package dev.kske.chess.uci;

import java.util.*;

import dev.kske.chess.board.Move;

/**
 * Project: <strong>Chess</strong><br>
 * File: <strong>UCIInfo.java</strong><br>
 * Created: <strong>28.07.2019</strong><br>
 *
 * @since Chess v0.3-alpha
 * @author Kai S. K. Engelbart
 */
public class UCIInfo {

	private int depth, seldepth, time, nodes, multipv, currmovenumber, hashfull,
		nps, tbhits, sbhits, cpuload, cpunr;
	private List<Move> pv = new ArrayList<>(), refutation = new ArrayList<>();
	private Map<Integer, List<Move>> currline = new HashMap<>();
	private Move currmove;
	private Score score;
	private String displayString;

	/**
	 * Contains every parameter for the UCI info command. Helpful for parsing
	 * multi-value parameters.
	 */
	private static final List<String> params = Arrays.asList(
		"depth",
		"seldepth",
		"time",
		"nodes",
		"multipv",
		"currmove",
		"currmovenumber",
		"hashfull",
		"nps",
		"tbhits",
		"sbhits",
		"cpuload",
		"string",
		"score",
		"pv",
		"refutation",
		"currline"
	);

	/**
	 * Creates an instance of {@link UCIInfo} by parsing the argument list of a
	 * UCI
	 * info command generated from an engine.
	 *
	 * @param line the UCI info argument list to parse
	 */
	public UCIInfo(String line) {
		String[] tokens = line.split(" ");

		for (int i = 0; i < tokens.length; i++)
			switch (tokens[i]) {
				// Single parameter info
				case "depth":
					depth = Integer.parseInt(tokens[++i]);
					break;
				case "seldepth":
					seldepth = Integer.parseInt(tokens[++i]);
					break;
				case "time":
					time = Integer.parseInt(tokens[++i]);
					break;
				case "nodes":
					nodes = Integer.parseInt(tokens[++i]);
					break;
				case "multipv":
					multipv = Integer.parseInt(tokens[++i]);
					break;
				case "currmove":
					currmove = Move.fromLAN(tokens[++i]);
					break;
				case "currmovenumber":
					currmovenumber = Integer.parseInt(tokens[++i]);
					break;
				case "hashfull":
					hashfull = Integer.parseInt(tokens[++i]);
					break;
				case "nps":
					nps = Integer.parseInt(tokens[++i]);
					break;
				case "tbhits":
					tbhits = Integer.parseInt(tokens[++i]);
					break;
				case "sbhits":
					sbhits = Integer.parseInt(tokens[++i]);
					break;
				case "cpuload":
					cpuload = Integer.parseInt(tokens[++i]);
					break;
				case "string":
					displayString = tokens[++i];
					break;
				case "score":
					score
						= new Score(line.substring(line.indexOf("score") + tokens[i].length() + 1));
					i += score.getLength() + 1;
					break;
				case "pv":
					while (++i < tokens.length && !params.contains(tokens[i]))
						pv.add(Move.fromLAN(tokens[i]));
					break;
				case "refutation":
					while (++i < tokens.length && !params.contains(tokens[i]))
						refutation.add(Move.fromLAN(tokens[i]));
					break;
				case "currline":
					// A CPU number of 1 can be omitted
					final Integer cpu = tokens[i].matches("\\d+")
						? Integer.parseInt(tokens[i++])
						: 1;
					final ArrayList<Move> moves = new ArrayList<>();
					while (i < tokens.length && !params.contains(tokens[i]))
						moves.add(Move.fromLAN(tokens[i++]));
					currline.put(cpu, moves);
					System.err.println(
						"The parameter 'currline' for command 'info' is not yet implemented"
					);
					break;
				default:
					System.err.printf(
						"Unknown parameter '%s' for command 'info' found!%n",
						tokens[i]
					);
			}
	}

	public int getDepth() { return depth; }

	public int getSeldepth() { return seldepth; }

	public int getTime() { return time; }

	public int getNodes() { return nodes; }

	public int getMultipv() { return multipv; }

	public int getCurrmovenumber() { return currmovenumber; }

	public int getHashfull() { return hashfull; }

	public int getNps() { return nps; }

	public int getTbhits() { return tbhits; }

	public int getSbhits() { return sbhits; }

	public int getCpuload() { return cpuload; }

	public int getCpunr() { return cpunr; }

	public List<Move> getPv() { return pv; }

	public List<Move> getRefutation() { return refutation; }

	public Map<Integer, List<Move>> getCurrline() { return currline; }

	public Move getCurrmove() { return currmove; }

	public Score getScore() { return score; }

	public String getDisplayString() { return displayString; }

	public static class Score {

		private int cp, mate;
		private boolean lowerbound, upperbound;
		private int length;

		public Score(String line) {
			String[] tokens = line.split(" ");
			int i = 0;
			for (; i < tokens.length; i++) {
				if (params.contains(tokens[i]))
					break;
				switch (tokens[i]) {
					case "cp":
						cp = Integer.parseInt(tokens[++i]);
						break;
					case "mate":
						mate = Integer.parseInt(tokens[++i]);
						break;
					case "lowerbound":
						lowerbound = true;
						break;
					case "upperbound":
						upperbound = true;
						break;
					default:
						System.err.printf(
							"Unknown parameter '%s' for command 'score' found!%n",
							tokens[i]
						);
				}
			}
			length = i + 1;
		}

		public int getCp() { return cp; }

		public int getMate() { return mate; }

		public boolean isLowerbound() { return lowerbound; }

		public boolean isUpperbound() { return upperbound; }

		/**
		 * @return The number of tokens this 'score' command contains (including
		 *         itself).
		 */
		public int getLength() { return length; }
	}
}