#include "Networking.hpp"
#include "../ConfigManager/ConfigManager.hpp"
#include "../Logging/Logging.hpp"
#include <WiFiManager.h>
#include <SPI.h>

// Static instance for callbacks (with safety checks)
Networking* Networking::_instance = nullptr;

Networking::Networking(ConfigManager& configManager)
    : _configManager(configManager)
    , _state(NetworkState::DISCONNECTED)
    , _activeConnection(ConnectionType::NONE)
    , _lastConnectionAttempt(0)
    , _bootStartTime(0)
    , _bootSequenceComplete(false)
    , _ethernetCableConnected(false)
    , _wifiManager(nullptr)
    , _reconnectionTimer(nullptr) {
    
    // Safety check for multiple instances
    if (_instance != nullptr) {
        LOG_WARNING("Multiple Networking instances detected! Previous instance will be overridden.");
    }
    
    _instance = this;
    _wifiManager = new WiFiManager();
}

Networking::~Networking() {
    // Clear static instance safely
    if (_instance == this) {
        _instance = nullptr;
    }
    
    // Cleanup timer
    if (_reconnectionTimer) {
        xTimerDelete(_reconnectionTimer, portMAX_DELAY);
        _reconnectionTimer = nullptr;
    }
    
    // Cleanup WiFiManager
    if (_wifiManager) {
        delete _wifiManager;
        _wifiManager = nullptr;
    }
}

void Networking::begin() {
    LOG_INFO("Initializing Networking System");
    
    _bootStartTime = millis();
    
    // Create reconnection timer
    _reconnectionTimer = xTimerCreate("reconnectionTimer", pdMS_TO_TICKS(RECONNECTION_INTERVAL), 
                                      pdTRUE, (void*)0, reconnectionTimerCallback);
    
    // Setup network event handler
    WiFi.onEvent(networkEventHandler);
    
    // Configure WiFiManager
    _wifiManager->setDebugOutput(false);
    _wifiManager->setConfigPortalTimeout(180); // 3 minutes
    
    // Start Ethernet hardware
    auto& hwConfig = _configManager.getHardwareConfig();
    ETH.begin(hwConfig.ethPhyType, hwConfig.ethPhyAddr, hwConfig.ethPhyCs, 
              hwConfig.ethPhyIrq, hwConfig.ethPhyRst, SPI);
    
    // Start connection sequence
    LOG_INFO("Starting network connection sequence...");
    startEthernetConnection();
}

void Networking::startEthernetConnection() {
    LOG_INFO("Attempting Ethernet connection...");
    setState(NetworkState::CONNECTING_ETHERNET);
    
    // Check if Ethernet hardware initialization failed
    if (!ETH.linkUp()) {
        LOG_WARNING("Ethernet hardware not detected or failed to initialize");
        LOG_INFO("Falling back to WiFi immediately");
        startWiFiConnection();
        return;
    }
    
    // Ethernet will auto-connect via events
    // Set timeout for Ethernet attempt (5 seconds)
    _lastConnectionAttempt = millis();
    
    // Start reconnection timer to handle timeout
    xTimerStart(_reconnectionTimer, 0);
}

void Networking::startWiFiConnection() {
    LOG_INFO("Attempting WiFi connection...");
    setState(NetworkState::CONNECTING_WIFI);
    
    if (!hasValidWiFiCredentials()) {
        LOG_WARNING("No valid WiFi credentials found");
        if (shouldStartPortal()) {
            startWiFiPortal();
        }
        return;
    }
    
    LOG_INFO("Using WiFiManager saved credentials");
    
    WiFi.mode(WIFI_STA);
    applyNetworkConfig(false); // false = WiFi config
    
    // Let WiFiManager handle credentials (uses saved SSID/password)
    WiFi.begin();
    
    _lastConnectionAttempt = millis();
    
    // Start reconnection timer to handle timeout
    xTimerStart(_reconnectionTimer, 0);
}

void Networking::startWiFiPortal() {
    LOG_INFO("Starting WiFi configuration portal...");
    setState(NetworkState::WIFI_PORTAL_MODE);
    
    WiFi.mode(WIFI_AP_STA);
    
    auto& netConfig = _configManager.getNetworkConfig();
    String apName = "Vesper-" + _configManager.getDeviceUID();
    
    LOG_INFO("WiFi Portal: SSID='%s', Password='%s'", apName.c_str(), netConfig.apPass.c_str());
    
    if (_wifiManager->autoConnect(apName.c_str(), netConfig.apPass.c_str())) {
        LOG_INFO("WiFi configured successfully via portal");
        onWiFiConnected();
    } else {
        LOG_ERROR("WiFi portal configuration failed");
        setState(NetworkState::DISCONNECTED);
        // Start reconnection timer to try again
        xTimerStart(_reconnectionTimer, 0);
    }
}

void Networking::handleReconnection() {
    if (_state == NetworkState::CONNECTED_ETHERNET || _state == NetworkState::CONNECTED_WIFI) {
        return; // Already connected
    }
    
    LOG_DEBUG("Attempting reconnection...");
    
    // Check for Ethernet timeout (fall back to WiFi)
    if (_state == NetworkState::CONNECTING_ETHERNET) {
        unsigned long now = millis();
        if (now - _lastConnectionAttempt > 5000) { // 5 second timeout
            LOG_INFO("Ethernet connection timeout - falling back to WiFi");
            startWiFiConnection();
            return;
        }
        return; // Still waiting for Ethernet
    }
    
    // Check for WiFi timeout (try again)
    if (_state == NetworkState::CONNECTING_WIFI) {
        unsigned long now = millis();
        if (now - _lastConnectionAttempt > 10000) { // 10 second timeout
            LOG_INFO("WiFi connection timeout - retrying");
            startWiFiConnection(); // Retry WiFi
        }
        return; // Still waiting for WiFi
    }
    
    // State is DISCONNECTED - decide what to try
    if (_ethernetCableConnected) {
        LOG_INFO("Ethernet cable detected - trying Ethernet");
        startEthernetConnection();
    } else {
        LOG_INFO("No Ethernet - trying WiFi");
        if (hasValidWiFiCredentials()) {
            startWiFiConnection();
        } else if (shouldStartPortal()) {
            startWiFiPortal();
        } else {
            LOG_WARNING("No WiFi credentials and boot sequence complete - waiting");
        }
    }
}

// ════════════════════════════════════════════════════════════════════════════
// HEALTH CHECK IMPLEMENTATION
// ════════════════════════════════════════════════════════════════════════════

bool Networking::isHealthy() const {
    // Check if we have any active connection
    if (_activeConnection == ConnectionType::NONE) {
        LOG_DEBUG("Networking: Unhealthy - No active connection");
        return false;
    }
    
    // Check connection state
    if (_state != NetworkState::CONNECTED_ETHERNET && _state != NetworkState::CONNECTED_WIFI) {
        LOG_DEBUG("Networking: Unhealthy - Not in connected state");
        return false;
    }
    
    // Check IP address validity
    String ip = getLocalIP();
    if (ip == "0.0.0.0" || ip.isEmpty()) {
        LOG_DEBUG("Networking: Unhealthy - Invalid IP address");
        return false;
    }
    
    // For WiFi connections, check signal strength
    if (_activeConnection == ConnectionType::WIFI) {
        if (WiFi.status() != WL_CONNECTED) {
            LOG_DEBUG("Networking: Unhealthy - WiFi not connected");
            return false;
        }
        
        // Check signal strength (RSSI should be better than -80 dBm)
        int32_t rssi = WiFi.RSSI();
        if (rssi < -80) {
            LOG_DEBUG("Networking: Unhealthy - Poor WiFi signal: %d dBm", rssi);
            return false;
        }
    }
    
    // For Ethernet connections, check link status
    if (_activeConnection == ConnectionType::ETHERNET) {
        if (!ETH.linkUp()) {
            LOG_DEBUG("Networking: Unhealthy - Ethernet link down");
            return false;
        }
    }
    
    return true;
}

void Networking::setState(NetworkState newState) {
    if (_state != newState) {
        LOG_DEBUG("Network state: %d -> %d", (int)_state, (int)newState);
        _state = newState;
    }
}

void Networking::setActiveConnection(ConnectionType type) {
    if (_activeConnection != type) {
        LOG_INFO("Active connection changed: %d -> %d", (int)_activeConnection, (int)type);
        _activeConnection = type;
    }
}

void Networking::notifyConnectionChange(bool connected) {
    if (connected && _onNetworkConnected) {
        _onNetworkConnected();
    } else if (!connected && _onNetworkDisconnected) {
        _onNetworkDisconnected();
    }
}

// Event handlers
void Networking::onEthernetConnected() {
    LOG_INFO("Ethernet connected successfully");
    setState(NetworkState::CONNECTED_ETHERNET);
    setActiveConnection(ConnectionType::ETHERNET);
    
    // Stop WiFi if it was running
    if (WiFi.getMode() != WIFI_OFF) {
        WiFi.disconnect(true);
        WiFi.mode(WIFI_OFF);
    }
    
    // Stop reconnection timer
    xTimerStop(_reconnectionTimer, 0);
    
    notifyConnectionChange(true);
}

void Networking::onEthernetDisconnected() {
    LOG_WARNING("Ethernet disconnected");
    
    if (_activeConnection == ConnectionType::ETHERNET) {
        setState(NetworkState::DISCONNECTED);
        setActiveConnection(ConnectionType::NONE);
        notifyConnectionChange(false);
        
        // Start reconnection attempts
        xTimerStart(_reconnectionTimer, 0);
    }
}

void Networking::onWiFiConnected() {
    LOG_INFO("WiFi connected successfully - IP: %s", WiFi.localIP().toString().c_str());
    setState(NetworkState::CONNECTED_WIFI);
    setActiveConnection(ConnectionType::WIFI);
    
    // Stop reconnection timer
    xTimerStop(_reconnectionTimer, 0);
    
    // Mark boot sequence as complete
    _bootSequenceComplete = true;
    
    notifyConnectionChange(true);
}

void Networking::onWiFiDisconnected() {
    LOG_WARNING("WiFi disconnected");
    
    if (_activeConnection == ConnectionType::WIFI) {
        setState(NetworkState::DISCONNECTED);
        setActiveConnection(ConnectionType::NONE);
        notifyConnectionChange(false);
        
        // Start reconnection attempts
        xTimerStart(_reconnectionTimer, 0);
    }
}

void Networking::onEthernetCableChange(bool connected) {
    _ethernetCableConnected = connected;
    LOG_INFO("Ethernet cable %s", connected ? "connected" : "disconnected");
    
    if (connected && _activeConnection != ConnectionType::ETHERNET) {
        // Cable connected and we're not using Ethernet - try to connect
        startEthernetConnection();
    }
}

// Utility methods
void Networking::applyNetworkConfig(bool ethernet) {
    auto& netConfig = _configManager.getNetworkConfig();
    
    if (netConfig.useStaticIP) {
        LOG_INFO("Applying static IP configuration");
        if (ethernet) {
            ETH.config(netConfig.ip, netConfig.gateway, netConfig.subnet, netConfig.dns1, netConfig.dns2);
        } else {
            WiFi.config(netConfig.ip, netConfig.gateway, netConfig.subnet, netConfig.dns1, netConfig.dns2);
        }
    } else {
        LOG_INFO("Using DHCP configuration");
    }
    
    if (ethernet) {
        ETH.setHostname(netConfig.hostname.c_str());
    } else {
        WiFi.setHostname(netConfig.hostname.c_str());
    }
}

bool Networking::hasValidWiFiCredentials() {
    // Check if WiFiManager has saved credentials
    return WiFi.SSID().length() > 0;
}

bool Networking::shouldStartPortal() {
    // Only start portal during boot sequence and if we're truly disconnected
    return !_bootSequenceComplete && 
           (millis() - _bootStartTime < BOOT_TIMEOUT) &&
           _activeConnection == ConnectionType::NONE;
}

// Status methods
bool Networking::isConnected() const {
    return _activeConnection != ConnectionType::NONE;
}

String Networking::getLocalIP() const {
    switch (_activeConnection) {
        case ConnectionType::ETHERNET:
            return ETH.localIP().toString();
        case ConnectionType::WIFI:
            return WiFi.localIP().toString();
        default:
            return "0.0.0.0";
    }
}

void Networking::forceReconnect() {
    LOG_INFO("Forcing reconnection...");
    setState(NetworkState::RECONNECTING);
    setActiveConnection(ConnectionType::NONE);
    
    // Disconnect everything
    if (WiFi.getMode() != WIFI_OFF) {
        WiFi.disconnect(true);
        WiFi.mode(WIFI_OFF);
    }
    
    // Restart connection sequence
    delay(1000);
    startEthernetConnection();
}

// Static callbacks
void Networking::networkEventHandler(arduino_event_id_t event, arduino_event_info_t info) {
    if (!_instance) return;

    LOG_DEBUG("Network event: %d", event);

    switch (event) {
        case ARDUINO_EVENT_ETH_START:
            LOG_DEBUG("ETH Started");
            break;
            
        case ARDUINO_EVENT_ETH_CONNECTED:
            LOG_DEBUG("ETH Cable Connected");
            _instance->onEthernetCableChange(true);
            break;
            
        case ARDUINO_EVENT_ETH_GOT_IP:
            LOG_INFO("ETH Got IP: %s", ETH.localIP().toString().c_str());
            _instance->applyNetworkConfig(true);
            _instance->onEthernetConnected();
            break;
            
        case ARDUINO_EVENT_ETH_DISCONNECTED:
            LOG_WARNING("ETH Cable Disconnected");
            _instance->onEthernetCableChange(false);
            _instance->onEthernetDisconnected();
            break;
            
        case ARDUINO_EVENT_ETH_STOP:
            LOG_INFO("ETH Stopped");
            _instance->onEthernetDisconnected();
            break;
            
        case ARDUINO_EVENT_WIFI_STA_GOT_IP:
            LOG_INFO("WiFi Got IP: %s", WiFi.localIP().toString().c_str());
            _instance->onWiFiConnected();
            break;
            
        case ARDUINO_EVENT_WIFI_STA_DISCONNECTED:
            LOG_WARNING("WiFi Disconnected");
            _instance->onWiFiDisconnected();
            break;
            
        case ARDUINO_EVENT_WIFI_STA_CONNECTED:
            LOG_DEBUG("WiFi STA Connected");
            break;
            
        default:
            break;
    }
}

void Networking::reconnectionTimerCallback(TimerHandle_t xTimer) {
    if (_instance) {
        _instance->handleReconnection();
        
        // Check if boot sequence should be marked complete
        if (!_instance->_bootSequenceComplete && 
            (millis() - _instance->_bootStartTime > BOOT_TIMEOUT)) {
            _instance->_bootSequenceComplete = true;
            LOG_INFO("Boot sequence timeout - no more portal attempts");
        }
    }
}