package jobshop.solvers;

import jobshop.Instance;
import jobshop.encodings.Schedule;
import jobshop.solvers.neighborhood.Neighborhood;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Optional;

public class DescentSolverMultiStart implements Solver {
    final Neighborhood neighborhood;
    final List<Solver> solvers = List.of(new GreedySolver(GreedySolver.Priority.SPT),
            new GreedySolver(GreedySolver.Priority.LRPT),
            new GreedySolver(GreedySolver.Priority.EST_SPT),
            new GreedySolver(GreedySolver.Priority.EST_LRPT));

    public DescentSolverMultiStart(Neighborhood neighborhood) {
        this.neighborhood = neighborhood;
    }

    @Override
    public Optional<Schedule> solve(Instance instance, long deadline, int randomness, int randomRunNumber){
        Integer best = Integer.MAX_VALUE;
        Schedule bestSchedule = null;

        // we try all greedy solvers for the starting solution
        for (Solver s : solvers){
            System.out.println();
            System.out.println("\u001b[36m" + "Trying with solver : " + s.toString() + "\u001b[0m");
            DescentSolver descentSolver = new DescentSolver(neighborhood, s);
            Schedule solution = descentSolver.solve(instance,deadline,randomness,randomRunNumber).get();
            if (solution.makespan() < best){
                best = solution.makespan();
                bestSchedule = solution;
            }
        }
        return Optional.of(bestSchedule);
    }
}