#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/event_groups.h"
#include "esp_system.h"
#include "esp_wifi.h"
#include "esp_event.h"
#include "esp_log.h"
#include "nvs_flash.h"
#include "esp_netif_sntp.h"

#include "wifi_connect.h"
#include "wifi_credentials.h"
#include "audio_driver.h"

#define ESP_MAXIMUM_RETRY  5

/* FreeRTOS event group to signal when we are connected */
static EventGroupHandle_t s_wifi_event_group;

/* The event group allows multiple bits for each event, but we only care about two events:
 * - we are connected to the AP with an IP
 * - we failed to connect after the maximum amount of retries */
#define WIFI_CONNECTED_BIT BIT0
#define WIFI_FAIL_BIT      BIT1

static const char *TAG = "wifi station";

static bool s_was_connected = false;
static bool s_first_time_connect = true;

static void event_handler(void* arg, esp_event_base_t event_base,
                                int32_t event_id, void* event_data)
{
    if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_START) {
        esp_wifi_connect();
    } else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED) {
        xEventGroupClearBits(s_wifi_event_group, WIFI_CONNECTED_BIT);
        xEventGroupSetBits(s_wifi_event_group, WIFI_FAIL_BIT);
        ESP_LOGI(TAG, "Disconnected from AP");
    } else if (event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP) {
        ip_event_got_ip_t* event = (ip_event_got_ip_t*) event_data;
        ESP_LOGI(TAG, "got ip:" IPSTR, IP2STR(&event->ip_info.ip));
        xEventGroupClearBits(s_wifi_event_group, WIFI_FAIL_BIT);
        xEventGroupSetBits(s_wifi_event_group, WIFI_CONNECTED_BIT);
    }
}

static void init_sntp(void)
{
    ESP_LOGI("SNTP", "Initializing SNTP...");
    esp_sntp_config_t config = ESP_NETIF_SNTP_DEFAULT_CONFIG("pool.ntp.org");
    ESP_ERROR_CHECK(esp_netif_sntp_init(&config));
}

static void wifi_manager_task(void *pvParameters)
{
    while (1) {
        EventBits_t bits = xEventGroupGetBits(s_wifi_event_group);
        if (!(bits & WIFI_CONNECTED_BIT)) {
            // We are not connected!
            if (s_was_connected) {
                // We lost connection!
                ESP_LOGW(TAG, "Wi-Fi connection lost! Playing alert...");
                set_led_state(LED_STATE_WIFI_CONNECTING);
                Audio_Play_Music_To_End("file://spiffs/disconnected_wifi.mp3");
                s_was_connected = false;
            }

            int retry_count = 0;
            bool success = false;
            while (retry_count < ESP_MAXIMUM_RETRY) {
                ESP_LOGI(TAG, "Attempting Wi-Fi connection (try %d/%d)...", retry_count + 1, ESP_MAXIMUM_RETRY);
                set_led_state(LED_STATE_WIFI_CONNECTING);
                xEventGroupClearBits(s_wifi_event_group, WIFI_FAIL_BIT);
                esp_wifi_connect();

                // Wait up to 6 seconds for connection bit
                bits = xEventGroupWaitBits(s_wifi_event_group, WIFI_CONNECTED_BIT, pdFALSE, pdFALSE, pdMS_TO_TICKS(6000));
                if (bits & WIFI_CONNECTED_BIT) {
                    success = true;
                    break;
                }
                retry_count++;
            }

            if (success) {
                ESP_LOGI(TAG, "Wi-Fi Connected successfully.");
                s_was_connected = true;
                set_led_state(LED_STATE_SERVER_CONNECTING);
                
                // Play connected audio prompt
                Audio_Play_Music_To_End("file://spiffs/connected_wifi.mp3");
                s_first_time_connect = false;
            } else {
                ESP_LOGW(TAG, "Wi-Fi connection failed. Retrying in 10 seconds...");
                set_led_state(LED_STATE_WIFI_FAILED);
                
                // Play "Still not working, let me try again in a moment"
                Audio_Play_Music_To_End("file://spiffs/retry_later.mp3");
                
                // Wait 10 seconds before next connection attempt
                vTaskDelay(pdMS_TO_TICKS(10000));
                
                // Play "Connecting to the Wi-Fi" chime before retrying
                Audio_Play_Music_To_End("file://spiffs/connecting_wifi.mp3");
            }
        } else {
            // Already connected! Keep monitoring
            vTaskDelay(pdMS_TO_TICKS(1000));
        }
    }
}

bool wifi_is_connected(void)
{
    if (s_wifi_event_group == NULL) return false;
    EventBits_t bits = xEventGroupGetBits(s_wifi_event_group);
    return (bits & WIFI_CONNECTED_BIT) != 0;
}

esp_err_t wifi_init_sta(void)
{
    s_wifi_event_group = xEventGroupCreate();

    ESP_ERROR_CHECK(esp_netif_init());

    // Only create event loop if it hasn't been created yet
    esp_err_t err = esp_event_loop_create_default();
    if (err != ESP_OK && err != ESP_ERR_INVALID_STATE) {
        ESP_ERROR_CHECK(err);
    }

    esp_netif_create_default_wifi_sta();

    // Initialize SNTP exactly once during startup
    init_sntp();

    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
    ESP_ERROR_CHECK(esp_wifi_init(&cfg));

    esp_event_handler_instance_t instance_any_id;
    esp_event_handler_instance_t instance_got_ip;
    ESP_ERROR_CHECK(esp_event_handler_instance_register(WIFI_EVENT,
                                                        ESP_EVENT_ANY_ID,
                                                        &event_handler,
                                                        NULL,
                                                        &instance_any_id));
    ESP_ERROR_CHECK(esp_event_handler_instance_register(IP_EVENT,
                                                        IP_EVENT_STA_GOT_IP,
                                                        &event_handler,
                                                        NULL,
                                                        &instance_got_ip));

    wifi_config_t wifi_config = {
        .sta = {
            .ssid = WIFI_SSID,
            .password = WIFI_PASSWORD,
            .threshold.authmode = WIFI_AUTH_WPA2_PSK,
        },
    };
    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA) );
    ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_STA, &wifi_config) );
    ESP_ERROR_CHECK(esp_wifi_start() );

    ESP_LOGI(TAG, "Starting Wi-Fi manager task...");
    xTaskCreate(wifi_manager_task, "wifi_manager_task", 4096, NULL, 5, NULL);

    // Wait blockingly on first boot for initial connection
    ESP_LOGI(TAG, "Waiting for initial Wi-Fi connection...");
    xEventGroupWaitBits(s_wifi_event_group, WIFI_CONNECTED_BIT, pdFALSE, pdFALSE, portMAX_DELAY);

    return ESP_OK;
}