#include <errno.h>

#include "exception.h"
#include "csvreader.h"
#include "parser.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 = !skip_hdr;
    }


int CsvReader::parseCSV(const std::string &filename, std::vector<ColDefNode> &cols_def, Table &table) {
	std::vector<ColDefNode> cdefs;
	cdefs.reserve(cols_def.size());
	for (auto &cd : cols_def) {
		cdefs.emplace_back(table.get_column_def(cd.name));
	}

	int row_cnt = 0;
	bool inQuote(false);
	std::string field;

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

	errno = 0;
	FILE* fp = fopen(filename.c_str(), "r");
	if (fp == NULL)
		throw Exception("load from csv, cannot read from file(" + std::to_string(errno) + ")");

	char* line_str = NULL;
	size_t len = 0;


	int read_chars;
	while ((read_chars = getline(&line_str, &len, fp)) != -1) {
		if (skip_header && !header_skiped) {
			header_skiped = true;
			continue;
		}
		if (read_chars > 0 && line_str[read_chars - 1] == '\n') {
 		     line_str[read_chars - 1] = '\0';
 		     --read_chars;
  		}
		std::string csvSource{line_str};
		
		std::string::const_iterator aChar = csvSource.begin();
		std::string::const_iterator strEnd = csvSource.end();
		while (aChar != strEnd) {
			if (*aChar == quote_character) {
				inQuote = !inQuote;
			} else if (*aChar == field_separator) {
				if (inQuote == true) {
					field += *aChar;
				} else {
					line.push_back(field);
					field.clear();
				}
			} else {
				field.push_back(*aChar);
			}

			++aChar;
		}

		if (!field.empty())
			line.push_back(field);

		table.create_row_from_vector(cols_def, line);
		row_cnt++;

		field.clear();
		line.clear();
// DEBUG 
// if (row_cnt > 50000) break;
//
	}

	fclose(fp);
	if (line_str)
	    free(line_str);


	return row_cnt;
}

    int CsvReader::parseCSV2(const std::string &csvSource, std::vector<ColDefNode> &cols_def, Table& table) {
    	int row_cnt = 0;
    	bool inQuote(false);
    	bool newLine(false);
    	std::string field;

    	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);
    					if (header_skiped) {
    						table.create_row_from_vector(cols_def, line);
						row_cnt++;
    					}
    					header_skiped = true;
    					field.clear();
    					line.clear();
    					newLine = true;
    				}
    			}
    		} else {
    			newLine = false;
    			field.push_back(*aChar);
    		}

    		aChar++;
    	}

    	if (!field.empty()) line.push_back(field);

	if (header_skiped) {
		table.create_row_from_vector(cols_def, line);
		row_cnt++;
		header_skiped = true;
	}

	return row_cnt;
}

}	// namespace