//
// Copyright 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 "../../transport/super_recv_packet_handler.hpp"
#include "b100_ctrl.hpp"
#include "b100_impl.hpp"
#include <uhd/transport/usb_zero_copy.hpp>
#include <uhd/transport/zero_copy.hpp>
#include <uhd/transport/vrt_if_packet.hpp>
#include <uhd/utils/thread_priority.hpp>
#include <uhd/utils/msg.hpp>
#include <uhd/types/metadata.hpp>
#include <uhd/types/serial.hpp>
#include "ctrl_packet.hpp"
#include <boost/thread.hpp>
#include <uhd/exception.hpp>

using namespace uhd::transport;
using namespace uhd;

bool b100_ctrl_debug = false;

class b100_ctrl_impl : public b100_ctrl {
public:
    b100_ctrl_impl(uhd::transport::usb_zero_copy::sptr ctrl_transport) : 
        sync_ctrl_fifo(2),
        async_msg_fifo(100),
        _ctrl_transport(ctrl_transport),
        _seq(0)
    {
        boost::barrier spawn_barrier(2);
        viking_marauders.create_thread(boost::bind(&b100_ctrl_impl::viking_marauder_loop, this, boost::ref(spawn_barrier)));
        spawn_barrier.wait();
    }
    
    int write(boost::uint32_t addr, const ctrl_data_t &data);
    ctrl_data_t read(boost::uint32_t addr, size_t len);
    
    ~b100_ctrl_impl(void) {
        viking_marauders.interrupt_all();
        viking_marauders.join_all();
    }
    
    bool get_ctrl_data(ctrl_data_t &pkt_data, double timeout);
    bool recv_async_msg(uhd::async_metadata_t &async_metadata, double timeout);
    
private:
    int send_pkt(boost::uint16_t *cmd);
    
    //änd hërë wë gö ä-Vïkïng för äsynchronous control packets
    void viking_marauder_loop(boost::barrier &);
    bounded_buffer<ctrl_data_t> sync_ctrl_fifo;
    bounded_buffer<async_metadata_t> async_msg_fifo;
    boost::thread_group viking_marauders;
    
    uhd::transport::usb_zero_copy::sptr _ctrl_transport;
    boost::uint8_t _seq;
};

/***********************************************************************
 * helper functions for packing/unpacking control packets
 **********************************************************************/
void pack_ctrl_pkt(boost::uint16_t *pkt_buff,
                          const ctrl_pkt_t &pkt){
    //first two bits are OP
    //next six bits are CALLBACKS
    //next 8 bits are SEQUENCE
    //next 16 bits are LENGTH (16-bit word)
    //next 32 bits are ADDRESS (16-bit word LSW)
    //then DATA (28 16-bit words)
    pkt_buff[0] = (boost::uint16_t(pkt.pkt_meta.op) << 14) | (boost::uint16_t(pkt.pkt_meta.callbacks) << 8) | pkt.pkt_meta.seq;
    pkt_buff[1] = pkt.pkt_meta.len;
    pkt_buff[2] = (pkt.pkt_meta.addr & 0x00000FFF);
    pkt_buff[3] = 0x0000; //address high bits always 0 on this device
    
    for(size_t i = 0; i < pkt.data.size(); i++) {
        pkt_buff[4+i] = pkt.data[i];
    }
}

void unpack_ctrl_pkt(const boost::uint16_t *pkt_buff,
                            ctrl_pkt_t &pkt){
    pkt.pkt_meta.seq = pkt_buff[0] & 0xFF;
    pkt.pkt_meta.op = CTRL_PKT_OP_READ; //really this is useless
    pkt.pkt_meta.len = pkt_buff[1];
    pkt.pkt_meta.callbacks = 0; //callbacks aren't implemented yet
    pkt.pkt_meta.addr = pkt_buff[2] | boost::uint32_t(pkt_buff[3] << 16);
    
    //let's check this so we don't go pushing 64K of crap onto the pkt
    if(pkt.pkt_meta.len > CTRL_PACKET_DATA_LENGTH) {
        throw uhd::runtime_error("Received control packet too long");
    }

    for(int i = 4; i < 4+pkt.pkt_meta.len; i++) pkt.data.push_back(pkt_buff[i]);
}

int b100_ctrl_impl::send_pkt(boost::uint16_t *cmd) {
    managed_send_buffer::sptr sbuf = _ctrl_transport->get_send_buff();
    if(!sbuf.get()) {
        throw uhd::runtime_error("Control channel send error");
    }
        
    //FIXME there's a better way to do this
    for(size_t i = 0; i < (CTRL_PACKET_LENGTH / sizeof(boost::uint16_t)); i++) {
        sbuf->cast<boost::uint16_t *>()[i] = cmd[i];
    }
    sbuf->commit(CTRL_PACKET_LENGTH); //fixed size transaction
    return 0;
}

int b100_ctrl_impl::write(boost::uint32_t addr, const ctrl_data_t &data) {
    UHD_ASSERT_THROW(data.size() <= (CTRL_PACKET_DATA_LENGTH / sizeof(boost::uint16_t)));
    ctrl_pkt_t pkt;
    pkt.data = data;
    pkt.pkt_meta.op = CTRL_PKT_OP_WRITE;
    pkt.pkt_meta.callbacks = 0;
    pkt.pkt_meta.seq = _seq++;
    pkt.pkt_meta.len = pkt.data.size();
    pkt.pkt_meta.addr = addr;
    boost::uint16_t pkt_buff[CTRL_PACKET_LENGTH / sizeof(boost::uint16_t)];
        
    pack_ctrl_pkt(pkt_buff, pkt);
    size_t result = send_pkt(pkt_buff);
    return result;
}

ctrl_data_t b100_ctrl_impl::read(boost::uint32_t addr, size_t len) {
    UHD_ASSERT_THROW(len <= (CTRL_PACKET_DATA_LENGTH / sizeof(boost::uint16_t)));

    ctrl_pkt_t pkt;
    pkt.pkt_meta.op = CTRL_PKT_OP_READ;
    pkt.pkt_meta.callbacks = 0;
    pkt.pkt_meta.seq = _seq++;
    pkt.pkt_meta.len = len;
    pkt.pkt_meta.addr = addr;
    boost::uint16_t pkt_buff[CTRL_PACKET_LENGTH / sizeof(boost::uint16_t)];

    pack_ctrl_pkt(pkt_buff, pkt);
    send_pkt(pkt_buff);
    
    //loop around waiting for the response to appear
    while(!get_ctrl_data(pkt.data, 0.05));

    return pkt.data;
}

/***********************************************************************
 * Viking marauders go pillaging for asynchronous control packets in the
 * control response endpoint. Sync packets go in sync_ctrl_fifo,
 * async TX error messages go in async_msg_fifo. sync_ctrl_fifo should
 * never have more than 1 message in it, since it's expected that we'll
 * wait for a control operation to finish before starting another one.
 **********************************************************************/
void b100_ctrl_impl::viking_marauder_loop(boost::barrier &spawn_barrier) {
    spawn_barrier.wait();
    set_thread_priority_safe();
    
    while (not boost::this_thread::interruption_requested()){
        managed_recv_buffer::sptr rbuf = _ctrl_transport->get_recv_buff();
        if(!rbuf.get()) continue; //that's ok, there are plenty of villages to pillage!
        const boost::uint16_t *pkt_buf = rbuf->cast<const boost::uint16_t *>();
        
        if(pkt_buf[0] >> 8 == CTRL_PACKET_HEADER_MAGIC) {
            //so it's got a control packet header, let's parse it.
            ctrl_pkt_t pkt;
            unpack_ctrl_pkt(pkt_buf, pkt);
        
            if(pkt.pkt_meta.seq != boost::uint8_t(_seq - 1)) {
                throw uhd::runtime_error("Sequence error on control channel");
            }
            if(pkt.pkt_meta.len > (CTRL_PACKET_LENGTH - CTRL_PACKET_HEADER_LENGTH)) {
                throw uhd::runtime_error("Control channel packet length too long");
            }
        
            //push it onto the queue
            sync_ctrl_fifo.push_with_wait(pkt.data);
        } else { //it's an async status pkt
            //extract the vrt header packet info
            vrt::if_packet_info_t if_packet_info;
            if_packet_info.num_packet_words32 = rbuf->size()/sizeof(boost::uint32_t);
            const boost::uint32_t *vrt_hdr = rbuf->cast<const boost::uint32_t *>();
            vrt::if_hdr_unpack_le(vrt_hdr, if_packet_info);
            
            if(    if_packet_info.sid == B100_ASYNC_SID
               and if_packet_info.packet_type != vrt::if_packet_info_t::PACKET_TYPE_DATA){
                //fill in the async metadata
                async_metadata_t metadata;
                metadata.channel = 0;
                metadata.has_time_spec = if_packet_info.has_tsi and if_packet_info.has_tsf;
                metadata.time_spec = time_spec_t(
                    time_t(if_packet_info.tsi), size_t(if_packet_info.tsf), 64e6 //FIXME get from clock_ctrl
                );
                metadata.event_code = async_metadata_t::event_code_t(sph::get_context_code(vrt_hdr, if_packet_info));
                async_msg_fifo.push_with_pop_on_full(metadata);
                if (metadata.event_code &
                    ( async_metadata_t::EVENT_CODE_UNDERFLOW 
                    | async_metadata_t::EVENT_CODE_UNDERFLOW_IN_PACKET)
                ) UHD_MSG(fastpath) << "U";
                else if (metadata.event_code &
                    ( async_metadata_t::EVENT_CODE_SEQ_ERROR
                    | async_metadata_t::EVENT_CODE_SEQ_ERROR_IN_BURST)
                ) UHD_MSG(fastpath) << "S";
                continue;
            }
            UHD_MSG(error) << "Control: unknown async response" << std::endl;
        }
    }
}

bool b100_ctrl_impl::get_ctrl_data(ctrl_data_t &pkt_data, double timeout){
    boost::this_thread::disable_interruption di; //disable because the wait can throw
    return sync_ctrl_fifo.pop_with_timed_wait(pkt_data, timeout);
}

bool b100_ctrl_impl::recv_async_msg(uhd::async_metadata_t &async_metadata, double timeout) {
    boost::this_thread::disable_interruption di; //disable because the wait can throw
    return async_msg_fifo.pop_with_timed_wait(async_metadata, timeout);
}

/***********************************************************************
 * Public make function for b100_ctrl interface
 **********************************************************************/
b100_ctrl::sptr b100_ctrl::make(uhd::transport::usb_zero_copy::sptr ctrl_transport){
    return sptr(new b100_ctrl_impl(ctrl_transport));
}