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#ifndef PPCONTEXT_H
#define PPCONTEXT_H

#include "../ParseHelper.h"

namespace glslang {

class TPpToken {
public:
    TPpToken() : token(0), ival(0), space(false), dval(0.0), atom(0)
    { 
        loc.line = 0; 
        loc.string = 0; 
        name[0] = 0;
    }

    bool operator==(const TPpToken& right)
    {
        return token == right.token && atom == right.atom &&
               ival == right.ival && dval == right.dval &&
               strcmp(name, right.name) == 0;
    }
    bool operator!=(const TPpToken& right) { return ! operator==(right); }

    static const int maxTokenLength = 1024;

    TSourceLoc loc;
    int    token;
    bool   space;  // true if a space (for white space or a removed comment) should also be recognized, in front of the token returned
    int    ival;
    double dval;
    int    atom;
    char   name[maxTokenLength+1];
};

class TInputScanner;

// This class is the result of turning a huge pile of C code communicating through globals
// into a class.  This was done to allowing instancing to attain thread safety.
// Don't expect too much in terms of OO design.
class TPpContext {
public:
    TPpContext(TParseContext&);
    virtual ~TPpContext();

    void setPreamble(const char* preamble, size_t length);
    void setInput(TInputScanner& input, bool versionWillBeError);

    const char* tokenize(TPpToken* ppToken);

    // TODO: preprocessor simplification: this should be a base class, not a set of function pointers
    struct InputSrc {
        InputSrc() : prev(0), scan(0), getch(0), ungetch(0) { }
        struct InputSrc	*prev;
        int			(*scan)(TPpContext*, struct InputSrc *, TPpToken *);
        int			(*getch)(TPpContext*, struct InputSrc *, TPpToken *);
        void		(*ungetch)(TPpContext*, struct InputSrc *, int, TPpToken *);
    };

    struct TokenStream {
        TokenStream() : current(0) { }
        TVector<unsigned char> data;
        size_t current;
    };

    struct MemoryPool {
        struct chunk        *next;
        uintptr_t           free, end;
        size_t              chunksize;
        uintptr_t           alignmask;
        struct cleanup      *cleanup;
    };

    //
    // From Pp.cpp
    //

    struct MacroSymbol {
        MacroSymbol() : argc(0), args(0), body(0), busy(0), undef(0) { }
        int argc;
        int *args;
        TokenStream *body;
        unsigned busy:1;
        unsigned undef:1;
    };

    struct Symbol {
        int atom;
        MacroSymbol mac;
    };

    struct SymbolList {
        struct SymbolList_Rec *next;
        Symbol *symb;
    };

    MemoryPool *pool;
    typedef std::map<int, Symbol*> TSymbolMap;
    TSymbolMap symbols; // this has light use... just defined macros

protected:
    char*   preamble;               // string to parse, all before line 1 of string 0, it is 0 if no preamble
    int     preambleLength;
    char**  strings;                // official strings of shader, starting a string 0 line 1
    size_t* lengths;
    int     numStrings;             // how many official strings there are
    int     currentString;          // which string we're currently parsing  (-1 for preamble)

    // Scanner data:
    int mostRecentToken;        // Most recent token seen by the scanner
    int previous_token;
    TParseContext& parseContext;

    static const int maxMacroArgs = 64;
    static const int maxIfNesting = 64;

    int ifdepth;                  // current #if-#else-#endif nesting in the cpp.c file (pre-processor)    
    bool elseSeen[maxIfNesting];  // Keep a track of whether an else has been seen at a particular depth
    int elsetracker;              // #if-#else and #endif constructs...Counter.
    const char *ErrMsg;

    struct MacroInputSrc : public InputSrc {
        MacroInputSrc() : mac(0) { }
        virtual ~MacroInputSrc()
        {
            for (size_t i = 0; i < args.size(); ++i)
                delete args[i];
        }
        MacroSymbol *mac;
        TVector<TokenStream*> args;
    };

    InputSrc *currentInput;
    bool errorOnVersion;
    bool versionSeen;

    //
    // from Pp.cpp
    //
    int bindAtom;
    int constAtom;
    int defaultAtom;
    int defineAtom;
    int definedAtom;
    int elseAtom;
    int elifAtom;
    int endifAtom;
    int ifAtom;
    int ifdefAtom;
    int ifndefAtom;
    int includeAtom;
    int lineAtom;
    int pragmaAtom;
    int texunitAtom;
    int undefAtom;
    int errorAtom;
    int __LINE__Atom;
    int __FILE__Atom;
    int __VERSION__Atom;
    int versionAtom;
    int coreAtom;
    int compatibilityAtom;
    int esAtom;
    int extensionAtom;
    TSourceLoc ifloc; /* outermost #if */

    int InitCPP();
    int CPPdefine(TPpToken * ppToken);
    int CPPundef(TPpToken * ppToken);
    int CPPelse(int matchelse, TPpToken * ppToken);
    int extraTokenCheck(int atom, TPpToken* ppToken, int token);
    int eval(int token, int precedence, bool shortCircuit, int& res, bool& err, TPpToken * ppToken);
    int CPPif (TPpToken * ppToken); 
    int CPPifdef(int defined, TPpToken * ppToken);
    int CPPline(TPpToken * ppToken); 
    int CPPerror(TPpToken * ppToken); 
    int CPPpragma(TPpToken * ppToken);
    int CPPversion(TPpToken * ppToken);
    int CPPextension(TPpToken * ppToken);
    int readCPPline(TPpToken * ppToken);
    void PushEofSrc();
    void PopEofSrc();
    TokenStream* PrescanMacroArg(TokenStream *a, TPpToken * ppToken);
    static int macro_scan(TPpContext* pp, InputSrc *inInput, TPpToken * ppToken); 
    static int zero_scan(TPpContext* pp, InputSrc *inInput, TPpToken * ppToken); 
    int MacroExpand(int atom, TPpToken* ppToken, int expandUndef);

    //
    // from PpSymbols.cpp
    //
    Symbol *NewSymbol(int name);
    Symbol *AddSymbol(int atom);
    Symbol *LookUpSymbol(int atom);

    //
    // From PpTokens.cpp
    //
    void lAddByte(TokenStream *fTok, unsigned char fVal);
    int lReadByte(TokenStream *pTok);
    void RecordToken(TokenStream* pTok, int token, TPpToken* ppToken);
    void RewindTokenStream(TokenStream *pTok);
    int ReadToken(TokenStream* pTok, TPpToken* ppToken);
    int ReadFromTokenStream(TokenStream *ts, int name, int (*final)(TPpContext *));
    void UngetToken(int token, TPpToken* ppToken);
    struct TokenInputSrc : public InputSrc {
        TokenStream *tokens;
        int (*final)(TPpContext *);
    };
    static int scan_token(TPpContext*, TokenInputSrc *in, TPpToken * ppToken);
    struct UngotToken : public InputSrc {
        int token;
        TPpToken lval;
    };
    static int reget_token(TPpContext *, UngotToken *t, TPpToken * ppToken);

    //
    // From PpScanner.cpp
    //
    struct StringInputSrc : public InputSrc {
        TInputScanner* input;
    };
    int InitScanner(TPpContext *cpp);
    static int sourceGetCh(TPpContext*, StringInputSrc *in);
    static void sourceUngetCh(TPpContext*, StringInputSrc *in, int ch, TPpToken *type);
    int ScanFromString(char *s);
    bool check_EOF(int token);
    int lFloatConst(char *str, int len, int ch, TPpToken * ppToken);
    static int sourceScan(TPpContext*, InputSrc *in, TPpToken * ppToken);

    //
    // From PpAtom.cpp
    //
    typedef std::map<const TString, int> TAtomMap;
    typedef TVector<const TString*> TStringMap;
    TAtomMap atomMap;
    TStringMap stringMap;
    int nextAtom;
    void InitAtomTable();
    int AddAtomFixed(const char *s, int atom);
    int LookUpAddString(const char *s);
    const char *GetAtomString(int atom);

    //
    // From PpMemory.cpp
    //
    MemoryPool *mem_CreatePool(size_t chunksize, unsigned align);
    void mem_FreePool(MemoryPool *);
    void *mem_Alloc(MemoryPool *p, size_t size);
    int mem_AddCleanup(MemoryPool *p, void (*fn)(void *, void*), void *arg1, void* arg2);
};

} // end namespace glslang

#endif  // PPCONTEXT_H