/*
CoPyright (c) by respective owners including Yahoo!, Microsoft, and
individual contributors. All rights reserved.  Released under a BSD (revised)
license as described in the file LICENSE.
 */
#include "search_multiclasstask.h"
#include "multiclass.h"
#include "memory.h"
#include "example.h"
#include "gd.h"
#include "ezexample.h"

namespace MulticlassTask { Search::search_task task = { "multiclasstask", run, initialize, finish, NULL, NULL };  }

namespace MulticlassTask {

  struct task_data {
    size_t max_label;
    size_t num_level;
    v_array<uint32_t> y_allowed;
  };

  void initialize(Search::search& sch, size_t& num_actions, po::variables_map& vm) {
    task_data * my_task_data = new task_data();
    sch.set_options( 0 );
    sch.set_num_learners(num_actions);
    my_task_data->max_label = num_actions;
	my_task_data->num_level = (size_t)ceil(log(num_actions) /log(2));
	my_task_data->y_allowed.push_back(1);
	my_task_data->y_allowed.push_back(2);
    sch.set_task_data(my_task_data);
  }

  void finish(Search::search& sch) {   
    task_data * my_task_data = sch.get_task_data<task_data>();
	my_task_data->y_allowed.delete_v();
	delete my_task_data;
  }

  void run(Search::search& sch, vector<example*>& ec) {
    task_data * my_task_data = sch.get_task_data<task_data>();
    size_t gold_label = ec[0]->l.multi.label;
    size_t label = 0;
    size_t learner_id = 0;

	for(size_t i=0; i<my_task_data->num_level;i++){
	  size_t mask = 1<<(my_task_data->num_level-i-1);
	  size_t y_allowed_size = (label+mask +1 <= my_task_data->max_label)?2:1;
      action oracle = (((gold_label-1)&mask)>0)+1;
      size_t prediction = sch.predict(*ec[0], 0, &oracle, 1, NULL, NULL, my_task_data->y_allowed.begin, y_allowed_size, learner_id); // TODO: do we really need y_allowed?
      learner_id= (learner_id << 1) + prediction;
	  if(prediction == 2)
	      label += mask;
	}
    label+=1;
    sch.loss(!(label == gold_label));
    if (sch.output().good())
        sch.output() << label << ' ';
  }
}