/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2019 Matthias P. Braendli, Maximilien Cuony
 *
 * 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 "stm32f4xx_conf.h"
#include "stm32f4xx_gpio.h"
#include "stm32f4xx_adc.h"

#include "GPIO/usart.h"
#include "Core/common.h"
#include "Audio/audio_in.h"
#include "queue.h"

// APB1 prescaler = 4, see bsp/system_stm32f4xx.c
#define APB1_FREQ (168000000ul / 4)
#define ADC2_CHANNEL_AUDIO ADC_Channel_9

// see doc/pio.txt for allocation
#define PINS_ADC2 /* PB1 on ADC2 IN9 */ (GPIO_Pin_1)

// The TIM6 ISR reads from ADC2 and writes into these double buffers
static int16_t adc2_values[2][AUDIO_IN_BUF_LEN];
static int     adc2_current_buffer = 0; // which buffer is being written into
static int     adc2_values_end = 0;
static int32_t adc2_lost_samples = 0;

// ADC2 data from interrupt to userspace. The queue contains the buffer index
static QueueHandle_t adc2_values_queue;

/* ISR for Timer6 and DAC1&2 underrun */
void TIM6_DAC_IRQHandler(void);

void TIM6_DAC_IRQHandler()
{
    if (TIM_GetITStatus(TIM6, TIM_IT_Update)) {
        ADC_SoftwareStartConv(ADC2);
        TIM_ClearITPendingBit(TIM6, TIM_IT_Update);
    }
    else {
        usart_debug("%x\r\n", TIM6->SR);
        trigger_fault(FAULT_SOURCE_TIM6_ISR);
    }
}

void ADC_IRQHandler(void);
void ADC_IRQHandler()
{
    BaseType_t require_context_switch = pdFALSE;

    if (ADC_GetFlagStatus(ADC2, ADC_FLAG_EOC) == SET) {
        uint16_t value = ADC_GetConversionValue(ADC2);

        ADC_ClearITPendingBit(ADC2, ADC_IT_EOC);

        tone_detect_push_sample_from_irq(value);

#if 0
        /* input range: 0 to 2^12
         * output range: -32768 to 32767 */
        adc2_values[adc2_current_buffer][adc2_values_end++] = (int32_t)value - (1 << 11);
        if (adc2_values_end == AUDIO_IN_BUF_LEN) {
            int success = xQueueSendToBackFromISR(
                    adc2_values_queue,
                    &adc2_current_buffer,
                    &require_context_switch);

            adc2_values_end = 0;
            adc2_current_buffer = (adc2_current_buffer + 1) % 2;

            if (success == pdFALSE) {
                adc2_lost_samples += AUDIO_IN_BUF_LEN;
            }
        }
#endif
    }
    else {
        adc2_lost_samples++;
    }

    portYIELD_FROM_ISR(require_context_switch);
}

// Timer6 is used for ADC2 sampling
static void setup_timer()
{
    /* TIM6 Periph clock enable */
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM6, ENABLE);

    /* Time base configuration */
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
    TIM_TimeBaseStructure.TIM_Period = (int)(APB1_FREQ/AUDIO_IN_RATE);
    TIM_TimeBaseStructure.TIM_Prescaler = 1;
    TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM6, &TIM_TimeBaseStructure);

    NVIC_InitTypeDef NVIC_InitStructure;
    NVIC_InitStructure.NVIC_IRQChannel = TIM6_DAC_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 5;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);
    NVIC_SetPriority(TIM6_DAC_IRQn, 5);

    TIM_ITConfig(TIM6, TIM_IT_Update, ENABLE);
}


void audio_in_initialize()
{
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC2, ENABLE);
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);

    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AN;
    GPIO_InitStructure.GPIO_Pin   = PINS_ADC2;
    GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_NOPULL;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_Init(GPIOB, &GPIO_InitStructure);

    // Init ADC2 for NF input
    ADC_InitTypeDef ADC_InitStruct;
    ADC_InitStruct.ADC_Resolution = ADC_Resolution_12b;
    ADC_InitStruct.ADC_ScanConvMode = DISABLE;
    ADC_InitStruct.ADC_ContinuousConvMode = DISABLE;
    ADC_InitStruct.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
    ADC_InitStruct.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T1_CC1;
    ADC_InitStruct.ADC_DataAlign = ADC_DataAlign_Right;
    ADC_InitStruct.ADC_NbrOfConversion = 1;
    ADC_Init(ADC2, &ADC_InitStruct);

    ADC_RegularChannelConfig(ADC2, ADC2_CHANNEL_AUDIO, /*rank*/ 1, ADC_SampleTime_15Cycles);
    ADC_ClearITPendingBit(ADC2, ADC_IT_EOC);
    ADC_ITConfig(ADC2, ADC_IT_EOC, ENABLE);

    NVIC_InitTypeDef NVIC_InitStructure;
    NVIC_InitStructure.NVIC_IRQChannel = ADC_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 7;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);
    NVIC_SetPriority(ADC_IRQn, 7);

    ADC_Cmd(ADC2, ENABLE);

    adc2_values_queue = xQueueCreate(2, sizeof(adc2_current_buffer));
    if (adc2_values_queue == 0) {
        trigger_fault(FAULT_SOURCE_ADC2_QUEUE);
    }

    setup_timer();
}

void audio_in_enable(int enable)
{
    TIM_Cmd(TIM6, enable ? ENABLE : DISABLE);
}

int32_t audio_in_get_buffer(int16_t **buffer /*of length AUDIO_IN_BUF_LEN*/ )
{
    int buf_ix = 0;
    while (!xQueueReceive(adc2_values_queue, &buf_ix, portMAX_DELAY)) {}

    *buffer = adc2_values[buf_ix];

    return adc2_lost_samples;
}


#warning "Test tone detector activation from FSM"
#warning "Test 1750 not triggered by start bip my yaesu makes"
#warning "Test DTMF detector"
#warning "Test if FAX mode gets enabled after 0-7-*"