/*
 * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
 * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Class.java to edit this template
 */
package generics;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 *
 * @author steve
 */
public class GenericHashMap<K,V> implements MinGenericMap<K,V> {
    
    List<GenericArrayMap<K,V>> buckets = new ArrayList<>();
    
    public GenericHashMap() { this(25); }
    public GenericHashMap(int n) {
        for(int i=0;i<n;i++) {
            buckets.add(new GenericArrayMap<>());
        }
    }
    
    int hashToIndex(K k) {
        return Math.abs(k.hashCode()) % buckets.size();
    }

    @Override
    public void put(K k, V v) {
        int index = hashToIndex(k);
        var bucket = buckets.get(index);
        bucket.put(k,v);
    }

    @Override
    public V get(K k) {
        int index = hashToIndex(k);
        var bucket = buckets.get(index);
        return bucket.get(k);
    }

    @Override
    public int size() {
        int sum=0;
        for(var bucket: buckets) {
            sum += bucket.size();
        }
        return sum;
    }

    @Override
    public Iterator<K> iterator() {
        return new Iterator<K>() {
            
            Iterator<GenericArrayMap<K, V>> bucketIter = buckets.iterator();
            Iterator<K> iter = bucketIter.next().iterator();
            
            @Override
            public boolean hasNext() {
                while(true) {
                    if(iter.hasNext()) { 
                        return true;
                    } else if(bucketIter.hasNext()) {
                        iter = bucketIter.next().iterator();
                    } else {
                        return false;
                    }
                }
            }

            @Override
            public K next() {
                return iter.next();
            }
        };
    }
    public static void main(String[] args) {
        MinGenericMap<String,Integer> map = new GenericHashMap<>();
        GenericMapTest.test(map);
    }
    
}