/*
Copyright (c) by respective owners including Yahoo!, Microsoft, and
individual contributors. All rights reserved.  Released under a BSD
license as described in the file LICENSE.
 */
#ifndef EXAMPLE_H
#define EXAMPLE_H

#include <stdint.h>
#include "v_array.h"

const size_t wap_ldf_namespace  = 126;
const size_t history_namespace  = 127;
const size_t constant_namespace = 128;
const size_t nn_output_namespace  = 129;
const size_t autolink_namespace  = 130;
const size_t neighbor_namespace  = 131;   // this is \x83 -- to do quadratic, say "-q a`printf "\x83"` on the command line
const size_t affix_namespace     = 132;   // this is \x84
const size_t spelling_namespace  = 133;   // this is \x85

struct feature {
  float x;
  uint32_t weight_index;
  bool operator==(feature j){return weight_index == j.weight_index;}
};

struct audit_data {
  char* space;
  char* feature;
  size_t weight_index;
  float x;
  bool alloced;
};

struct example // core example datatype.
{
  void* ld;

  v_array<char> tag;//An identifier for the example.
  size_t example_counter;

  v_array<unsigned char> indices;
  v_array<feature> atomics[256]; // raw parsed data
  uint32_t ft_offset;
  
  v_array<audit_data> audit_features[256];
  
  size_t num_features;//precomputed, cause it's fast&easy.
  float partial_prediction;//shared data for prediction.
  v_array<float> topic_predictions;
  float loss;
  float eta_round;
  float eta_global;
  float example_t;//sum of importance weights so far.
  float sum_feat_sq[256];//helper for total_sum_feat_sq.
  float total_sum_feat_sq;//precomputed, cause it's kind of fast & easy.
  float revert_weight;

  bool test_only;
  bool end_pass;//special example indicating end of pass.
  bool sorted;//Are the features sorted or not?
  bool in_use; //in use or not (for the parser)
};

 struct vw;  
 
namespace VW {
struct flat_example 
{
	void* ld;  

	size_t tag_len;
	char* tag;//An identifier for the example.  

	size_t example_counter;  
	uint32_t ft_offset;  
	float global_weight;

	size_t num_features;//precomputed, cause it's fast&easy.  
	size_t feature_map_len;
	feature* feature_map; //map to store sparse feature vectors  
};
flat_example* flatten_example(vw& all, example *ec);
void free_flatten_example(flat_example* fec);
}

example *alloc_examples(size_t,size_t);
void dealloc_example(void(*delete_label)(void*), example&);

inline int example_is_newline(example& ec)
{
  // if only index is constant namespace or no index
  return ((ec.indices.size() == 0) || 
          ((ec.indices.size() == 1) &&
           (ec.indices.last() == constant_namespace)));
}

#endif