/***
 * @file Algorithm.hpp
 *
 * The general algorithm.
 */

#include <boost/property_tree/ptree.hpp>
using boost::property_tree::ptree;

#include <iostream>
#include <string>
using namespace std;


#ifndef ALGORITHM_HPP_
#define	ALGORITHM_HPP_

/**
 * This is the main algorithm base class; actual algorithms should be
 * derived. This base class offers the general framework for setup and
 * iterative running, but knows nothing about individual
 * representation or operators actually used. This also handles the
 * "dirty and mundane work" of logging outputs etc. Formatting can, of
 * course, be done only by derived classes that know about the actual
 * representation.
 *
 * Boost property_tree is used for setup, because of its nice parser
 * for structured configuration.
 */
class Algorithm {
protected:
    /** Number of generations to carry out. */
    size_t _maxiter;
    /** Output directory in which all the results and traces will be saved. */
    string _outputdirname;
    /** Next ID to give to a modified individual (unique running index). */
    size_t _nextID = 1;

    // Tracing of information that gives insight to the algorithmic progression.
    // TODO: In final application use, we'd probably want to turn off the tracing.

    /** The IDs of parents; for tracing the algorithm progression. */
    vector< vector <size_t> > _parentsOf; // needs to be vector of vectors..
    /** Traced measures; for tracing the algorithm progression. */
    vector< vector <double> > _tracedMeasures;
protected:
    /** Derived classes must know how to setup their additional data
     *  structures. 
     */
    virtual void impl_setup(const ptree & all) = 0;
    /** Give the next available ID (running index) */
    virtual size_t nextID();
    /** Remember a parenting relationship, for tracing the runs.*/
    void markAsParents(size_t childID, const vector<size_t> & parentIDs);
    /** Trace some measures of an individual, possibly more than just objectives. */
    void traceMeasures(size_t childID, const vector<double> & measures);
    /** Write the traced parenting history to a stream.*/
    void writeParentHistory(ostream & os) const;
    /** Write the traced measures to a stream. */
    void writeTracedMeasures(ostream & os) const;

public:
    /** Default constructor; doesn't initialize much, so setup() must be called.*/
    Algorithm();
    /** Setup case-specific settings. */
    virtual void setup(const ptree & all, const string & outputdirname);
    /** Run the algorithm as the setup tells us to. */
    virtual void run();
};

#endif