#!/usr/bin/env bash

installGo() {
	echo "Fetching latest tags from github"
	local tags=$(curl -s https://github.com/golang/go/tags | awk '/golang\/go\/releases\/tag/{print $7}' FS='["/]')

	local latest=""

	if [[ ${tags} = "" ]]; then
		echo "Could not fetch the tags"
		return 2
	fi

	echo "Fetched the latest tags, deciding which one to use..."

	for tag in ${tags}[@]; do
		tag=${tag//go}
		if [[ ${tag} = *"rc"* ]]; then
		  continue
		elif [[ ${tag} = *"beta"* ]]; then
		  continue
		elif [[ ${tag} = *"alpha"* ]]; then
		  continue
		fi

		echo "Found the latest tag: ${tag}"
		latest=${tag}

		break
	done

	if [[ "${latest}" = "" ]]; then
		__err "Could not fetch the latest release"
		return 2
	fi

	echo "Downloading golang ${latest}"
	sudo curl -L --output "go.tar.gz" "https://storage.googleapis.com/golang/go${latest}.linux-amd64.tar.gz"

	echo "Installing golang in /usr/local/go"
	sudo tar -C /usr/local -xzf "go.tar.gz"

	[[ ! -e /usr/local/go/bin ]] && echo "Did not install go properly" && return 137

	grep -q /usr/local/go/bin ~/.bashrc

	if [[ $? -ne 0 ]]; then
		echo "Adding PATH export to .bashrc to include golang binary location"
		echo "export PATH=\$PATH:/usr/local/go/bin" | tee -a ~/.bashrc
	fi

	echo "Removing the downloaded file"
	sudo rm -f "go.tar.gz"

	return 0
}

installRelay() {
	echo "Fetching the docker relay from github"
	/usr/local/go/bin/go get -d github.com/jstarks/npiperelay
	[[ $? -ne 0 ]] && echo "Could not fetch the relay" && return 137

	echo "Building the relay for windows"
	export GOOS=windows
	/usr/local/go/bin/go build -o /mnt/c/Users/${USER}/go/bin/npiperelay.exe github.com/jstarks/npiperelay
	[[ $? -ne 0 ]] && echo "Could not build the binary" && return 137

	echo "Linking the relay binary"
	sudo ln -s /mnt/c/Users/${USER}/go/bin/npiperelay.exe /usr/local/bin/npiperelay.exe
	[[ $? -ne 0 ]] && echo "Could not link the binary" && return 137

	echo "Installing socat and docker.io"
	sudo apt update
	sudo apt install -y socat docker.io
	[[ $? -ne 0 ]] && echo "Could not install the requirements" && return 137

	return 0
}

addStartupScript() {
	echo "Creating the docker relay startup script"
	local relayLocation=~/.docker-relay

	touch "${relayLocation}"
	chmod +x "${relayLocation}"

	cat << "EOF" | tee -a "${relayLocation}" > /dev/null
#!/usr/bin/env bash

isRelayRunning() {
	[[ $(ps aux | grep -v grep | grep "socat UNIX-LISTEN:/var/run/docker.sock,fork,group=docker,umask=007 EXEC" | wc -l) -eq 0 ]] && return 0

	return 1
}

isRelayRunning
RUNNING=$?

if [[ ${RUNNING} -eq 0 ]]; then
	echo "Starting docker relay"
	sudo ls > /dev/null
	exec sudo socat UNIX-LISTEN:/var/run/docker.sock,fork,group=docker,umask=007 EXEC:"npiperelay.exe -ep -s //./pipe/docker_engine",nofork &
fi

RETRIES=20
until [[ ${RUNNING} -eq 1 ]] || [[ ${RETRIES} -eq 0 ]]; do
	isRelayRunning
	RUNNING=$?
	sleep 1
	RETRIES=$((RETRIES-1))
done

if [[ ${RUNNING} -ne 1 ]] && [[ ${RETRIES} -eq 0 ]]; then
	echo "Could not initialize the docker relay!"
	echo "Exiting..."
	exit 137
fi

exit 0
EOF

	echo "Aliasing docker to run the relay script first in ~/.bash_aliases"

	cat << EOF | tee -a ~/.bash_aliases > /dev/null
alias docker="${relayLocation} && docker"
EOF

	echo "Done, try running 'docker ps'"
	return 0
}

createRelay() {
	installGo
	[[ $? -ne 0 ]] && echo "Could not install Go" && return 137

	installRelay
	[[ $? -ne 0 ]] && echo "Could not install relay" && return 137

	addStartupScript
	[[ $? -ne 0 ]] && echo "Could not add the startup script" && return 137

	return 0
}


[[ ${1} = "" ]] && createRelay || "$@"

exit $?