package com.roboclub.robobuggy.messages;

import com.roboclub.robobuggy.main.RobobuggyLogicNotification;
import com.roboclub.robobuggy.main.RobobuggyMessageLevel;
import com.roboclub.robobuggy.ros.Message;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * Abstract class used to represent the base message sent over BuggyROS
 */
public abstract class BaseMessage implements Message {
    private static final String DATE_FORMAT = "yyyy-MM-dd HH:mm:ss.SSS";
    protected long timestamp;
    private String topicName;
    private long sequenceNumber = -1;

    /**
     * sets the date of the message to the current time
     */
    public BaseMessage() {
        timestamp = new Date().getTime();
    }

    /**
     * Publishers number their messages, increasing one each time.
     * If a message is dropped, then the subscriber will know if they keep
     * track of the current sequence number.
     *
     * @return sequence number of the current message
     */
    public long getSequenceNumber() {
        return sequenceNumber;
    }

    /**
     * Sets the sequence number of this message.
     * This should only be called by Publisher; it will
     * be overwritten if anyone else writes to it.
     *
     * @param sequenceNumber sequence number of the current message. Ignored if not called from publisher.java
     */
    public void setSequenceNumber(long sequenceNumber) {
        this.sequenceNumber = sequenceNumber;
    }

    /**
     * Creates a {@link String} representing the {@link Date}
     *
     * @param dt {@link Date} to format
     * @return a {@link String} representing the {@link Date} dt
     */
    public static String formatDate(long dt) {
        Date date = new Date(dt);
        DateFormat formatter = new SimpleDateFormat(DATE_FORMAT);
        return formatter.format(date);
    }

    /**
     * Converts a {@link String} into a valid {@link Date} object, if possible
     *
     * @param maybeDate {@link String} representing the {@link Date}
     * @return a new {@link Date} object representing maybeDate, or null if
     * maybeDate is an invalid format
     */
    public static Date tryToParseDate(String maybeDate) {
        try {
            DateFormat formatter = new SimpleDateFormat(DATE_FORMAT);
            return formatter.parse(maybeDate);
        } catch (ParseException e) {
            new RobobuggyLogicNotification("could not parse date stack trace: " + e.getMessage(), RobobuggyMessageLevel.WARNING);
            return null;
        }
    }

    /**
     * Returns the timestamp of the message
     *
     * @return time that this message was instantiated
     */
    public Date getTimestamp() {
        return new Date(timestamp);
    }

    /**
     * Sets the topic name that the message is on
     * This allows us to know which topic a message came from; very useful for serialization
     *
     * @param topicName Topic to set the name to
     */
    public void setTopicName(String topicName) {
        this.topicName = topicName;
    }

    /**
     * Gets the topic name for this message
     *
     * @return name of the current topic
     */
    public String getTopicName() {
        return this.topicName;
    }
}