/*
  strobe_esp32.cpp

  Part of WiFlash_esp32

  Copyright (c) 2020 Kevin Matz (kevin.matz@gmail.com)

  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:

  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  SOFTWARE.
*/

#include <Arduino.h>
#include <AsyncUDP.h>
#include <algorithm>
#include <iterator>
#include "strobe_esp32.h"

/*
   calculate period from DMX value
*/
uint32_t hz_to_micros(uint8_t dmx) {
  if (dmx == 0) {
    return 0;
  }
  // ( millis / ( percent * scalor ) + offset ) * micros
  return (1000 / (((dmx / 255.0) * 24.5) + 0.5)) * 1000;
}


/*
   calculate duration from DMX value
*/
uint32_t dr_to_micros(uint8_t dmx) {
  //      (( percent * scalor) + offset) * micros
  return (((dmx / 255.0) * .5 ) + .01 ) * 1000 * 1000;
}


/*
   Constructor
*/
Strobe::Strobe(uint16_t address) {
  address_ = address;
}

/*
   call durring setup()
*/
bool Strobe::begin(uint8_t pin, uint8_t pwm) {
  bool success = true;
  // set state
  pwm_   = pwm;
  state_ = STROBE_INACTIVE;

  // configure hardware
  ledcAttachPin(pin, pwm_);    // Attach GPIO to PWM timer
  ledcSetup(pwm_, 2400, 15);   // 2.4KHz PWM, 15 bit resolutio
  ledcWrite(pwm_, 0);          // LED to 0%

  // start update task
  xTaskCreate(this->update,         // function name
              "StrobeUpdateThread", // task name
              2048,                 // stack size (bytes)
              this,                 // parameter to pass
              1,                    // task priority
              NULL);                // task handle

  return success;
}

void Strobe::update(void * param) {
  Strobe *tThis = (Strobe *) param;
  uint32_t last_time = 0;
  TickType_t xDelay;
  for (;;) {
    xDelay = (1000 / 40.0) / portTICK_PERIOD_MS; // sleep 1 dmx frame
    // intensity changes start/stop the cycle
    uint16_t intensity = tThis->profile_.intensity << 8 |
                         tThis->profile_.intensity >> 8;
    if (intensity == 0) {
      // intensity off breaks the cycle
      tThis->state_ = STROBE_INACTIVE;
    } else {
      if (tThis->state_ == STROBE_INACTIVE) {
        // going active
        tThis->state_ = STROBE_ACTIVE_ON;
      }
    }

    // time based cycle changes
    if (tThis->state_ == STROBE_ACTIVE_ON ||
        tThis->state_ == STROBE_ACTIVE_OFF) {
      uint32_t now, elapsed, period, dur;
      now = micros();
      elapsed = now - last_time;
      period = hz_to_micros(tThis->profile_.rate);
      dur = dr_to_micros(tThis->profile_.duration);

      if (elapsed > period ||         // hz period completed
          now < last_time) {      // micros() wraps 32 bits every ~70 min.
        // cycle restarts
        tThis->state_ = STROBE_ACTIVE_ON;
        last_time = now;
        // yield task until end of duration
        xDelay = std::min(xDelay, dur / portTICK_PERIOD_MS);
      } else if (elapsed > dur) {    // durration period completed
        // cycle enters dark phase
        tThis->state_ = STROBE_ACTIVE_OFF;
        // yield task until end of period
        xDelay = std::min(xDelay, (period - dur) / portTICK_PERIOD_MS);
      } else {
        if (tThis->state_ = STROBE_ACTIVE_ON) {
          // yield task for remainder of duration
          xDelay = std::min(xDelay, (dur - elapsed) / portTICK_PERIOD_MS);
        } else {
          // yield task for remainder of period
          xDelay = std::min(xDelay, (period - elapsed) / portTICK_PERIOD_MS);
        }
      }
    }

    // set LED output
    if (tThis->state_ == STROBE_ACTIVE_ON) {
      tThis->setLevel(intensity);
    } else {
      tThis->setLevel(0);
    }

    // yield task
    vTaskDelay(xDelay);
  }
  vTaskDelete( NULL );
}


/*
   Write a 15bit level to PWM
*/
void Strobe::setLevel(uint16_t level) {
  ledcWrite(pwm_, ((level >> 1) & 0xffff)); // write at 15 bit PWM
}

void Strobe::recvData(Universe * univ) {
  if ( sizeof(profile_.dmx) + address_ > sizeof(univ->data()->data)) {
    // address is higher than allowable
    Serial.println("Bad Address");
    return;
  }
  std::copy(univ->data()->data + address_,
            univ->data()->data + address_ + sizeof(profile_.dmx),
            std::begin(profile_.dmx));
}