// -----------------------------------------------------------------------------
// Event Counter Sensor
// Copyright (C) 2017 by Xose Pérez <xose dot perez at gmail dot com>
// -----------------------------------------------------------------------------

#pragma once

#include "Arduino.h"
#include "BaseSensor.h"

class EventSensor : public BaseSensor {

    public:

        // ---------------------------------------------------------------------
        // Public
        // ---------------------------------------------------------------------

        EventSensor(): BaseSensor() {
            _count = 1;
            _sensor_id = SENSOR_EVENTS_ID;
        }

        ~EventSensor() {
            _enableInterrupts(false);
        }

        // ---------------------------------------------------------------------

        void setGPIO(unsigned char gpio) {
            _gpio = gpio;
        }

        void setMode(unsigned char mode) {
            _mode = mode;
        }

        void setInterruptMode(unsigned char mode) {
            _interrupt_mode = mode;
        }

        void setDebounceTime(unsigned long debounce) {
            _debounce = debounce;
        }

        // ---------------------------------------------------------------------

        unsigned char getGPIO() {
            return _gpio;
        }

        unsigned char getMode() {
            return _mode;
        }

        unsigned char getInterruptMode() {
            return _interrupt_mode;
        }

        unsigned long getDebounceTime() {
            return _debounce;
        }

        // ---------------------------------------------------------------------
        // Sensors API
        // ---------------------------------------------------------------------

        // Initialization method, must be idempotent
        // Defined outside the class body
        void begin() {
            pinMode(_gpio, _mode);
            _enableInterrupts(true);
        }

        // Descriptive name of the sensor
        String description() {
            char buffer[20];
            snprintf(buffer, sizeof(buffer), "INTERRUPT @ GPIO%d", _gpio);
            return String(buffer);
        }

        // Type for slot # index
        magnitude_t type(unsigned char index) {
            _error = SENSOR_ERROR_OK;
            if (index == 0) return MAGNITUDE_EVENTS;
            _error = SENSOR_ERROR_OUT_OF_RANGE;
            return MAGNITUDE_NONE;
        }

        // Current value for slot # index
        double value(unsigned char index) {
            _error = SENSOR_ERROR_OK;
            if (index == 0) {
                double value = _events;
                _events = 0;
                return value;
            };
            _error = SENSOR_ERROR_OUT_OF_RANGE;
            return 0;
        }

        // Handle interrupt calls
        void handleInterrupt(unsigned char gpio) {
            (void) gpio;
            static unsigned long last = 0;
            if (millis() - last > _debounce) {
                _events = _events + 1;
                last = millis();
            }
        }

    protected:

        // ---------------------------------------------------------------------
        // Interrupt management
        // ---------------------------------------------------------------------

        void _attach(EventSensor * instance, unsigned char gpio, unsigned char mode);
        void _detach(unsigned char gpio);

        void _enableInterrupts(bool value) {

            static unsigned char _interrupt_gpio = GPIO_NONE;

            if (value) {
                if (_interrupt_gpio != GPIO_NONE) _detach(_interrupt_gpio);
                _attach(this, _gpio, _interrupt_mode);
                _interrupt_gpio = _gpio;
            } else if (_interrupt_gpio != GPIO_NONE) {
                _detach(_interrupt_gpio);
                _interrupt_gpio = GPIO_NONE;
            }

        }

        // ---------------------------------------------------------------------
        // Protected
        // ---------------------------------------------------------------------

        volatile unsigned long _events = 0;
        unsigned long _debounce = EVENTS_DEBOUNCE;
        unsigned char _gpio;
        unsigned char _mode;
        unsigned char _interrupt_mode;

};

// -----------------------------------------------------------------------------
// Interrupt helpers
// -----------------------------------------------------------------------------

EventSensor * _event_sensor_instance[10] = {NULL};

void ICACHE_RAM_ATTR _event_sensor_isr(unsigned char gpio) {
    unsigned char index = gpio > 5 ? gpio-6 : gpio;
    if (_event_sensor_instance[index]) {
        _event_sensor_instance[index]->handleInterrupt(gpio);
    }
}

void ICACHE_RAM_ATTR _event_sensor_isr_0() { _event_sensor_isr(0); }
void ICACHE_RAM_ATTR _event_sensor_isr_1() { _event_sensor_isr(1); }
void ICACHE_RAM_ATTR _event_sensor_isr_2() { _event_sensor_isr(2); }
void ICACHE_RAM_ATTR _event_sensor_isr_3() { _event_sensor_isr(3); }
void ICACHE_RAM_ATTR _event_sensor_isr_4() { _event_sensor_isr(4); }
void ICACHE_RAM_ATTR _event_sensor_isr_5() { _event_sensor_isr(5); }
void ICACHE_RAM_ATTR _event_sensor_isr_12() { _event_sensor_isr(12); }
void ICACHE_RAM_ATTR _event_sensor_isr_13() { _event_sensor_isr(13); }
void ICACHE_RAM_ATTR _event_sensor_isr_14() { _event_sensor_isr(14); }
void ICACHE_RAM_ATTR _event_sensor_isr_15() { _event_sensor_isr(15); }

static void (*_event_sensor_isr_list[10])() = {
    _event_sensor_isr_0, _event_sensor_isr_1, _event_sensor_isr_2,
    _event_sensor_isr_3, _event_sensor_isr_4, _event_sensor_isr_5,
    _event_sensor_isr_12, _event_sensor_isr_13, _event_sensor_isr_14,
    _event_sensor_isr_15
};

void EventSensor::_attach(EventSensor * instance, unsigned char gpio, unsigned char mode) {
    if (!gpioValid(gpio)) return;
    _detach(gpio);
    unsigned char index = gpio > 5 ? gpio-6 : gpio;
    _event_sensor_instance[index] = instance;
    attachInterrupt(gpio, _event_sensor_isr_list[index], mode);
    #if SENSOR_DEBUG
        DEBUG_MSG("[SENSOR] GPIO%d interrupt attached to %s\n", gpio, instance->description().c_str());
    #endif
}

void EventSensor::_detach(unsigned char gpio) {
    if (!gpioValid(gpio)) return;
    unsigned char index = gpio > 5 ? gpio-6 : gpio;
    if (_event_sensor_instance[index]) {
        detachInterrupt(gpio);
        #if SENSOR_DEBUG
            DEBUG_MSG("[SENSOR] GPIO%d interrupt detached from %s\n", gpio, _event_sensor_instance[index]->description().c_str());
        #endif
        _event_sensor_instance[index] = NULL;
    }
}