#ifndef XGBOOST_REG_DATA_H
#define XGBOOST_REG_DATA_H

/*!
 * \file xgboost_reg_data.h
 * \brief input data structure for regression and binary classification task.
 *     Format:
 *        The data should contain each data instance in each line.
 *		  The format of line data is as below:
 *        label <nonzero feature dimension> [feature index:feature value]+
 * \author Kailong Chen: chenkl198812@gmail.com, Tianqi Chen: tianqi.tchen@gmail.com
 */
#include <cstdio>
#include <vector>
#include "../booster/xgboost_data.h"
#include "../utils/xgboost_utils.h"
#include "../utils/xgboost_stream.h"

namespace xgboost{
    namespace regression{
        /*! \brief data matrix for regression content */
        struct DMatrix{
        public:
            /*! \brief maximum feature dimension */
            unsigned num_feature;
            /*! \brief feature data content */
            booster::FMatrixS data;
            /*! \brief label of each instance */
            std::vector<float> labels;
        public:
            /*! \brief default constructor */
            DMatrix(void){}

            /*! \brief get the number of instances */
            inline size_t Size() const{
                return labels.size();
            }
            /*!
            * \brief load from text file
            * \param fname name of text data
            * \param silent whether print information or not
            */
            inline void LoadText(const char* fname, bool silent = false){
                data.Clear();
                FILE* file = utils::FopenCheck(fname, "r");
                float label; bool init = true;
                char tmp[1024];
                std::vector<booster::bst_uint> findex;
                std::vector<booster::bst_float> fvalue;

                while (fscanf(file, "%s", tmp) == 1){
                    unsigned index; float value;
                    if (sscanf(tmp, "%u:%f", &index, &value) == 2){
                        findex.push_back(index); fvalue.push_back(value);
                    }
                    else{
                        if (!init){
                            labels.push_back(label);
                            data.AddRow(findex, fvalue);
                        }
                        findex.clear(); fvalue.clear();
                        utils::Assert(sscanf(tmp, "%f", &label) == 1, "invalid format");
                        init = false;
                    }
                }

                labels.push_back(label);
                data.AddRow(findex, fvalue);
                // initialize column support as well
                data.InitData();

                if (!silent){
                    printf("%ux%u matrix with %lu entries is loaded from %s\n",
                        (unsigned)data.NumRow(), (unsigned)data.NumCol(), (unsigned long)data.NumEntry(), fname);
                }
                fclose(file);
            }
            /*!
            * \brief load from binary file
            * \param fname name of binary data
            * \param silent whether print information or not
            * \return whether loading is success
            */
            inline bool LoadBinary(const char* fname, bool silent = false){
                FILE *fp = fopen64(fname, "rb");
                if (fp == NULL) return false;
                utils::FileStream fs(fp);
                data.LoadBinary(fs);
                labels.resize(data.NumRow());
                utils::Assert(fs.Read(&labels[0], sizeof(float)* data.NumRow()) != 0, "DMatrix LoadBinary");
                fs.Close();
                // initialize column support as well
                data.InitData();

                if (!silent){
                    printf("%ux%u matrix with %lu entries is loaded from %s\n",
                        (unsigned)data.NumRow(), (unsigned)data.NumCol(), (unsigned long)data.NumEntry(), fname);
                }
                return true;
            }
            /*!
            * \brief save to binary file
            * \param fname name of binary data
            * \param silent whether print information or not
            */
            inline void SaveBinary(const char* fname, bool silent = false){
                // initialize column support as well
                data.InitData();

                utils::FileStream fs(utils::FopenCheck(fname, "wb"));
                data.SaveBinary(fs);
                fs.Write(&labels[0], sizeof(float)* data.NumRow());
                fs.Close();
                if (!silent){
                    printf("%ux%u matrix with %lu entries is saved to %s\n",
                        (unsigned)data.NumRow(), (unsigned)data.NumCol(), (unsigned long)data.NumEntry(), fname);
                }
            }
            /*!
            * \brief cache load data given a file name, if filename ends with .buffer, direct load binary
            *        otherwise the function will first check if fname + '.buffer' exists,
            *        if binary buffer exists, it will reads from binary buffer, otherwise, it will load from text file,
            *        and try to create a buffer file
            * \param fname name of binary data
            * \param silent whether print information or not
            * \param savebuffer whether do save binary buffer if it is text
            */
            inline void CacheLoad(const char *fname, bool silent = false, bool savebuffer = true){
                int len = strlen(fname);
                if (len > 8 && !strcmp(fname + len - 7, ".buffer")){
                    this->LoadBinary(fname, silent); return;
                }
                char bname[1024];
                sprintf(bname, "%s.buffer", fname);
                if (!this->LoadBinary(bname, silent)){
                    this->LoadText(fname, silent);
                    if (savebuffer) this->SaveBinary(bname, silent);
                }
            }
        private:
            /*! \brief update num_feature info */
            inline void UpdateInfo(void){
                this->num_feature = 0;
                for (size_t i = 0; i < data.NumRow(); i++){
                    booster::FMatrixS::Line sp = data[i];
                    for (unsigned j = 0; j < sp.len; j++){
                        if (num_feature <= sp[j].findex){
                            num_feature = sp[j].findex + 1;
                        }
                    }
                }
            }
        };
    };
};
#endif