/* PCU Interface codec poart in TTCN-3
 * (C) 2018 Harald Welte <laforge@gnumonks.org>
 * contributions by sysmocom - s.f.m.c. GmbH
 * All rights reserved.
 *
 * Released under the terms of GNU General Public License, Version 2 or
 * (at your option) any later version.
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

module PCUIF_CodecPort {

import from Osmocom_Types all;
import from PCUIF_Types all;
import from UD_PortType all;
import from UD_Types all;

type record PCUIF_send_data {
	PCUIF_Message	data,
	integer		id
};

private function PCUIF_to_UD(in PCUIF_send_data pin, out UD_send_data pout) {
	pout.id := pin.id;
	pout.data := enc_PCUIF_Message(pin.data);
} with { extension "prototype(fast)" };

private function fix_padding(inout PCUIF_data data) {
	data.data := substr(data.data, 0, data.len);
}

private function UD_to_PCUIF(in UD_send_data pin, out PCUIF_send_data pout) {
	pout.id := pin.id;
	pout.data := dec_PCUIF_Message(pin.data);

	/* HACK: fix padding in decoded message. Due to a bug in TITAN, we
	 * cannot just use its 'PADDING' attribute because it breaks decoding. */
	if (ischosen(pout.data.u.data_req)) { fix_padding(pout.data.u.data_req); }
	if (ischosen(pout.data.u.data_cnf)) { fix_padding(pout.data.u.data_cnf); }
	if (ischosen(pout.data.u.data_ind)) { fix_padding(pout.data.u.data_ind); }
} with { extension "prototype(fast)" };

type port PCUIF_CODEC_PT message {
	out	UD_close, UD_listen, UD_shutdown, UD_connect, PCUIF_send_data;
	in	UD_listen_result, UD_connect_result, UD_connected, PCUIF_send_data;
} with { extension "user UD_PT
	out (
		UD_close -> UD_close:simple;
		UD_listen -> UD_listen:simple;
		UD_shutdown -> UD_shutdown:simple;
		UD_connect -> UD_connect:simple;
		PCUIF_send_data -> UD_send_data: function(PCUIF_to_UD)
		)
	in (
		UD_listen_result -> UD_listen_result:simple;
		UD_connect_result -> UD_connect_result:simple;
		UD_send_data -> PCUIF_send_data: function(UD_to_PCUIF);
		UD_connected -> UD_connected:simple
		)"
};

template PCUIF_send_data t_SD_PCUIF(integer id, template PCUIF_Message pdu) := {
	data := pdu,
	id := id
}

template PCUIF_send_data t_SD_PCUIF_MSGT(integer id, template PCUIF_MsgType msg_type,
					 template uint8_t bts_nr := ?) := {
	data := {
		msg_type := msg_type,
		bts_nr := bts_nr,
		spare := ?,
		u := ?
	},
	id := id
}

function f_pcuif_connect(PCUIF_CODEC_PT pt, charstring sock) return integer {
	var UD_connect_result res;
	timer T := 5.0;

	T.start;
	pt.send(UD_connect:{sock, -1});
	alt {
	[] pt.receive(UD_connect_result:?) -> value res {
		if (ispresent(res.result) and ispresent(res.result.result_code) and
		    res.result.result_code == ERROR) {
			if (ispresent(res.result.err)) {
				setverdict(fail, "Error connecting to PCU socket ", sock, ": ", res.result.err);
			} else {
				setverdict(fail, "Error connecting to PCU socket ", sock);
			}
			mtc.stop;
		} else {
			return res.id;
		}
		}
	[] T.timeout {
		setverdict(fail, "Timeout connecting to PCU socket ", sock);
		mtc.stop;
		}
	}
	return -23;
}

function f_pcuif_close(PCUIF_CODEC_PT pt, integer id)
{
	pt.send(UD_close:{id := id});
}

function f_pcuif_listen(PCUIF_CODEC_PT pt, charstring sock) return integer {
	var UD_listen_result res;
	var UD_connected udc;
	timer T := 5.0;

	pt.send(UD_listen:{sock});
	T.start;
	alt {
	[] pt.receive(UD_listen_result:?) -> value res {
		if (ispresent(res.result) and ispresent (res.result.result_code) and
		    res.result.result_code == ERROR) {
			if (ispresent(res.result.err)) {
				setverdict(fail, "Error listening on PCU socket ", sock, ": ", res.result.err);
			} else {
				setverdict(fail, "Error listening on PCU socket ", sock);
			}
			mtc.stop;
		} else {
			return res.id;
		}
		}
	[] T.timeout {
		setverdict(fail, "Timeout waiting for PCU socket ", sock, " connection");
		mtc.stop;
		}
	}
	return -23;
}

function f_PCUIF_tx_imm_ass_pch(PCUIF_CODEC_PT pt, integer conn_id, octetstring imm_ass, hexstring imsi,
				uint8_t bts_nr := 0, boolean wait_for_cnf := true) return uint32_t {
	var PCUIF_send_data sd;
	timer T := 3.0;
	/* append 3 last imsi digits so BTS can compute pagng group */
	var hexstring last_digits := substr(imsi, lengthof(imsi)-3, 3);
	var octetstring prefix := ''O;
	log("3 last imsi digits: ", last_digits);
	for (var integer i := 0; i < 3; i := i+1) {
		prefix := prefix & int2oct(hex2int('30'H) + hex2int(last_digits[i]), 1);
	}
	pt.send(t_SD_PCUIF(conn_id,
			ts_PCUIF_DATA_REQ(bts_nr, 0, 0, 0, 0, PCU_IF_SAPI_PCH, prefix & imm_ass)));

	/* Exit early when the caller is not interested in the confirmation message */
	if (wait_for_cnf == false) {
		return 0;
	}

	T.start;
	alt {
	[] pt.receive(t_SD_PCUIF(conn_id,
				tr_PCUIF_DATA_CNF(bts_nr, 0, 0, PCU_IF_SAPI_PCH))) -> value sd {
		log("IMM.ASS was sent on fn ", sd.data.u.data_cnf.fn);
		return sd.data.u.data_cnf.fn;
		}
	[] pt.receive { repeat; }
	[] T.timeout {
		setverdict(fail, "Timeout waiting for PCU DATA.cnf");
		mtc.stop;
		}
	}
	return 0;
}


}