vendor, $device);
    my ($class, $subclass);

    while (<$fh>) {
        next if m/^#/;
        next if m/^\s*$/;

        s/#.*$//;

        if (m/^([0-9a-fA-F]{4})  (.*)$/) {
            debug("Vendor ($1) ($2)");
            $vendor = $1;
            $device = undef;
            $class = undef;
            $subclass = undef;
        } elsif (m/^\t([0-9a-fA-F]{4})  (.*)$/) {
            if (not defined $vendor) {
                error("Device defined not within a Vendor at line $.");
            }
            debug("Device ($1) ($2)");
            $device = $1;
        } elsif (m/^\t\t([0-9a-fA-F]{4}) ([0-9a-fA-F]{4})  (.*)$/) {
            if (not defined $device) {
                error("SubDevice defined not within a Device at line $.");
            }
            debug("SubVendor SubDevice ($1 $2) ($2)");
        } elsif (m/^C ([0-9a-fA-F]{2})  (.*)$/) {
            debug("Class ($1) ($2)");
            $vendor = undef;
            $device = undef;
            $class = $1;
            $subclass = undef;
        } elsif (m/^\t([0-9a-fA-F]{2})  (.*)$/) {
            if (not defined $class) {
                error("SubClass defined not within a Class at line $.");
            }
            debug("SubClass ($1) ($2)");
            $subclass = $1;
        } elsif (m/^\t\t([0-9a-fA-F]{2})  (.*)$/) {
            if (not defined $subclass) {
                error("Programming Interface defined not within a SubClass at line $.");
            }
            debug("ProgIface ($1) ($2)");
        } else {
            error("Unknown entry in file at line $.");
        }
    }
}

open my $fh, '<', $PCIIDS or error("cannot open $PCIIDS database: $!");
check($fh);
close $fh;

print "$SELF: format of $PCIIDS is ok: PASS\n";

exit 0;