//
// WSPRHAB: Minimal high-altitude balloon tracker with WSPR telemetry
//

#include "stm32f0xx_hal.h"
#include "adc.h"
#include "system.h"
#include "i2c.h"
#include "uart.h"
#include "gpio.h"
#include "wspr.h"
#include "gps.h"


// We have access to the 1PPS pin of the gps... could have trim routine for internal oscillator based on this when we have a fix
// Probabl wake up 1 minute early -- 0.45min possible +/- on wakeup time with 15min sync intervals


enum _state
{
    SYSTEM_POWERUP_SYNC = 0, // on powerup, get a GPS fix and set the RTC
    SYSTEM_IDLE, // awaiting RTC interrupt for wakeup TODO wake up before scheduled time to get fix?
    SYSTEM_GPSACQ, // RTC interrupted
    SYSTEM_WSPRTX, // Wait for timeslot and actually transmit the message
}


int main(void)
{
    HAL_Init();

    sysclk_init();
    gpio_init();
    adc_init();
    i2c_init();
    gps_init();
    wspr_init();

    uint32_t led_timer = HAL_GetTick();

    led_blink(4);

    uint16_t blink_rate = BLINK_FAST;
    uint8_t state = SYSTEM_GPSACQ;


    while (1)
    {
        switch(state)
        {

            // Idling: sleep and wait for RTC timeslot trigger
            case SYSTEM_IDLE:
            {
                blink_rate = BLINK_SLOW;
                // Wait for RTC wakeup interrupt
                wfi();
                //enter_sleep();

                // Somehow go to another state when we get an interrupt
                state = SYSTEM_GPSACQ;
            } break;


            // Attempt to acquire GPS fix
            case SYSTEM_GPSACQ:
            {
                blink_rate = BLINK_FAST;

                // TODO: probably don't power on all the time, just on state transition
                gps_poweron();
                HAL_Delay(500);
                gps_update_position();

                if(fix_ok)
                {
                    // Disable GPS module
                    gps_poweroff();

                    // TODO: Set RTC from GPS time

                    // TODO: Set RTC for countdown to next transmission timeslot!

                    // TODO: Set wspr countdown timer for this transmission!
                    state = SYSTEM_WSPRTX;
                }
                else if(fix_timeout)
                {
                    // Flash error code and go to idle probably? or just try forever?
                }

            } break;

            
            // Wait for wspr timeslot and start transmitting
            case SYSTEM_WSPRTX:
            {
                // Wait for wspr countdown timer to expire and go to tx
                if(timeout_expired)
                {
                    wspr_transmit();
                }

                // Schedule next wakeup (maybe 2mins prior ot timeslot if no osc trim)
                // Next wakeup should enter SYSTEM_GPSACQ state...

                state = SYSTEM_IDLE;

            } break;

        }


        if(HAL_GetTick() - led_timer > blink_rate)
        {
            HAL_GPIO_TogglePin(LED_BLUE);
            led_timer = HAL_GetTick();
        }

    }
}