#!/usr/bin/env bash
set -e;

# Interesting chars:
# 🛰 - Satellite - looks very cool indeed in Firefox

lantern_path="../lantern-build-engine";
if [[ -z "${do_parallel}" ]]; then
	do_parallel="true";
fi

###############################################################################

# Make sure the current directory is the location of this script to simplify matters
cd "$(dirname "$(readlink -f "$0")")";

# Check out the lantern git submodule if needed
if [ ! -f "${lantern_path}/lantern.sh" ]; then git submodule update --init "${lantern_path}"; fi

#shellcheck disable=SC1090
source "${lantern_path}/lantern.sh";

###############################################################################

if [[ -z "${2}" ]]; then
	echo "Usage:";
	echo "	./execute {{path/to/jobfile}} {{path/to/hostsfile_a}} {{path/to/hostsfile_n}}";
	exit 1;
fi

job_filepath="$1";
if [[ ! -f "${job_filepath}" ]]; then
	job_filepath="jobs/${job_filepath}/${job_filepath}.job";
fi

shift;

hosts="";
while [[ ! -z "${1}" ]]; do
	hosts_filename="${1}";
	if [[ ! -f "${hosts_filename}" ]]; then
		hosts_filename="hosts/${hosts_filename}.txt";
	fi
	
	hosts="$(echo "${hosts}" && cat "${hosts_filename}")";
	shift;
done

ssh_configfile="./ssh-config";

if [[ ! -x "${job_filepath}" ]]; then
	echo -e "${FRED}Error: ${job_filepath} doesn't exist, or is not executable.${RS}" >&2;
	exit 1;
fi

log_msg() {
	echo -e "[ $(date -u +"%Y-%m-%dT%H:%M:%SZ") ] $*" >&2;
}

# $1	Command to execute
RUN_ONCE() {
	command="${1}";
	hash="$(echo "${command}" | sha256sum | cut -d- -f1)";
	
	if [[ -z "${EXECUTE_HOSTNAME}" ]]; then
		task_end 1 "Oops! The hostname to execute on wasn't found. This is probably a bug.";
	fi
	
	log_msg "️🛡️ ${HC}[ ${EXECUTE_HOSTNAME} ]${RS} ${FBLE}RUN_ONCE${RS} ${command}";
	
	if [[ "${INTERACTIVE}" == "true" ]]; then
		echo "Enabling interactive mode";
		SSH_FLAGS="-t ";
	fi
	
	echo "
if [[ ! -d /etc/remote-exec ]]; then sudo mkdir /etc/remote-exec; fi
if [[ ! -f /etc/remote-exec/${hash} ]]; then
	echo \"[ \${HOSTNAME} ] [ \$(date -u +\"%Y-%m-%dT%H:%M:%SZ\") ] Executing once\"
	${command}
	sudo touch /etc/remote-exec/${hash};
fi
" | ssh ${SSH_FLAGS} -F "${ssh_configfile}" "${EXECUTE_HOSTNAME}" bash;
	
}

# $1	Command to execute
RUN() {
	command="${1}";
	
	if [[ -z "${EXECUTE_HOSTNAME}" ]]; then
		task_end 1 "Oops! The hostname to execute on wasn't found. This is probably a bug.";
	fi
	
	log_msg "🚏 ${HC}[ ${EXECUTE_HOSTNAME} ]${RS} ${FBLE}RUN${RS} ${command}";
	
	if [[ "${INTERACTIVE}" == "true" ]]; then
		echo "Enabling interactive mode";
		SSH_FLAGS="-t ";
	fi
		
	echo "${command}" | ssh ${SSH_FLAGS} -F "${ssh_configfile}" "${EXECUTE_HOSTNAME}" bash;
}

# $1	Filepath to script to copy & execute
SCRIPT() {
	script_filepath="${1}";
	
	remote_filepath="/tmp/$(basename ${script_filepath})";
	
	if [[ -z "${EXECUTE_HOSTNAME}" ]]; then
		task_end 1 "Oops! The hostname to execute on wasn't found. This is probably a bug.";
	fi
	
	log_msg "🚂 ${HC}[ ${EXECUTE_HOSTNAME} ]${RS} ${FMAG}SCRIPT${RS} ${command}";
	
	scp -F "${ssh_configfile}" "${script_filepath}" "${EXECUTE_HOSTNAME}:${remote_filepath}";
	echo -e "${remote_filepath}\nrm ${remote_filepath}" | ssh -F "${ssh_configfile}" "${EXECUTE_HOSTNAME}" bash;
	echo ""
}

# $1	The filepath to copy
# $2	The location to copy it to on the remote host
COPY() {
	filepath_local="${1}";
	filepath_remote="${2}";
	
	log_msg "🚚 ${HC}[ ${EXECUTE_HOSTNAME} ]${RS} ${FMAG}COPY${RS} ${filepath_local} → ${filepath_remote}";
	
	if [[ ! -f "${filepath_local}" ]]; then
		task_end 1 "[ ${HC}COPY${RS} ] Error: Couldn't find ${filepath_local} on disk (CWD is ${PWD}).";
	fi
	
	if [[ -z "${EXECUTE_HOSTNAME}" ]]; then
		task_end 1 "[ ${HC}COPY${RS} ] Oops! The hostname to copy to wasn't found. This is probably a bug.";
	fi
	
	
	scp -F "${ssh_configfile}" "${filepath_local}" "${EXECUTE_HOSTNAME}:${filepath_remote}";
}

# $1	job filepath
# $2	hostname
__do_execute() {
	job_filepath="${1}";
	hostname="${2}";
	log_msg "${FBLE}${HC}⌛${RS} Starting on ${HC}${hostname}${RS}";
	
	export EXECUTE_HOSTNAME="${hostname}";
	export JOBFILE_DIR; JOBFILE_DIR="$(dirname "${job_filepath}")";
	
	#shellcheck disable=SC1090
	source "${job_filepath}";
	
	log_msg "${FGRN}${HC}✔${RS} Finished on ${HC}${hostname}${RS}";
}

task_begin "Executing ${job_filepath}";

while read -r hostname; do
	if [[ -z "${hostname}" ]]; then
		continue;
	fi
	
	if [[ "${do_parallel}" == "true" ]]; then
		__do_execute "${job_filepath}" "${hostname}" &
	else
		__do_execute "${job_filepath}" "${hostname}";
	fi
done < <(echo "${hosts}");

wait