#include "wifi_manager.h"
#include "config.h"
#include "esp_log.h"
#include "esp_event.h"
#include "esp_netif.h"
#include "freertos/FreeRTOS.h"
#include "freertos/event_groups.h"
#include <string.h>
#include <stdio.h>

// Private state
static struct {
    wifi_status_t status;
    EventGroupHandle_t event_group;
    esp_netif_t* netif;
    char current_ssid[33];
    char current_password[65];
    uint8_t max_retries;
    uint8_t retry_count;
    uint32_t connect_start_time;
    bool auto_reconnect;
    bool initialized;
    
    // Statistics
    uint32_t total_attempts;
    uint32_t successful_connections;
    esp_err_t last_error;
} wifi_state = {
    .status = WIFI_STATUS_DISCONNECTED,
    .event_group = NULL,
    .netif = NULL,
    .current_ssid = "",
    .current_password = "",
    .max_retries = WIFI_MAXIMUM_RETRY,
    .retry_count = 0,
    .connect_start_time = 0,
    .auto_reconnect = true,
    .initialized = false,
    .total_attempts = 0,
    .successful_connections = 0,
    .last_error = ESP_OK
};

// Private function declarations
static void wifi_event_handler(void* arg, esp_event_base_t event_base, int32_t event_id, void* event_data);
static esp_err_t start_connection_attempt(void);

// Private function implementations
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) {
        switch (event_id) {
            case WIFI_EVENT_STA_START:
                ESP_LOGI(SYSTEM_TAG, "WiFi station started");
                break;
                
            case WIFI_EVENT_STA_CONNECTED:
                ESP_LOGI(SYSTEM_TAG, "Connected to WiFi network: %s", wifi_state.current_ssid);
                wifi_state.status = WIFI_STATUS_CONNECTED;
                break;
                
            case WIFI_EVENT_STA_DISCONNECTED: {
                wifi_event_sta_disconnected_t* disconnected = (wifi_event_sta_disconnected_t*) event_data;
                ESP_LOGW(SYSTEM_TAG, "WiFi disconnected, reason: %d", disconnected->reason);
                
                if (wifi_state.status == WIFI_STATUS_CONNECTED) {
                    // We were connected, so this is a disconnection
                    if (wifi_state.auto_reconnect) {
                        wifi_state.status = WIFI_STATUS_RECONNECTING;
                        wifi_state.retry_count = 0;
                        ESP_LOGI(SYSTEM_TAG, "Auto-reconnect enabled, attempting to reconnect...");
                        esp_wifi_connect();
                    } else {
                        wifi_state.status = WIFI_STATUS_DISCONNECTED;
                    }
                } else {
                    // Connection attempt failed
                    wifi_state.retry_count++;
                    wifi_state.last_error = ESP_ERR_WIFI_NOT_CONNECT;
                    
                    if (wifi_state.max_retries == 0 || wifi_state.retry_count < wifi_state.max_retries) {
                        wifi_state.status = WIFI_STATUS_CONNECTING;
                        ESP_LOGI(SYSTEM_TAG, "Retry %d/%d connecting to WiFi...", 
                                wifi_state.retry_count, wifi_state.max_retries);
                        esp_wifi_connect();
                    } else {
                        wifi_state.status = WIFI_STATUS_FAILED;
                        ESP_LOGE(SYSTEM_TAG, "Failed to connect to WiFi after %d attempts", wifi_state.retry_count);
                        xEventGroupSetBits(wifi_state.event_group, WIFI_FAIL_BIT);
                    }
                }
                break;
            }
                
            default:
                break;
        }
    } 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(SYSTEM_TAG, "Got IP address: " IPSTR, IP2STR(&event->ip_info.ip));
        
        wifi_state.status = WIFI_STATUS_CONNECTED;
        wifi_state.successful_connections++;
        wifi_state.retry_count = 0;
        wifi_state.last_error = ESP_OK;
        
        xEventGroupSetBits(wifi_state.event_group, WIFI_CONNECTED_BIT);
    }
}

static void update_connection_time(void) {
    if (wifi_state.connect_start_time > 0) {
        wifi_state.connect_start_time = xTaskGetTickCount() * portTICK_PERIOD_MS;
    }
}

static esp_err_t start_connection_attempt(void) {
    wifi_state.total_attempts++;
    wifi_state.connect_start_time = xTaskGetTickCount() * portTICK_PERIOD_MS;
    wifi_state.retry_count = 0;
    wifi_state.status = WIFI_STATUS_CONNECTING;
    
    // Clear event bits
    xEventGroupClearBits(wifi_state.event_group, WIFI_CONNECTED_BIT | WIFI_FAIL_BIT);
    
    return esp_wifi_connect();
}

// Public API implementation
esp_err_t wifi_manager_init(void) {
    if (wifi_state.initialized) {
        ESP_LOGW(SYSTEM_TAG, "WiFi manager already initialized");
        return ESP_OK;
    }
    
    ESP_LOGI(SYSTEM_TAG, "Initializing WiFi manager...");
    
    // Create event group
    wifi_state.event_group = xEventGroupCreate();
    if (!wifi_state.event_group) {
        ESP_LOGE(SYSTEM_TAG, "Failed to create WiFi event group");
        return ESP_FAIL;
    }
    
    // Initialize network interface
    esp_err_t ret = esp_netif_init();
    if (ret != ESP_OK) {
        ESP_LOGE(SYSTEM_TAG, "Failed to initialize netif: %s", esp_err_to_name(ret));
        return ret;
    }
    
    ret = esp_event_loop_create_default();
    if (ret != ESP_OK && ret != ESP_ERR_INVALID_STATE) {
        ESP_LOGE(SYSTEM_TAG, "Failed to create event loop: %s", esp_err_to_name(ret));
        return ret;
    }
    
    wifi_state.netif = esp_netif_create_default_wifi_sta();
    if (!wifi_state.netif) {
        ESP_LOGE(SYSTEM_TAG, "Failed to create default WiFi STA netif");
        return ESP_FAIL;
    }
    
    // Initialize WiFi
    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
    ret = esp_wifi_init(&cfg);
    if (ret != ESP_OK) {
        ESP_LOGE(SYSTEM_TAG, "Failed to initialize WiFi: %s", esp_err_to_name(ret));
        return ret;
    }
    
    // Register event handlers
    ret = esp_event_handler_instance_register(WIFI_EVENT, ESP_EVENT_ANY_ID, 
                                             &wifi_event_handler, NULL, NULL);
    if (ret != ESP_OK) {
        ESP_LOGE(SYSTEM_TAG, "Failed to register WiFi event handler: %s", esp_err_to_name(ret));
        return ret;
    }
    
    ret = esp_event_handler_instance_register(IP_EVENT, IP_EVENT_STA_GOT_IP, 
                                             &wifi_event_handler, NULL, NULL);
    if (ret != ESP_OK) {
        ESP_LOGE(SYSTEM_TAG, "Failed to register IP event handler: %s", esp_err_to_name(ret));
        return ret;
    }
    
    // Set WiFi mode
    ret = esp_wifi_set_mode(WIFI_MODE_STA);
    if (ret != ESP_OK) {
        ESP_LOGE(SYSTEM_TAG, "Failed to set WiFi mode: %s", esp_err_to_name(ret));
        return ret;
    }
    
    // Start WiFi
    ret = esp_wifi_start();
    if (ret != ESP_OK) {
        ESP_LOGE(SYSTEM_TAG, "Failed to start WiFi: %s", esp_err_to_name(ret));
        return ret;
    }
    
    wifi_state.initialized = true;
    wifi_state.status = WIFI_STATUS_DISCONNECTED;
    
    ESP_LOGI(SYSTEM_TAG, "WiFi manager initialized successfully");
    return ESP_OK;
}

esp_err_t wifi_manager_connect(const char* ssid, const char* password, uint8_t max_retries) {
    if (!wifi_state.initialized) {
        ESP_LOGE(SYSTEM_TAG, "WiFi manager not initialized");
        return ESP_FAIL;
    }
    
    if (!ssid || strlen(ssid) == 0 || strlen(ssid) > 32) {
        ESP_LOGE(SYSTEM_TAG, "Invalid SSID");
        return ESP_ERR_INVALID_ARG;
    }
    
    if (!password || strlen(password) > 64) {
        ESP_LOGE(SYSTEM_TAG, "Invalid password");
        return ESP_ERR_INVALID_ARG;
    }
    
    // Store connection parameters
    strncpy(wifi_state.current_ssid, ssid, sizeof(wifi_state.current_ssid) - 1);
    wifi_state.current_ssid[sizeof(wifi_state.current_ssid) - 1] = '\0';
    
    strncpy(wifi_state.current_password, password, sizeof(wifi_state.current_password) - 1);
    wifi_state.current_password[sizeof(wifi_state.current_password) - 1] = '\0';
    
    wifi_state.max_retries = max_retries;
    
    // Configure WiFi
    wifi_config_t wifi_config = {0};
    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);
    wifi_config.sta.threshold.authmode = WIFI_AUTH_WPA2_PSK;
    wifi_config.sta.pmf_cfg.capable = true;
    wifi_config.sta.pmf_cfg.required = false;
    
    esp_err_t ret = esp_wifi_set_config(WIFI_IF_STA, &wifi_config);
    if (ret != ESP_OK) {
        ESP_LOGE(SYSTEM_TAG, "Failed to set WiFi config: %s", esp_err_to_name(ret));
        return ret;
    }
    
    ESP_LOGI(SYSTEM_TAG, "Connecting to WiFi SSID: %s", ssid);
    return start_connection_attempt();
}

esp_err_t wifi_manager_connect_default(void) {
    return wifi_manager_connect(WIFI_SSID, WIFI_PASS, WIFI_MAXIMUM_RETRY);
}

esp_err_t wifi_manager_disconnect(void) {
    if (!wifi_state.initialized) {
        return ESP_FAIL;
    }
    
    wifi_state.auto_reconnect = false;
    wifi_state.status = WIFI_STATUS_DISCONNECTED;
    
    esp_err_t ret = esp_wifi_disconnect();
    if (ret != ESP_OK) {
        ESP_LOGE(SYSTEM_TAG, "Failed to disconnect WiFi: %s", esp_err_to_name(ret));
    }
    
    return ret;
}

wifi_status_t wifi_manager_get_status(void) {
    return wifi_state.status;
}

esp_err_t wifi_manager_get_info(wifi_info_t* info) {
    if (!info) {
        return ESP_ERR_INVALID_ARG;
    }
    
    info->status = wifi_state.status;
    strncpy(info->ssid, wifi_state.current_ssid, sizeof(info->ssid) - 1);
    info->ssid[sizeof(info->ssid) - 1] = '\0';
    info->ip_address = wifi_manager_get_ip();
    info->rssi = wifi_manager_get_rssi();
    info->retry_count = wifi_state.retry_count;
    info->auto_reconnect = wifi_state.auto_reconnect;
    
    if (wifi_state.connect_start_time > 0) {
        uint32_t current_time = xTaskGetTickCount() * portTICK_PERIOD_MS;
        info->connect_time_ms = current_time - wifi_state.connect_start_time;
    } else {
        info->connect_time_ms = 0;
    }
    
    return ESP_OK;
}

bool wifi_manager_is_connected(void) {
    return wifi_state.status == WIFI_STATUS_CONNECTED;
}

uint32_t wifi_manager_get_ip(void) {
    if (!wifi_state.initialized || !wifi_manager_is_connected()) {
        return 0;
    }
    
    esp_netif_ip_info_t ip_info;
    if (esp_netif_get_ip_info(wifi_state.netif, &ip_info) == ESP_OK) {
        return ip_info.ip.addr;
    }
    
    return 0;
}

esp_err_t wifi_manager_get_ip_string(char* ip_str, size_t max_len) {
    if (!ip_str || max_len < 16) {
        return ESP_ERR_INVALID_ARG;
    }
    
    uint32_t ip = wifi_manager_get_ip();
    if (ip == 0) {
        strncpy(ip_str, "0.0.0.0", max_len - 1);
        ip_str[max_len - 1] = '\0';
        return ESP_FAIL;
    }
    
    // Convert uint32_t IP to string manually
    uint8_t* ip_bytes = (uint8_t*)&ip;
    snprintf(ip_str, max_len, "%d.%d.%d.%d", 
             ip_bytes[0], ip_bytes[1], ip_bytes[2], ip_bytes[3]);
    return ESP_OK;
}

int8_t wifi_manager_get_rssi(void) {
    if (!wifi_state.initialized || !wifi_manager_is_connected()) {
        return 0;
    }
    
    wifi_ap_record_t ap_info;
    if (esp_wifi_sta_get_ap_info(&ap_info) == ESP_OK) {
        return ap_info.rssi;
    }
    
    return 0;
}

esp_err_t wifi_manager_set_auto_reconnect(bool enable) {
    wifi_state.auto_reconnect = enable;
    ESP_LOGI(SYSTEM_TAG, "Auto-reconnect %s", enable ? "enabled" : "disabled");
    return ESP_OK;
}

esp_err_t wifi_manager_wait_for_connection(uint32_t timeout_ms) {
    if (!wifi_state.initialized) {
        return ESP_FAIL;
    }
    
    if (wifi_manager_is_connected()) {
        return ESP_OK;
    }
    
    TickType_t timeout_ticks = (timeout_ms == 0) ? portMAX_DELAY : pdMS_TO_TICKS(timeout_ms);
    
    EventBits_t bits = xEventGroupWaitBits(wifi_state.event_group,
                                          WIFI_CONNECTED_BIT | WIFI_FAIL_BIT,
                                          pdFALSE, pdFALSE, timeout_ticks);
    
    if (bits & WIFI_CONNECTED_BIT) {
        return ESP_OK;
    } else if (bits & WIFI_FAIL_BIT) {
        return ESP_FAIL;
    } else {
        return ESP_ERR_TIMEOUT;
    }
}

const char* wifi_manager_status_to_string(wifi_status_t status) {
    switch (status) {
        case WIFI_STATUS_DISCONNECTED: return "DISCONNECTED";
        case WIFI_STATUS_CONNECTING: return "CONNECTING";
        case WIFI_STATUS_CONNECTED: return "CONNECTED";
        case WIFI_STATUS_FAILED: return "FAILED";
        case WIFI_STATUS_RECONNECTING: return "RECONNECTING";
        default: return "UNKNOWN";
    }
}

esp_err_t wifi_manager_start_scan(void) {
    if (!wifi_state.initialized) {
        return ESP_FAIL;
    }
    
    wifi_scan_config_t scan_config = {
        .ssid = NULL,
        .bssid = NULL,
        .channel = 0,
        .show_hidden = false,
        .scan_type = WIFI_SCAN_TYPE_ACTIVE,
        .scan_time.active.min = 100,
        .scan_time.active.max = 300
    };
    
    return esp_wifi_scan_start(&scan_config, false);
}

esp_err_t wifi_manager_get_scan_results(wifi_ap_record_t* ap_info, uint16_t max_aps, uint16_t* num_aps) {
    if (!ap_info || !num_aps) {
        return ESP_ERR_INVALID_ARG;
    }
    
    return esp_wifi_scan_get_ap_records(&max_aps, ap_info);
}

esp_err_t wifi_manager_reconnect(void) {
    if (!wifi_state.initialized) {
        return ESP_FAIL;
    }
    
    ESP_LOGI(SYSTEM_TAG, "Forcing WiFi reconnection...");
    wifi_state.retry_count = 0;
    return start_connection_attempt();
}

esp_err_t wifi_manager_get_stats(uint32_t* total_attempts, uint32_t* successful_connections, esp_err_t* last_error) {
    if (total_attempts) *total_attempts = wifi_state.total_attempts;
    if (successful_connections) *successful_connections = wifi_state.successful_connections;
    if (last_error) *last_error = wifi_state.last_error;
    return ESP_OK;
}

esp_err_t wifi_manager_reset_stats(void) {
    wifi_state.total_attempts = 0;
    wifi_state.successful_connections = 0;
    wifi_state.last_error = ESP_OK;
    ESP_LOGI(SYSTEM_TAG, "WiFi statistics reset");
    return ESP_OK;
}