#ifndef COMMON_H
#define COMMON_H
#include <iostream>
#include <memory>
#include <set>
#include <string>
#include <sstream>
#include <typeindex>
#include <typeinfo>
#include <vector>

#define EXPORT __attribute__ ((visibility ("default")))

enum debug_level {INTERNALREQUEST,MOREDEBUG,DEBUG,INFO,NORMAL,WARNING,ERROR};
EXPORT std::ostream& COUT(debug_level dl);

typedef std::set<std::string> UsedType;

// Base class for all objects
class EXPORT ObjectBase
{
protected:
// No save by default
virtual const int8_t* Blob(size_t* size) const { *size=0; return 0; }
virtual void DeallocBlob(const void* ptr) const {};
public:

 ObjectBase() = default;
 ObjectBase(const ObjectBase&) = delete;
 bool Save(const char* fname) const;
 // Pure virtual api
 virtual ~ObjectBase(){}
 virtual ObjectBase* Copy() const=0;
 virtual bool Print() const=0;
 virtual std::string Type() const=0;

 // Virtual api with default functions. Modules types must not override them.
 virtual std::string Dump() const {return "%"+Type()+"%";}
 virtual ObjectBase* Evaluate(bool* err) {*err=false; return 0;}
 virtual ObjectBase* ReplaceVar(const std::string& vname, ObjectBase* ob) {return 0;}
 virtual void UsedFuncs(UsedType& funcs) const {}
 virtual void UsedIdents(UsedType& ids) const {}
};


// Template for checking and using ObjectBase derivative classes
// Checking if arg is pointer on Derived: if(OBType<Derived>(arg))
// Using const ObjectBase* arg as const Derived*: OBType<Derived>(arg)->SomeCall()
template<class O>
class OBType
{
 const O* p;
 public:
 OBType() = delete;
 OBType(OBType&&) = delete;
 OBType(OBType&) = delete;
 OBType(const ObjectBase* arg) {if(typeid(*arg)==typeid(O)) p=dynamic_cast<const O*>(arg); else p=0;}
 const O* operator->() const {return p;}
 operator bool() const {return 0!=p;}
};


// Template for objects without specific constructor/destructor
template<class T>
class EXPORT ObjectSimple: public ObjectBase
{
private:
 T val;
 static std::string type;

 const int8_t* Blob(size_t* size) const override {*size=sizeof(T); return reinterpret_cast<const int8_t*>(&val);}

public:
 ObjectSimple(T t):val(t) {}
 ObjectSimple(const T* t):val(*t) {}
 ~ObjectSimple() {}
 // Pure virtual overrides
 ObjectBase* Copy() const override {return new ObjectSimple<T>(val);}
 bool Print() const override
 {
  COUT(NORMAL)<<std::endl<<"Object type: "<<Type()<<std::endl;
  COUT(NORMAL)<<"Value: "<<val<<std::endl;
  return true;
 }
 std::string Type() const override {return type;}

 // Non-default overrides
 std::string Dump() const override
 {
  std::stringstream s;
  if(std::type_index(typeid(T))==std::type_index(typeid(std::string)))
   s<<"\""<<val<<"\"";
  else
   s<<val;
  return s.str();
 }

 // Own functions
 T Value() const {return val;}
 void SetValue(T s) {val=s;}
};

// Simple objects
typedef ObjectSimple<bool> ObjectBool;
typedef ObjectSimple<int64_t> ObjectInt;
typedef ObjectSimple<double> ObjectReal;
typedef ObjectSimple<std::string> ObjectString;

template<>
inline const int8_t* ObjectString::Blob(size_t* size) const
{
 *size=val.length();
 return reinterpret_cast<const int8_t*>(val.c_str());
}

// Class for name-value pair
class EXPORT ObjectPair: public ObjectBase
{
private:
 std::string name;
 std::shared_ptr<ObjectBase> val;

public:
 ObjectPair() {}
 ObjectPair(const std::string& n, ObjectBase* v):name(n) {val.reset(v);}
 ObjectPair(const std::string* n, ObjectBase* v):name(*n) {val.reset(v);}
 ~ObjectPair() {}
 // Pure virtual overrides
 ObjectBase* Copy() const override
 {
  auto ret=new ObjectPair;
  ret->name=name; ret->val=val;
  return ret;
 }
 bool Print() const override
 {
  if(!Exist()) return false;
  COUT(NORMAL)<<std::endl<<"Object type: "<<Type()<<std::endl;
  COUT(NORMAL)<<"Name is: "<<Name()<<std::endl;
  COUT(NORMAL)<<"Value type: "<<val->Type()<<std::endl;
  return true;
 }
 std::string Type() const override {return "pair";}

 // Non-default overrides
 std::string Dump() const override { return Name()+"="+val->Dump(); }
 ObjectBase* Evaluate(bool* err) override
 {
  auto p=val->Evaluate(err);
  if(*err)
  {
   COUT(ERROR)<<" in pair "<<Dump()<<std::endl;
   return 0;
  }
  if(0==p) return 0;
  val.reset(p);
  return 0;
 }
 ObjectBase* ReplaceVar(const std::string& vname, ObjectBase* ob) override
 {
  auto p=val->ReplaceVar(vname,ob);
  if(0!=p) val.reset(p);
  return 0;
 }
 void UsedFuncs(UsedType& funcs) const override {return val->UsedFuncs(funcs);}
 void UsedIdents(UsedType& ids) const override {return val->UsedIdents(ids);}

 // Own functions
 bool Exist() const {return 0!=val.get();}
 ObjectBase* Get(const std::string& gname) const
 {
  if(gname==name) return val->Copy();
  else return 0;
 }
 std::string Name() const {return name;}
 void SetPair(const std::string& n, ObjectBase* v) {if(!Exist()) {name=n; val.reset(v);}}
 const ObjectBase* Value() const {return val.get();}
};

// Class for objects list
class EXPORT ObjectList: public ObjectBase
{
public:
 typedef std::vector<ObjectBase*> ListValues;
private:
 std::shared_ptr<ListValues> vals;

public:
 ObjectList() {vals.reset(new ListValues, [](ListValues* p){for(auto& i: *p) delete i; delete p;});}
 ObjectList(ObjectBase* o) {vals.reset(new ListValues, [](ListValues* p){for(auto& i: *p) delete i; delete p;}); PushBack(o);}
 ~ObjectList() {}
 // Pure virtual overrides
 ObjectBase* Copy() const override
 {
  auto ret=new ObjectList;
  ret->vals=vals;
  return ret;
 }
 bool Print() const override
 {
  if(!Exist()) return false;
  COUT(NORMAL)<<std::endl<<"Object type: "<<Type()<<std::endl;
  COUT(NORMAL)<<"Number of elements: "<<Size()<<std::endl;
  return true;
 }
 std::string Type() const override {return "list";}

 // Non-default overrides
 std::string Dump() const override
 {
  std::string s("(");
  for(auto& i: *vals) s+=i->Dump()+", ";
  if(vals->size()!=0) s.resize(s.length()-2);
  return s+")";
 }
 ObjectBase* Evaluate(bool* err) override
 {
  ObjectBase* p;
  for(auto& i: *vals)
  {
   p=i->Evaluate(err);
   if(*err)
   {
    COUT(ERROR)<<" in list member "<<i->Dump()<<std::endl;
    return 0;
   }
   if(0!=p)
   {
    delete i;
    i=p;
   }
  }
  return 0;
 }
 ObjectBase* ReplaceVar(const std::string& vname, ObjectBase* ob) override
 {
  ObjectBase* p;
  for(auto& i: *vals)
  {
   p=i->ReplaceVar(vname,ob);
   if(0!=p)
   {
    delete i;
    i=p;
   }
  }
  return 0;
 }
 void UsedFuncs(UsedType& funcs) const override {for(auto& i: *vals) i->UsedFuncs(funcs);}
 void UsedIdents(UsedType& ids) const override {for(auto& i: *vals) i->UsedIdents(ids);}

 // Own functions
 const ObjectBase* At(ListValues::size_type i) const {return (*vals)[i];}
 bool Exist() const {return 0!=vals->size();}
 ObjectBase* Get(const std::string& gname) const
 {
  ObjectBase* p;
  for(auto& i: *vals)
  {
   p=0;
   OBType<ObjectPair> pair(i);
   OBType<ObjectList> list(i);
   if(pair) p=pair->Get(gname);
   else if(list) p=list->Get(gname);
   if(0!=p) return p;
  }
  return 0;
 }
 ListValues::size_type Size() const {return vals->size();}
 ObjectList* PushBack(ObjectBase* p) {vals->push_back(p); return this;}
};

typedef ObjectBase* (*Func)(const ObjectList*);
typedef int (*ModuleInitFunc)(const void*);

extern "C" {
EXPORT void RegisterFunction(const std::string& name, Func func);
EXPORT int LoadModule(const std::string& name, const void* p, const std::string& modname="");
}

#endif