#include "CSVReader.h"
#include <iostream>
#include <fstream>

CSVReader::CSVReader()
{

}

std::vector<OrderBookEntry> CSVReader::readCSV(std::string csvFilename)
{
    std::vector<OrderBookEntry> entries;
    unsigned int errors = 0;
    std::ifstream csvFile{csvFilename};
    std::string line;
    std::cout << "Loading data..." << std::endl;
    if (csvFile.is_open())
    {
        while(std::getline(csvFile, line))
        {
            try
            {
                OrderBookEntry obe = stringsToOBE(tokenise(line, ','));
                entries.push_back(obe);
            }
            catch(const std::exception& e)
            {
                ++errors;
            }
        }// end of while
        std::cout << "Success! " << entries.size() << " entries found."  << std::endl;
        if(errors > 0)
            std::cout << errors << " errors found." << std::endl;
    }
    return entries;
}

std::vector<std::string> CSVReader::tokenise(std::string csvLine, char separator)
{
   std::vector<std::string> tokens;
   signed int start, end;
   std::string token;
    start = csvLine.find_first_not_of(separator, 0);
    do{
        end = csvLine.find_first_of(separator, start);
        if (start == csvLine.length() || start == end) break;
        if (end >= 0) token = csvLine.substr(start, end - start);
        else token = csvLine.substr(start, csvLine.length() - start);
        tokens.push_back(token);
        start = end + 1;
    }
    while(end > 0);

   return tokens; 
}

OrderBookEntry CSVReader::stringsToOBE(std::vector<std::string> tokens)
{
    double price, amount;

    if (tokens.size() != 5) // bad
    {
        //std::cout << "Bad line " << std::endl;
        throw std::exception{};
    }
    // we have 5 tokens
    try
    {
        price = std::stod(tokens[3]);
        amount = std::stod(tokens[4]);
    }
    catch(const std::exception& e)
    {
        throw;        
    }

    OrderBookEntry obe{price, 
                        amount, 
                        tokens[0],
                        tokens[1], 
                        OrderBookEntry::stringToOrderBookType(tokens[2])};

    return obe;
}