#!/bin/sh

set -e

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)"
export REL_NAME="{{ rel_name }}"
REL_VSN="{{ rel_vsn }}"

# export these to match mix release environment variables
export RELEASE_NAME="{{ rel_name }}"
export RELEASE_VSN="{{ rel_vsn }}"
export RELEASE_PROG="${SCRIPT}"

ERTS_VSN="{{ erts_vsn }}"
REL_DIR="$RELEASE_ROOT_DIR/releases/$REL_VSN"
ERL_OPTS="{{ erl_opts }}"
export ESCRIPT_NAME="${ESCRIPT_NAME-$SCRIPT}"

find_erts_dir() {
    __erts_dir="$RELEASE_ROOT_DIR/erts-$ERTS_VSN"
    if [ -d "$__erts_dir" ]; then
        ERTS_DIR="$__erts_dir";
    else
        __erl="$(command -v erl)"
        code="io:format(\"~s\", [code:root_dir()]), halt()."
        __erl_root="$("$__erl" -boot no_dot_erlang -noshell -eval "$code")"
        ERTS_DIR="$__erl_root/erts-$ERTS_VSN"
    fi
}

find_sys_config() {
    __possible_sys="$REL_DIR/sys.config"
    if [ -f "$__possible_sys" ]; then
        SYS_CONFIG="$__possible_sys"
    else 
       if [ -L "$__possible_sys".orig ]; then
          mv "$__possible_sys".orig "$__possible_sys"  
          SYS_CONFIG="$__possible_sys"
       fi
    fi
}

find_vm_args() {
    __possible_vm_args="$REL_DIR/vm.args"
    if [ -f "$__possible_vm_args" ]; then
        VM_ARGS="$__possible_vm_args"
    else 
       if [ -L "$__possible_vm_args".orig ]; then
          mv "$__possible_vm_args".orig "$__possible_vm_args"  
          VM_ARGS="$__possible_vm_args"
       fi
    fi
}

find_erts_dir
find_sys_config
find_vm_args
export ROOTDIR="$RELEASE_ROOT_DIR"
export BINDIR="$ERTS_DIR/bin"
export EMU="beam"
export PROGNAME="erl"
export LD_LIBRARY_PATH="$ERTS_DIR/lib:$LD_LIBRARY_PATH"
SYSTEM_LIB_DIR="$(dirname "$ERTS_DIR")/lib"
[ -f "$REL_DIR/$REL_NAME.boot" ] && BOOTFILE="$REL_NAME" || BOOTFILE=start
cd "$ROOTDIR"

{{! Define alternative field separator using ASCII US (unit separator). US is
    not expected to appear in any argument. }}
IFS_NORM="$IFS"
IFS_ARGS="$(printf '\x1f')"

# Save extra arguments
{{! Join extra arguments into a US-delimited string. }}
IFS="$IFS_ARGS"
ARGS="$*"
IFS="$IFS_NORM"

# Build arguments for erlexec
set --
[ "$ERL_OPTS" ] && set -- "$@" "$ERL_OPTS"
[ "$SYS_CONFIG" ] && set -- "$@" -config "$SYS_CONFIG"
[ "$VM_ARGS" ] && set -- "$@" -args_file "$VM_ARGS"
set -- "$@" -boot_var SYSTEM_LIB_DIR "$SYSTEM_LIB_DIR" -boot "$REL_DIR/$BOOTFILE"
{{! Split string with extra arguments back into an argument list. }}
IFS="$IFS_ARGS"
# shellcheck disable=SC2086
set -- "$@" $ARGS
IFS="$IFS_NORM"

exec "$BINDIR/erlexec" "$@"