#!/bin/sh

# MM Shell bot
# By 0xDEADCADE

# Config
MM="${HOME}/go/bin/mm"
MMDIR="mm"
CMDDIR="bin"
HOMESERVER="https://matrix.example.org"
USERNAME="user"
MMCONF="${PWD}/mm.yml"
PREFIX="\\"
TIMEOUT=60
# Ensure access to ADMIN env var to subprocesses
export ADMIN="@deadcade:deadca.de"

# Create mm directory
mkdir -p "${MMDIR}"
# Ensure real paths instead of relative
MMDIR=$(readlink -nf "${MMDIR}")
CMDDIR=$(readlink -nf "${CMDDIR}")

# Generate mm config
if [ ! -f "${MMCONF}" ]; then
	# No config was found, create a new one
	PASSWORD=$(pass "${HOMESERVER}/${USERNAME}")
	echo "server: ${HOMESERVER}
username: ${USERNAME}
password: ${PASSWORD}
certificate: ''
directory: ${MMDIR}
login:
  userid: ''
  deviceid: ''
  accesstoken: ''
" > "${MMCONF}"
	unset PASSWORD
fi

# Start mm
cd "${MMDIR}" || exit
$MM -c "${MMCONF}" 2>> "${MMDIR}/log" 1>> "${MMDIR}/out" &
MMPID="${!}"

# Ensure mm is started
sleep 3

# Remove password from file (otherwise password would be stored in plaintext)
grep -vF "password" "${MMCONF}" > /tmp/mm.yml
cp /tmp/mm.yml "${MMCONF}"
rm /tmp/mm.yml

# Get some variables from created config
HOMESERVER=$(echo "${HOMESERVER}" | cut -d "/" -f 3)
USERID=$(grep "userid" "${MMCONF}" | awk '{ print $2 }' | cut -d "'" -f 2)

# Ensure log in was successful
cd "${MMDIR}/${HOMESERVER}/${USERID}" || exit

# Separate function to execute the command, for async support
execute() {
	CMD=$1
	# Grab args without command
    ARGS=$(printf '%s' "$MESSAGE" | tail -c"+$((${#PREFIX} + ${#CMD} + 2))")
    # Execute command, keeping every Matrix command argument as a shell command argument
    # shellcheck disable=SC2086
    OUT=$(timeout "$((TIMEOUT + 5))" timeout -s INT "${TIMEOUT}" "${CMDDIR}/${CMD}" ${ARGS} 2>&1)
    if [ "$OUT" != "" ]; then
	    # Send back output
		printf '%s' "${OUT}" > "${INFILE}"
	fi
}

# Process a message
message() {
    while read -r MSG; do
    	cd "${MMDIR}/${HOMESERVER}/${USERID}" || exit
    	# Give detail about message to subprocess
        FILE="!"$(echo "${MSG}" | cut -d "!" -f 2)
		MESSAGE=$(cat "${FILE}")
        ROOMID=$(echo "${FILE}" | cut -d "/" -f 1)
        SENDER=$(echo "${FILE}" | cut -d "/" -f 2)
        INFILE="${MMDIR}/${HOMESERVER}/${USERID}/${ROOMID}/in"
        export FILE MESSAGE ROOMID SENDER INFILE
        # If this message is a command
        case "${MESSAGE}" in
        	"${PREFIX}"*)
        		cd "${CMDDIR}" || exit
        		for CMD in *; do
        			# Check if the command is valid, either with args or exact
        			if [ "${MESSAGE}" = "${PREFIX}${CMD}" ]; then
        				execute "${CMD}" &
					fi
					case "${MESSAGE}" in
						"${PREFIX}${CMD} "*)
							execute "${CMD}" &
						;;
					esac
        		done
        esac
    done
}

# Ensure ctrl+c continues the script
trap true INT

# Give new messages to message function
tail -n0 -f "${MMDIR}/out" | message

# Kill the mm instance after ctrl+c
kill "${MMPID}"