/*
  xdrv_52_3_berry_mqtt.ino - Berry scripting language, native fucnctions

  Copyright (C) 2021 Stephan Hadinger, Berry language by Guan Wenliang https://github.com/Skiars/berry

  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/>.
*/

// Mappgin from internal light and a generic `light_state` Berry class

#ifdef USE_BERRY

#include "berry.h"

// Berry: `tasmota.publish(topic, payload [, retain:bool, start:int, len:int]) -> nil``
// is_method is true if called from Tasmota class, false if called from mqtt module
int32_t be_mqtt_publish(struct bvm *vm, bool is_method) {
  int32_t top = be_top(vm); // Get the number of arguments
  if (top >= 2+is_method && be_isstring(vm, 1+is_method) && (be_isstring(vm, 2+is_method) || be_isbytes(vm, 2+is_method))) {  // 2 mandatory string arguments
    bool retain = false;
    int32_t payload_start = 0;
    int32_t len = -1;   // send all of it
    if (top >= 3+is_method) { retain = be_tobool(vm, 3+is_method); }
    if (top >= 4+is_method) {
      payload_start = be_toint(vm, 4+is_method);
      if (payload_start < 0) payload_start = 0;
    }
    if (top >= 5+is_method) { len = be_toint(vm, 5+is_method); }
    const char * topic = be_tostring(vm, 1+is_method);
    const char * payload = nullptr;
    size_t payload_len = 0;

    if (be_isstring(vm, 2+is_method)) {
      payload = be_tostring(vm, 2+is_method);
      payload_len = strlen(payload);
    } else {
      payload = (const char *) be_tobytes(vm, 2+is_method, &payload_len);
    }
    if (!payload) { be_raise(vm, "value_error", "Empty payload"); }

    // adjust start and len
    if (payload_start >= payload_len) { len = 0; }              // send empty packet
    else if (len < 0) { len = payload_len - payload_start; }    // send all packet, adjust len
    else if (payload_start + len > payload_len) { len = payload_len - payload_start; }    // len is too long, adjust
    // adjust start
    payload = payload + payload_start;

    be_pop(vm, be_top(vm));   // clear stack to avoid any indirect warning message in subsequent calls to Berry

    MqttPublishPayload(topic, payload, len, retain);

    be_return_nil(vm); // Return
  }
  be_raise(vm, kTypeError, nullptr);
}

extern "C" {
  int32_t l_publish(struct bvm *vm);
  int32_t l_publish(struct bvm *vm) {
    return be_mqtt_publish(vm, true);
  }
}

int32_t be_mqtt_publish(struct bvm *vm) {
  return be_mqtt_publish(vm, false);
}

void be_mqtt_subscribe(const char* topic) {
  if (!topic) { return; }
  MqttSubscribe(topic);
}

void be_mqtt_unsubscribe(const char* topic) {
  if (!topic) { return; }
  MqttUnsubscribe(topic);
}

#endif  // USE_BERRY