#!/system/bin/sh
# This is runs a shell in an environment configured for git-annex.
# Nearly the only command that can be used in here is busybox!
# lib.start.so will run us in the root of our app directory
base=$(./busybox pwd)
cmd=$base/busybox

set -e

prep () {
	# Cannot rely on Android providing a sane HOME
	HOME="/sdcard/git-annex.home"
	export HOME
}

buildtree () {
	$cmd echo "Installation starting to $base"
	$cmd cat "lib/lib.version.so"

	if $cmd test -e "$base/bin"; then
		$cmd mv "$base/bin" "$base/bin.old"
	fi
	$cmd mkdir -p "$base/bin"

	for prog in busybox git-annex git-shell git-upload-pack git gpg rsync ssh ssh-keygen; do
		$cmd echo "installing $prog"
		if $cmd test -e "$base/bin/$prog"; then
			$cmd rm -f "$base/bin/$prog"
		fi
		$cmd ln -s "$base/lib/lib.$prog.so" "$base/bin/$prog"
	done

	$cmd --install -s $base/bin

	$cmd rm -rf "$base/bin.old"

	$cmd tar zxf $base/lib/lib.git.tar.gz.so
	for prog in git git-shell git-upload-pack; do
		for link in $($cmd cat "$base/links/$prog"); do
			$cmd echo "linking $link to $prog"
			if $cmd test -e "$base/$link"; then
				$cmd rm -f "$base/$link"
			fi
			$cmd ln -s "$base/bin/$prog" "$base/$link"
		done
		$cmd rm -f "$base/links/$prog"
	done

	$cmd mkdir -p "$base/templates"
	$cmd mkdir -p "$base/tmp"

	$cmd echo "#!/system/bin/sh" > "$base/runshell"
	$cmd echo "exec $base/lib/lib.start.so" >> "$base/runshell"
	$cmd chmod 755 runshell

	$cmd cat "$base/lib/lib.trustedkeys.so" > "$base/bin/trustedkeys.gpg"
	$cmd cat "$base/lib/lib.version.so" > "$base/installed-version"
	$cmd echo "Installation complete"
}

install () {
	if ! $cmd mkdir -p "$HOME"; then
		$cmd echo "mkdir of $HOME failed!"
	fi
	if $cmd test ! -e "$base/bin/git-annex"; then
		if ! buildtree > $HOME/git-annex-install.log 2>&1; then
			$cmd echo "Installation failed! Please report a bug and attach $HOME/git-annex-install.log"
			$cmd sh
		fi
	elif $cmd test ! -e "$base/installed-version" || ! $cmd cmp "$base/installed-version" "$base/lib/lib.version.so" >/dev/null; then
		if ! buildtree > $HOME/git-annex-install.log 2>&1; then
			$cmd echo "Upgrade failed! Please report a bug and attach $HOME/git-annex-install.log"
		fi
	fi
}

run () {
	PATH="$base/bin:$PATH"
	export PATH
	
	ORIG_GIT_EXEC_PATH="$GIT_EXEC_PATH"
	export ORIG_GIT_EXEC_PATH
	GIT_EXEC_PATH=$base/libexec/git-core
	export GIT_EXEC_PATH
	
	ORIG_GIT_TEMPLATE_DIR="$GIT_TEMPLATE_DIR"
	export ORIG_GIT_TEMPLATE_DIR
	GIT_TEMPLATE_DIR="$base/templates"
	export GIT_TEMPLATE_DIR

	# Indicate which variables were exported above.
	GIT_ANNEX_STANDLONE_ENV="GIT_EXEC_PATH GIT_TEMPLATE_DIR"
	export GIT_ANNEX_STANDLONE_ENV
	
	# This is a temporary directory on a non-crippled filesystem.
	# Needs to be as short a path as possible, for ssh sockets.
	GIT_ANNEX_TMP_DIR=$base/tmp
	export GIT_ANNEX_TMP_DIR
	# /tmp probably doesn't exist, so also use it as TMPDIR
	TMPDIR=$GIT_ANNEX_TMP_DIR
	export TMPDIR

	if $cmd test ! -e "$HOME/.gitconfig"; then
		git config --global user.email "git-annex@android"
		git config --global user.name "android"
	fi

	if $cmd test "$1"; then
		cmd="$1"
		shift 1
		exec "$cmd" "$@"
	else
		# As good a start point as any.
		cd "$HOME"

		/system/bin/sh
	fi
}

if $cmd test -n "$MKFIFO"; then
	# because java is insane
	$cmd mkfifo "$MKFIFO"
else
	if ! prep; then
		$cmd echo "prep failed. Please report a bug."
		read line
	fi
	if ! install; then
		$cmd echo "install failed. Please report a bug."
		read line
	fi
	run
fi