package com.archmage.toolbox;

import java.util.ArrayList;
import java.util.HashMap;

public abstract class Unique {

	private final int id;

	private static HashMap<String, ArrayList<Integer>>	register	= new HashMap<>();
	private static final int									START_ID	= 1;

	public Unique() {
		String idClass = getIdCode();
		if(!register.containsKey(idClass)) {
			register.put(idClass, new ArrayList<>());
		}
		for(int i = START_ID; i < Integer.MAX_VALUE; ++i) {
			if(!register.get(idClass).contains(Integer.valueOf(i))) {
				register.get(idClass).add((id = i));
				return;
			}
		}
		// this should never happen
		throw new UnsupportedOperationException("no suitable id was available!");
	}

	protected abstract String getIdCode();

	public final String getId() {
		return getIdCode() + (id + "");
	}

	/**
	 * Receives an "id" argument and parses it into an array of valid ids.
	 *
	 * Expected format is [idClass][rangeStart]-[rangeEnd]
	 *
	 * e.g. for idClass "d", the following inputs are valid:
	 *
	 * "d1" = returns "d1"
	 * "d4-6" = returns ["d4", "d5", "d6"]
	 * "all" = returns all ids for idClass "d"
	 *
	 * If a larger rangeEnd than highest id is specified, it will return all
	 * from rangeStart to the highest id.
	 *
	 * It is assumed that idClass does not contain spaces, numerals or hyphens.
	 *
	 * @param input
	 * @return
	 */
	public static String[] getIdsFromRange(String input) {
		if(input == null) return null;
		if((input = input.trim()).isEmpty()) return null;
		String idClass = input.replaceAll("[0-9]", "").replaceAll("\\-", "");
		if(idClass.length() == 0) return null;
		if(!register.containsKey(idClass)) return null;
		ArrayList<String> output = new ArrayList<>();
		int[] integers;
		try {
			String[] temp = input.replaceAll(idClass, "").split("\\-");
			if(temp.length == 0) return null;

			int low = Integer.valueOf(temp[0]);
			int high = Integer.valueOf(temp[temp.length - 1]);

			integers = new int[high - low + 1];
			for(int i = low; i <= high; ++i) {
				integers[i - low] = i;
			}

			// was I high when I wrote this?!
			// integers = new int[temp.length];
			// for(int i = 0; i < temp.length; ++i)
			// integers[i] = Integer.valueOf(temp[i]);
		}
		catch(NumberFormatException nfe) {
			return null;
		}
		for(int i = integers[0]; i <= integers[integers.length - 1]; ++i) {
			if(register.get(idClass).contains(i)) {
				output.add(idClass + i);
			}
			else break;
		}

		return output.toArray(new String[0]);
	}
}