#include <stdio.h>
#include <stdint.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_err.h"
#include "driver/i2c_master.h"
#include "driver/gpio.h"

// Пины I2C
#define I2C_MASTER_SCL_IO    GPIO_NUM_22
#define I2C_MASTER_SDA_IO    GPIO_NUM_21
#define I2C_MASTER_FREQ_HZ   100000
#define I2C_TIMEOUT_MS       100

// Кнопка BOOT
#define BOOT_BUTTON_GPIO     GPIO_NUM_0

// ------------------------------------------------------------
// Имитация функции из ESP-IoT-Solution: i2c_bus_scan()
// ------------------------------------------------------------
int simulate_i2c_bus_scan(i2c_master_bus_handle_t bus_handle, uint8_t *addresses, int max_count)
{
    if (!addresses || max_count <= 0) return 0;

    int count = 0;
    for (uint8_t addr = 1; addr < 127; addr++) {
        esp_err_t ret = i2c_master_probe(bus_handle, addr, I2C_TIMEOUT_MS);
        if (ret == ESP_OK) {
            if (count < max_count) {
                addresses[count] = addr;
                count++;
            }
        }
    }
    return count;
}

// ------------------------------------------------------------
// Вывод результатов в формате таблицы (как в задании)
// ------------------------------------------------------------
void print_scan_results(const uint8_t *addresses, int count)
{
    printf("Scanning the bus...\r\n\r\n");
    printf("     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f\r\n");

    for (int i = 0; i < 128; i += 16) {
        printf("%02x: ", i);
        for (int j = 0; j < 16; j++) {
            uint8_t target = i + j;
            bool found = false;
            for (int k = 0; k < count; k++) {
                if (addresses[k] == target) {
                    printf("%02x ", target);
                    found = true;
                    break;
                }
            }
            if (!found) {
                printf("-- ");
            }
        }
        printf("\r\n");
    }
    printf("\r\n");
}

// ------------------------------------------------------------
// Основная функция
// ------------------------------------------------------------
void app_main(void)
{
    // Настройка кнопки BOOT (GPIO0)
    gpio_config_t btn_cfg = {
        .pin_bit_mask = (1ULL << BOOT_BUTTON_GPIO),
        .mode = GPIO_MODE_INPUT,
        .pull_up_en = GPIO_PULLUP_ENABLE,
        .pull_down_en = GPIO_PULLDOWN_DISABLE,
        .intr_type = GPIO_INTR_DISABLE,
    };
    gpio_config(&btn_cfg);

    // Инициализация I2C
    i2c_master_bus_config_t i2c_mst_cfg = {
        .clk_source = I2C_CLK_SRC_DEFAULT,
        .i2c_port = I2C_NUM_0,
        .scl_io_num = I2C_MASTER_SCL_IO,
        .sda_io_num = I2C_MASTER_SDA_IO,
        .glitch_ignore_cnt = 7,
        .flags.enable_internal_pullup = false, // pull-up на модуле
    };
    i2c_master_bus_handle_t bus_handle;
    ESP_ERROR_CHECK(i2c_new_master_bus(&i2c_mst_cfg, &bus_handle));

    printf("I2C Scanner (ESP-IoT-Solution style) ready!\n");
    printf("Press BOOT button (GPIO0) to scan...\n");

    uint8_t detected_addresses[127];
    bool was_pressed = false;

    while (1) {
        int btn_state = gpio_get_level(BOOT_BUTTON_GPIO);

        if (btn_state == 0) { // кнопка нажата
            if (!was_pressed) {
                vTaskDelay(pdMS_TO_TICKS(50)); // антидребезг
                if (gpio_get_level(BOOT_BUTTON_GPIO) == 0) {
                    // Имитация вызова i2c_bus_scan()
                    int num_devices = simulate_i2c_bus_scan(bus_handle, detected_addresses, 127);
                    print_scan_results(detected_addresses, num_devices);
                    was_pressed = true;
                }
            }
        } else {
            was_pressed = false;
        }

        vTaskDelay(pdMS_TO_TICKS(20));
    }

    // Очистка (недостижима)
    i2c_del_master_bus(bus_handle);
}