package com.digi.config.util;

import com.digi.config.core.*;
import java.io.Serializable;


/**
 * This is a helper class for logging messages in the Config system. This class
 * includes a variety of logging methods to simplify accessing the system log
 * controller and logging a message.
 *
 * The helper methods in this class create and manage a singleton instance of the
 * SystemLogCtlr. There will be one instance running on each system in the network.
 *
 * Since the helper methods are all static, users do not have to have a reference to
 * the SystemLogCtlr, the static methods grab the singleton instance and use it
 * directly.
 *
 * This class primarily exports simple log methods. For more intricate controller
 * methods use the getSystemLogCtlr() method to access the singleton.
 *
 * For more detailed information on log messages and their use see:
 * @see SystemLogEntry
 *
 */
public class SystemLog {

    //==============================================================================
    //=                  Class Fields
    //==============================================================================
    private static SystemLogCtlrImpl systemLogCtlr; // A singleton instance of the log
    static String defaultRBName=
        "com.digi.config.resources.ConfigResourceBundle";

    //==============================================================================
    //=                  Static Methods
    //==============================================================================

    /**
     * Helper to send a simple message to the system log.
     *
     * Uses default resource bundle and severity of MSG_LEVEL_INFORMATION.
     *
     * Note: If Severity is specified in the message file using the key
     *       of msgId+"_SEVERITY" it will be assigned to the message.
     *
     * @param msgId The Id of the message to send to the log
     */
    public static SystemLogEntry log(String msgId) {
        return log(msgId, (Serializable[]) null);
    }

    /**
     * Helper to send a simple message & associated exception to the system log.
     *
     * Uses default resource bundle and severity of MSG_LEVEL_ERROR.
     *
     * Note: If Severity is specified in the message file using the key
     *       of msgId+"_SEVERITY" it will be assigned to the message.
     *
     * @param msgId The Id of the message to send to the log
     * @param t the error that occured. The exception information will be attached to the log entry.
     */
    public static SystemLogEntry log(String msgId, Throwable t) {
        return log(msgId, (Serializable[]) null, t);
    }


    /**
     * Helper to send a parameterized message to the system log.
     *
     * Uses default resource bundle and severity of MSG_LEVEL_INFORMATION.
     *
     * Note: If Severity is specified in the message file using the key
     *       of msgId+"_SEVERITY" it will be assigned to the message.
     *
     * @param msgId The Id of the message to send to the log
     * @param msgParams parameters available for both the message & the detailed message
     */
    public static SystemLogEntry log(String msgId, Serializable[] msgParams) {
        // by default, pass the msgParams through as the params for the 2nd level msg as well
        return log(msgId, msgParams, msgParams);
    }

    /**
     * Helper to send a parameterized message & associated exception to the system log.
     *
     * Uses default resource bundle and severity of MSG_LEVEL_ERROR.
     *
     * Note: If Severity is specified in the message file using the key
     *       of msgId+"_SEVERITY" it will be assigned to the message.
     *
     * @param msgId The Id of the message to send to the log
     * @param msgParams parameters available for both the message & the detailed message
     * @param t the error that occured. The exception information will be attached to the log entry.
     */
    public static SystemLogEntry log(String msgId, Serializable[] msgParams, Throwable t) {
            // by default, pass the msgParams through as the params for the 2nd level msg as well
            return log(msgId, msgParams, msgParams, t);
    }


    /**
     * Helper to send a parameterized message with detailed text to the system log.
     * Note: The detailed message is another entry in the message file using the
     * key of msgId+"_DETAIL"
     *
     * Uses default resource bundle and severity of MSG_LEVEL_INFORMATION.
     *
     * Note: If Severity is specified in the message file using the key
     *       of msgId+"_SEVERITY" it will be assigned to the message.
     *
     * @param msgId The Id of the message to send to the log
     * @param msgParams parameters for the message
     * @param detailMsgParams parameters for the detailed message
     */
    public static SystemLogEntry log(String msgId, Serializable[] msgParams,
        Serializable[] detailMsgParams) {
            return log(msgId, msgParams, detailMsgParams, SystemLogEntry.MSG_LEVEL_INFORMATION);
    }

    /**
     * Helper to send a parameterized message & associated exception with detailed text to the system log.
     * Note: The detailed message is another entry in the message file using the
     * key of msgId+"_DETAIL"
     *
     * Uses default resource bundle and severity of MSG_LEVEL_ERROR.
     *
     * Note: If Severity is specified in the message file using the key
     *       of msgId+"_SEVERITY" it will be assigned to the message.
     *
     * @param msgId The Id of the message to send to the log
     * @param msgParams parameters for the message
     * @param detailMsgParams parameters for the detailed message
     * @param t the error that occured. The exception information will be attached to the log entry.
     */
    public static SystemLogEntry log(String msgId, Serializable[] msgParams,
        Serializable[] detailMsgParams, Throwable t) {
            return log(msgId, msgParams, detailMsgParams, SystemLogEntry.MSG_LEVEL_ERROR, t);
    }

    /**
     * Helper to send a parameterized message with detailed text to the system log.
     * Note: The detailed message is another entry in the message file using the
     * key of msgId+"_DETAIL"
     *
     * Uses default resource bundle and specified severity.
     *
     * Note: If Severity is specified in the message file using the key
     *       of msgId+"_SEVERITY" it will be assigned to the message.
     *
     *
     * @param msgId The Id of the message to send to the log
     * @param msgParams parameters for the message
     * @param detailMsgParams parameters for the detailed message
     * @param severity the severity to assign to this message
     */
    public static SystemLogEntry log(String msgId, Serializable[] msgParams,
        Serializable[] detailMsgParams, int severity) {
            return log(msgId, defaultRBName, msgParams, detailMsgParams, severity, null);
    }

    /**
     * Helper to send a parameterized message with detailed text & associated exception to the system log.
     * Note: The detailed message is another entry in the message file using the
     * key of msgId+"_DETAIL"
     *
     * Uses default resource bundle and specified severity.
     *
     * Note: If Severity is specified in the message file using the key
     *       of msgId+"_SEVERITY" it will be assigned to the message.
     *
     *
     * @param msgId The Id of the message to send to the log
     * @param msgParams parameters for the message
     * @param detailMsgParams parameters for the detailed message
     * @param severity the severity to assign to this message
     * @param t the error that occured. The exception information will be attached to the log entry.
     */
    public static SystemLogEntry log(String msgId, Serializable[] msgParams,
        Serializable[] detailMsgParams, int severity, Throwable t) {
            return log(msgId, defaultRBName, msgParams, detailMsgParams, severity, t);
    }

    /**
     * Helper to send a parameterized message with detailed text to the system log.
     * Note: The detailed message is another entry in the message file using the
     * key of msgId+"_DETAIL"
     *
     * Uses specified resource bundle and severity.
     *
     * Note: If Severity is specified in the message file using the key
     *       of msgId+"_SEVERITY" it will be assigned to the message.
     *
     * @param msgId The Id of the message to send to the log
     * @param msgRbName The name of the resource bundle to locate the message in
     * @param msgParams parameters for the message
     * @param detailMsgParams parameters for the detailed message
     * @param severity the severity to assign to this message
     */
    public static SystemLogEntry log(String msgId, String msgRbName, Serializable[] msgParams,
        Serializable[] detailMsgParams, int severity, Throwable t) {
            // If this is a debug message & debug logging is not enabled then do nothing.
            if ((severity==SystemLogEntry.MSG_LEVEL_DEBUG)&&
                (!getSystemLogCtlr().isDebugLoggingEnabled())) {
                    return null;
            }
            // otherwise, create the entry and log it!
            SystemLogEntry entry=
                new SystemLogEntry(msgId, msgParams, detailMsgParams, severity, t);
            return log(entry);
    }


    /**
     * Helper to send an Exception message to the system log. This message
     * will be assigned a severity of MSG_LEVEL_ERROR
     *
     * @param t The exception or throwable to send to the log
     */
    public static SystemLogEntry log(Throwable t) {
        return log("GeneralException",
            new Serializable[] { t.getClass().getName() }, t);
    }

    /**
     * Helper to send a SystemLogEntry to the SystemLogCtlr
     *
     * Note that all the other helper methods end up calling this one. It in turn
     * looks up the SystemLogCtlr singleton and makes to log call on it.
     *
     * @param entry The entry to send to the system log
     */
    public static SystemLogEntry log(SystemLogEntry entry) {
        try {
            getSystemLogCtlr().add(entry);
        }
        catch (Exception e) {
            System.out.println("Error sending a message to the System Log. Here is the message we were trying to log:");
            System.out.println(entry.getMsg());
            if (entry.hasDetailedMsg()) {
                System.out.println(entry.getDetailedMsg());
            }
            System.out.println("Here are the details of the error that prevented us from logging the message:");
            e.printStackTrace();
        }
        return entry;
    }

    /**
     * Helper to send a debug message to the system log.
     *
     * Uses default resource bundle and severity of DEBUG.
     *
     * @param msg The text of the message to include in the debug message.
     */
    public static SystemLogEntry debug(String msg) {
        Serializable[] msgParams=
        {"DEBUG["+Thread.currentThread().getName()+"]: "+msg};
        SystemLogEntry entry=log("DebugMsg", msgParams);
        if (ConfigSettings.getBoolean("DebugSettings", "GeneralDebug")) {
            System.out.println(msgParams[0]);
        }
        return entry;
    }

    /**
     * Helper to send a debug message & associated exception to the system log.
     *
     * Uses default resource bundle and severity of DEBUG.
     *
     * @param msg The text of the message to include in the debug message.
     * @param t The exception or throwable to send to the log
     */
    public static SystemLogEntry debug(String msg, Throwable t) {
        Serializable[] msgParams=
        {"DEBUG["+Thread.currentThread().getName()+"]: "+msg};
        SystemLogEntry entry=log("DebugMsg", msgParams, t);
        if (ConfigSettings.getBoolean("DebugSettings", "GeneralDebug")) {
            System.out.println(msgParams[0]);
            if (t!=null) {
                System.out.println("Detail Message:"+t.getMessage());
                t.printStackTrace();
            }
        }
        return entry;
    }


//     /**
//      * Clears all entries in the SystemLogCtlr
//      */
//     public static void clearLog() throws Exception {
//         getSystemLogCtlr().removeAll();
//     }
//
//
//     /**
//      * Add a ControllerMembershipListener to the listener list. This listener is
//      * called when items are added or removed from the SystemLogCtlr
//      *
//      * @param listener - The ControllerMembershipListener to be added
//      */
//     public static void addLogListener(ControllerMembershipListener listener) {
//         getSystemLogCtlr().addControllerMembershipListener(listener);
//     }
//
//     /**
//      * Remove a ControllerMembershipListener from the listener list.
//      *
//      * @param listener - The ControllerMembershipListener to be removed
//      */
//     public static void removeLogListener(ControllerMembershipListener
//         listener) {
//             getSystemLogCtlr().removeControllerMembershipListener(listener);
//     }
//
//
//
//     /**
//      * Returns the name of the log file
//      *
//      */
//     public static String getLogFileName() {
//         StringSetting logName=(StringSetting)getSystemLogCtlr().getSetting(SystemLogCtlrImpl.LOG_FILE_NAME_KEY);
//         return logName.getValue();
//     }
//
//     /**
//      * Updates the name of the log file. Closes the old log, creates a new log under
//      * the new name, and deletes the old log file.
//      *
//      * @param fileName The new name for the log file.
//      */
//     public static void setLogFileName(String fileName) {
//         getSystemLogCtlr().addSetting(
//             new StringSetting(SystemLogCtlrImpl.LOG_FILE_NAME_KEY, fileName));
//         // Finish this... we need to close the old log and create the new...
//     }
//
//
    /**
     * Returns the SystemLogCtlr singleton, creating it if necessary.
     * Assumes a server system log is to be created if it does not exist.
     */
    public static SystemLogCtlrImpl getSystemLogCtlr() {
        if (systemLogCtlr==null) {
            try {
                systemLogCtlr=new SystemLogCtlrImpl(SystemLogCtlr.CONFIG_LOG_FILE_NAME_KEY);
            }
            catch (Exception e) {
                System.out.println("Error creating singleton instance of SystemLogCtlr");
                e.printStackTrace();
            }
        }
        return systemLogCtlr;
    }

    /**
     * Returns the SystemLogCtlr singleton, creating it if necessary.
     * @param resourceKey the resource key that defines the name of the system log file
     */
    public static SystemLogCtlrImpl getSystemLogCtlr(String resourceKey) {
        if (systemLogCtlr==null) {
            try {
                systemLogCtlr=new SystemLogCtlrImpl(resourceKey);
            }
            catch (Exception e) {
                System.out.println("Error creating singleton instance of SystemLogCtlr");
                e.printStackTrace();
            }
        }
        return systemLogCtlr;
    }



}