#include <stdint.h>
#include "stm32f103_hal.h"

/* ================= VARIABLES ================= */
volatile uint32_t last_count = 0;
volatile uint32_t current_count = 0;
volatile uint32_t pulse_count = 0;

volatile float rpm = 0;
volatile uint32_t delta_t = 0;
volatile uint8_t flag_90 = 0;

/* ================= PROTOTIPOS ================= */
float leer_temp(void);
uint32_t calcular_delta_t(float rpm, float temp);

/* ================= MAIN ================= */
int main(void)
{
    /* Clock a 72 MHz */
    rcc_set_clock(RCC_SYSCLK_HSI, RCC_PLL_X9);

    /* GPIO */
    gpio_set_mode(GPIOA, 0, 0); // PA0 -> CKPSENS
    gpio_set_mode(GPIOA, 1, 0); // PA1 -> CKPZSENS
    gpio_set_mode(GPIOB, 6, 2); // PB6 -> PWM salida

    /* EXTI en PA1 (referencia 0°) */
    exti_set_interrupt(PA1, EXTI_IRQ_RISING);

    /* ================= TIMER 1: ENCODER ================= */
    rcc_clock_enable(RCC_TIM1);
    timer_set_encoder_mode(TIM1, TIMER_ENCODER_MODE_TI1);

    /* ================= TIMER 3: 90° ================= */
    rcc_clock_enable(RCC_TIM3);

    /* ================= TIMER 2: Δt ================= */
    rcc_clock_enable(RCC_TIM2);

    /* ================= TIMER 4: PWM ================= */
    rcc_clock_enable(RCC_TIM4);

    /* PWM 100 kHz, 20% duty */
    TIM4->PSC = 0;
    TIM4->ARR = 720 - 1;
    TIM4->CCR1 = 144;

    TIM4->CCMR1 |= (6 << 4); // PWM mode
    TIM4->CCER |= 1;         // Enable CH1
    TIM4->CR1 |= (1 << 3);   // One-shot

    /* ================= ADC ================= */
    rcc_clock_enable(RCC_ADC1);
    adc_set_channel(ADC1, ADC_CHANNEL_0, ADC_SMP_71_5);

    /* ================= LOOP ================= */
    while (1)
    {
        /* Leer encoder */
        current_count = timer_get_encoder_count(TIM1);

        if(current_count != last_count)
        {
            pulse_count++;

            /* 180 pulsos = 1 vuelta */
            if(pulse_count >= 180)
            {
                rpm = 60.0f; // simplificado
                pulse_count = 0;
            }

            last_count = current_count;
        }

        /* Si ya llegaste a 90° */
        if(flag_90)
        {
            float temp = leer_temp();
            delta_t = calcular_delta_t(rpm, temp);

            /* Timer Δt */
            TIM2->PSC = 72 - 1; // 1 MHz
            TIM2->ARR = delta_t;

            TIM2->CR1 |= (1 << 3); // one-shot
            TIM2->CR1 |= 1;

            flag_90 = 0;
        }
    }
}

/* ================= EXTI (0°) ================= */
void EXTI1_IRQHandler(void)
{
    /* Configurar timer para 90° */
    TIM3->PSC = 72 - 1;
    TIM3->ARR = 45; // 90°

    TIM3->CR1 |= (1 << 3);
    TIM3->CR1 |= 1;

    EXTI->PR |= (1 << 1);
}

/* ================= TIMER 3 ================= */
void TIM3_IRQHandler(void)
{
    flag_90 = 1;
    TIM3->SR &= ~(1);
}

/* ================= TIMER 2 ================= */
void TIM2_IRQHandler(void)
{
    /* Activar PWM (inyector) */
    TIM4->CR1 |= 1;
    TIM2->SR &= ~(1);
}

/* ================= FUNCIONES ================= */
float leer_temp(void)
{
    uint16_t adc = adc_read(ADC1);
    return (adc * 3.3f / 4096.0f) / 0.01f;
}

uint32_t calcular_delta_t(float rpm, float temp)
{
    if(temp < 85)
        return (uint32_t)(1000 + rpm * 2);
    else
        return (uint32_t)(800 + rpm);
}