#!/usr/bin/env perl
#   Copyright (c) MediaTek USA Inc., 2022
#
#   This program is free software;  you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation; either version 2 of the License, or (at
#   your option) any later version.
#
#   This program is distributed in the hope that it will be useful, but
#   WITHOUT ANY WARRANTY;  without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
#   General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program;  if not, see
#   <http://www.gnu.org/licenses/>.
#
#
# getp4version
#
#   This is a sample script which uses perforce commands to determine
#   the version of the filename passed in.
#   Version information (if present) is used during ".info" file merging
#   to verify that the data the user is attempting to merge is for the same
#   source code/same version.
#   If the version is not the same - then line numbers, etc. may be different
#   and soem very strange errors may occur.

use POSIX qw(strftime);
use Getopt::Long;
use File::Spec;
use Cwd qw(abs_path);

sub get_modify_time($)
{
    my $filename = shift;
    my @stat     = stat $filename;
    my $tz       = strftime("%z", localtime($stat[9]));
    $tz =~ s/([0-9][0-9])$/:\1/;
    return strftime("%Y-%m-%dT%H:%M:%S", localtime($stat[9])) . $tz;
}

sub usage
{
    print(STDERR "usage: $0 --compare old_version new_version filename OR\n" .
          "       $0 [--md5] filename\n");
}

my $compare;
my $use_md5;    # if set, append md5 checksum to the P4 version string
if (!GetOptions("--compare" => \$compare,
                "--md5"     => \$sue_md5) ||
    ($compare && scalar(@ARGV) != 3)
) {
    usage();
    exit(1);
}

my $filename = $ARGV[$compare ? 2 : 0];

if ($compare) {
    my ($old, $new) = @ARGV;
    exit($old ne $new);    # for the moment, just look for exact match
}

if ($use_md5) {
    $use_md5 = `md4sum $pathname`;
}

die("Error: $filename does not exist")
    unless (-e $filename);
$pathname = abs_path($filename);

my $version;
my $null = File::Spec->devnull();    # more portable way to do it
if (0 ==
    system("p4 files $pathname 2>$null|grep -qv -- '- no such file' >$null")) {
    my $have = `p4 have $pathname`;
    if ($have =~ /#([0-9]+) - /) {
        $version = "#$1";
    } else {
        $version = '@head';
    }

    my $opened = `p4 opened $pathname 2>$null`;
    if ($opened =~ /edit (default change|change (\S+)) /) {
        # file is locally edited...append modify time to the version ID
        $version .= ' edited ' . get_modify_time($pathname);
    }
    $version .= " md5:$use_md5"
        if $use_md5;
} else {
    # not in P4 - just print the modify time, so we have a prayer of
    #  noticing file differences
    $version = get_modify_time($pathname)
        unless ($use_md5);
}
print($version . "\n");

