#include <core.p4>
#include <sume_switch.p4>

/********************************************************************************
 * Header
 */

typedef bit<48> EthAddr_t;
header Ethernet_h {
    EthAddr_t dstAddr;
    EthAddr_t srcAddr;
    bit<16> etherType;
}

struct Parsed_packet {
    Ethernet_h ethernet;
}

// user defined metadata: can be used to share information between
// TopParser, TopPipe, and TopDeparser
struct user_metadata_t {
    bit<8>  unused;
}

// digest_data, MUST be 256 bits -- what is this used for?
struct digest_data_t {
    bit<256> unused;
}


/********************************************************************************
 * Parser
 */

@Xilinx_MaxPacketRegion(1024)
parser TopParser(packet_in b,
                 out Parsed_packet p,
                 out user_metadata_t user_metadata,
                 out digest_data_t digest_data,
                 inout sume_metadata_t sume_metadata) {
    state start {
        b.extract(p.ethernet);
        user_metadata.unused = 0;
        digest_data.unused = 0;

        transition accept;
    }
}

/********************************************************************************
 * Main
 */
control TopPipe(inout Parsed_packet p,
                inout user_metadata_t user_metadata,
                inout digest_data_t digest_data,
                inout sume_metadata_t sume_metadata) {

    action swap_eth_addresses() {
        EthAddr_t temp = p.ethernet.dstAddr;
        p.ethernet.dstAddr = p.ethernet.srcAddr;
        p.ethernet.srcAddr = temp;
    }

    action do_nothing() {
        EthAddr_t temp = p.ethernet.dstAddr;
    }

    table lookup_table {
        key = {
            p.ethernet.dstAddr: exact;
        }

        actions = {
            swap_eth_addresses;
            do_nothing;
        }
        size = 64;
        default_action = swap_eth_addresses;
    }

    apply {
        lookup_table.apply();
    }
}

/********************************************************************************
 * Deparser
 */

@Xilinx_MaxPacketRegion(1024)
control TopDeparser(packet_out b,
                    in Parsed_packet p,
                    in user_metadata_t user_metadata,
                    inout digest_data_t digest_data,
                    inout sume_metadata_t sume_metadata) {
    apply {
        b.emit(p.ethernet);
    }
}

/********************************************************************************
 * Switch
 */

SimpleSumeSwitch(
    TopParser(),
    TopPipe(),
    TopDeparser()
) main;