package yannakakis;

import com.google.common.collect.Lists;
import net.automatalib.automata.transout.impl.compact.CompactMealy;
import net.automatalib.util.automata.builders.AutomatonBuilders;
import net.automatalib.util.automata.builders.MealyBuilder;
import net.automatalib.words.Alphabet;
import net.automatalib.words.impl.Alphabets;

import java.io.IOException;
import java.nio.file.Path;
import java.util.HashSet;
import java.util.List;
import java.util.Scanner;
import java.util.Set;

/**
 * A class which is just able to parse the output generated by LearnLib (why is this not included in LearnLib itself?
 * I have no clue.) It is *not* a general graphviz parser, it only parses the things I needed for the mealy machines.
 */
public class GraphvizParser {
	public static class Edge {
		public String from;
		public String to;
		public String label;
		Edge(String b, String e, String l){
			from = b;
			to = e;
			label = l;
		}
	}

	public Set<String> nodes;
	public Set<Edge> edges;

	GraphvizParser(Path filename) throws IOException {
		nodes = new HashSet<>();
		edges = new HashSet<>();

		Scanner s = new Scanner(filename);
		while(s.hasNextLine()){
			String line = s.nextLine();

			if(!line.contains("label")) continue;

			if(line.contains("->")){
				int e1 = line.indexOf('-');
				int e2 = line.indexOf('[');
				int b3 = line.indexOf('"');
				int e3 = line.lastIndexOf('"');

				String from = line.substring(0, e1).trim();
				String to = line.substring(e1+2, e2).trim();
				String label = line.substring(b3+1, e3).trim();

				edges.add(new Edge(from, to, label));
			} else {
				int end = line.indexOf('[');
				if(end <= 0) continue;
				String node = line.substring(0, end).trim();

				nodes.add(node);
			}
		}
	}

	CompactMealy<String, String> createMachine(){
		Set<String> inputs = new HashSet<>();
		for(GraphvizParser.Edge e : edges){
			String[] io = e.label.split("/");
			inputs.add(io[0].trim());
		}

		List<String> inputList = Lists.newArrayList(inputs.iterator());
		Alphabet<String> alphabet = Alphabets.fromList(inputList);

		MealyBuilder<?, String, ?, String, CompactMealy<String, String>>.MealyBuilder__1 builder = AutomatonBuilders.<String, String>newMealy(alphabet).withInitial("s0");
		for(GraphvizParser.Edge e : edges){
			String[] io = e.label.split("/");

			builder.from(e.from).on(io[0].trim()).withOutput(io[1].trim()).to(e.to);
		}

		return builder.create();
	}
}