//
// Copyright (c) 2009-present Benjamin Kaufmann
//
// This file is part of Clasp. See https://potassco.org/clasp/
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//

// Add the libclasp directory to the list of
// include directories of your build system.
#include "example.h"
#include <clasp/clasp_facade.h>
#include <clasp/solver.h>

// This example uses the ClaspFacade to compute the stable models of the program:
//    a :- not b.
//    b :- not a.
//
// The ClaspFacade is a convenient wrapper for the services of the clasp library.
// See clasp_facade.h for details.

// To get models from the ClaspFacade, we must provide a suitable event handler.
class ModelPrinter : public Clasp::EventHandler {
public:
    ModelPrinter() = default;
    bool onModel(const Clasp::Solver& s, const Clasp::Model& m) override {
        printModel(s.outputTable(), m);
        return true;
    }
};

void addSimpleProgram(Clasp::Asp::LogicProgram& prg) {
    Potassco::Atom_t      a = prg.newAtom();
    Potassco::Atom_t      b = prg.newAtom();
    Potassco::RuleBuilder rb;
    prg.addRule(rb.start().addHead(a).addGoal(Potassco::neg(b)));
    prg.addRule(rb.start().addHead(b).addGoal(Potassco::neg(a)));
    prg.addAtomOutput(a, "a");
    prg.addAtomOutput(b, "b");
}

void example2() {
    // Aggregates configuration options.
    // Using config, you can control many parts of the search, e.g.
    // - the amount and kind of preprocessing
    // - the enumerator to use and the number of models to compute
    // - the heuristic used for decisions
    // - the restart strategy
    // - ...
    Clasp::ClaspConfig config;
    // We want to compute all models, but
    // otherwise we use the default configuration.
    config.solve.numModels = 0;

    // The "interface" to the clasp library.
    Clasp::ClaspFacade libclasp;

    // LogicProgram provides the interface for defining logic programs.
    // The returned object is already setup and ready to use.
    // See logic_program.h for details.
    Clasp::Asp::LogicProgram& asp = libclasp.startAsp(config);
    addSimpleProgram(asp);
    // We are done with problem setup.
    // Prepare the problem for solving.
    libclasp.prepare();

    // Start the actual solving process.
    ModelPrinter printer;
    libclasp.solve(&printer);
    std::cout << "No more models!" << std::endl;
}
