// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-

/*
  Common GCS MAVLink functions for all vehicle types

   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 <GCS.h>
#include <AP_AHRS.h>

extern const AP_HAL::HAL& hal;

GCS_MAVLINK::GCS_MAVLINK() :
    waypoint_receive_timeout(1000)
{
    AP_Param::setup_object_defaults(this, var_info);
}

void
GCS_MAVLINK::init(AP_HAL::UARTDriver *port)
{
    GCS_Class::init(port);
    if (port == (AP_HAL::BetterStream*)hal.uartA) {
        mavlink_comm_0_port = port;
        chan = MAVLINK_COMM_0;
        initialised = true;
    } else if (port == (AP_HAL::BetterStream*)hal.uartC) {
        mavlink_comm_1_port = port;
        chan = MAVLINK_COMM_1;
        initialised = true;
#if MAVLINK_COMM_NUM_BUFFERS > 2
    } else if (port == (AP_HAL::BetterStream*)hal.uartD) {
        mavlink_comm_2_port = port;
        chan = MAVLINK_COMM_2;
        initialised = true;
#endif
    }
    _queued_parameter = NULL;
    reset_cli_timeout();
}


uint16_t
GCS_MAVLINK::_count_parameters()
{
    // if we haven't cached the parameter count yet...
    if (0 == _parameter_count) {
        AP_Param  *vp;
        AP_Param::ParamToken token;

        vp = AP_Param::first(&token, NULL);
        do {
            _parameter_count++;
        } while (NULL != (vp = AP_Param::next_scalar(&token, NULL)));
    }
    return _parameter_count;
}

/**
 * @brief Send the next pending parameter, called from deferred message
 * handling code
 */
void
GCS_MAVLINK::queued_param_send()
{
    if (!initialised || _queued_parameter == NULL) {
        return;
    }

    uint16_t bytes_allowed;
    uint8_t count;
    uint32_t tnow = hal.scheduler->millis();

    // use at most 30% of bandwidth on parameters. The constant 26 is
    // 1/(1000 * 1/8 * 0.001 * 0.3)
    bytes_allowed = 57 * (tnow - _queued_parameter_send_time_ms) * 26;
    if (bytes_allowed > comm_get_txspace(chan)) {
        bytes_allowed = comm_get_txspace(chan);
    }
    count = bytes_allowed / (MAVLINK_MSG_ID_PARAM_VALUE_LEN + MAVLINK_NUM_NON_PAYLOAD_BYTES);

    while (_queued_parameter != NULL && count--) {
        AP_Param      *vp;
        float value;

        // copy the current parameter and prepare to move to the next
        vp = _queued_parameter;

        // if the parameter can be cast to float, report it here and break out of the loop
        value = vp->cast_to_float(_queued_parameter_type);

        char param_name[AP_MAX_NAME_SIZE];
        vp->copy_name_token(_queued_parameter_token, param_name, sizeof(param_name), true);

        mavlink_msg_param_value_send(
            chan,
            param_name,
            value,
            mav_var_type(_queued_parameter_type),
            _queued_parameter_count,
            _queued_parameter_index);

        _queued_parameter = AP_Param::next_scalar(&_queued_parameter_token, &_queued_parameter_type);
        _queued_parameter_index++;
    }
    _queued_parameter_send_time_ms = tnow;
}

/**
 * @brief Send the next pending waypoint, called from deferred message
 * handling code
 */
void
GCS_MAVLINK::queued_waypoint_send()
{
    if (initialised &&
        waypoint_receiving &&
        waypoint_request_i <= waypoint_request_last) {
        mavlink_msg_mission_request_send(
            chan,
            waypoint_dest_sysid,
            waypoint_dest_compid,
            waypoint_request_i);
    }
}

void GCS_MAVLINK::reset_cli_timeout() {
      _cli_timeout = hal.scheduler->millis();
}

void GCS_MAVLINK::send_meminfo(void)
{
#if CONFIG_HAL_BOARD == HAL_BOARD_APM1 || CONFIG_HAL_BOARD == HAL_BOARD_APM2
    extern unsigned __brkval;
#else
    unsigned __brkval = 0;
#endif
    mavlink_msg_meminfo_send(chan, __brkval, hal.util->available_memory());
}

// report power supply status
void GCS_MAVLINK::send_power_status(void)
{
#ifdef CONFIG_ARCH_BOARD_PX4FMU_V2
    mavlink_msg_power_status_send(chan,
                                  hal.analogin->board_voltage() * 1000,
                                  hal.analogin->servorail_voltage() * 1000,
                                  hal.analogin->power_status_flags());
#endif
}

// report AHRS2 state
void GCS_MAVLINK::send_ahrs2(AP_AHRS &ahrs)
{
#if AP_AHRS_NAVEKF_AVAILABLE
    Vector3f euler;
    struct Location loc;
    if (ahrs.get_secondary_attitude(euler) && ahrs.get_secondary_position(loc)) {
        mavlink_msg_ahrs2_send(chan,
                               euler.x,
                               euler.y,
                               euler.z,
                               loc.alt*1.0e-2f,
                               loc.lat,
                               loc.lng);
    }
#endif
}

/*
  handle a MISSION_REQUEST_LIST mavlink packet
 */
void GCS_MAVLINK::handle_mission_request_list(AP_Mission &mission, mavlink_message_t *msg)
{
    // decode
    mavlink_mission_request_list_t packet;
    mavlink_msg_mission_request_list_decode(msg, &packet);

    // exit immediately if this command is not meant for this vehicle
    if (mavlink_check_target(packet.target_system, packet.target_component)) {
        return;
    }

    // reply with number of commands in the mission.  The GCS will then request each command separately
    mavlink_msg_mission_count_send(chan,msg->sysid, msg->compid, mission.num_commands());

    // set variables to help handle the expected sending of commands to the GCS
    waypoint_receiving = false;             // record that we are sending commands (i.e. not receiving)
    waypoint_dest_sysid = msg->sysid;       // record system id of GCS who has requested the commands
    waypoint_dest_compid = msg->compid;     // record component id of GCS who has requested the commands
}

/*
  handle a MISSION_REQUEST mavlink packet
 */
void GCS_MAVLINK::handle_mission_request(AP_Mission &mission, mavlink_message_t *msg, 
                                         AP_Mission::Mission_Command &cmd)
{
    // decode
    mavlink_mission_request_t packet;
    mavlink_msg_mission_request_decode(msg, &packet);

    // exit immediately if this command is not meant for this vehicle
    if (mavlink_check_target(packet.target_system, packet.target_component)) {
        return;
    }

    // retrieve mission from eeprom
    if (!mission.read_cmd_from_storage(packet.seq, cmd)) {
        goto mission_item_send_failed;
    }

    // convert mission command to mavlink mission item packet
    mavlink_mission_item_t ret_packet;
    memset(&ret_packet, 0, sizeof(ret_packet));
    if (!AP_Mission::mission_cmd_to_mavlink(cmd, ret_packet)) {
        goto mission_item_send_failed;
    }

    // set packet's current field to 1 if this is the command being executed
    if (cmd.id == (uint16_t)mission.get_current_nav_cmd().index) {
        ret_packet.current = 1;
    } else {
        ret_packet.current = 0;
    }

    // set auto continue to 1
    ret_packet.autocontinue = 1;     // 1 (true), 0 (false)

    /*
      avoid the _send() function to save memory on APM2, as it avoids
      the stack usage of the _send() function by using the already
      declared ret_packet above
     */
    ret_packet.target_system = msg->sysid;
    ret_packet.target_component = msg->compid;
    ret_packet.seq = packet.seq;
    ret_packet.command = cmd.id;

    _mav_finalize_message_chan_send(chan, 
                                    MAVLINK_MSG_ID_MISSION_ITEM,
                                    (const char *)&ret_packet,
                                    MAVLINK_MSG_ID_MISSION_ITEM_LEN,
                                    MAVLINK_MSG_ID_MISSION_ITEM_CRC);
    return;

mission_item_send_failed:
    // send failure message
    mavlink_msg_mission_ack_send(chan, msg->sysid, msg->compid, MAV_MISSION_ERROR);
}

/*
  handle a MISSION_SET_CURRENT mavlink packet
 */
void GCS_MAVLINK::handle_mission_set_current(AP_Mission &mission, mavlink_message_t *msg)
{
    // decode
    mavlink_mission_set_current_t packet;
    mavlink_msg_mission_set_current_decode(msg, &packet);

    // exit immediately if this command is not meant for this vehicle
    if (mavlink_check_target(packet.target_system,packet.target_component)) {
        return;
    }

    // set current command
    if (mission.set_current_cmd(packet.seq)) {
        mavlink_msg_mission_current_send(chan, mission.get_current_nav_cmd().index);
    }
}

/*
  handle a MISSION_COUNT mavlink packet
 */
void GCS_MAVLINK::handle_mission_count(AP_Mission &mission, mavlink_message_t *msg)
{
    // decode
    mavlink_mission_count_t packet;
    mavlink_msg_mission_count_decode(msg, &packet);

    // exit immediately if this command is not meant for this vehicle
    if (mavlink_check_target(packet.target_system,packet.target_component)) {
        return;
    }

    // start waypoint receiving
    if (packet.count > mission.num_commands_max()) {
        // send NAK
        mavlink_msg_mission_ack_send(chan, msg->sysid, msg->compid, MAV_MISSION_NO_SPACE);
        return;
    }

    // new mission arriving, truncate mission to be the same length
    mission.truncate(packet.count);

    // set variables to help handle the expected receiving of commands from the GCS
    waypoint_timelast_receive = hal.scheduler->millis();    // set time we last received commands to now
    waypoint_receiving = true;              // record that we expect to receive commands
    waypoint_request_i = 0;                 // reset the next expected command number to zero
    waypoint_request_last = packet.count;   // record how many commands we expect to receive
    waypoint_timelast_request = 0;          // set time we last requested commands to zero
}

/*
  handle a MISSION_CLEAR_ALL mavlink packet
 */
void GCS_MAVLINK::handle_mission_clear_all(AP_Mission &mission, mavlink_message_t *msg)
{
    // decode
    mavlink_mission_clear_all_t packet;
    mavlink_msg_mission_clear_all_decode(msg, &packet);

    // exit immediately if this command is not meant for this vehicle
    if (mavlink_check_target(packet.target_system, packet.target_component)) {
        return;
    }

    // clear all waypoints
    if (mission.clear()) {
        // send ack
        mavlink_msg_mission_ack_send(chan, msg->sysid, msg->compid, MAV_RESULT_ACCEPTED);
    }else{
        // send nack
        mavlink_msg_mission_ack_send(chan, msg->sysid, msg->compid, 1);
    }
}

/*
  handle a MISSION_WRITE_PARTIAL_LIST mavlink packet
 */
void GCS_MAVLINK::handle_mission_write_partial_list(AP_Mission &mission, mavlink_message_t *msg)
{
    // decode
    mavlink_mission_write_partial_list_t packet;
    mavlink_msg_mission_write_partial_list_decode(msg, &packet);

    // exit immediately if this command is not meant for this vehicle
    if (mavlink_check_target(packet.target_system,packet.target_component)) {
        return;
    }

    // start waypoint receiving
    if (packet.start_index > mission.num_commands() ||
        packet.end_index > mission.num_commands() ||
        packet.end_index < packet.start_index) {
        send_text_P(SEVERITY_LOW,PSTR("flight plan update rejected"));
        return;
    }

    waypoint_timelast_receive = hal.scheduler->millis();
    waypoint_timelast_request = 0;
    waypoint_receiving   = true;
    waypoint_request_i   = packet.start_index;
    waypoint_request_last= packet.end_index;
}