#!/bin/bash

usage() {
        echo "Usage ${0} [[--ignore|-i] dir_name] [--main]"
        echo "        --help        Show this help"
        echo "        --main        Checkout to main branch"
        echo "        --ignore=*    Ignore folders"
        echo "        --only=*      Update only folders (comma-separated)"
        exit 1
}

find_folders() {
        local FIND_ARGS=(.)
        FIND_ARGS+=("-name" ".git")
        FIND_ARGS+=("-type" "d")

	# If only specific folders are requested
	local ONLY_PATHS=()
        for ONLY_FOLDER in ${ONLY_FOLDERS}
	do
		ONLY_PATHS+=("-o" "-path" "*/${ONLY_FOLDER}/*")
		# Remove first -o and add parentheses
	done
	if [[ ${#ONLY_PATHS[@]} -gt 1 ]]
	then
		unset 'ONLY_PATHS[0]'
		FIND_ARGS+=("(" "${ONLY_PATHS[@]}" ")")
	fi

	# Exclude ignored folders
        for IGNORE_FOLDER in ${IGNORE_FOLDERS}
        do
                FIND_ARGS+=("-not" "-path" "*/${IGNORE_FOLDER}/*")
        done
        find "${FIND_ARGS[@]}"
}

# Map long options to short ones and rebuild argv
translated=()
while (( $# )); do
  case "$1" in
    --help)      translated+=("-h"); shift ;;
    --main)      translated+=("-m"); shift ;;
    --ignore=*)  translated+=("-i" "${1#*=}"); shift ;;
    --only=*)    translated+=("-o" "${1#*=}"); shift ;;
    --)          translated+=("--"); shift; translated+=("$@"); set -- ;;
    *)           translated+=("$1"); shift ;;
  esac
done
set -- "${translated[@]}"

IGNORE_FOLDERS=""
ONLY_FOLDERS=""
FLAG_SWITCH_TO_MAIN=""

while getopts ":hmi:o:" opt; do
  case "$opt" in
    h) usage;;
    m) FLAG_SWITCH_TO_MAIN=1;;
    i) IGNORE_FOLDERS="${IGNORE_FOLDERS} ${OPTARG}";;
    o) ONLY_FOLDERS="${ONLY_FOLDERS} ${OPTARG}";;
    :) echo "Missing arg for -$OPTARG"; usage;;
    \?) echo "Invalid option: -$OPTARG"; usage;;
  esac
done

if [ ${#IGNORE_FOLDERS[@]} -gt 0 ]; then
	echo "[DEBUG] Ignoring folders to update: ${IGNORE_FOLDERS[*]}"
fi
if [ ${#ONLY_FOLDERS[@]} -gt 0 ]; then
	echo "[DEBUG] Only folders to update: ${ONLY_FOLDERS[*]}"
fi

for DIR in $(find_folders)
do
        pushd ${PWD} > /dev/null
        echo "[DEBUG] Work with $(dirname ${DIR})"
        cd $(dirname ${DIR})
        if [[ -n $(git status --porcelain) ]]
        then
                echo "[WARN] There are uncommitted changes."
                declare UNCOMMIT_CHANGES=1
                git stash
        fi
        declare MASTER_BRANCH="$(git symbolic-ref refs/remotes/origin/HEAD | sed 's@^refs/remotes/origin/@@')"
        declare CURRENT_BRANCH="$(git branch --show-current)"
        if [[ "$MASTER_BRANCH" == "$CURRENT_BRANCH" ]]
        then
                git pull --all
                git remote prune origin
        else
                git checkout ${MASTER_BRANCH}
                git pull --all
                git remote prune origin
                if [[ -z "${FLAG_SWITCH_TO_MAIN}" ]]
                then
                        git checkout ${CURRENT_BRANCH} || echo "[WARN] current brach has been deleted"
                fi
        fi
        git branch --merged | grep -v "^*\|${MASTER_BRANCH}" | xargs -r git branch -D
        if [ ! -z "$UNCOMMIT_CHANGES" ]
        then
                git stash pop
        fi
        unset UNCOMMIT_CHANGES MASTER_BRANCH CURRENT_BRANCH
        popd > /dev/null
done