#!/usr/local/bin/perl -w
#
# Created by Robert Cowham (robert@vaccaperna.co.uk)
# This is totally unsupported - use entirely at your own risk!
#
# Usage:
#
#  ./version_differ.pl filename
#
#
# The results of the following command gives us the files to process:
#  p4 diff2 -q //depot/main/... //depot/snap/... | grep '=== content'
#
#==== //depot/main/www/components/util/ftse.epl#5 (xtext) - //depot/snap/www/components/util/ftse.epl#1 (text) ==== content
#==== //depot/main/www/components/util/hidden_elements.epl#2 (text) - //depot/snap/www/components/util/hidden_elements.epl#1 (text) ==== content

use strict;

#-----------------------------------------------------------------------
# get file names

while (<>) {
  if (/^==== ([^#]*)#(\d*)\s+\S* - ([^#]*)#(\d*)/) {
    my ($main_file, $main_ver, $snap_file, $snap_ver) = ($1, $2, $3, $4);
    # print "File: $main_file, ver: $main_ver, file2: $snap_file, ver: $snap_ver\n";

    &find_same_version($main_file, $main_ver, $snap_file, $snap_ver);
  }
}

exit;


#-----------------------------------------------------------------------
# for each file - do a diff2 on each version
# Only prints out summary info for file

sub find_same_version() {
  my ($main_file, $main_ver_param, $snap_file, $snap_ver) = @_;
  my $main_ver = $main_ver_param;

#  print "Checking $main_file\n";

  my $identical = 0;
  my ($depot_main, $depot_snap);

  while ($main_ver > 0 && !$identical) {
    $depot_main = $main_file . '#' . $main_ver;
    $depot_snap = $snap_file . '#' . $snap_ver;

#    print "FROM: $depot_main\n";
#    print "TO:   $depot_snap\n";

    my $cmd = "p4 diff2 -q $depot_main $depot_snap";
#    print "Executing: $cmd\n";

    open(P4DIFF2, "$cmd |") || die "didn't open p4 diff2";

    my @diff2 = <P4DIFF2>;

    close(P4DIFF2);

    if (scalar(@diff2) == 1) {

      my $report_string = '-- NO INFO FOUND --';

      if ($diff2[0] =~ /====\s+([^\s]+)$/) {
            $report_string = $1;
      }

      if ($report_string =~ /^types$/) {
        $identical = 1;
        print "$report_string: $depot_main\n";
      } elsif ($report_string !~ /^content$/) {
        print "$report_string: $depot_main\n";
      }

    }
    elsif (scalar(@diff2) == 0)
      {
        $identical = 1;
        print "Identical: $depot_main\n";
      }

    $main_ver -= 1;

  }

  if (!$identical) {
    my $rev = $main_file;
    $rev =~ s/#.*//;
    $rev .= "#" . $main_ver_param;
    print "No revision: $rev\n";
#    &find_same_version_verbose($main_file, $main_ver_param, $snap_file, $snap_ver);
  }

#  print "\n";

}

#-----------------------------------------------------------------------
# for each file - do a diff2 on each version - print out some info
# so that these files can be integrated by hand

sub find_same_version_verbose() {
  my ($main_file, $main_ver, $snap_file, $snap_ver) = @_;

  print "Checking $main_file\n";

  my $identical = 0;
  my ($depot_main, $depot_snap);

  while ($main_ver > 0 && !$identical) {
    $depot_main = $main_file . '#' . $main_ver;
    $depot_snap = $snap_file . '#' . $snap_ver;

#    print "FROM: $depot_main\n";
#    print "TO:   $depot_snap\n";

    open(P4DIFF2, "p4 diff2 $depot_main $depot_snap |") || die "didn't open p4 diff2";

    my @diff2 = <P4DIFF2>;

    close(P4DIFF2);

    if (scalar(@diff2) == 1) {

      my $report_string = '-- NO INFO FOUND --';

      if ($diff2[0] =~ /====\s+([^\s]+)$/) {
        $report_string = $1;
      }

      print $depot_main, "\t", $depot_snap, "\t",
        "SINGLE LINE DIFF2: $report_string\n";

      if ($report_string =~ /^identical$/) {
        $identical = 1;
        print "Identical: $depot_main\n";
      }
      else {
        print "$report_string: $depot_main\n";
      }

    }
    else
      {
        print $depot_main, "\t", $depot_snap, "\t",
	  "DIFF LINES: " , scalar(@diff2), "\n";
        my $l;
#       foreach $l (@diff2) {
#           print "$l";
#       }
      }

    $main_ver -= 1;

  }

  if (!$identical) {
    print "No revision: $depot_main\n";
  }

  print "\n";

}