package de.ostfalia.algo.ws18.s1;

import java.time.LocalDate;
import java.time.format.DateTimeFormatter;

import de.ostfalia.algo.ws18.base.Gender;
import de.ostfalia.algo.ws18.base.IMember;
import de.ostfalia.algo.ws18.base.KindOfSport;

public class Member implements IMember {
	/**
	 * Schlüssel kodiert als:
	 *   Anfangsbuchstabe des Namens, codiert in
	 *     zwei Dezimalziffern a -> 01, b -> 02, …, z -> 26.
	 *     Diese Zuordnung gilt für Groß- und Kleinbuchstaben,
	 *     Umlaute werden als ae, oe, ue dargestellt.
	 *   Anfangsbuchstabe des Vornamens, codiert in
	 *     zwei Dezimalziffern, siehe Name
	 *   Geburtsdatum, ttmmjjjj
	 *
	 *   Sie können davon ausgehen, dass doppelte Schlüssel nicht vorkommen.
	 */
	private long key;

	/**
	 * Name.
	 */
	private String name;
	
	/**
	 * Firstname.
	 */
	private String firstname;

	/**
	 * Date.
	 */
	private LocalDate date;

	/**
	 * Gender.
	 */
	private Gender gender;
	
	/**
	 * Associated kind of sport.
	 */
	private KindOfSport kindOfSport;
	
	/**
	 * Parse a CSV to a Member.
	 * 
	 * @param csv A CSV String separated by ', ',
	 * with the row signature 'name, firstname, date, gender, kind of sport'
	 * @return A Member.
	 */
	public Member(String csv) {
		final String DELIMITER = ", ";
		String[] columns = csv.split(DELIMITER);
		
		if (columns.length != 5) {
			throw new IllegalArgumentException(
					"Row '" + csv + "' is not a valid format!");
		}

		this.name = columns[0];
		this.firstname = columns[1];
		this.date = LocalDate.parse(columns[2],
				DateTimeFormatter.ISO_DATE);
		this.gender = Gender.valueOf(columns[3]);
		this.kindOfSport = KindOfSport.valueOf(columns[4]);
		this.key = encode(this);
	}

	/**
	 * Member constructor.
	 * 
	 * @param name The name.
	 * @param firstname The firstname.
	 * @param date The date.
	 * @param gender The gender.
	 * @param kindOfSport The associated kind of sport.
	 */
	public Member(String name,
			String firstname,
			LocalDate date,
			Gender gender,
			KindOfSport kindOfSport) {
		this.name = name;
		this.firstname = firstname;
		this.date = date;
		this.gender = gender;
		this.kindOfSport = kindOfSport;
		this.key = encode(this);
	}
	
	/**
	 * Generate a unique key from a member's attributes. 
	 * 
	 * @param member A member.
	 * @return A key.
	 */
	private static Long encode(Member member) {
		String nameKeyPart = encodeLetters(member.name.substring(0, 1));
		String surnameKeyPart = encodeLetters(member.firstname.substring(0, 1));
		String dateKeyPart = encodeDate(member.date);
		String key = nameKeyPart + surnameKeyPart + dateKeyPart;
		return Long.valueOf(key);
	}

	/**
	 * Format the given date as part of a key.
	 * 
	 * @param date A LocalDate.
	 * @return A String ttmmjjjj.
	 */
	private static String encodeDate(LocalDate date) {
		return String.format("%02d%02d%02d", // 2 digits, left pad
				date.getDayOfMonth(),
				date.getMonthValue(),
				date.getYear());
	}

	/**
	 * Map each letter in the given string to a value
	 * between '01' and '26'.
	 * 
	 * @param string A string containing only letters.
	 * @return A string of zero padded digits.
	 */
	private static String encodeLetters(String string) {
		String encodedString = "";

		for (char letter : sanitizeLetters(string).toCharArray()) {
			int letterIndex = letter - 'a' + 1;

			if (letterIndex < 1 || letterIndex > 26) {
				throw new IllegalArgumentException(
						letter + " cannot be encoded!");
			}

			encodedString += String.format("%02d", letterIndex);
		}

		return encodedString;
	}

	/**
	 * Replace ä, ö, ü and lowercase the string.
	 * 
	 * @param string A string.
	 * @return A lowercase string without umlauts.
	 */
	private static String sanitizeLetters(String string) {
		return string
				.toLowerCase()
				.replace("ä", "ae")
				.replace("ö", "oe")
				.replace("ü", "ue");
	}

	/**
	 * Return this member as string.
	 */
	@Override
	public String toString() {
		return this.key + ", "
				+ this.name + ", "
				+ this.firstname + ", "
				+ this.date + ", "
				+ this.gender + ", "
				+ this.kindOfSport;
	}
	
	/**
	 * Implement the Comparable interface by comparing the keys.
	 * 
	 * @return @see Comparable
	 */
	@Override
	public int compareTo(IMember member) {
		return Long.compare(this.key, member.getKey());
	}
	
	@Override
	public String getName() {
		return this.name;
	}
	
	@Override
	public Gender getGender() {
		return this.gender;
	}
	
	@Override
	public LocalDate getDate() {
		return this.date;
	}
	
	@Override
	public String getFirstName() {
		return this.firstname;
	}
	
	@Override
	public long getKey() {
		return this.key;
	}
	
	@Override
	public KindOfSport getKindOfSport() {
		return this.kindOfSport;
	}
}