/**
 *   @file yapq.hh
 *
 *   @defgroup yap-cplus-query-handling Query Handling in the YAP interface.
 *   @brief Engine and Query Management
 *
 *   @ingroup yap-cplus-interface
 *
 * @{
 *
 * These classes wrap  engine and query. An engine is an environment where we
 * can rum Prolog, that is, where we can run queries.
 *
 * Also, supports callbacks and engine configuration.
 *
 */

#ifndef YAPQ_HH
#define YAPQ_HH 1

class X_API YAPPredicate;

/**
   Queries and engines
*/

#if __ANDROID__

#endif

/**
 * @brief Queries
 *
 * interface to a YAP Query;
 * uses an SWI-like status info internally.
 */
class X_API YAPQuery : public YAPPredicate {
  bool q_open;
  int q_state;
  yhandle_t q_handles;
  struct yami *q_p, *q_cp;
  int q_flags;
  YAP_dogoalinfo q_h;
  YAPPairTerm names;
  Term goal;
  CELL *nts;
  // temporaries
  YAPError *e;

  inline void setNext() { // oq = LOCAL_execution;
    //  LOCAL_execution = this;
    q_open = true;
    q_state = 0;
    q_flags = true; // PL_Q_PASS_EXCEPTION;

    q_p = P;
    q_cp = CP;
    // make sure this is safe
    q_handles = LOCAL_CurSlot;
  };

  void openQuery();

  PredEntry *rewriteUndefQuery();

public:
  YAPQuery() {
    goal = TermTrue;
    openQuery();
  };
  inline ~YAPQuery() { close(); }
  /// main constructor, uses a predicate and an array of terms
  ///
  /// It is given a YAPPredicate _p_ , and an array of terms that must have at
  /// least
  /// the same arity as the functor.
  YAPQuery(YAPPredicate p, YAPTerm t[]);
  /// full constructor,
  ///
  ///
  /// It is given a functor, module, and an array of terms that must have at
  /// least
  /// the same arity as the functor.
  YAPQuery(YAPFunctor f, YAPTerm mod, YAPTerm t[]);
  /// functor/term constructor,
  ///
  /// It is given a functor, and an array of terms that must have at least
  /// the same arity as the functor. Works within the current module.
  // YAPQuery(YAPFunctor f, YAPTerm t[]);
  /// string constructor without varnames
  ///
  /// It is given a string, calls the parser and obtains a Prolog term that
  /// should be a callable
  /// goal.
  inline YAPQuery(const char *s) : YAPPredicate(s, goal, names, (nts = &ARG1)) {
    __android_log_print(ANDROID_LOG_INFO, "YAPDroid", "got game %ld",
                        LOCAL_CurSlot);

    openQuery();
  };
  // inline YAPQuery() : YAPPredicate(s, tgoal, tnames)
  // {
  //     __android_log_print(ANDROID_LOG_INFO, "YAPDroid", "got game %ld",
  //     if (!ap)
  //         return;
  //     __android_log_print(ANDROID_LOG_INFO, "YAPDroid", "%s", vnames.text());
  //     goal = YAPTerm(tgoal);
  //     names = YAPPairTerm(tnames);
  //     openQuery(tgoal);
  // };
  /// string constructor with just an atom
  ///
  /// It i;
  ///};
  /// build a query from a term
  YAPQuery(YAPTerm t) : YAPPredicate((goal = t.term()), (nts = &ARG1)) {
    BACKUP_MACHINE_REGS();
    openQuery();
    names = YAPPairTerm(TermNil);
    RECOVER_MACHINE_REGS();
  }
  /// set flags for query execution, currently only for exception handling
  void setFlag(int flag) { q_flags |= flag; }
  /// reset flags for query execution, currently only for exception handling
  void resetFlag(int flag) { q_flags &= ~flag; }
  /// first query
  ///
  /// actually implemented by calling the next();
  inline bool first() { return next(); }
  /// ask for the next solution of the current query
  /// same call for every solution
  bool next();
  /// does this query have open choice-points?
  /// or is it deterministic?
  bool deterministic();
  /// represent the top-goal
  const char *text();
  /// remove alternatives in the current search space, and finish the current
  /// query
  /// finish the current query: undo all bindings.
  void close();
  /// query variables.
  void cut();
  Term namedVars() { return names.term(); };
  YAPPairTerm namedVarTerms() { return names; };
  /// query variables, but copied out
  std::vector<Term> namedVarsVector() { return names.listToArray(); };
  /// convert a ref to a binding.
  YAPTerm getTerm(yhandle_t t);
  /// simple YAP Query;
  /// just calls YAP and reports success or failure, Useful when we just
  /// want things done, eg YAPCommand("load_files(library(lists), )")
  inline bool command() {
    bool rc = next();
    close();
    return rc;
  };
};

// Java support

/// This class implements a callback Prolog-side. It will be inherited by the
/// Java or Python
/// class that actually implements the callback.
class X_API YAPCallback {
public:
  virtual ~YAPCallback() {}
  virtual void run() { LOG("callback"); }
  virtual void run(char *s) {}
};

/// @brief Setup all arguments to a new engine
struct X_API YAPEngineArgs : YAP_init_args {

public:
  YAPEngineArgs() {
    // const std::string *s = new std::string("startup.yss");
    Embedded = true;
    install = false;

    Yap_InitDefaults(this, nullptr, 0, nullptr);
#if YAP_PYTHON
    Embedded = true;
    python_in_python = Py_IsInitialized();
#endif
#if __ANDROID__
#endif
  };

  inline void setEmbedded(bool fl) { Embedded = fl; };

  inline bool getEmbedded() { return Embedded; };

  inline void setStackSize(bool fl) { StackSize = fl; };

  inline bool getStackSize() { return StackSize; };

  inline void setTrailSize(bool fl) { TrailSize = fl; };

  inline bool getTrailSize() { return TrailSize; };

  inline bool getMStackSize() { return StackSize; };

  inline void setMaxTrailSize(bool fl) { MaxTrailSize = fl; };

  inline bool getMaxTrailSize() { return MaxTrailSize; };

  inline void createSavedState(bool fl) { install = fl; };

  inline bool creatingSavedState() { return install; };

  inline void setPLDIR(const char *fl) {
    LIBDIR = (const char *)malloc(strlen(fl) + 1);
    strcpy((char *)LIBDIR, fl);
  };

  inline const char *getPLDIR() { return PLDIR; };

  inline void setINPUT_STARTUP(const char *fl) {
    INPUT_STARTUP = (const char *)malloc(strlen(fl) + 1);
    strcpy((char *)INPUT_STARTUP, fl);
  };

  inline const char *getINPUT_STARTUP() { return INPUT_STARTUP; };

  inline void setOUTPUT_RESTORE(const char *fl) {
    OUTPUT_STARTUP = (const char *)malloc(strlen(fl) + 1);
    strcpy((char *)OUTPUT_STARTUP, fl);
  };

  inline const char *getOUTPUT_STARTUP() { return OUTPUT_STARTUP; };

  inline void setBOOTFILE(const char *fl) {
    BOOTFILE = (const char *)malloc(strlen(fl) + 1);
    strcpy((char *)BOOTFILE, fl);
  };

  inline const char *getBOOTFILE() { return BOOTFILE; };

  inline void setPrologBOOTSTRAP(const char *fl) {
    BOOTSTRAP = (const char *)malloc(strlen(fl) + 1);
    strcpy((char *)BOOTSTRAP, fl);
  };

  inline const char *getBOOTSTRAP() { return BOOTSTRAP; };

  inline void setPrologGoal(const char *fl) { PrologGoal = fl; };

  inline const char *getPrologGoal() { return PrologGoal; };

  inline void setPrologTopLevelGoal(const char *fl) {
    PrologTopLevelGoal = fl;
  };

  inline const char *getPrologTopLevelGoal() { return PrologTopLevelGoal; };

  inline void setHaltAfterBoot(bool fl) { HaltAfterBoot = fl; };

  inline bool getHaltAfterBoot() { return HaltAfterBoot; };

  inline void setFastBoot(bool fl) { FastBoot = fl; };

  inline bool getFastBoot() { return FastBoot; };

  inline void setArgc(int fl) { Argc = fl; };

  inline int getArgc() { return Argc; };

  inline void setArgv(char **fl) { Argv = fl; };

  inline char **getArgv() { return Argv; };

    inline void setROOTDIR(char *fl) { ROOTDIR = fl; };
};

/**
 * @brief YAP Engine: takes care of the execution environment
 where we can go executing goals.
 *
 *
 */
class YAPEngine {
private:
  YAPEngineArgs *engine_args;
  YAPCallback *_callback;
  YAPError yerror;
  void doInit(YAP_file_type_t BootMode, YAPEngineArgs *cargs);
  YAP_dogoalinfo q;
  YAPError e;
  PredEntry *rewriteUndefEngineQuery(PredEntry *ap, Term &t, Term tmod);

public:
  /// construct a new engine; may use a variable number of arguments
  YAPEngine(YAPEngineArgs *cargs) {
    engine_args = cargs;
    // doInit(cargs->boot_file_type);
      __android_log_print(
    ANDROID_LOG_INFO, "YAPDroid", "start engine  ");
#ifdef __ANDROID__
    doInit(YAP_BOOT_PL, cargs);

#else
    doInit(YAP_QLY, cargs);
#endif
  }; /// construct a new engine, including aaccess to callbacks
  /// construct a new engine using argc/argv list of arguments
  YAPEngine(int argc, char *argv[],
            YAPCallback *callback = (YAPCallback *)NULL);
  /// kill engine
  ~YAPEngine() { delYAPCallback(); };
  /// remove current callback
  void delYAPCallback() { _callback = 0; };
  /// set a new callback
  void setYAPCallback(YAPCallback *cb) {
    delYAPCallback();
    _callback = cb;
  };
  /// execute the callback.
  ////void run() { if (_callback) _callback.run(); }
  /// execute the callback with a text argument.
  void run(char *s) {
    if (_callback)
      _callback->run(s);
  }
  /// stop yap
  void close() { Yap_exit(0); }

  /// execute the callback with a text argument.
  bool hasError() { return LOCAL_Error_TYPE != YAP_NO_ERROR; }
  /// build a query on the engine
  YAPQuery *query(const char *s) { return new YAPQuery(s); };
  /// build a query from a term
  YAPQuery *query(YAPTerm t) { return new YAPQuery(t); };
  /// build a query from a Prolog term (internal)
  YAPQuery *qt(Term t) { return new YAPQuery(YAPTerm(t)); };
  /// current module for the engine
  Term Yap_CurrentModule() { return CurrentModule; }
  /// given a handle, fetch a term from the engine
  inline YAPTerm getTerm(yhandle_t h) { return YAPTerm(h); }
  /// current directory for the engine
  bool call(YAPPredicate ap, YAPTerm ts[]);
  /// current directory for the engine
  bool goal(YAPTerm Yt, YAPModule module, bool release = false) {
    return mgoal(Yt.term(), module.term(), release);
  };
  /// ru1n a goal in a module.
  ///
  /// By default, memory will only be fully
  /// recovered on backtracking. The release option ensures
  /// backtracking is called at the very end.
  bool mgoal(Term t, Term tmod, bool release = false);
  /// current directory for the engine

  bool goal(Term t, bool release = false) {
    return mgoal(t, Yap_CurrentModule(), release);
  }
  /// reset Prolog state
  void reSet();
  /// assune that there are no stack pointers, just release memory
  // for last execution
  void release();

  const char *currentDir() {
    char dir[1024];
    std::string s = Yap_getcwd(dir, 1024 - 1);
    return s.c_str();
  };
  /// report YAP version as a string
  const char *version() {
    std::string s = Yap_version();
    return s.c_str();
  };
  //> call a deterninistic predicate: the user will construct aterm of
  //> arity N-1. YAP adds an extra variable which will have the
  //> output.
  YAPTerm funCall(YAPTerm t) { return YAPTerm(fun(t.term())); };
  Term fun(Term t);
  //Term fun(YAPTerm t) { return fun(t.term()); };
  //> set a StringFlag, usually a path
  //>
  bool setStringFlag(std::string arg, std::string path) {
    return setYapFlag(MkAtomTerm(Yap_LookupAtom(arg.data())),
                      MkAtomTerm(Yap_LookupAtom(path.data())));
  };

  Term top_level(std::string s);
  Term next_answer(YAPQuery *&Q);
};

#endif /* YAPQ_HH */

/// @}