Connection Management

/**
 * Main factory interface for PLC driver management and connection creation
 */
public interface PlcDriverManager {
    /**
     * Get the default driver manager instance
     * @return Default PlcDriverManager implementation
     */
    static PlcDriverManager getDefault();
    
    /**
     * Get all registered protocol codes
     * @return Set of available protocol codes
     */
    Set<String> getProtocolCodes();
    
    /**
     * Get a specific driver by protocol code
     * @param protocolCode Protocol identifier (e.g., "modbus-tcp", "s7")
     * @return PlcDriver instance
     * @throws PlcConnectionException If protocol is not supported or driver cannot be created
     */
    PlcDriver getDriver(String protocolCode) throws PlcConnectionException;
    
    /**
     * Get driver for a specific connection URL
     * @param url Connection URL
     * @return PlcDriver instance
     * @throws PlcConnectionException If protocol is not supported or driver cannot be created
     */
    PlcDriver getDriverForUrl(String url) throws PlcConnectionException;
    
    /**
     * Get the connection manager interface
     * @return PlcConnectionManager instance
     */
    PlcConnectionManager getConnectionManager();
}

/**
 * Default implementation providing driver discovery and connection creation
 */
public class DefaultPlcDriverManager implements PlcDriverManager, PlcConnectionManager {
    /**
     * Create driver manager using current context classloader
     */
    public DefaultPlcDriverManager();
    
    /**
     * Create driver manager with custom classloader for driver discovery
     * @param classLoader Classloader for driver discovery
     */
    public DefaultPlcDriverManager(ClassLoader classLoader);
}

/**
 * Interface for connection management providing methods to create and manage PLC connections
 */
public interface PlcConnectionManager {
    /**
     * Create a connection from a connection URL
     * @param url Connection URL (e.g., "modbus-tcp://192.168.1.100:502")
     * @return PlcConnection instance
     * @throws PlcConnectionException If connection cannot be established
     */
    PlcConnection getConnection(String url) throws PlcConnectionException;
    
    /**
     * Create an authenticated connection from a connection URL
     * @param url Connection URL
     * @param authentication Authentication credentials
     * @return PlcConnection instance
     * @throws PlcConnectionException If connection cannot be established
     */
    PlcConnection getConnection(String url, PlcAuthentication authentication) throws PlcConnectionException;
}

/**
 * Main connection interface extending AutoCloseable for resource management
 */
public interface PlcConnection extends AutoCloseable {
    /**
     * Establish the connection to the PLC
     * @throws PlcConnectionException If connection fails
     */
    void connect() throws PlcConnectionException;
    
    /**
     * Check if connection is currently active
     * @return true if connected, false otherwise
     */
    boolean isConnected();
    
    /**
     * Close the connection and release resources
     * @throws Exception If closing fails
     */
    void close() throws Exception;
    
    /**
     * Parse a tag address string into a PlcTag object
     * @param tagAddress String representation of tag address
     * @return Optional PlcTag if parsing succeeds
     */
    Optional<PlcTag> parseTagAddress(String tagAddress);
    
    /**
     * Parse values for a specific tag
     * @param tag The PlcTag to parse values for
     * @param values Raw values to parse
     * @return Optional PlcValue if parsing succeeds
     */
    Optional<PlcValue> parseTagValue(PlcTag tag, Object... values);
    
    /**
     * Get connection metadata including supported capabilities
     * @return PlcConnectionMetadata with capability information
     */
    PlcConnectionMetadata getMetadata();
    
    /**
     * Ping the PLC connection
     * @return CompletableFuture with ping response
     */
    CompletableFuture<? extends PlcPingResponse> ping();
    
    /**
     * Create a read request builder
     * @return PlcReadRequest.Builder instance
     */
    PlcReadRequest.Builder readRequestBuilder();
    
    /**
     * Create a write request builder
     * @return PlcWriteRequest.Builder instance
     */
    PlcWriteRequest.Builder writeRequestBuilder();
    
    /**
     * Create a subscription request builder
     * @return PlcSubscriptionRequest.Builder instance
     */
    PlcSubscriptionRequest.Builder subscriptionRequestBuilder();
    
    /**
     * Create an unsubscription request builder
     * @return PlcUnsubscriptionRequest.Builder instance
     */
    PlcUnsubscriptionRequest.Builder unsubscriptionRequestBuilder();
    
    /**
     * Create a browse request builder
     * @return PlcBrowseRequest.Builder instance
     */
    PlcBrowseRequest.Builder browseRequestBuilder();
}

/**
 * Extended connection interface for event-driven communication
 */
public interface EventPlcConnection extends PlcConnection {
    /**
     * Add an event listener for connection events
     * @param listener EventListener implementation
     */
    void addEventListener(EventListener listener);
    
    /**
     * Remove an event listener
     * @param listener EventListener to remove
     */
    void removeEventListener(EventListener listener);
}

/**
 * Protocol-specific driver interface
 */
public interface PlcDriver {
    /**
     * Get the protocol short code
     * @return Protocol identifier (e.g., "modbus-tcp", "s7")
     */
    String getProtocolCode();
    
    /**
     * Get the full protocol name
     * @return Human-readable protocol name
     */
    String getProtocolName();
    
    /**
     * Get driver metadata including capabilities
     * @return PlcDriverMetadata with driver information
     */
    PlcDriverMetadata getMetadata();
    
    /**
     * Create a connection using this driver
     * @param url Connection URL
     * @return PlcConnection instance
     * @throws PlcConnectionException If connection cannot be established
     */
    PlcConnection getConnection(String url) throws PlcConnectionException;
    
    /**
     * Create an authenticated connection using this driver
     * @param url Connection URL
     * @param authentication Authentication credentials
     * @return PlcConnection instance
     * @throws PlcConnectionException If connection cannot be established
     */
    PlcConnection getConnection(String url, PlcAuthentication authentication) throws PlcConnectionException;
    
    /**
     * Prepare a tag from an address string
     * @param tagAddress Tag address string
     * @return PlcTag instance
     * @throws PlcInvalidTagException If tag address is invalid
     */
    PlcTag prepareTag(String tagAddress) throws PlcInvalidTagException;
    
    /**
     * Create a discovery request builder for this driver
     * @return PlcDiscoveryRequest.Builder instance
     */
    PlcDiscoveryRequest.Builder discoveryRequestBuilder();
}

import org.apache.plc4x.java.DefaultPlcDriverManager;
import org.apache.plc4x.java.api.PlcConnection;
import org.apache.plc4x.java.api.PlcConnectionManager;
import org.apache.plc4x.java.api.PlcDriverManager;
import org.apache.plc4x.java.api.authentication.PlcUsernamePasswordAuthentication;

// Basic connection
PlcDriverManager driverManager = new DefaultPlcDriverManager();
PlcConnectionManager connectionManager = driverManager.getConnectionManager();
try (PlcConnection connection = connectionManager.getConnection("modbus-tcp://192.168.1.100:502")) {
    connection.connect();
    System.out.println("Connected: " + connection.isConnected());
    
    // Use connection for operations...
    
} // Auto-close when done

// Authenticated connection
PlcUsernamePasswordAuthentication auth = new PlcUsernamePasswordAuthentication("admin", "password");
try (PlcConnection connection = connectionManager.getConnection("s7://192.168.1.200/0/1", auth)) {
    connection.connect();
    
    // Check capabilities
    if (connection.getMetadata().isReadSupported()) {
        // Perform read operations
    }
}

// Driver discovery
Set<String> protocols = driverManager.getProtocolCodes();
System.out.println("Available protocols: " + protocols);

PlcDriver modbusDriver = driverManager.getDriver("modbus-tcp");
System.out.println("Driver: " + modbusDriver.getProtocolName());

public interface PlcPingRequest extends PlcRequest {
    CompletableFuture<? extends PlcPingResponse> execute();
}

public interface PlcPingResponse extends PlcResponse {
    PlcRequest getRequest();
}

public interface PlcConnectionMetadata {
    boolean isReadSupported();
    boolean isWriteSupported();
    boolean isSubscribeSupported();
    boolean isBrowseSupported();
}

public interface PlcDriverMetadata {
    Optional<String> getDefaultTransportCode();
    List<String> getSupportedTransportCodes();
    Optional<OptionMetadata> getProtocolConfigurationOptionMetadata();
    Optional<OptionMetadata> getTransportConfigurationOptionMetadata(String transportCode);
    boolean isDiscoverySupported();
}

public interface PlcTag {
    String getAddressString();
    PlcValueType getPlcValueType();
    List<ArrayInfo> getArrayInfo();
}

public interface ArrayInfo {
    int getSize();
    int getLowerBound(); 
    int getUpperBound();
}