/**
 * @file ui_task.c
 * @brief UI task - button handling and OLED display
 */
#include <stdio.h>
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/queue.h"
#include "esp_log.h"
#include "driver/gpio.h"
#include "app_main.h"

static const char *TAG = "ui";

/* Button debounce parameters */
#define DEBOUNCE_MS     50
#define LONG_PRESS_MS   1000

/* Button state tracking */
typedef struct {
    uint8_t gpio;
    uint8_t last_state;
    uint32_t last_change_ms;
    uint32_t press_start_ms;
    uint8_t long_press_sent;
} btn_state_t;

static btn_state_t buttons[] = {
    {BTN_UP_GPIO,   1, 0, 0, 0},
    {BTN_DOWN_GPIO, 1, 0, 0, 0},
    {BTN_SEL_GPIO,  1, 0, 0, 0},
    {BTN_BACK_GPIO, 1, 0, 0, 0},
};

static void handle_button(btn_state_t *btn, uint8_t idx)
{
    uint8_t state = gpio_get_level(btn->gpio);
    uint32_t now = xTaskGetTickCount() * portTICK_PERIOD_MS;
    
    if (state != btn->last_state) {
        btn->last_change_ms = now;
        btn->last_state = state;
        
        if (state == 0) { /* Pressed */
            btn->press_start_ms = now;
            btn->long_press_sent = 0;
            
            ui_event_t evt = {.key = idx, .action = 0}; /* press */
            if (ui_event_queue) {
                xQueueSend(ui_event_queue, &evt, 0);
            }
        } else { /* Released */
            if (!btn->long_press_sent) {
                ui_event_t evt = {.key = idx, .action = 1}; /* release */
                if (ui_event_queue) {
                    xQueueSend(ui_event_queue, &evt, 0);
                }
            }
        }
    } else if (state == 0 && !btn->long_press_sent) {
        /* Check for long press */
        if ((now - btn->press_start_ms) >= LONG_PRESS_MS) {
            btn->long_press_sent = 1;
            ui_event_t evt = {.key = idx, .action = 2}; /* long press */
            if (ui_event_queue) {
                xQueueSend(ui_event_queue, &evt, 0);
            }
        }
    }
}

void ui_task(void *pvParameters)
{
    ESP_LOGI(TAG, "UI task started");
    
    /* OLED initialization would go here */
    /* display_init(); */
    
    /* Button state initialization */
    for (int i = 0; i < 4; i++) {
        buttons[i].last_state = gpio_get_level(buttons[i].gpio);
    }
    
    while (1) {
        /* Scan buttons */
        for (int i = 0; i < 4; i++) {
            handle_button(&buttons[i], i);
        }
        
        /* Process UI events */
        ui_event_t evt;
        while (xQueueReceive(ui_event_queue, &evt, 0)) {
            const char *key_names[] = {"UP", "DOWN", "SEL", "BACK"};
            const char *actions[] = {"press", "release", "long_press"};
            ESP_LOGI(TAG, "Button: %s - %s", key_names[evt.key], actions[evt.action]);
        }
        
        /* Read ADC data for display */
        adc_data_t adc_data;
        if (adc_data_queue && xQueuePeek(adc_data_queue, &adc_data, 0)) {
            /* Update OLED display with ADC data */
            /* display_update(&adc_data); */
        }
        
        vTaskDelay(pdMS_TO_TICKS(20));  /* 50Hz scan rate */
    }
}