#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/queue.h"
#include "driver/gpio.h"
#include "esp_log.h"
#include "keypad.h"

// ───────────── CONFIGURATION ─────────────

typedef enum {
    BUTTON1_GPIO = GPIO_NUM_36,
    BUTTON2_GPIO = GPIO_NUM_39,
} button_gpio_t;

#define BUTTON_COUNT    2

// If your buttons are active‐low, set this to 0. If active‐high, set it to 1.
#define KEYPAD_INACTIVE     1
#define KEYPAD_ACTIVE       0

// Now we run the task every 50 ms and assume that is enough to debounce:
#define DEBOUNCE_INTERVAL_MS    50   // Poll once every 50 ms
// No more stable‐count logic—one sample/50 ms is considered “debounced.”

// Short vs. long press threshold (in ms):
#define LONG_PRESS_MS       1000    // ≥1000 ms = “long press”

// Queue length for pending button events:
#define BTN_EVT_QUEUE_LEN     10

// ───────────── EVENT ENUM & QUEUE HANDLE ─────────────

typedef struct 
{
    keycode_t key;
    gpio_num_t gpio;
    int prevState;
    int currentState;
    TickType_t activeTime;
    uint32_t event;
} button_t;

static button_t _buttons[2];

// The queue handle that the debounce task will push events into:
static QueueHandle_t s_btn_evt_queue = NULL;

// Call this to get the queue, so the main task can xQueueReceive():
QueueHandle_t  keypad_getQueue(void) {
    return s_btn_evt_queue;
}

// ───────────── INTERNAL STATE ─────────────

// Current debounced state: 0 = released, 1 = pressed
static int s_debounced[2] = { 0, 0 };

// Tick count when each button was debounced to “pressed”
static TickType_t s_press_tick[2] = { 0, 0 };

// If we suppress an individual‐button event (because it was part of a “both” press), this is true
static bool s_suppress_event[2] = { false, false };

// Tracks if we are currently in “both buttons pressed” phase:
static bool s_was_both = false;

// Tick count when “both buttons” first became debounced‐pressed:
static TickType_t s_both_press_tick = 0;

// ───────────── TAG FOR LOGGING ─────────────

static const char *TAG = "btn_debounce";

// ───────────── GPIO SETUP ─────────────

static void init_button_gpio(void)
{
    // Configure both as inputs with pull‐up (assuming active‐low buttons)
    gpio_config_t io_conf = {
        .pin_bit_mask = (1ULL << BUTTON1_GPIO) | (1ULL << BUTTON2_GPIO),
        .mode         = GPIO_MODE_INPUT,
        .pull_up_en   = GPIO_PULLUP_ENABLE,
        .pull_down_en = GPIO_PULLDOWN_DISABLE,
        .intr_type    = GPIO_INTR_DISABLE
    };
    ESP_ERROR_CHECK(gpio_config(&io_conf));

    _buttons[0].activeTime = 0;
    _buttons[0].gpio = BUTTON1_GPIO;
    _buttons[0].key = KEY0;
    _buttons[0].prevState = KEYPAD_INACTIVE;
    _buttons[0].currentState = KEYPAD_INACTIVE;

    _buttons[1].activeTime = 0;
    _buttons[1].gpio = BUTTON2_GPIO;
    _buttons[1].key = KEY1;
    _buttons[1].prevState = KEYPAD_INACTIVE;
    _buttons[1].currentState = KEYPAD_INACTIVE;
    
}

// ───────────── BUTTON DEBOUNCE & PRESS‐TYPE TASK ─────────────

static void vButtonDebounceTask(void *arg)
{
    (void)arg;

    TickType_t now = xTaskGetTickCount();
    TickType_t xLastWake = now;
    const TickType_t long_press_thresh = pdMS_TO_TICKS(LONG_PRESS_MS);

    while (1) {

        now = xTaskGetTickCount();

        for (int i=0; i < BUTTON_COUNT; ++i)
        {
            button_t *button = &_buttons[i];

            button->currentState = gpio_get_level(button->gpio);

            if (button->currentState == KEYPAD_ACTIVE)
            {
                // just pressed
                if (button->prevState == KEYPAD_INACTIVE)
                {
                    button->activeTime = now;
                }
                else
                {
                    if ((now - button->activeTime) >= long_press_thresh)
                    {
                        if (button->event == 0)
                        {
                            ESP_LOGI(TAG, "%d LONG", button->key);
                            button->event = (button->key << KEY_LONG_PRESS);
                            xQueueSend(s_btn_evt_queue, &button->event, 0);
                        }
                    }
                }
            }
            else
            if (button->currentState == KEYPAD_INACTIVE)
            {
                // just released
                if (button->prevState == KEYPAD_ACTIVE)
                {
                    if (button->event == 0)
                    {
                        ESP_LOGI(TAG, "%d SHORT", button->key);
                        button->event = (button->key << KEY_SHORT_PRESS);
                        xQueueSend(s_btn_evt_queue, &button->event, 0);
                    }
                    else
                    {
                        ESP_LOGI(TAG, "%d LONG RELEASE", button->key);
                    }
                    button->event = 0;
                    
                }
                button->activeTime = 0;
            }

            button->prevState = button->currentState;
        }




        // 7) Wait 50 ms and repeat
        vTaskDelayUntil(&xLastWake, pdMS_TO_TICKS(DEBOUNCE_INTERVAL_MS));
        xLastWake = now;
    }
}

// ───────────── PUBLIC “START” FUNCTION ─────────────

void keypad_start(void)
{
    // 1) Create the queue for button events
    s_btn_evt_queue = xQueueCreate(BTN_EVT_QUEUE_LEN, sizeof(uint32_t));
    if (s_btn_evt_queue == NULL) {
        ESP_LOGE(TAG, "Failed to create button event queue");
        return;
    }

    // 2) Initialize GPIOs & initial state
    init_button_gpio();

    // 3) Launch the FreeRTOS task (low priority)
	xTaskCreate(vButtonDebounceTask,
        "btn_debounce",
        2048,
        NULL,
        tskIDLE_PRIORITY + 1,
        NULL);

}