/*
 * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Unlicense OR CC0-1.0
 */
#include <stdint.h>
#include <stdbool.h>
#include "sdkconfig.h"
#include "ulp_lp_core.h"
#include "ulp_lp_core_utils.h"
#include "ulp_lp_core_gpio.h"
#include "ulp_lp_core_interrupts.h"
#include "ulp_lp_core_print.h"
#include "riscv/csr.h"

#define DEBOUNCE_INTERVAL_CYCLES 16000000 // 1000 ms at 16 MHz

uint32_t pulse_count = 0;
static uint32_t last_trigger_time_cycles = 0;

/* Interrupt handler - not currently used (polling mode) */



int main (void)
{
    /* Configure GPIO as input in LP Core */
    ulp_lp_core_gpio_init(CONFIG_PULSE_COUNT_PIN);
    ulp_lp_core_gpio_input_enable(CONFIG_PULSE_COUNT_PIN);
    ulp_lp_core_gpio_output_disable(CONFIG_PULSE_COUNT_PIN);
    ulp_lp_core_gpio_pullup_enable(CONFIG_PULSE_COUNT_PIN);
    ulp_lp_core_gpio_pulldown_disable(CONFIG_PULSE_COUNT_PIN);

    /* Poll GPIO for rising edges (LOW -> HIGH transitions when reed switch releases from GND) */
    int last_gpio_state = ulp_lp_core_gpio_get_level(CONFIG_PULSE_COUNT_PIN);

    while(1) {
        int current_gpio_state = ulp_lp_core_gpio_get_level(CONFIG_PULSE_COUNT_PIN);

        /* Detect rising edge only (LOW -> HIGH transition) */
        if (last_gpio_state == 0 && current_gpio_state == 1) {
            uint32_t edge_time = RV_READ_CSR(mcycle);
            uint32_t time_since_last = edge_time - last_trigger_time_cycles;

            /* Debounce: only count if enough time has passed (200ms) */
            if (time_since_last > DEBOUNCE_INTERVAL_CYCLES) {
                pulse_count++;
                last_trigger_time_cycles = edge_time;

                /* Wake main CPU when threshold is reached */
                if (pulse_count % CONFIG_PULSE_COUNT_WAKEUP_LIMIT == 0) {
                    ulp_lp_core_wakeup_main_processor();
                }
            }
        }

        last_gpio_state = current_gpio_state;
        ulp_lp_core_delay_us(100000);  // Poll every 100ms
    }

    return 0;
}