#!/bin/bash

#
# Dump patches from git (current coring directory) to be usable in --spec file
# The script does not modify your spec file! You have to copy & past the output manually.
#
# !!! 
#    Script read bugs summary from bugzilla. Don't forget "bugzilla login"
#    before you execute the script.
# !!!
# 
#

TEMP=$(getopt -o hs:o:x:p: --long help,spec:,output-directory:,head:,split-point:, -n 'git2spec' -- "$@")

BASE=
SPEC_FILE=
HEAD=
OFFSET=0
n_patches=0

declare -a PATCHES
declare -a BUGNUMS
declare -a SUMMARY

bold=$(tput setaf 3)
normal=$(tput sgr0)

function die() {
	echo "$1"
	exit 0
}

function add_to_array() {
	local -n a=$1
	local idx=$2
	a[$idx]=$3
}

function get_filename() {
	local -n a=PATCHES
	echo "${a[$1]}"
}

function get_bznum() {
	local -n a=BUGNUMS
	echo "${a[$1]}"
}

function get_bzsummary() {
	local -n a=SUMMARY
	echo "${a[$1]}"
}

function patch_get_bz() {
	local filename=$(get_filename $1)

	awk '/^Addresses:/ { match($0, "id=([0-9]*)", x); bz=substr($0, x[1, "start"], x[1, "length"]); print bz }' "${filename}"
}

function bugzilla_get_summary() {
	local bz="$1"

	bugzilla query --bug_id=${bz} --outputformat="%{summary}"
}

function dump_patches() {
	local head="$1"
	local bz
	local num

	if [ $OFFSET -eq 0 ]; then
		num=1
	else
		num=$OFFSET
	fi

	while read line; do
		add_to_array PATCHES $n_patches $line
		n_patches=$(($n_patches + 1))
	done < <(git format-patch -o ${BASE} ${head} --start-number $num)

	[ $n_patches -eq 0 ] && return

	# read BZ numbers from patch files
	for i in $(seq 0 $(($n_patches - 1))); do
		bz=$(patch_get_bz $i)
		add_to_array BUGNUMS $i $bz
	done
}

function read_bugzilla() {
	local bz
	local summary

	echo -n "Reading bugzillas..."
	for i in $(seq 0 $(($n_patches - 1))); do
		bz=$(get_bznum $i)
		echo -n "$bz "
		summary="$(bugzilla_get_summary $bz)"

		add_to_array SUMMARY $i "$summary"
	done
	echo "done"
	echo
}

function section_s() {
	echo "${bold}### ${1}${normal}"
}
function section_e() {
	echo "${bold}### ${1}${normal}"
	echo
}

function usage() {
	echo "git2spec [options]"
	echo
	echo "Options:"
	echo "  -s, --spec <path>              path to specfile"
	echo "  -o, --output-directory <path>  optional, default is specfile directory"
	echo "  -x, --head <gitism>            where to start generate patches in git history"
	echo "  -p, --split-point <gitism>     optional, where in git history begins stuff maintaind by your spec file"
	echo

	exit 0
}

#
# main()
#
eval set -- "$TEMP"
while true ; do
	case "$1" in
		-s|--spec)    SPEC_FILE="$2" ; shift 2 ;;
		-o|--output*) BASE="$2"      ; shift 2 ;;
		-x|--head)    HEAD="$2"      ; shift 2 ;;
		-p|--split*)  START="$2"     ; shift 2 ;;
		-h|--help)    usage          ; ;;

		--) shift ; break ;;
		*) echo "Internal error!" ; exit 1 ;;
	esac
done

#[ -z "$SPEC_FILE" ] && die "No spec file specified (use --spec <path>)."
[ -z "$HEAD" ] && die "No start-point specified (use --head <tag|hash>)."

if [ -z "$BASE" ]; then
	BASE="$(dirname $SPEC_FILE)"
fi

if [ -n "$START" ]; then
	OFFSET=$(git rev-list --count ${START}..${HEAD})
fi

dump_patches $HEAD
[ $n_patches -eq 0 ] && die "Not found patches."

read_bugzilla

USERNAME="$(git config --get user.name)"
USEREMAIL="$(git config --get user.email)"
TODAY="$(date '+%a %b %d %Y')"
VERSION="$(awk '/^Version/ {print $2}' ${SPEC_FILE})"
RELEASE="$(awk '/^Release/ {print $2}' ${SPEC_FILE} | sed -e 's/%{?dist}.*//')"
NEW_RELEASE=$(( $RELEASE + 1 ))


section_s "SPEC FILE PATCHES (generated from git)"
for i in $(seq 0 $(($n_patches - 1))); do
	bz=$(get_bznum $i)
	filename="$(basename $(get_filename $i))"
	summary="$(get_bzsummary $i)"
	if [ $OFFSET -eq 0 ]; then
		num=$i
	else
		num=$(( $OFFSET + $i ))
	fi

	echo "# $bz - $summary"
	echo "Patch${num}: ${filename}"
done
section_e "END OF PATCHES"

section_s "spec file changelog"
echo "* ${TODAY} ${USERNAME} <${USEREMAIL}> ${VERSION}-${NEW_RELEASE}"
for i in $(seq 0 $(($n_patches - 1))); do
	bz=$(get_bznum $i)
	summary="$(get_bzsummary $i)"
	echo "- fix #$bz - ${summary}"
done
section_e


section_s "git"
echo -n "git add "
for i in $(seq 0 $(($n_patches - 1))); do
	echo -n "$(basename $(get_filename $i)) "
done
echo
section_e


section_s "dist-git commit"
echo "${VERSION}-${NEW_RELEASE}"
echo
echo -n "Resolves: "
for i in $(seq 0 $(($n_patches - 1))); do
	echo -n "#$(get_bznum $i) "
done
echo
section_e