// Copyright (2019-2022) Paul Scherrer Institute
// SPDX-License-Identifier: CERN-OHL-S-2.0 or GPL-3.0-or-later

#include "hls_jfjoch.h"

void sls_detector(AXI_STREAM &udp_payload_in,
                hls::stream<ap_uint<UDP_METADATA_STREAM_WIDTH> > &udp_metadata_in,
                AXI_STREAM &data_out,
                hls::stream<ap_uint<ADDR_STREAM_WIDTH> > &addr_out,
                uint64_t& counter,
                uint32_t& counter_eth_error,
                uint32_t& counter_len_error,
                volatile ap_uint<1> &in_clear_counters) {
#pragma HLS INTERFACE ap_ctrl_none port=return

#pragma HLS INTERFACE axis register both port=udp_payload_in
#pragma HLS INTERFACE axis register both port=data_out
#pragma HLS INTERFACE axis register both port=udp_metadata_in
#pragma HLS INTERFACE axis register both port=addr_out
#pragma HLS INTERFACE ap_vld register port=counter
#pragma HLS INTERFACE ap_vld register port=counter_eth_error
#pragma HLS INTERFACE ap_vld register port=counter_len_error
#pragma HLS INTERFACE ap_none register port=in_clear_counters

#pragma HLS pipeline II=1 style=flp

    enum   sls_detector_state {INSPECT_HEADER, FORWARD, DISCARD};
    static sls_detector_state state = INSPECT_HEADER;

    static ap_uint<128> reminder = 0;
    packet_512_t packet_in;
    packet_512_t packet_out;

    packet_out.user = 0;
    packet_out.dest = 0;
    packet_out.id = 0;

    ap_uint<UDP_METADATA_STREAM_WIDTH> udp_metadata;
    static ap_uint<8> beat_counter;

    static uint64_t internal_counter = 0;
    static uint32_t internal_counter_eth_error = 0;
    static uint32_t internal_counter_len_error = 0;

    ap_uint<1> tmp = in_clear_counters;
    if (tmp) {
        internal_counter = 0;
        internal_counter_len_error = 0;
        internal_counter_eth_error = 0;
    }

#pragma HLS RESET variable=internal_counter
#pragma HLS RESET variable=internal_counter_eth_error
#pragma HLS RESET variable=internal_counter_len_error
#pragma HLS RESET variable=state

    if (udp_payload_in.read_nb(packet_in)) {

        switch (state) {
            case INSPECT_HEADER:
                udp_metadata_in >> udp_metadata;

                if ((udp_metadata_payload_size(udp_metadata) == 8240)
                    && (udp_metadata_eth_err(udp_metadata) == 0)
                    && (udp_metadata_len_err(udp_metadata) == 0)) {

                    ap_uint<8> ipv4_addr_host = udp_metadata_src_ipv4(udp_metadata);

                    ap_uint < 64 > frame_number = packet_in.data(63, 0);
                    ap_uint < 32 > jf_debug = packet_in.data(5 * 64 + 31, 5 * 64);
                    ap_uint < 64 > timestamp = packet_in.data(3 * 64 + 63, 3 * 64);
                    ap_uint < 64 > bunchid = packet_in.data(2 * 64 + 63, 2 * 64);
                    ap_uint < 5 > module = (ipv4_addr_host % 32) / 2;
                    ap_uint < 1 > module_part = ipv4_addr_host[0];
                    ap_uint < 7 > eth_packet = (packet_in.data(127, 96) % 128) | (module_part * 64);

                    beat_counter = 0;
                    reminder = packet_in.data(511, 384);

                    addr_out << addr_packet(eth_packet, module, frame_number, jf_debug, timestamp, bunchid);
                    state = FORWARD;
                    internal_counter++;
                } else {
                    if (udp_metadata_eth_err(udp_metadata))
                        internal_counter_eth_error++;
                    else if (udp_metadata_len_err(udp_metadata))
                        internal_counter_len_error++;
                    state = DISCARD;
                }
                break;
            case FORWARD:
                packet_out.last = (beat_counter == 127);
                packet_out.data = (packet_in.data(383, 0), reminder);
                data_out << packet_out;
                reminder = packet_in.data(511, 384);
                beat_counter++;
                break;
            case DISCARD:
                break;
        }

        if (packet_in.last)
            state = INSPECT_HEADER;
    }

    counter = internal_counter;
    counter_eth_error = internal_counter_eth_error;
    counter_len_error = internal_counter_len_error;
}