#!/usr/bin/perl

# this script takes in a Job or Jobs from Perforce and integrates all the changes
# associated with it using a branch spec. This way I only have to write this
# script once and you can use it to merge changes from any branch to any other branch,
# assuming your workspace can view both branches.
# 
# You also need to pass in a client/workspace name that has both branches in view.
#
# This script does NOT submit the code, you'll have to do that manually after you verify it.
#
# Example, note there is a comma and no spaces between the job names:
#
# perl publish_changelist.pl [job[,job,job]] [workspace] [branchspec]
# perl publish_changelist.pl SD-6662,SD-6605 matthewja_generic "publish_main->qa_stream"

$fixes = $ARGV[0];
$workspace = $ARGV[1];
$branch_spec = $ARGV[2];

my @master_changelists;  # this is used to queue the total list of changelists we are merging

# parse out the passed in Jobs into an array, then get all the changelists involved
@fixlist = split(/,/, $fixes); # get Jobs list into an array

# let's sort the fixlist so it's pretty when we put them in the changelist comment
@fixlist = sort(@fixlist);

# go through each Job, get the associated changelists, queue said changelists into a master array
foreach (@fixlist) { 
	$p4_changelists = `p4 fixes -j $_`;  # get output of p4 fixes command
	@current_changelists = split(/\n/, $p4_changelists);  # turn the current list into an array
	
	# go through each changelist on the current Job and parse out just the number
	# then pop it onto a new array of all involved changelists
	foreach (@current_changelists) {
		$_ =~ s/^.*change //m;  # chop of beginning of line
		$_ =~ s/ on ....\/..\/.. .*$//m;  # chop end of line
		push(@master_changelists, $_);
	}
}  # foreach

# let's sort all the changelists we want to merge, we have to do them in numerical order
@master_changelists = sort(@master_changelists);

# create a new changelist to do the integration with
$new_changelist = create_changelist();

# go through the changes list and integrate them using our newly created changelist
foreach (@master_changelists) {
	$integrate_results = `p4 -c $workspace integrate -c $new_changelist -i -d -t -b \"$branch_spec\" //...\@$_,\@$_`;
}  # foreach

# before we auto-resolve the files they should be synced. some files might not need it, so
# we parse those out (only things marked for 'integrate' need to (possibly) be synced)

# get the pending files
$files_to_sync = `p4 -c $workspace opened -c $new_changelist`;

# make pending files list into an array
@sync_me = split (/\n/, $files_to_sync);

# loop through the files in the pending changelist and sync them
foreach (@sync_me) {
	# only things being integrated need to be synced, everything else
	# will be either an add or delete
	if ($_ =~ m/ - integrate/) {
		$_ =~ s/#.*$//; # delete line after pound sign
		$_ =~ s/#//; # ditch the pound sign
		$sync_result = `p4 -c $workspace sync $_`;
	}
}

# now auto-resolve the files
$resolve_results = `p4 resolve -at`;

# add the original jobs to the new changelist
foreach (@fixlist) {
	$job_attach_result = `p4 -c $workspace fix -c $new_changelist $_`;
}

# print out a message
print "\n**************************************************\n";
print " Changelist $new_changelist is resolved but not Submitted! \n";
print " Please verify it then check it in!\n";
print "**************************************************\n";

# now you're done!!!

# create a changelist and use it so our changes can be isolated
sub create_changelist() {
	
	# create the new changelist
	open IN, "| p4 -c $workspace change -i";
	print IN "Change: new\n";
	print IN "Description:\n";
	print IN "\tMerging changelists using branch spec $branch_spec.\n";
	print IN "\t\n";
	print IN "\tSource Jobs:\n";
	print IN "\t\n";
	
	# print out all the jobs we're merging
	foreach (@fixlist) {
		print IN "\t\t$_\n";
	}
	
	print IN "\t\n";
	print IN "\tSource changelists:\n";
	print IN "\t\n";
	
	# print out all the changelists we're dealing with
	foreach (@master_changelists) {
		print IN "\t\t$_\n";
	}  # foreach
	close IN;
	print IN;

	# now that the changelist is created, we have to find out what number it is.
	# since we used filehandles to create it, the output result is lost. Good thing
	# we put a unique description in the changelist that we can search for now, eh?
	
	# get the list of pending changes in our workspace 
	$changes = `p4 changes -c $workspace -s pending`;
	
	# turn that list into an array
	@current_changes = split(/\n/, $changes);

	# go through and find our comment. note that it stops when it finds the first
	# match. do not keep multiple merges for the same job around. submit them!
	foreach (@current_changes) {
		if ($_ =~ m/Merging changelists using branc/) {
			# found it, let's parse out the change number and return it
			$_ =~ m/^Change (\d*) /;
			return $1;
		}
		else {
			print "What the heck? Where did our changelist go? How could you have 
			deleted it in the half second it took to run this script? Merge failed!";
			exit;
		} #if
	}  # foreach
}  # sub create_changelist