#ifndef COMDEL_LEXER_H
#define COMDEL_LEXER_H

#include "parse_context.h"
#include "presult.h"
#include "source_error.h"
#include "token.h"


#include <sstream>
#include <string>
#include <vector>

/** Contains results of tokenizing,
 * if errors isn't empty tokenizing has failed */
struct LexerResult {
    std::vector<Token> tokens;
    std::vector<SourceError> errors;
};

/** Used to tokenize input string */
class ComdelLexer {

    enum Radix {
        BIN_NUMBER = 2,
        DEC_NUMBER = 10,
        HEX_NUMBER = 16
    };

    /** Source file */
    std::string source;
    std::vector<Token> tokens;
    std::vector<SourceError> errors;
    /** Source file */
    ParseContext *parseContext;
    unsigned fileId;

public:
    ComdelLexer(std::string fileName, std::string source, ParseContext *parseContext);

    LexerResult tokenize();

private:
    /** Current parsing info */
    Position tokenBegin;
    Position position;
    char ch;

    /** Methods used to skip unused content */
    void skipWhitespace();
    void skipComment();
    bool skipMultilineComment();
    void bump(unsigned count = 1);

    /** Metods used for number parsing */
    unsigned takeNumberInRadix(Radix radix);
    bool digitIsValid(char ch, Radix radix);
    Radix takeRadix();

    unsigned takeHexColor();

    PResult<TokenType> nextTokenType();

    PResult<TokenType> takeString();
    PResult<TokenType> takeRawString();

    char peek();

    /** Checks if we reached end of file */
    bool eof();
};

#endif // COMDEL_LEXER_H