#pragma once

#include <chrono>
#include <stm32f1xx_hal_tim.h>
#include <stm32f103x6.h>

template<unsigned Fcpu, typename SecondsPerTimerTick>
struct from_f_cpu_and_time_per_timer_tick {
    template<std::intmax_t Num, std::intmax_t Den>
    using r = std::ratio<Num, Den>;

    using f_cpu = r<Fcpu, 1>;
    using seconds_per_cpu_tick = r<1, f_cpu::num>;
    using seconds_per_timer_tick = SecondsPerTimerTick;
    using timer_frequency = r<SecondsPerTimerTick::den, SecondsPerTimerTick::num>;

//    static constexpr std::intmax_t prescaler = std::ratio_divive<f_cpu, timer_frequency>::value;
    using prescaler_t = std::ratio_divide<f_cpu, timer_frequency>;
    static_assert(prescaler_t::den == 1, "Could not represent the prescaler as an integer");
    static constexpr std::intmax_t prescaler = prescaler_t::num;

    // us_per_timer_tick = seconds_per_timer_tick * 1'000'000
    using us_per_timer_tick_t = typename std::ratio_multiply<seconds_per_timer_tick, r<1'000'000, 1>>::type;

    static constexpr uint16_t us_per_timer_tick = static_cast<uint16_t>(us_per_timer_tick_t::num);

    template<typename T>
    __always_inline constexpr
    static T to_us(unsigned int count)
    {
        return T(count * us_per_timer_tick);
    }
};

using values = from_f_cpu_and_time_per_timer_tick<72'000'000, std::ratio_multiply<std::ratio<5, 1>, std::micro>>;

//static_assert(values::timer_frequency::num == 200'000, "timer_frequency::num");
static_assert(values::timer_frequency::den == 1, "timer_frequency::den");
//static_assert(std::is_same<
//    values::timer_frequency,
//    std::ratio<200'000, 1>>::value, "Timer frequency is not 200kHz");
static_assert(values::prescaler == 360, "Timer frequency is not 200kHz");
static_assert(values::prescaler - 1 == RADIO_RX_TIMER_PRESCALER, "Bad prescaler from STM32CubeMX");
static_assert(values::us_per_timer_tick == 5, "bad us_per_timer_tick");

static inline
void debug_pin(int count) {
    for(int i = 0; i < count; i++) {
        HAL_GPIO_WritePin(DEBUG_PIN_GPIO_Port, DEBUG_PIN_Pin, GPIO_PIN_SET);
        __NOP();
        __NOP();
        __NOP();
        HAL_GPIO_WritePin(DEBUG_PIN_GPIO_Port, DEBUG_PIN_Pin, GPIO_PIN_RESET);
        __NOP();
        __NOP();
        __NOP();
    }
    __NOP();
    __NOP();
    __NOP();
}