/*
 *  rhmidi
 *
 *  Copyright (C) 2014 Christian Pointner <equinox@helsinki.at>
 *
 *  This file is part of rhmidi.
 *
 *  rhmidi 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
 *  any later version.
 *
 *  rhmidi 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 rhmidi. If not, see <http://www.gnu.org/licenses/>.
 */

#include <avr/io.h>
#include "analog.h"
#include "eventqueue.h"

#define ANALOG_PIN PINF
#define ANALOG_PORT PORTF
#define ANALOG_DDR DDRF

#include <LUFA/Drivers/Peripheral/ADC.h>

static struct {
  uint8_t enabled;
  uint8_t last_sent;
} analog_input_state[ANALOG_NUM_INPUTS];

static uint8_t analog_channels[] = { ADC_CHANNEL0, ADC_CHANNEL1, ADC_CHANNEL2, ADC_CHANNEL3,
                                     ADC_CHANNEL4, ADC_CHANNEL5, ADC_CHANNEL6, ADC_CHANNEL7 };

void analog_init(void)
{
  ANALOG_DDR = 0x00;
  ANALOG_PORT = 0x00;

  int i;
  for(i = 0; i < ANALOG_NUM_INPUTS; ++i) {
    analog_input_state[i].enabled = 0;
    analog_input_state[i].last_sent = 0;
  }

  ADC_Init(ADC_SINGLE_CONVERSION | ADC_PRESCALE_32);
}

static void analog_channel_set_enabled(uint8_t channel, uint8_t enabled)
{
  if(enabled) {
    ADC_SetupChannel(channel);
    analog_input_state[channel].enabled = 1;
  } else {
    ADC_DisableChannel(channel);
    analog_input_state[channel].enabled = 0;
  }
}

void analog_enable_channel(uint8_t channel)
{
  if(channel < ANALOG_NUM_INPUTS)
    analog_channel_set_enabled(channel, 1);
  else if(channel == ANALOG_MIDI_NOTE_ALL_INPUTS - ANALOG_MIDI_NOTE_OFFSET) {
    int i;
    for(i = 0; i < ANALOG_NUM_INPUTS; ++i)
      analog_channel_set_enabled(i, 1);
  }
}

void analog_disable_channel(uint8_t channel)
{
  if(channel < ANALOG_NUM_INPUTS)
    analog_channel_set_enabled(channel, 0);
  else if(channel == ANALOG_MIDI_NOTE_ALL_INPUTS - ANALOG_MIDI_NOTE_OFFSET) {
    int i;
    for(i = 0; i < ANALOG_NUM_INPUTS; ++i)
      analog_channel_set_enabled(i, 0);
  }
}

uint8_t analog_get_value(uint8_t channel)
{
  if(channel >= ANALOG_NUM_INPUTS)
    return 0;

  return analog_input_state[channel].last_sent;
}

void analog_task(void)
{
  uint8_t i;
  for(i = 0; i < ANALOG_NUM_INPUTS; ++i) {
    if(analog_input_state[i].enabled) {
      uint8_t tmp = (ADC_GetChannelReading(ADC_REFERENCE_AVCC | ADC_RIGHT_ADJUSTED | analog_channels[i])) >> 3;
      if(analog_input_state[i].last_sent != tmp) {
        analog_input_state[i].last_sent = tmp;
        eventqueue_push(ANALOG_MIDI_NOTE_OFFSET + i, 0);
      }
    }
  }
}