/*  Starshatter: The Open Source Project
    Copyright (c) 2021-2022, Starshatter: The Open Source Project Contributors
    Copyright (c) 2011-2012, Starshatter OpenSource Distribution Contributors
    Copyright (c) 1997-2006, Destroyer Studios LLC.

     AUTHOR:       John DiCamillo


     OVERVIEW
     ========
     Scanner class definition
*/

#ifndef Token_h
#define Token_h

#include "Text.h"
#include "Dictionary.h"

#pragma warning( disable : 4237)

// +-------------------------------------------------------------------+

class Reader;
class Token;
class Scanner;

// +-------------------------------------------------------------------+

class Token
{
    friend class Scanner;

public:
    // keywords must be alphanumeric identifiers or symbolic identifiers
    enum Types { Undefined, Keyword, AlphaIdent, SymbolicIdent, Comment,
                     IntLiteral, FloatLiteral, StringLiteral, CharLiteral,
                     Dot, Comma, Colon, Semicolon,
                     LParen, RParen, LBracket, RBracket, LBrace, RBrace,
                     EOT, LastTokenType };

    enum Alias { CompoundSeparator   = Dot,
                     ItemSeparator       = Comma,
                     StatementTerminator = Semicolon,
                     TypeIndicator       = Colon,
                     Lambda              = LastTokenType + 1 };

    Token();
    Token(const Token& rhs);
    Token(int t);
    Token(const char* s, int t, int k=0, int l=0, int c=0);
    Token(const Text& s, int t, int k=0, int l=0, int c=0);
    ~Token();

    Token& operator = (const Token& rhs);

    bool     match(const Token& ref) const;

    Text     symbol()   const;
    int      type()     const { return mType;   }
    int      key()      const { return mKey;    }
    int      line()     const { return mLine;   }
    int      column()   const { return mColumn; }

    Text     typestr()  const;

    static Text   describe(const Text& tok);
    static void   addKey(const Text& k, int v);
    static void   addKeys(Dictionary<int>& keys);
    static bool   findKey(const Text& k, int& v);
    static void   comments(const Text& begin, const Text& end);
    static void   altComments(const Text& begin, const Text& end);
    static void   hideComments(bool hide = true) { hidecom = hide; }

    static char   comBeg(unsigned int i) { return combeg[i]; }
    static char   comEnd(unsigned int i) { return comend[i]; }
    static char   altBeg(unsigned int i) { return altbeg[i]; }
    static char   altEnd(unsigned int i) { return altend[i]; }

    static void   close();

protected:
    int      mLength;
    union {
        char  mSymbol[8];
        char* mFullSymbol;
    };
    int      mType;
    int      mKey;
    int      mLine;
    int      mColumn;

    static bool             hidecom;
    static char             combeg[3];
    static char             comend[3];
    static char             altbeg[3];
    static char             altend[3];

    static Dictionary<int> keymap;
};

// +-------------------------------------------------------------------+

class Scanner
{
public:
    Scanner(Reader* r = 0);
    Scanner(const Text&  s);
    Scanner(const Scanner& rhs);
    virtual ~Scanner();

    Scanner& operator = (const Scanner& rhs);

    void           Load(const Text& s);

    enum Need { Demand, Request };
    virtual Token  Get(Need n = Demand);

    void           PutBack()     { index = old_index; line = old_line; }
    int            GetCursor()   { return index;     }
    int            GetLine()     { return line;      }
    void           Reset(int c, int l) { index = old_index = c; line = old_line = l; }
    Token          Best() const  { return best;      }

protected:
    virtual int    GetNumeric();
    virtual bool   IsSymbolic(char c);
    virtual bool   IsAlpha(char c);

    Reader*     reader;
    char*       str;

    const char* p;
    const char* eos;

    size_t      index;
    size_t      old_index;
    Token       best;
    size_t      length;
    size_t      line;
    size_t      old_line;
    size_t      lineStart;
};


#endif  // Token_h