#include "csvreader.h"

namespace usql {

    CsvReader::CsvReader(bool skip_hdr, char field_sep, char quote_ch, char line_sep, char line_sep2) {
	    skip_header = skip_hdr;
	    field_separator = field_sep;
	    quote_character = quote_ch;
	    line_separator = line_sep;
	    line_separator2 = line_sep2;

	    header_skiped = false;
    }

    std::vector<std::vector<std::string>> CsvReader::parseCSV(const std::string &csvSource) {
	    int linesRead = 0;
	    bool inQuote(false);
	    bool newLine(false);
	    std::string field;

	    std::vector<std::vector<std::string>> parsed_data;
	    parsed_data.reserve(128);

	    std::vector<std::string> line;
	    line.reserve(32);

	    std::string::const_iterator aChar = csvSource.begin();
	    while (aChar != csvSource.end()) {
		    if (*aChar == quote_character) {
			    newLine = false;
			    inQuote = !inQuote;
		    } else if (*aChar == field_separator) {
			    newLine = false;
			    if (inQuote == true) {
				    field += *aChar;
			    } else {
				    line.push_back(field);
				    field.clear();
			    }
		    } else if (*aChar == line_separator || *aChar == line_separator2) {
			    if (inQuote == true) {
				    field += *aChar;
			    } else {
				    if (newLine == false) {
					    line.push_back(field);
					    add_line(line, parsed_data);
					    field.clear();
					    line.clear();
					    linesRead++;
					    if (linesRead == 16) {
						    int linesEstimation =
								csvSource.size() /
								(std::distance(csvSource.begin(), aChar) / linesRead);
						    if (linesEstimation > parsed_data.capacity())
							    parsed_data.reserve(linesEstimation);
					    }
					    newLine = true;
				    }
			    }
		    } else {
			    newLine = false;
			    field.push_back(*aChar);
		    }

		    aChar++;
	    }

	    if (field.size())
		    line.push_back(field);

	    add_line(line, parsed_data);

	    return parsed_data;
    }


    void CsvReader::add_line(const std::vector<std::string> &line, std::vector<std::vector<std::string>> &lines) {
	    if (skip_header && !header_skiped) {
		    header_skiped = true;
	    } else {
		    if (line.size())
			    lines.push_back(line);
	    }
    }

}