//
// Copyright 2010-2011 Ettus Research LLC
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.
//

#include "usrp2_impl.hpp"
#include "fw_common.h"
#include <uhd/utils/log.hpp>
#include <uhd/utils/msg.hpp>
#include <uhd/exception.hpp>
#include <uhd/transport/if_addrs.hpp>
#include <uhd/transport/udp_zero_copy.hpp>
#include <uhd/usrp/device_props.hpp>
#include <uhd/exception.hpp>
#include <uhd/utils/static.hpp>
#include <uhd/utils/byteswap.hpp>
#include <boost/assign/list_of.hpp>
#include <boost/format.hpp>
#include <boost/foreach.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/bind.hpp>
#include <boost/asio/ip/address_v4.hpp>
#include <boost/asio.hpp> //used for htonl and ntohl
#include <vector>

using namespace uhd;
using namespace uhd::usrp;
using namespace uhd::transport;
namespace asio = boost::asio;

/***********************************************************************
 * Discovery over the udp transport
 **********************************************************************/
static device_addrs_t usrp2_find(const device_addr_t &hint_){
    //handle the multi-device discovery
    device_addrs_t hints = separate_device_addr(hint_);
    if (hints.size() > 1){
        device_addrs_t found_devices;
        BOOST_FOREACH(const device_addr_t &hint_i, hints){
            device_addrs_t found_devices_i = usrp2_find(hint_i);
            if (found_devices_i.size() != 1) throw uhd::value_error(str(boost::format(
                "Could not resolve device hint \"%s\" to a single device."
            ) % hint_i.to_string()));
            found_devices.push_back(found_devices_i[0]);
        }
        return device_addrs_t(1, combine_device_addrs(found_devices));
    }

    //initialize the hint for a single device case
    UHD_ASSERT_THROW(hints.size() <= 1);
    hints.resize(1); //in case it was empty
    device_addr_t hint = hints[0];
    device_addrs_t usrp2_addrs;

    //return an empty list of addresses when type is set to non-usrp2
    if (hint.has_key("type") and hint["type"] != "usrp2") return usrp2_addrs;

    //if no address was specified, send a broadcast on each interface
    if (not hint.has_key("addr")){
        BOOST_FOREACH(const if_addrs_t &if_addrs, get_if_addrs()){
            //avoid the loopback device
            if (if_addrs.inet == asio::ip::address_v4::loopback().to_string()) continue;

            //create a new hint with this broadcast address
            device_addr_t new_hint = hint;
            new_hint["addr"] = if_addrs.bcast;

            //call discover with the new hint and append results
            device_addrs_t new_usrp2_addrs = usrp2_find(new_hint);
            usrp2_addrs.insert(usrp2_addrs.begin(),
                new_usrp2_addrs.begin(), new_usrp2_addrs.end()
            );
        }
        return usrp2_addrs;
    }

    //create a udp transport to communicate
    std::string ctrl_port = boost::lexical_cast<std::string>(USRP2_UDP_CTRL_PORT);
    udp_simple::sptr udp_transport = udp_simple::make_broadcast(
        hint["addr"], ctrl_port
    );

    //send a hello control packet
    usrp2_ctrl_data_t ctrl_data_out;
    ctrl_data_out.proto_ver = uhd::htonx<boost::uint32_t>(USRP2_FW_COMPAT_NUM);
    ctrl_data_out.id = uhd::htonx<boost::uint32_t>(USRP2_CTRL_ID_WAZZUP_BRO);
    udp_transport->send(boost::asio::buffer(&ctrl_data_out, sizeof(ctrl_data_out)));

    //loop and recieve until the timeout
    boost::uint8_t usrp2_ctrl_data_in_mem[udp_simple::mtu]; //allocate max bytes for recv
    const usrp2_ctrl_data_t *ctrl_data_in = reinterpret_cast<const usrp2_ctrl_data_t *>(usrp2_ctrl_data_in_mem);
    while(true){
        size_t len = udp_transport->recv(asio::buffer(usrp2_ctrl_data_in_mem));
        if (len > offsetof(usrp2_ctrl_data_t, data) and ntohl(ctrl_data_in->id) == USRP2_CTRL_ID_WAZZUP_DUDE){

            //make a boost asio ipv4 with the raw addr in host byte order
            boost::asio::ip::address_v4 ip_addr(ntohl(ctrl_data_in->data.ip_addr));
            device_addr_t new_addr;
            new_addr["type"] = "usrp2";
            new_addr["addr"] = ip_addr.to_string();

            //Attempt to read the name from the EEPROM and perform filtering.
            //This operation can throw due to compatibility mismatch.
            try{
                mboard_eeprom_t mb_eeprom = usrp2_iface::make(udp_simple::make_connected(
                    new_addr["addr"], boost::lexical_cast<std::string>(USRP2_UDP_CTRL_PORT)
                ))->mb_eeprom;
                new_addr["name"] = mb_eeprom["name"];
                new_addr["serial"] = mb_eeprom["serial"];
            }
            catch(const std::exception &){
                //set these values as empty string so the device may still be found
                //and the filter's below can still operate on the discovered device
                new_addr["name"] = "";
                new_addr["serial"] = "";
            }

            //filter the discovered device below by matching optional keys
            if (
                (not hint.has_key("name")   or hint["name"]   == new_addr["name"]) and
                (not hint.has_key("serial") or hint["serial"] == new_addr["serial"])
            ){
                usrp2_addrs.push_back(new_addr);
            }

            //dont break here, it will exit the while loop
            //just continue on to the next loop iteration
        }
        if (len == 0) break; //timeout
    }

    return usrp2_addrs;
}

/***********************************************************************
 * Make
 **********************************************************************/
static device::sptr usrp2_make(const device_addr_t &device_addr){
    return device::sptr(new usrp2_impl(device_addr));
}

UHD_STATIC_BLOCK(register_usrp2_device){
    device::register_device(&usrp2_find, &usrp2_make);
}

/***********************************************************************
 * MTU Discovery
 **********************************************************************/
struct mtu_result_t{
    size_t recv_mtu, send_mtu;
};

static mtu_result_t determine_mtu(const std::string &addr, const mtu_result_t &user_mtu){
    udp_simple::sptr udp_sock = udp_simple::make_connected(
        addr, BOOST_STRINGIZE(USRP2_UDP_CTRL_PORT)
    );

    //The FPGA offers 4K buffers, and the user may manually request this.
    //However, multiple simultaneous receives (2DSP slave + 2DSP master),
    //require that buffering to be used internally, and this is a safe setting.
    std::vector<boost::uint8_t> buffer(std::max(user_mtu.recv_mtu, user_mtu.send_mtu));
    usrp2_ctrl_data_t *ctrl_data = reinterpret_cast<usrp2_ctrl_data_t *>(&buffer.front());
    static const double echo_timeout = 0.020; //20 ms

    //test holler - check if its supported in this fw version
    ctrl_data->id = htonl(USRP2_CTRL_ID_HOLLER_AT_ME_BRO);
    ctrl_data->proto_ver = htonl(USRP2_FW_COMPAT_NUM);
    ctrl_data->data.echo_args.len = htonl(sizeof(usrp2_ctrl_data_t));
    udp_sock->send(boost::asio::buffer(buffer, sizeof(usrp2_ctrl_data_t)));
    udp_sock->recv(boost::asio::buffer(buffer), echo_timeout);
    if (ntohl(ctrl_data->id) != USRP2_CTRL_ID_HOLLER_BACK_DUDE)
        throw uhd::not_implemented_error("holler protocol not implemented");

    size_t min_recv_mtu = sizeof(usrp2_ctrl_data_t), max_recv_mtu = user_mtu.recv_mtu;
    size_t min_send_mtu = sizeof(usrp2_ctrl_data_t), max_send_mtu = user_mtu.send_mtu;

    while (min_recv_mtu < max_recv_mtu){

        size_t test_mtu = (max_recv_mtu/2 + min_recv_mtu/2 + 3) & ~3;

        ctrl_data->id = htonl(USRP2_CTRL_ID_HOLLER_AT_ME_BRO);
        ctrl_data->proto_ver = htonl(USRP2_FW_COMPAT_NUM);
        ctrl_data->data.echo_args.len = htonl(test_mtu);
        udp_sock->send(boost::asio::buffer(buffer, sizeof(usrp2_ctrl_data_t)));

        size_t len = udp_sock->recv(boost::asio::buffer(buffer), echo_timeout);

        if (len >= test_mtu) min_recv_mtu = test_mtu;
        else                 max_recv_mtu = test_mtu - 4;

    }

    while (min_send_mtu < max_send_mtu){

        size_t test_mtu = (max_send_mtu/2 + min_send_mtu/2 + 3) & ~3;

        ctrl_data->id = htonl(USRP2_CTRL_ID_HOLLER_AT_ME_BRO);
        ctrl_data->proto_ver = htonl(USRP2_FW_COMPAT_NUM);
        ctrl_data->data.echo_args.len = htonl(sizeof(usrp2_ctrl_data_t));
        udp_sock->send(boost::asio::buffer(buffer, test_mtu));

        size_t len = udp_sock->recv(boost::asio::buffer(buffer), echo_timeout);
        if (len >= sizeof(usrp2_ctrl_data_t)) len = ntohl(ctrl_data->data.echo_args.len);

        if (len >= test_mtu) min_send_mtu = test_mtu;
        else                 max_send_mtu = test_mtu - 4;
    }

    mtu_result_t mtu;
    mtu.recv_mtu = min_recv_mtu;
    mtu.send_mtu = min_send_mtu;
    return mtu;
}

/***********************************************************************
 * Structors
 **********************************************************************/
usrp2_impl::usrp2_impl(const device_addr_t &_device_addr){
    device_addr_t device_addr = _device_addr;

    //setup the dsp transport hints (default to a large recv buff)
    if (not device_addr.has_key("recv_buff_size")){
        #if defined(UHD_PLATFORM_MACOS) || defined(UHD_PLATFORM_BSD)
            //limit buffer resize on macos or it will error
            device_addr["recv_buff_size"] = "1e6";
        #elif defined(UHD_PLATFORM_LINUX) || defined(UHD_PLATFORM_WIN32)
            //set to half-a-second of buffering at max rate
            device_addr["recv_buff_size"] = "50e6";
        #endif
    }

    device_addrs_t device_args = separate_device_addr(device_addr);

    //extract the user's requested MTU size or default
    mtu_result_t user_mtu;
    user_mtu.recv_mtu = size_t(device_addr.cast<double>("recv_frame_size", udp_simple::mtu));
    user_mtu.send_mtu = size_t(device_addr.cast<double>("recv_frame_size", udp_simple::mtu));

    try{
        //calculate the minimum send and recv mtu of all devices
        mtu_result_t mtu = determine_mtu(device_args[0]["addr"], user_mtu);
        for (size_t i = 1; i < device_args.size(); i++){
            mtu_result_t mtu_i = determine_mtu(device_args[i]["addr"], user_mtu);
            mtu.recv_mtu = std::min(mtu.recv_mtu, mtu_i.recv_mtu);
            mtu.send_mtu = std::min(mtu.send_mtu, mtu_i.send_mtu);
        }

        device_addr["recv_frame_size"] = boost::lexical_cast<std::string>(mtu.recv_mtu);
        device_addr["send_frame_size"] = boost::lexical_cast<std::string>(mtu.send_mtu);

        UHD_MSG(status) << boost::format("Current recv frame size: %d bytes") % mtu.recv_mtu << std::endl;
        UHD_MSG(status) << boost::format("Current send frame size: %d bytes") % mtu.send_mtu << std::endl;
    }
    catch(const uhd::not_implemented_error &){
        //just ignore this error, makes older fw work...
    }

    device_args = separate_device_addr(device_addr); //update args for new frame sizes

    //setup rx otw type
    _rx_otw_type.width = 16;
    _rx_otw_type.shift = 0;
    _rx_otw_type.byteorder = uhd::otw_type_t::BO_BIG_ENDIAN;

    //setup tx otw type
    _tx_otw_type.width = 16;
    _tx_otw_type.shift = 0;
    _tx_otw_type.byteorder = uhd::otw_type_t::BO_BIG_ENDIAN;

    //!!!!! set the otw type here before continuing, its used below

    //create a new mboard handler for each control transport
    for(size_t i = 0; i < device_args.size(); i++){
        device_addr_t dev_addr_i = device_args[i];
        BOOST_FOREACH(const std::string &key, device_addr.keys()){
            if (dev_addr_i.has_key(key)) continue;
            dev_addr_i[key] = device_addr[key];
        }
        _mboards.push_back(usrp2_mboard_impl::sptr(
            new usrp2_mboard_impl(dev_addr_i, i, *this)
        ));
        //use an empty name when there is only one mboard
        std::string name = (device_args.size() > 1)? boost::lexical_cast<std::string>(i) : "";
        _mboard_dict[name] = _mboards.back();
    }

    //init the send and recv io
    io_init();

}

usrp2_impl::~usrp2_impl(void){
    /* NOP */
}

/***********************************************************************
 * Device Properties
 **********************************************************************/
void usrp2_impl::get(const wax::obj &key_, wax::obj &val){
    named_prop_t key = named_prop_t::extract(key_);

    //handle the get request conditioned on the key
    switch(key.as<device_prop_t>()){
    case DEVICE_PROP_NAME:
        if (_mboards.size() > 1) val = std::string("USRP2/N Series multi-device");
        else                     val = std::string("USRP2/N Series device");
        return;

    case DEVICE_PROP_MBOARD:
        val = _mboard_dict[key.name]->get_link();
        return;

    case DEVICE_PROP_MBOARD_NAMES:
        val = prop_names_t(_mboard_dict.keys());
        return;

    default: UHD_THROW_PROP_GET_ERROR();
    }
}

void usrp2_impl::set(const wax::obj &, const wax::obj &){
    UHD_THROW_PROP_SET_ERROR();
}