// Copyright (C) 2011  Davis E. King (davis@dlib.net)
// License: Boost Software License   See LICENSE.txt for the full license.

#include "../matrix.h"
#include <vector>
#include "structural_svm_problem_threaded_abstract.h"
#include "assignment_function_abstract.h"

// ----------------------------------------------------------------------------------------

namespace dlib

    template <
        typename feature_extractor
    class structural_svm_assignment_problem : noncopyable,
                                              public structural_svm_problem_threaded<matrix<double,0,1>, 
                                                     typename feature_extractor::feature_vector_type >
            REQUIREMENTS ON feature_extractor
                It must be an object that implements an interface compatible with 
                the example_feature_extractor defined in dlib/svm/assignment_function_abstract.h.

                This object is a tool for learning the parameters needed to use an
                assignment_function object.  It learns the parameters by formulating the
                problem as a structural SVM problem.  

        typedef matrix<double,0,1> matrix_type;
        typedef typename feature_extractor::feature_vector_type feature_vector_type;
        typedef typename feature_extractor::lhs_element lhs_element;
        typedef typename feature_extractor::rhs_element rhs_element;
        typedef std::pair<std::vector<lhs_element>, std::vector<rhs_element> > sample_type;
        typedef std::vector<long> label_type;

            const std::vector<sample_type>& samples,
            const std::vector<label_type>& labels,
            const feature_extractor& fe,
            bool force_assignment,
            unsigned long num_threads,
            const double loss_per_false_association,
            const double loss_per_missed_association
                - loss_per_false_association > 0
                - loss_per_missed_association > 0
                - is_assignment_problem(samples,labels) == true
                - if (force_assignment) then
                    - is_forced_assignment_problem(samples,labels) == true
                - This object attempts to learn a mapping from the given samples to the 
                  given labels.  In particular, it attempts to learn to predict labels[i] 
                  based on samples[i].  Or in other words, this object can be used to learn 
                  a parameter vector and bias, w and b, such that an assignment_function declared as:
                    assignment_function<feature_extractor> assigner(w,b,fe,force_assignment)
                  results in an assigner object which attempts to compute the following mapping:
                    labels[i] == labeler(samples[i])
                - This object will use num_threads threads during the optimization 
                  procedure.  You should set this parameter equal to the number of 
                  available processing cores on your machine.
                - When solving the structural SVM problem, we will use
                  loss_per_false_association as the loss for incorrectly associating
                  objects that shouldn't be associated.
                - When solving the structural SVM problem, we will use
                  loss_per_missed_association as the loss for failing to associate to
                  objects that are supposed to be associated with each other.


// ----------------------------------------------------------------------------------------