#!/bin/sh

# Git Trach, track the state of multiple repos from a single file.

# dependencies:
# - git
# - $EDITOR: -e
# - parallel: optional, if installed will run the commands on all repos with parallel
# - gt-cmd, gt-st

if [ "$GIT_TRACK_REPOS" ]; then
	export REPOS="$GIT_TRACK_REPOS"
else
	export REPOS="$HOME/sync/share/git-track.txt"
fi

# prevent file not found errors
touch "$REPOS" || exit 1

which parallel >/dev/null 2>&1 && parallel=1

help() {
	>&2 cat <<EOF
usage: gt [OPTION]
-a PATH         add repo 
-c COMMAND      run 'git COMMAND' in each repo
-d              be done in every project
-h              show this help
-l              list repos
-e 		edit repos in \$EDITOR
-f FILE         use FILE as list of repos
-u 		pull in repos out of sync
-s 		show status of files and remotes
EOF
}

list_repos() { cut -f 1 -d ' ' "$REPOS"; }
quit_when_no_repos() { 
	if [ "$(wc -l <"$REPOS")" -eq 0 ];
	then 
		>&2 printf 'No repositories added.\n'
		exit 1
	fi
}

# fetch repository prettily, outputs nothing if failed
fetch() {
	# fetch with one-line printing of progress
	git fetch --progress 2>/dev/null | while read -r line; do # \r\033[0K : clear current line
		printf >&2 '\r\033[0K%s' "$line"
	done
}

# no options
if [ -z "$1" ]; then
	help
	exit 1
fi


while getopts ":a:c:f:dlsheu" opt; do
	case "$opt" in
	a)
		if ! cd "$OPTARG" 2>/dev/null; then
			>&2 printf 'Not a directory.\n'
			exit 1
		fi

		repo="$(git rev-parse --show-toplevel 2>/dev/null)"
  remote_name=
  if git remote show -n | grep 'origin' 2>/dev/null
  then
   remote_name="origin"
  else
   remote_name="$(git remote show -n | head -n 1)"
  fi
		remote_url="$(git remote show -n "$remote_name" 2>/dev/null | awk '/^  Fetch/ {print $NF}')"
  if [ -z "$repo" ] || [ -z "$remote_url" ]
  then
   >&2 printf 'Couldn'\''t add '\''%s'\'', not a git repository.\n' "$OPTARG"
   exit 1
  fi

		if grep "^$repo " "$REPOS" >/dev/null 2>&1; then
			>&2 printf 'added already.\n'
			exit 1
		fi

		printf '%s %s\n' "$repo" "$remote_url" >>"$REPOS"

		>&2 printf 'added.\n'
		;;
	c)
		quit_when_no_repos
		list_repos |
			if [ "$parallel" ]; then
				parallel gt-cmd "{}" "$OPTARG"
			else
				xargs -I{} gt-cmd "{}" "$OPTARG"
			fi
		;;
    d)
        if [ "$parallel" ]; then
            list_repos |
                parallel 'cd {};
            cd "$(git rev-parse --show-toplevel || printf '\''.\\n'\'')"
            git pull --ff > /dev/null 2>&1
            git add .
            git commit --all -m "checkpoint" > /dev/null 2>&1
            git push > /dev/null 2>&1
            printf '\''{}: done.\n'\'' | sed "s@^$HOME@~@"
            '
        else
            list_repos | while read -r proj
            do
                (
                    cd "$proj"
                    cd "$(git rev-parse --show-toplevel || printf '.\n')"
                    git pull --ff > /dev/null 2>&1
                    git add .
                    git commit --all -m "checkpoint" > /dev/null 2>&1
                    git push > /dev/null 2>&1
                    printf '%s: done.\n' "$proj" | sed "s@^$HOME@~@"
                )
            done
        fi
        ;;
    s) 
		quit_when_no_repos
		list_repos | xargs -I{} gt-st {} ;;
	l) 
		quit_when_no_repos
		list_repos ;;
	e) $EDITOR "$REPOS" ;;
	f) REPOS="$OPTARG" ;;
	u)
		quit_when_no_repos
		>&2 printf 'pull:\n'
		if [ "$parallel" ]; then
			list_repos | parallel gt-cmd {} pull  
		else
			list_repos | xargs -I{} gt-cmd {} pull
		fi

		>&2 printf 'push:\n'
		list_repos |
			xargs -I{} gt-st {} |
			awk -F: '/↑/ {print $1}' |
			sed "s@^~@$HOME@" |
			if [ "$parallel" ]; then
				parallel gt-cmd {} push
			else
				xargs -I{} gt-cmd {} push
			fi
		;;
	h) help ;;
	:)
		>&2 printf -- '-%s requires argument\n' "$OPTARG"
		exit 1
		;;
	?)
		>&2 printf -- 'Invalid option: -%s\n' "$OPTARG"
		exit 1
		;;
	esac
done