#include "wifi_manager.h"
#include "esp_log.h"
#include "esp_system.h"
#include "nvs_flash.h"
#include <string.h>

static const char *TAG = "WIFI_MANAGER";

// WiFi manager state
static bool is_initialized = false;
static wifi_status_t current_status = WIFI_STATUS_DISCONNECTED;
static EventGroupHandle_t wifi_event_group = NULL;
static wifi_event_callback_t user_callback = NULL;
static char stored_ip[16] = {0};

// Event group bits
#define WIFI_CONNECTED_BIT BIT0
#define WIFI_FAIL_BIT BIT1

// Event handler instances
static esp_event_handler_instance_t instance_any_id;
static esp_event_handler_instance_t instance_got_ip;

// WiFi event handler
static void wifi_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_LOGI(TAG, "WiFi started, connecting...");
        current_status = WIFI_STATUS_CONNECTING;
        esp_wifi_connect();
        if (user_callback)
        {
            user_callback(current_status, NULL);
        }
    }
    else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED)
    {
        ESP_LOGI(TAG, "WiFi disconnected, trying to reconnect...");
        current_status = WIFI_STATUS_DISCONNECTED;
        memset(stored_ip, 0, sizeof(stored_ip));
        esp_wifi_connect();
        xEventGroupClearBits(wifi_event_group, WIFI_CONNECTED_BIT);
        if (user_callback)
        {
            user_callback(current_status, NULL);
        }
    }
    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;
        snprintf(stored_ip, sizeof(stored_ip), IPSTR, IP2STR(&event->ip_info.ip));
        ESP_LOGI(TAG, "WiFi connected! IP: %s", stored_ip);
        current_status = WIFI_STATUS_CONNECTED;
        xEventGroupSetBits(wifi_event_group, WIFI_CONNECTED_BIT);
        if (user_callback)
        {
            user_callback(current_status, stored_ip);
        }
    }
}

esp_err_t wifi_manager_init(const char *ssid, const char *password, wifi_event_callback_t event_callback)
{
    if (is_initialized)
    {
        ESP_LOGW(TAG, "WiFi manager already initialized");
        return ESP_OK;
    }

    if (ssid == NULL || password == NULL)
    {
        ESP_LOGE(TAG, "SSID and password cannot be NULL");
        return ESP_ERR_INVALID_ARG;
    }

    ESP_LOGI(TAG, "Initializing WiFi manager");

    user_callback = event_callback;
    current_status = WIFI_STATUS_DISCONNECTED;

    // Create event group
    wifi_event_group = xEventGroupCreate();
    if (wifi_event_group == NULL)
    {
        ESP_LOGE(TAG, "Failed to create WiFi event group");
        return ESP_ERR_NO_MEM;
    }

    // Initialize netif
    ESP_ERROR_CHECK(esp_netif_init());

    // Create default event loop if not exists
    esp_err_t ret = esp_event_loop_create_default();
    if (ret != ESP_OK && ret != ESP_ERR_INVALID_STATE)
    {
        ESP_LOGE(TAG, "Failed to create event loop: %s", esp_err_to_name(ret));
        vEventGroupDelete(wifi_event_group);
        wifi_event_group = NULL;
        return ret;
    }

    // Create default WiFi STA
    esp_netif_create_default_wifi_sta();

    // Initialize WiFi
    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
    ret = esp_wifi_init(&cfg);
    if (ret != ESP_OK)
    {
        ESP_LOGE(TAG, "Failed to initialize WiFi: %s", esp_err_to_name(ret));
        vEventGroupDelete(wifi_event_group);
        wifi_event_group = NULL;
        return ret;
    }

    // Register event handlers
    ret = esp_event_handler_instance_register(WIFI_EVENT,
                                              ESP_EVENT_ANY_ID,
                                              &wifi_event_handler,
                                              NULL,
                                              &instance_any_id);
    if (ret != ESP_OK)
    {
        ESP_LOGE(TAG, "Failed to register WiFi event handler: %s", esp_err_to_name(ret));
        esp_wifi_deinit();
        vEventGroupDelete(wifi_event_group);
        wifi_event_group = NULL;
        return ret;
    }

    ret = esp_event_handler_instance_register(IP_EVENT,
                                              IP_EVENT_STA_GOT_IP,
                                              &wifi_event_handler,
                                              NULL,
                                              &instance_got_ip);
    if (ret != ESP_OK)
    {
        ESP_LOGE(TAG, "Failed to register IP event handler: %s", esp_err_to_name(ret));
        esp_event_handler_instance_unregister(WIFI_EVENT, ESP_EVENT_ANY_ID, instance_any_id);
        esp_wifi_deinit();
        vEventGroupDelete(wifi_event_group);
        wifi_event_group = NULL;
        return ret;
    }

    // Configure WiFi
    wifi_config_t wifi_config = {
        .sta = {
            .threshold.authmode = WIFI_AUTH_WPA2_PSK,
        },
    };

    strncpy((char *)wifi_config.sta.ssid, ssid, sizeof(wifi_config.sta.ssid) - 1);
    strncpy((char *)wifi_config.sta.password, password, sizeof(wifi_config.sta.password) - 1);

    ret = esp_wifi_set_mode(WIFI_MODE_STA);
    if (ret != ESP_OK)
    {
        ESP_LOGE(TAG, "Failed to set WiFi mode: %s", esp_err_to_name(ret));
        wifi_manager_deinit();
        return ret;
    }

    ret = esp_wifi_set_config(WIFI_IF_STA, &wifi_config);
    if (ret != ESP_OK)
    {
        ESP_LOGE(TAG, "Failed to set WiFi config: %s", esp_err_to_name(ret));
        wifi_manager_deinit();
        return ret;
    }

    is_initialized = true;
    ESP_LOGI(TAG, "WiFi manager initialized successfully");
    return ESP_OK;
}

esp_err_t wifi_manager_start(void)
{
    if (!is_initialized)
    {
        ESP_LOGE(TAG, "WiFi manager not initialized");
        return ESP_ERR_INVALID_STATE;
    }

    ESP_LOGI(TAG, "Starting WiFi");
    esp_err_t ret = esp_wifi_start();
    if (ret != ESP_OK)
    {
        ESP_LOGE(TAG, "Failed to start WiFi: %s", esp_err_to_name(ret));
        current_status = WIFI_STATUS_ERROR;
        return ret;
    }

    return ESP_OK;
}

esp_err_t wifi_manager_stop(void)
{
    if (!is_initialized)
    {
        ESP_LOGE(TAG, "WiFi manager not initialized");
        return ESP_ERR_INVALID_STATE;
    }

    ESP_LOGI(TAG, "Stopping WiFi");
    current_status = WIFI_STATUS_DISCONNECTED;
    memset(stored_ip, 0, sizeof(stored_ip));

    esp_err_t ret = esp_wifi_stop();
    if (ret != ESP_OK)
    {
        ESP_LOGE(TAG, "Failed to stop WiFi: %s", esp_err_to_name(ret));
        return ret;
    }

    return ESP_OK;
}

wifi_status_t wifi_manager_get_status(void)
{
    return current_status;
}

bool wifi_manager_wait_for_connection(uint32_t timeout_ms)
{
    if (!is_initialized || wifi_event_group == NULL)
    {
        ESP_LOGE(TAG, "WiFi manager not initialized");
        return false;
    }

    TickType_t timeout_ticks = (timeout_ms == 0) ? portMAX_DELAY : pdMS_TO_TICKS(timeout_ms);

    EventBits_t bits = xEventGroupWaitBits(wifi_event_group,
                                           WIFI_CONNECTED_BIT,
                                           pdFALSE,
                                           pdFALSE,
                                           timeout_ticks);

    return (bits & WIFI_CONNECTED_BIT) != 0;
}

esp_err_t wifi_manager_get_ip_address(char *ip_str, size_t buffer_size)
{
    if (ip_str == NULL || buffer_size < 16)
    {
        ESP_LOGE(TAG, "Invalid parameters for IP address");
        return ESP_ERR_INVALID_ARG;
    }

    if (current_status != WIFI_STATUS_CONNECTED || strlen(stored_ip) == 0)
    {
        ESP_LOGW(TAG, "WiFi not connected or no IP address available");
        return ESP_ERR_INVALID_STATE;
    }

    strncpy(ip_str, stored_ip, buffer_size - 1);
    ip_str[buffer_size - 1] = '\0';

    return ESP_OK;
}

bool wifi_manager_is_connected(void)
{
    return current_status == WIFI_STATUS_CONNECTED;
}

esp_err_t wifi_manager_deinit(void)
{
    if (!is_initialized)
    {
        ESP_LOGW(TAG, "WiFi manager not initialized");
        return ESP_OK;
    }

    ESP_LOGI(TAG, "Deinitializing WiFi manager");

    // Stop WiFi if running
    esp_wifi_stop();

    // Unregister event handlers
    if (instance_any_id != NULL)
    {
        esp_event_handler_instance_unregister(WIFI_EVENT, ESP_EVENT_ANY_ID, instance_any_id);
        instance_any_id = NULL;
    }

    if (instance_got_ip != NULL)
    {
        esp_event_handler_instance_unregister(IP_EVENT, IP_EVENT_STA_GOT_IP, instance_got_ip);
        instance_got_ip = NULL;
    }

    // Deinitialize WiFi
    esp_wifi_deinit();

    // Delete event group
    if (wifi_event_group != NULL)
    {
        vEventGroupDelete(wifi_event_group);
        wifi_event_group = NULL;
    }

    current_status = WIFI_STATUS_DISCONNECTED;
    memset(stored_ip, 0, sizeof(stored_ip));
    user_callback = NULL;
    is_initialized = false;

    ESP_LOGI(TAG, "WiFi manager deinitialized");
    return ESP_OK;
}