// Copyright satoren
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)

#pragma once

#include <vector>
#include <map>
#include <cassert>
#include <algorithm>
#include <ostream>
#include <istream>

#include "kaguya/config.hpp"
#include "kaguya/error_handler.hpp"
#include "kaguya/type.hpp"
#include "kaguya/utility.hpp"
#include "kaguya/detail/lua_ref_impl.hpp"
#include "kaguya/detail/lua_variant_def.hpp"

namespace kaguya {
namespace util {
template <class Result>
inline Result get_result_impl(lua_State *l, int startindex,
                              types::typetag<Result>) {
  return lua_type_traits<Result>::get(l, startindex);
}
#if KAGUYA_USE_CPP11
inline standard::tuple<>
get_result_tuple_impl(lua_State *, int, types::typetag<standard::tuple<> >) {
  return standard::tuple<>();
}
template <typename T, typename... TYPES>
inline standard::tuple<T, TYPES...>
get_result_tuple_impl(lua_State *l, int index,
                      types::typetag<standard::tuple<T, TYPES...> >) {
  return standard::tuple_cat(
      standard::tuple<T>(lua_type_traits<T>::get(l, index)),
      get_result_tuple_impl(l, index + 1,
                            types::typetag<standard::tuple<TYPES...> >()));
}
template <typename... TYPES>
inline standard::tuple<TYPES...>
get_result_impl(lua_State *l, int startindex,
                types::typetag<standard::tuple<TYPES...> > tag) {
  return get_result_tuple_impl<TYPES...>(l, startindex, tag);
}
#else

inline standard::tuple<> get_result_impl(lua_State *l, int startindex,
                                         types::typetag<standard::tuple<> >) {
  KAGUYA_UNUSED(l);
  KAGUYA_UNUSED(startindex);
  return standard::tuple<>();
}

#define KAGUYA_GET_DEF(N)                                                      \
  lua_type_traits<KAGUYA_PP_CAT(A, N)>::get(l, N + startindex - 1)
#define KAGUYA_GET_TUPLE_DEF(N)                                                \
  template <KAGUYA_PP_TEMPLATE_DEF_REPEAT(N)>                                  \
  inline standard::tuple<KAGUYA_PP_TEMPLATE_ARG_REPEAT(N)> get_result_impl(    \
      lua_State *l, int startindex,                                            \
      types::typetag<standard::tuple<KAGUYA_PP_TEMPLATE_ARG_REPEAT(N)> >) {    \
    return standard::tuple<KAGUYA_PP_TEMPLATE_ARG_REPEAT(N)>(                  \
        KAGUYA_PP_REPEAT_ARG(N, KAGUYA_GET_DEF));                              \
  }
KAGUYA_PP_REPEAT_DEF(KAGUYA_FUNCTION_MAX_TUPLE_SIZE, KAGUYA_GET_TUPLE_DEF)
#undef KAGUYA_GET_DEF
#undef KAGUYA_GET_TUPLE_DEF
#endif

template <class Result> inline Result get_result(lua_State *l, int startindex) {
  return get_result_impl(l, startindex, types::typetag<Result>());
}
template <> inline void get_result<void>(lua_State *, int) {}
}

/// @addtogroup Lua_reference_types

/// @ingroup Lua_reference_types
/// @brief Reference to any Lua data.
class LuaRef : public Ref::RegistoryRef, public detail::LuaVariantImpl<LuaRef> {
private:
  static lua_State *toMainThread(lua_State *state) {
#if LUA_VERSION_NUM >= 502
    if (state) {
      lua_rawgeti(state, LUA_REGISTRYINDEX, LUA_RIDX_MAINTHREAD);
      lua_State *mainthread = lua_tothread(state, -1);
      lua_pop(state, 1);
      if (mainthread) {
        return mainthread;
      }
    }
#endif
    return state;
  }

public:
  LuaRef(const Ref::RegistoryRef &src) : Ref::RegistoryRef(src) {}
  LuaRef(const LuaRef &src) : Ref::RegistoryRef(src) {}
  LuaRef &operator=(const LuaRef &src) {
    static_cast<RegistoryRef &>(*this) = src;
    return *this;
  }

#if KAGUYA_USE_CPP11

  LuaRef(LuaRef &&src) : Ref::RegistoryRef(std::move(src)) {}

  LuaRef &operator=(LuaRef &&src) throw() {
    swap(src);
    return *this;
  }

  LuaRef(RegistoryRef &&src) throw() : Ref::RegistoryRef(std::move(src)) {}
  template <typename T>
  LuaRef(lua_State *state, T &&v, Ref::NoMainCheck)
      : Ref::RegistoryRef(state, std::move(v), Ref::NoMainCheck()) {}
  template <typename T>
  LuaRef(lua_State *state, T &&v) : Ref::RegistoryRef(state, std::move(v)) {}
#endif

  LuaRef() {}
  LuaRef(lua_State *state) : Ref::RegistoryRef(state) {}

  LuaRef(lua_State *state, StackTop, Ref::NoMainCheck)
      : Ref::RegistoryRef(state, StackTop(), Ref::NoMainCheck()) {}

  LuaRef(lua_State *state, StackTop) : Ref::RegistoryRef(state, StackTop()) {}

  template <typename T>
  LuaRef(lua_State *state, const T &v, Ref::NoMainCheck)
      : Ref::RegistoryRef(state, v, Ref::NoMainCheck()) {}
  template <typename T>
  LuaRef(lua_State *state, const T &v) : Ref::RegistoryRef(state, v) {}

  const void *native_pointer() const {
    util::ScopedSavedStack save(state());
    push(state());
    return lua_topointer(state(), -1);
  }
  static void putindent(std::ostream &os, int indent) {
    while (indent-- > 0) {
      os << "  ";
    }
  }
};

/// @ingroup lua_type_traits
/// @brief lua_type_traits for LuaRef
template <> struct lua_type_traits<LuaRef> {
  typedef LuaRef get_type;
  typedef const LuaRef &push_type;

  static bool checkType(lua_State *l, int index) {
    KAGUYA_UNUSED(l);
    KAGUYA_UNUSED(index);
    return true;
  }
  static bool strictCheckType(lua_State *l, int index) {
    KAGUYA_UNUSED(l);
    KAGUYA_UNUSED(index);
    return false;
  }

  static get_type get(lua_State *l, int index) {
    lua_pushvalue(l, index);
    return LuaRef(l, StackTop());
  }
  static int push(lua_State *l, push_type v) { return v.push(l); }
};
/// @ingroup lua_type_traits
/// @brief lua_type_traits for LuaRef
template <> struct lua_type_traits<const LuaRef &> : lua_type_traits<LuaRef> {};

class LuaStackRef : public Ref::StackRef,
                    public detail::LuaVariantImpl<LuaStackRef> {
public:
  LuaStackRef() : Ref::StackRef() {}
  LuaStackRef(lua_State *s, int index) : Ref::StackRef(s, index, false) {}
  LuaStackRef(lua_State *s, int index, bool popAtDestruct)
      : Ref::StackRef(s, index, popAtDestruct) {}
#if KAGUYA_USE_CPP11
  LuaStackRef(LuaStackRef &&src) : Ref::StackRef(std::move(src)) {
    src.pop_ = false;
  }
  LuaStackRef &operator=(LuaStackRef &&src) {
    if (this != &src) {
      Ref::StackRef::operator=(std::move(src));
      src.pop_ = false;
    }
    return *this;
  }
  LuaStackRef(const LuaStackRef &src) = delete;
#else
  LuaStackRef(const LuaStackRef &src) : Ref::StackRef(src) { src.pop_ = false; }
  LuaStackRef &operator=(const LuaStackRef &src) {
    if (this != &src) {
      Ref::StackRef::operator=(src);
      src.pop_ = false;
    }
    return *this;
  }
#endif
};

/// @ingroup lua_type_traits
/// @brief lua_type_traits for LuaStackRef
template <> struct lua_type_traits<LuaStackRef> {
  typedef LuaStackRef get_type;
  typedef const LuaStackRef &push_type;

  static bool checkType(lua_State *l, int index) {
    KAGUYA_UNUSED(l);
    KAGUYA_UNUSED(index);
    return true;
  }
  static bool strictCheckType(lua_State *l, int index) {
    KAGUYA_UNUSED(l);
    KAGUYA_UNUSED(index);
    return false;
  }

  static get_type get(lua_State *l, int index) { return LuaStackRef(l, index); }
  static int push(lua_State *l, push_type v) { return v.push(l); }
};
/// @ingroup lua_type_traits
/// @brief lua_type_traits for LuaStackRef
template <>
struct lua_type_traits<const LuaStackRef &> : lua_type_traits<LuaStackRef> {};

/// @ingroup Lua_reference_types
/// @brief Reference to Lua userdata.
class LuaUserData : public Ref::RegistoryRef,
                    public detail::LuaUserDataImpl<LuaUserData>,
                    public detail::LuaTableOrUserDataImpl<LuaUserData>,
                    public detail::LuaBasicTypeFunctions<LuaUserData> {

  void typecheck() {
    int t = type();
    if (t != TYPE_USERDATA && t != TYPE_LIGHTUSERDATA && t != TYPE_NIL &&
        t != TYPE_NONE) {
      except::typeMismatchError(state(), "not user data");
      unref();
    }
  }

public:
  operator LuaRef() {
    push(state());
    return LuaRef(state(), StackTop());
  }
  LuaUserData(lua_State *state, StackTop)
      : Ref::RegistoryRef(state, StackTop()) {
    typecheck();
  }
  template <typename TYPE>
  LuaUserData(lua_State *state, const TYPE &table)
      : Ref::RegistoryRef(state, table) {
    typecheck();
  }
  explicit LuaUserData(lua_State *state)
      : Ref::RegistoryRef(state, NilValue()) {
    typecheck();
  }
  LuaUserData() { typecheck(); }
};

/// @ingroup lua_type_traits
/// @brief lua_type_traits for LuaUserData
template <> struct lua_type_traits<LuaUserData> {
  typedef LuaUserData get_type;
  typedef LuaUserData push_type;

  static bool strictCheckType(lua_State *l, int index) {
    return lua_type(l, index) == LUA_TUSERDATA;
  }
  static bool checkType(lua_State *l, int index) {
    return lua_type(l, index) == LUA_TUSERDATA || lua_isnil(l, index);
  }
  static LuaUserData get(lua_State *l, int index) {
    lua_pushvalue(l, index);
    return LuaUserData(l, StackTop());
  }
  static int push(lua_State *l, const LuaUserData &ref) { return ref.push(l); }
};
/// @ingroup lua_type_traits
/// @brief lua_type_traits for LuaUserData
template <>
struct lua_type_traits<const LuaUserData &> : lua_type_traits<LuaUserData> {};

/// @ingroup Lua_reference_types
/// @brief Reference to Lua table.
class LuaTable : public Ref::RegistoryRef,
                 public detail::LuaTableImpl<LuaTable>,
                 public detail::LuaTableOrUserDataImpl<LuaTable>,
                 public detail::LuaBasicTypeFunctions<LuaTable> {

  void typecheck() {
    int t = type();
    if (t != TYPE_TABLE && t != TYPE_NIL && t != TYPE_NONE) {
      except::typeMismatchError(state(), "not table");
      unref();
    }
  }

public:
  operator LuaRef() {
    push(state());
    return LuaRef(state(), StackTop());
  }
  LuaTable(lua_State *state, StackTop) : Ref::RegistoryRef(state, StackTop()) {
    typecheck();
  }
  LuaTable(lua_State *state, const NewTable &table)
      : Ref::RegistoryRef(state, table) {
    typecheck();
  }
  explicit LuaTable(lua_State *state) : Ref::RegistoryRef(state, NewTable()) {
    typecheck();
  }
  LuaTable() { typecheck(); }
};

/// @ingroup lua_type_traits
/// @brief lua_type_traits for LuaTable
template <> struct lua_type_traits<LuaTable> {
  typedef LuaTable get_type;
  typedef LuaTable push_type;

  static bool strictCheckType(lua_State *l, int index) {
    return lua_istable(l, index);
  }
  static bool checkType(lua_State *l, int index) {
    return lua_istable(l, index) || lua_isnil(l, index);
  }
  static LuaTable get(lua_State *l, int index) {
    lua_pushvalue(l, index);
    return LuaTable(l, StackTop());
  }
  static int push(lua_State *l, const LuaTable &ref) { return ref.push(l); }
};
/// @ingroup lua_type_traits
/// @brief lua_type_traits for LuaTable
template <>
struct lua_type_traits<const LuaTable &> : lua_type_traits<LuaTable> {};

/// @ingroup Lua_reference_types
/// @brief Reference to Lua function.
class LuaFunction : public Ref::RegistoryRef,
                    public detail::LuaFunctionImpl<LuaFunction>,
                    public detail::LuaBasicTypeFunctions<LuaFunction> {
  void typecheck() {
    int t = type();
    if (t != TYPE_FUNCTION && t != TYPE_NIL && t != TYPE_NONE) {
      except::typeMismatchError(state(), "not function");
      RegistoryRef::unref();
    }
  }

  struct LuaLoadStreamWrapper {
    LuaLoadStreamWrapper(std::istream &stream)
        : preloaded_(false), stream_(stream) {
      buffer_.reserve(512);
      skipComment();
      preloaded_ = !buffer_.empty();
    }

    void skipComment() {
      // skip bom
      const char *bom = "\xEF\xBB\xBF";
      const char *bomseq = bom;
      char c;
      while (stream_.get(c)) {
        if (c != *bomseq) // not bom sequence
        {
          buffer_.assign(bom, bomseq);
          buffer_.push_back(c);
          break;
        }
        bomseq++;
        if ('\0' == *bomseq) {
          return;
        }
      }

      // skip comment
      if (!buffer_.empty() && buffer_.front() == '#') {
        buffer_.clear();
        std::string comment;
        std::getline(stream_, comment);
      }
    }

    static const char *getdata(lua_State *, void *ud, size_t *size) {
      LuaLoadStreamWrapper *loader = static_cast<LuaLoadStreamWrapper *>(ud);

      if (loader->preloaded_) {
        loader->preloaded_ = false;
      } else {
        loader->buffer_.clear();
      }

      char c = 0;
      while (loader->buffer_.size() < loader->buffer_.capacity() &&
             loader->stream_.get(c)) {
        loader->buffer_.push_back(c);
      }
      *size = loader->buffer_.size();
      return loader->buffer_.empty() ? 0 : &loader->buffer_[0];
    }

  private:
    bool preloaded_;
    std::vector<char> buffer_;
    std::istream &stream_;
  };

public:
  /// @brief construct with state and function .
  /// @param state pointer to lua_State
  /// @param f execute function for lua thread. e.g.
  /// kaguya::function(function_ptr),kaguya::overload(function_ptr)
  template <typename F>
  LuaFunction(lua_State *state, F f) : Ref::RegistoryRef(state, f) {
    typecheck();
  }

  /// @brief construct with stack top value.
  /// @param state pointer to lua_State
  LuaFunction(lua_State *state, StackTop)
      : Ref::RegistoryRef(state, StackTop()) {
    typecheck();
  }

  /// @brief construct with nil reference.
  LuaFunction() {}

  /// @brief load lua code .
  /// @param state pointer to lua_State
  /// @param luacode string
  static LuaFunction loadstring(lua_State *state, const std::string &luacode) {
    return loadstring(state, luacode.c_str());
  }
  /// @brief load lua code .
  /// @param state pointer to lua_State
  /// @param luacode string
  static LuaFunction loadstring(lua_State *state, const char *luacode) {
    util::ScopedSavedStack save(state);
    int status = luaL_loadstring(state, luacode);

    if (status) {
      ErrorHandler::handle(status, state);
      lua_pushnil(state);
    }
    return LuaFunction(state, StackTop());
  }

  /// @brief If there are no errors,compiled file as a Lua function and return.
  ///  Otherwise send error message to error handler and return nil reference
  /// @param state pointer to lua_State
  /// @param file  file path of lua script
  /// @return reference of lua function
  static LuaFunction loadfile(lua_State *state, const std::string &file) {
    return loadfile(state, file.c_str());
  }

  /// @brief If there are no errors,compiled file as a Lua function and return.
  ///  Otherwise send error message to error handler and return nil reference
  /// @param state pointer to lua_State
  /// @param file  file path of lua script
  /// @return reference of lua function
  static LuaFunction loadfile(lua_State *state, const char *file) {
    util::ScopedSavedStack save(state);

    int status = luaL_loadfile(state, file);

    if (status) {
      ErrorHandler::handle(status, state);
      lua_pushnil(state);
    }
    return LuaFunction(state, StackTop());
  }

  /// @brief If there are no errors,compiled stream as a Lua function and
  /// return.
  ///  Otherwise send error message to error handler and return nil reference
  /// @param state pointer to lua_State
  /// @param stream  stream of lua script data
  /// @param chunkname  use for error message.
  /// @return reference of lua function
  static LuaStackRef loadstreamtostack(lua_State *state, std::istream &stream,
                                       const char *chunkname = 0) {
    LuaLoadStreamWrapper wrapper(stream);
#if LUA_VERSION_NUM >= 502
    int status =
        lua_load(state, &LuaLoadStreamWrapper::getdata, &wrapper, chunkname, 0);
#else
    int status =
        lua_load(state, &LuaLoadStreamWrapper::getdata, &wrapper, chunkname);
#endif
    if (status) {
      ErrorHandler::handle(status, state);
      lua_pushnil(state);
    }
    return LuaStackRef(state, -1, true);
  }

  /// @brief If there are no errors,compiled stream as a Lua function and
  /// return.
  ///  Otherwise send error message to error handler and return nil reference
  /// @param state pointer to lua_State
  /// @param stream  stream of lua script data
  /// @param chunkname  use for error message.
  /// @return reference of lua function
  static LuaFunction loadstream(lua_State *state, std::istream &stream,
                                const char *chunkname = 0) {
    util::ScopedSavedStack save(state);
    LuaLoadStreamWrapper wrapper(stream);
#if LUA_VERSION_NUM >= 502
    int status =
        lua_load(state, &LuaLoadStreamWrapper::getdata, &wrapper, chunkname, 0);
#else
    int status =
        lua_load(state, &LuaLoadStreamWrapper::getdata, &wrapper, chunkname);
#endif
    if (status) {
      ErrorHandler::handle(status, state);
      lua_pushnil(state);
    }
    return LuaFunction(state, StackTop());
  }
};

/// @ingroup Lua_reference_types
/// @brief Reference to Lua thread(coroutine).
class LuaThread : public Ref::RegistoryRef,
                  public detail::LuaThreadImpl<LuaThread>,
                  public detail::LuaBasicTypeFunctions<LuaThread> {
  void typecheck() {
    int t = type();
    if (t != TYPE_THREAD && t != TYPE_NIL && t != TYPE_NONE) {
      except::typeMismatchError(state(), "not lua thread");
      RegistoryRef::unref();
    }
  }

public:
  /// @brief construct with stack top value.
  LuaThread(lua_State *state, StackTop) : Ref::RegistoryRef(state, StackTop()) {
    typecheck();
  }
  /// @brief construct with new thread.
  LuaThread(lua_State *state, const NewThread &t)
      : Ref::RegistoryRef(state, t) {}
  /// @brief construct with nil reference.
  LuaThread(lua_State *state) : Ref::RegistoryRef(state, NewThread()) {}
  /// @brief construct with nil reference.
  LuaThread() {}
  /// @brief get lua thread
  operator lua_State *() { return getthread(); }
};
}

#if KAGUYA_USE_CPP11
#else
namespace std {
template <> inline void swap(kaguya::LuaUserData &a, kaguya::LuaUserData &b) {
  a.swap(b);
}
template <> inline void swap(kaguya::LuaTable &a, kaguya::LuaTable &b) {
  a.swap(b);
}
template <> inline void swap(kaguya::LuaFunction &a, kaguya::LuaFunction &b) {
  a.swap(b);
}
template <> inline void swap(kaguya::LuaThread &a, kaguya::LuaThread &b) {
  a.swap(b);
}
template <> inline void swap(kaguya::LuaRef &a, kaguya::LuaRef &b) {
  a.swap(b);
}
}
#endif