package org.sef4j.core.helpers.senders;

import java.util.List;
import java.util.Queue;

import org.sef4j.core.helpers.senders.BulkAsyncSender.IAsyncDisruptorErrorHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * default implementation of IAsyncDisruptorErrorHandler<T>, to be used within BulkAsyncSender<T>
 */
public class DefaultAsyncDisrupterErrorHandler<T> implements IAsyncDisruptorErrorHandler<T> {

    private static final Logger LOG = LoggerFactory.getLogger(DefaultAsyncDisrupterErrorHandler.class);
    
    protected int currentRetryIndex = 0;
    protected int maxRetryCount = 3;

    protected int maxQueueBulksCount = 100;
    
    protected int delayOnError = 60; // 1 minute
    
    // ------------------------------------------------------------------------

    public DefaultAsyncDisrupterErrorHandler() {
    }
    
    // ------------------------------------------------------------------------

    @Override
    public void onSendEventsOK(List<T> events) {
        this.currentRetryIndex = 0;
    }

    @Override
    public int onSendEventsFailed(List<T> events, RuntimeException ex, 
            List<List<T>> retryPrependBulkEvents,
            List<List<T>> retryAppendBulkEvents) {
        currentRetryIndex++;
        String retryInfo = (1 + currentRetryIndex) + "/" + maxRetryCount;
        if (currentRetryIndex < maxRetryCount) {
            // re-put (or re-prepend) requests in current Bulk request to send!
            // TODO ... retryable/not-retryable => should analyse exception...

            int skipCount = 0; 
            // TODO skip somes events?
            
            retryPrependBulkEvents.add(events);
            
            
            if (skipCount != 0) {
                LOG.error("Failed bulk request, retry " + retryInfo
                        + ": skipping " + skipCount + " old request(s)" 
                        + " .. reschedule, no rethrow", ex);
            } else {
                LOG.warn("Failed bulk request, retry " + retryInfo
                        + " .. reschedule, no rethrow, ex:" + ex.getMessage());
            }
        } else {
            // giving up ... current messages
            // keep incremented currentRetryIndex ?
            String msg = "Retry failed " + retryInfo
                    + ": skipping " + events.size() + " bulk request(s) !";
            if (currentRetryIndex > maxRetryCount) {
                // do not print with exception stack trace again and again
                LOG.error(msg + " ex=" + ex.getMessage());
            } else {
                LOG.error(msg, ex);
            }
        }
        
        return delayOnError; // + bulkAsyncSender.getFlushPeriod(); 
    }

    @Override
    public void onQueued(Queue<List<T>> queue, List<T> events) {
        while (queue.size() > maxQueueBulksCount) { // avoid out of memory, at least! (retain max= 100 bulks of ~20 requests)
            queue.poll();
        }
    }
    
}