//
// Created by misaki on 2025/9/2.
//
#include "CommClass.h"
#include <cstring>      // 引入字符串处理库头文件
#include <chrono>       // 时间库头文件
#include <memory>
#include <esp_event.h>
#include <esp_log.h>
#include <esp_netif_types.h>

#include "ToolsClass.h"
#include "sys_conf_singleton.h"

// 静态成员初始化
WebSocketManager* WebSocketManager::instance = nullptr;
std::mutex WebSocketManager::instance_mutex;
std::string WebSocketManager::sn = SysConfJson::getInstance()->loadSN();    // 获取SN(同时也能初始化文件系统，如果还没有初始化这个文件系统的话)

// 标签用于日志
static const char* TAG = "WebSocketManager";


// 构造函数
WebSocketManager::WebSocketManager()
    : client(nullptr), threads_running(false),
    connected(false), connecting(false), reconnect_attempts(0),
    stats{0, 0, 0, 0},
    wifi(WifiConnectors::getInstance())

{

}


// 析构函数
WebSocketManager::~WebSocketManager() {
    disconnect();

    // 停止线程
    threads_running = false;
    queue_cv.notify_all();

    if (reconnect_thread.joinable()) {
        reconnect_thread.join();
    }

    if (heartbeat_thread.joinable()) {
        heartbeat_thread.join();
    }

    if (send_thread.joinable()) {
        send_thread.join();
    }
}

WebSocketManager* WebSocketManager::getInstance() {
    std::lock_guard<std::mutex> lock(instance_mutex);   // 加锁
    if (instance == nullptr) {
        instance = new WebSocketManager();
    }
    return instance;
}

bool WebSocketManager::initialize(const WebSocketConfig& ws_config) {
    this->config = ws_config;

    // 注册WiFi事件处理
    esp_event_handler_instance_t wifi_instance;
    esp_event_handler_instance_register(IP_EVENT, IP_EVENT_STA_GOT_IP,
                                       &WebSocketManager::wifiEventHandler,
                                       this, &wifi_instance);

    // 启动发送线程
    // 只在线程未运行时启动发送线程
    if (!send_thread.joinable()) {
        threads_running = true;
        ThreadConfig thread_config;
        thread_config.name = "WS_Send";
        thread_config.stack_size = 4096;
        send_thread = ThreadManager::createMemberThread(thread_config, this,
                                                      &WebSocketManager::sendThread);
    }
    return true;
}

bool WebSocketManager::connect() {
    if (connecting || connected) {
        ESP_LOGI(TAG, "Already connected or connecting");
        return true;
    }

    // 检查WiFi连接
    if (!wifi->isWifiConnect()) {
        ESP_LOGE(TAG, "WiFi not connected, cannot establish WebSocket connection");
        if (event_callback) {
            event_callback(WebSocketEvent::ERROR, "WiFi not connected");
        }
        return false;
    }

    connecting = true;
    stats.connection_attempts++;

    // 创建WebSocket客户端
    if (!createWebSocketClient()) {
        connecting = false;
        return false;
    }

    // 启动WebSocket客户端
    esp_err_t err = esp_websocket_client_start(client);
    if (err != ESP_OK) {
        ESP_LOGE(TAG, "Failed to start WebSocket client: %d", err);
        destroyWebSocketClient();
        connecting = false;
        return false;
    }

    // 启动重连和心跳线程
    // 只有在线程未运行时才启动新线程
    if (!reconnect_thread.joinable()) {
        ThreadConfig thread_config;
        thread_config.name = "WS_Reconnect";
        thread_config.stack_size = 3072;

        reconnect_thread = ThreadManager::createMemberThread(thread_config, this,
                                                           &WebSocketManager::reconnectThread);
    }

    if (!heartbeat_thread.joinable()) {
        ThreadConfig thread_config;
        thread_config.name = "WS_Heartbeat";
        thread_config.stack_size = 3072;

        heartbeat_thread = ThreadManager::createMemberThread(thread_config, this,
                                                           &WebSocketManager::heartbeatThread);
    }
    return true;
}

void WebSocketManager::disconnect() {
    if (client) {
        esp_websocket_client_stop(client);
        destroyWebSocketClient();
    }

    connected = false;
    connecting = false;

    // 通知事件回调
    if (event_callback) {
        event_callback(WebSocketEvent::DISCONNECTED, "Disconnected by user");
    }
}

bool WebSocketManager::sendJson(const cppjson::Json& json) {
    if (!connected) {   // 检查连接状态
        ESP_LOGE(TAG, "Not connected, cannot send data");
        return false;
    }
    std::string json_str = json.dump();     // 序列化 JSON
    if (json_str.empty() || json_str == "null") {       // 检查序列化结果
        ESP_LOGE(TAG, "Failed to stringify JSON");
        return false;
    }

    {   // 临界区
        std::lock_guard<std::mutex> lock(queue_mutex);
        send_queue.emplace(std::move(json_str));  // 移动进队列，零拷贝
    }
    queue_cv.notify_one();             // 通知发送线程
    return true;
}

bool WebSocketManager::sendRaw(const std::string& data) {
    if (!connected) {   // 检查连接状态
        ESP_LOGE(TAG, "Not connected, cannot send data");
        return false;
    }

    std::lock_guard<std::mutex> lock(queue_mutex);  // 锁定队列
    send_queue.push(data);      // 添加到队列
    queue_cv.notify_one();      // 通知发送线程
    return true;
}

void WebSocketManager::setJsonCallback(const JsonDataCallback &callback) {
    json_callback = callback;
}

void WebSocketManager::setEventCallback(const EventCallback &callback) {
    event_callback = callback;
}

bool WebSocketManager::isConnected() const {
    return connected;
}

WebSocketConfig WebSocketManager::getConfig() const {
    return config;
}

void WebSocketManager::updateConfig(const WebSocketConfig& ws_config) {
    this->config = ws_config;
}

WebSocketManager::Stats WebSocketManager::getStats() const {
    return stats;
}

void WebSocketManager::websocketEventHandler(void* handler_args, esp_event_base_t base,
                                           int32_t event_id, void* event_data) {
    auto* ws_instance = static_cast<WebSocketManager*>(handler_args);
    auto* data = static_cast<esp_websocket_event_data_t *>(event_data);

    switch(event_id) {
        case WEBSOCKET_EVENT_CONNECTED:
            ws_instance->connected = true;
            ws_instance->connecting = false;
            ws_instance->reconnect_attempts = 0;
            ws_instance->stats.successful_connections++;

            ESP_LOGI(TAG, "WebSocket connected");
            if (ws_instance->event_callback) {
                ws_instance->event_callback(WebSocketEvent::CONNECTED, "Connected successfully");
            }
            break;

        case WEBSOCKET_EVENT_DISCONNECTED:
            ws_instance->connected = false;
            ws_instance->connecting = false;

            ESP_LOGI(TAG, "WebSocket disconnected");
            if (ws_instance->event_callback) {
                ws_instance->event_callback(WebSocketEvent::DISCONNECTED, "Disconnected");
            }
            break;

        case WEBSOCKET_EVENT_DATA:
            if (data->data_len > 0) {
                ws_instance->stats.messages_received++;
                ws_instance->handleReceivedData((const char*)data->data_ptr, data->data_len);
            }
            break;

        case WEBSOCKET_EVENT_ERROR: // 错误事件
            ws_instance->connected = false;
            ws_instance->connecting = false;

            ESP_LOGE(TAG, "WebSocket error");
            if (ws_instance->event_callback) {
                ws_instance->event_callback(WebSocketEvent::ERROR, "WebSocket error occurred");
            }
            break;
        default:
            ESP_LOGW(TAG, "Unhandled WebSocket event: %ld", event_id);
            break;
    }
}

void WebSocketManager::handleReceivedData(const char* data, const int len) const {
    // 解析JSON
    cppjson::Json json = cppjson::Json::parse(std::string(data, len)); // 失败会得到空 Json
    if (!json.isNull()) {                // 解析成功
        if (json_callback) json_callback(json);
    } else {                             // 解析失败，当原始文本处理
        if (event_callback)
            event_callback(WebSocketEvent::DATA_RECEIVED, std::string(data, len));
    }
}

void WebSocketManager::reconnectThread() {
    while (threads_running) {
        if (!connected && config.auto_reconnect &&
            (config.max_reconnect_attempts == 0 ||
             reconnect_attempts < config.max_reconnect_attempts)) {     // 检查重连条件

            // 检查WiFi连接
            if (!wifi->isWifiConnect()) {
                ESP_LOGI(TAG, "WiFi not connected, waiting before WebSocket reconnect");
                std::this_thread::sleep_for(std::chrono::milliseconds(config.reconnect_interval));
                continue;
            }

            reconnect_attempts++;
            ESP_LOGI(TAG, "Attempting to reconnect (%ld/%d)",
                    reconnect_attempts, config.max_reconnect_attempts);

            if (connect()) {
                ESP_LOGI(TAG, "Reconnection attempt initiated");
            } else {
                ESP_LOGE(TAG, "Reconnection attempt failed");
            }
        }
        // sleep
        std::this_thread::sleep_for(std::chrono::milliseconds(config.reconnect_interval));
    }
}

void WebSocketManager::heartbeatThread() {
    while (threads_running) {
        if (connected && config.heartbeat_interval > 0) {   // 如果处于连接状态且心跳间隔大于0
            // 发送心跳消息
            cppjson::Json hb = cppjson::Json::object();
            hb.set("type", cppjson::Json("heartbeat"))
              .set("timestamp", cppjson::Json(esp_log_timestamp()));
            sendJson(hb);          // 已经重载好了，直接塞

            std::this_thread::sleep_for(std::chrono::milliseconds(config.heartbeat_interval));
        } else {    // 否则就让出CPU
            std::this_thread::sleep_for(std::chrono::milliseconds(1000));
        }
    }
}

void WebSocketManager::sendThread() {
    while (threads_running) {
        std::unique_lock<std::mutex> lock(queue_mutex);
        queue_cv.wait(lock,     // 传入已持有的 unique_lock
            [this]() {  // 等待队列非空或者线程停止
            return !send_queue.empty() || !threads_running;
        });

        if (!threads_running) {     // 其实永远不会进入这里，写上只是保险起见
            break;
        }

        if (!send_queue.empty() && connected) {     // 如果队列非空且已连接
            std::string data = std::move(send_queue.front());
            send_queue.pop();
            lock.unlock();      // 释放锁

            // 发送数据
            int sent = esp_websocket_client_send_text(client, data.c_str(), static_cast<int>(data.length()), portMAX_DELAY);
            if (sent >= 0) {
                stats.messages_sent++;      // 发送成功
            } else {
                ESP_LOGE(TAG, "Failed to send data");
                // 将数据重新放回队列
                lock.lock();
                send_queue.push(std::move(data));
                lock.unlock();
            }
        }
    }
}

bool WebSocketManager::createWebSocketClient() {
    esp_websocket_client_config_t ws_config = {};
    ws_config.uri = config.uri.c_str();
    ws_config.user_context = this;

    client = esp_websocket_client_init(&ws_config);
    if (!client) {
        ESP_LOGE(TAG, "Failed to initialize WebSocket client");
        return false;
    }

    // 处理sn码逻辑
    // 一般情况下sn码会在开机的时候从flash当中读出，因此此处判断是否为空
    sn = SysConfJson::getInstance()->loadSN();      // 再读一次sn码
    if (!sn.empty()) {    // 如果sn码不为空
        // 则在头部加入sn码提交
        esp_websocket_client_append_header(client, "X-SN", sn.c_str());
        // 同时在头部加入mac码和芯片序列号，方便服务端做验证
        esp_websocket_client_append_header(client, "X-MAC", ToolsClass::getChipMAC().c_str());
        esp_websocket_client_append_header(client, "X-CHIP-ID", ToolsClass::getChipSerialNumber().c_str());
    }
    else {
        // 如果sn码为空，设备可能存在问题
        ESP_LOGE(TAG, "SN is empty, please check your device");
        return false;
    }


    // 注册事件处理
    esp_websocket_register_events(client, WEBSOCKET_EVENT_ANY,
                                 &WebSocketManager::websocketEventHandler, this);

    return true;
}

void WebSocketManager::destroyWebSocketClient() {
    if (client) {
        esp_websocket_client_stop(client);
        esp_websocket_client_destroy(client);
        client = nullptr;
    }
}

void WebSocketManager::wifiEventHandler(void* arg, esp_event_base_t event_base,
                                      int32_t event_Id, void* event_data) {
    auto* ws_instance = static_cast<WebSocketManager*>(arg);

    if (event_base == IP_EVENT && event_Id == IP_EVENT_STA_GOT_IP) {
        // WiFi已连接，尝试重新连接WebSocket
        if (ws_instance->config.auto_reconnect && !ws_instance->connected) {
            ESP_LOGI(TAG, "WiFi connected, attempting to reconnect WebSocket");
            ws_instance->connect();
        }
    }
}