#!/usr/bin/env bash

set -euo pipefail
# uncomment to see all execution
#set -x

echo "creating necessary erllambda run dirs"
export RUN_DIR="/tmp/erllambda_rundir"
export VAR_DIR=${RUN_DIR}
$(mkdir -p "${RUN_DIR}/cachefs")
$(mkdir -p "${RUN_DIR}/checkpointfs")
$(mkdir -p "${RUN_DIR}/tmpfs")
$(mkdir -p "${RUN_DIR}/ramfs")

echo "OpenSSL is $(openssl version)"
# ciphers=$(openssl ciphers 'ALL:eNULL' | sed -e 's/:/ /g')
# echo "OpenSSL cyphers are $ciphers"

echo "starting ErlangVM"

SCRIPT=$(readlink $0 || true)
if [ -z $SCRIPT ]; then
    SCRIPT=$0
fi;
SCRIPT_DIR="$(cd `dirname "$SCRIPT"` && pwd -P)"
RELEASE_ROOT_DIR="$(cd "$SCRIPT_DIR/.." && pwd -P)"
REL_DIRS=(${RELEASE_ROOT_DIR}/releases/[0-9]*)
REL_DIR=${REL_DIRS[-1]}
ERTS_DIR=(${RELEASE_ROOT_DIR}/erts-*)
ERTS_LIB_DIR="${ERTS_DIR}/lib"
export NATIVELIB_DIR=${ERTS_LIB_DIR}
export REL_NAME="$(basename $SCRIPT)"
PROGNAME=appmod;
export ERL_CRASH_DUMP="/dev/null"

replace_os_vars() {
    awk '{
        while(match($0,"[$]{[^}]*}")) {
            var=substr($0,RSTART+2,RLENGTH -3)
            gsub("[$]{"var"}",ENVIRON[var])
        }
    }1' < "$1" > "$2"
}

# perform environment variable substitution into run- files
VMARGS_SRC="${REL_DIR}/vm.args"
VMARGS_PATH="${RUN_DIR}/vm.args"
replace_os_vars ${VMARGS_SRC} ${VMARGS_PATH}
CONFIG_SRC="${REL_DIR}/sys.config"
CONFIG_PATH="${RUN_DIR}/sys.config"
replace_os_vars ${CONFIG_SRC} ${CONFIG_PATH}

export HOME="$RELEASE_ROOT_DIR"
export ROOTDIR="$RELEASE_ROOT_DIR"
export BINDIR="$ERTS_DIR/bin"
export EMU="beam"
export LD_LIBRARY_PATH="${ERTS_DIR}/lib:${LD_LIBRARY_PATH}"

# Store passed arguments since they will be erased by `set`
ARGS="$@"

set -- "$ERTS_DIR/bin/erlexec" -noshell -noinput -Bd \
     -boot "$REL_DIR/$REL_NAME" \
     -mode embedded \
     -boot_var ERTS_LIB_DIR "$ERTS_LIB_DIR" \
     -config "$CONFIG_PATH" \
     -args_file "$VMARGS_PATH"

date '+%T.%6N'
echo "Exec: $@" -- ${1+$ARGS}
echo "Root: $ROOTDIR"
cd $ROOTDIR
exec "$@" -- ${1+$ARGS} 2>&1