#!/bin/bash
###########################################################################
# copies outstanding changesets for a set of tickets between branches
###########################################################################
# $1    = name of source branch
# $2    = name of target branch
# $3    = ticket prefix
# $4    = (optional) message suffix
# $5... = tickets whose changesets are to be moved
###########################################################################
# the mapping of branch names to file system paths is done in
# ~/.fli4l/repo-info
###########################################################################

rootdir=${0%/*}
allowed_options="-q --continue-merge --review-merge --placebo-merge --no-merge-details"
# if non-empty, a clean target branch is required
clean_before_merge=1
# if non-empty, the script shows the resulting merge via "svn diff" and waits
# afterwards for a RETURN before committing
review_merge=
# by default, all changes are merged
recordonly=
# by default, provide details for merge commits
mergedetails=1

if [ "$(type -t usage)" != "function" ]
then
	usage()
	{
		echo "Usage: $(basename $0) (-q|--continue-merge|--review-merge|--placebo-merge)* <source-branch-name> <target-branch-name> <ticket-prefix> <message-suffix> <ticket-id>+ (: <secondary-ticket-id>+)?"
		exit 1
	}
fi

. "$rootdir/include/config.inc"
. "$rootdir/include/options.inc"
. "$rootdir/include/display.inc"
. "$rootdir/include/utility.inc"
. "$rootdir/include/cleanup.inc"
. "$rootdir/include/svn.inc"
. "$rootdir/include/repo-info.inc"
. "$rootdir/include/branching.inc"
. "$rootdir/include/ticket.inc"

case $1 in
-*)
	warning "Unknown option: $1"
	usage
	;;
esac

has_option "--continue-merge" && clean_before_merge=
has_option "--review-merge" && review_merge=1
has_option "--placebo-merge" && recordonly="--record-only"
has_option "--no-merge-details" && mergedetails=

if [ $# -lt 5 ]
then
	usage
fi

[ -n "$1" ] || error "Source branch name is missing"
[ -n "$2" ] || error "Target branch name is missing"
[ -n "$3" ] || error "Ticket prefix is missing"

src="$1"
tgt="$2"
prefix="$3"
msgsfx="$4"
shift 4

message "Loading repository information" standout
load_repo_info

message "Initializing local branches" standout
init_local_branch "$src"
init_local_branch "$tgt" $clean_before_merge

tgtmax=$(get_head_rev "$tgt")
[ -n "$tgtmax" ] || error "Computing maximum revision of $tgt failed"

srcrevs=$(get_revs "$src" "$tgt")
tgtmerged=$(get_merged_revs "$tgt" "$src")
tgtnotmerged=$(subtract_list "$srcrevs" "$(expand_list "$tgtmerged")")

round=1
revs=

tickets=
while [ -n "$1" -a "$1" != ":" ]
do
	tickets="$tickets $prefix-$(mask_for_regex "$1")"
	shift
done
tickets=${tickets# }
shift

secondary_tickets=
while [ -n "$1" ]
do
	secondary_tickets="$secondary_tickets $prefix-$(mask_for_regex "$1")"
	shift
done
secondary_tickets=${secondary_tickets# }

old_tickets=""

while [ -n "$tickets" -a "$(sort_list "$old_tickets")" != "$(sort_list "$tickets")" ]
do
	message "Determining changesets to be merged (round $round)" standout
	old_tickets="$tickets"
	tickets=""

	while read rev
	do
		msg=$(get_log_message "$src" $rev)
		ok=
		for ticket in $old_tickets
		do
			if echo "$msg" | grep -q "\<$ticket\>"
			then
				for t in $(extract_tickets "$msg" "$prefix")
				do
					echo "$secondary_tickets" | grep -q "\<$t\>" &&
						continue
					echo "$tickets" | grep -q "\<$t\>" ||
						tickets+="$t "
				done
				ok=1
				break
			fi
		done
		if [ -n "$ok" ]
		then
			if ! echo "$revs" | grep -q "\<$rev\>"
			then
				revs+="$rev "
				print_log_messages "$src" $rev $mergedetails
			fi
		fi
	done <<< "$tgtnotmerged"

	tickets="${tickets% }"
	round=$((round+1))
done

if [ -n "$revs" -a -n "$secondary_tickets" ]
then
	message "Determining secondary changesets to be merged" standout
	set -- $revs
	eval lastrev=\$\{$#\}
	[ -n "$tickets" ] && tickets+=" "

	while read rev
	do
		[ $rev -lt $lastrev ] || break

		msg=$(get_log_message "$src" $rev)
		ok=
		for ticket in $secondary_tickets
		do
			if echo "$msg" | grep -q "\<$ticket\>"
			then
				for t in $(extract_tickets "$msg" "$prefix")
				do
					echo "$tickets" | grep -q "\<$t\>" ||
						tickets+="$t "
				done
				ok=1
				break
			fi
		done
		if [ -n "$ok" ]
		then
			if ! echo "$revs" | grep -q "\<$rev\>"
			then
				revs+="$rev "
				print_log_messages "$src" $rev $mergedetails
			fi
		fi
	done <<< "$tgtnotmerged"
fi

# sort revisions
revs=$(echo "$revs" | $SED 's/ /\n/g' | sort -n | $SED ':a;N;$!ba;s/\n/ /g')
# make comma-separated list
revs=$(echo "$revs" | $SED -e 's/[[:space:]]*$//;s/[[:space:]]\+/,/g')

if [ -n "$tickets" ]
then
	message="Tickets to be considered"
	[ -n "$recordonly" ] && message+=" (record only)"
	message "$message:" standout
	for t in $tickets
	do
		message "  $t: " -n
		message "$(get_ticket_title "$t")" yellow
	done

	message "Please review and press Ctrl+C to abort or RETURN to continue..." -n standout
	read

	if [ -n "$recordonly" ]
	then
		rev_ranges="${revs#,}"
	else
		rev_ranges=$(partition_revs $src ${revs//,/ })
	fi

	set -- $rev_ranges
	num_ranges=$#
	part=1
	part_message=""

	push_cleanup clean_branch_if_enabled "$tgt"

	for range in $rev_ranges
	do
		if [ $num_ranges -gt 1 ]
		then
			part_message=" (part $part/$num_ranges)"
			part=$((part+1))
		fi

		while true
		do
			message "Merging changesets for $tickets from $src to $tgt${part_message}" standout

			do_svn_quiet merge $recordonly -c $range --non-interactive \
				"$remote_root/$src" "$local_root/$tgt"

			conflicts=$(get_merge_conflicts "$tgt")
			if [ -n "$conflicts" ]
			then
				while [ -n "$conflicts" ]
				do
					analyse_conflicts "$src" "$tgt" "$conflicts" "$tgtnotmerged" \
						"${range//,/ }" max_rev -gt "$prefix"

					answer=
					while [ "$answer" != y -a "$answer" != n ]
					do
						message "Trying to resolve interactively (y/n)? " -n standout
						read answer
					done
					if [ "$answer" = y ] &&
						analyse_conflicts "$src" "$tgt" "$conflicts" \
							"$tgtnotmerged" "${range//,/ }" \
							max_rev -gt "$prefix" 1
					then
						review_merge=1
						conflicts=$(get_merge_conflicts "$tgt")
					else
						answer=
						while [ "$answer" != y -a "$answer" != n ]
						do
							message "Cleanup target branch after failed merge (y/n)? " -n standout
							read answer
						done
						case $answer in
						n)
							cleanup_after_merge=
							error "Conflict(s) encountered while merging${part_message}. Please resolve conflicts manually and restart merge using --continue-merge option."
							;;
						*)
							error "Conflict(s) encountered while merging${part_message}"
							;;
						esac
					fi
				done
			else
				break
			fi
		done

		if [ -n "$review_merge" ]
		then
			while true
			do
				svn diff "$local_root/$tgt" | $PAGER

				answer=
				while [ "$answer" != y -a "$answer" != n -a "$answer" != r ]
				do
					message "Commit merge result? Choose (y)es, (n)o, (r)eview again: " -n standout
					read answer
				done
				case $answer in
				n)
					error "Merge aborted"
					;;
				y)
					break
					;;
				esac
			done
		fi

		message "Building commit message" standout
		msg="MERGE $tickets${part_message}${msgsfx:+ $msgsfx}${recordonly:+ (record only)}
  (from /$src)"
		for rev in $(decompress_revs $range)
		do
			msg+="
$(print_log_messages "$src" $rev 1 nocolor)"
		done

		message "Committing merge result into $tgt${part_message}" standout
		do_svn_quiet commit -m "$msg" "$local_root/$tgt" ||
			svn_error "Committing merge result into $tgt${part_message} failed"

		update_branch "$tgt" || error "Update of branch $1 failed"
	done

	do_message "Success: $tickets committed to $tgt, commit [$(_get_head_rev "$remote_root/$tgt")]" green
	pop_cleanup
else
	error "No changesets for specified tickets found"
fi