package com.malagasys.slidingwindow;

import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

public class SlidingWindowMap {
	private final Map<String, SlidingWindow> map = new HashMap<>();
	
	public SlidingWindowMap(Set<String> keys, int maxCount, long periodMs) {
		//Just create a sliding window per key.
		for (String key : keys) {
			map.put(key, new SlidingWindow(periodMs, maxCount));
		}
	}

	public String getNextKey() {
		String nextKey = null;
		long currentTime = System.currentTimeMillis();

		for (Map.Entry<String, SlidingWindow> e : map.entrySet()) {
			//Slide the window to match current timestamp
			e.getValue().slideTo(currentTime);
			
			//If the window is not full yet, accept the key as the next key
			if (!e.getValue().isFull()) {
				e.getValue().logcall(currentTime);
				nextKey = e.getKey();
				break;
			}
		}
		
		return nextKey;
	}
	
	//========= Run ============
	public static void main(String[] args) throws Exception {
		Set<String> keys = new HashSet<>(Arrays.asList("key_a", "key_b", "key_c", "key_d"));
		SlidingWindowMap map = new SlidingWindowMap(keys, 5, 30000);
		
		for (int i = 0; i < 40; i++) {
			System.out.println(map.getNextKey());
			if (i%3 == 0) {
				Thread.sleep(5000);
			}
		}
	}
}