filval/datafile.hpp

/**
 * @file
 * @author  Caleb Fangmeier <caleb@fangmeier.tech>
 * @version 0.1
 *
 * @section LICENSE
 *
 *
 * MIT License
 *
 * Copyright (c) 2017 Caleb Fangmeier
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * @section DESCRIPTION
 */
#ifndef datafile_hpp
#define datafile_hpp

#include <vector>
#include <string>
#include <fstream>
#include <iostream>

namespace fv::util{

/**
 * Splits input string into substrings based on provided sep char.
 * For example, split("1,2,3", ',') -> {"1","2","3"}.
 */
std::vector<std::string> split(const std::string& to_split, char sep){
    std::vector<std::string> substrings;
    std::string substring;

    for(const char &c : to_split){
        if(c == sep){
            substrings.push_back(substring);
            substring.clear();
        } else{
            substring.push_back(c);
        }
    }
    if(substring.size() > 0){
        substrings.push_back(substring);
    }
    return substrings;
}

/**
 * Removes leading and trailing whitespace from s
 */
std::string& strip(std::string& s){
    int idx;
    //strip left side whitespace
    for(idx=0; idx<s.size(); idx++){
        char& c = s[idx];
        if(c == ' ' || c == '\t') continue;
        break;
    }
    s.erase(0,idx);
    //strip right side whitespace
    for(idx=s.size()-1; idx>=0; idx--){
        char& c = s[idx];
        if(c == ' ' || c == '\t') continue;
        break;
    }
    s.erase(idx+1,s.size()-idx-1);
    return s;
}

struct DataFileDescriptor{
    std::string filename;
    std::string label;
    std::string category;
    int file_number;

    DataFileDescriptor():filename(""), label(""),category(""),file_number(-1) { }

    DataFileDescriptor(const std::string filename, const std::string label, const std::string category, const int file_number)
      :filename(filename), label(label),category(category),file_number(file_number) { }

    DataFileDescriptor(const std::string filename, const std::string label, const std::string category)
      :filename(filename), label(label),category(category),file_number(-1) { }

    DataFileDescriptor(const std::string line)
      :filename(""),label(""),category(""),file_number(-1){
        auto fields = split(line, ':');
        filename = strip(fields[0]);
        if(fields.size()>1) label=strip(fields[1]);
        if(fields.size()>2) label=strip(fields[2]);
    }

};

// input list should be a file containing line-delineated filename for all Data
// Files with an optional label separated by a comma.
std::vector<DataFileDescriptor> read_input_list(const std::string &filename){
    std::ifstream istrm(filename, std::ios::in);

    std::string line;
    std::vector<DataFileDescriptor> dfds;
    std::string prefix = filename.substr(0, filename.find_last_of("/")+1);
    while(std::getline(istrm, line)){
        strip(line);
        if(line[0] != '#')
        dfds.push_back(DataFileDescriptor(prefix+line));
    }
    return dfds;
}
}
#endif // datafile_hpp