#!/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
			$cmd rm "$base/bin/$prog"
		fi
		$cmd ln "$base/lib/lib.$prog.so" "$base/bin/$prog"
	done

	$cmd --install $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
				$cmd rm "$base/$link"
			fi
			$cmd ln "$base/bin/$prog" "$base/$link"
		done
		$cmd rm "$base/links/$prog"
	done

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

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

install () {
	if $cmd test ! -e "$base/git-annex"; then
		if ! $cmd mkdir -p "$HOME"; then
			$cmd echo "mkdir of $HOME failed!"
		fi
		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 () {
	# As good a start point as any.
	cd "$HOME"

	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.
	# This needs to be as short a path as possible.
	GIT_ANNEX_TMP_DIR=$base/tmp
	export GIT_ANNEX_TMP_DIR
	
	if $cmd test "$1"; then
		cmd="$1"
		shift 1
		exec "$cmd" "$@"
	else
		$cmd sh
	fi
}

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