/*
  Copyright(C) 2011-2016 Brazil

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/

#pragma once

#ifndef _MSC_VER
# include <stddef.h>
# include <stdint.h>
#endif  // _MSC_VER

#include <cstddef>
#include <exception>

#ifdef _DEBUG
# include <iostream>
#endif  // _DEBUG

#ifdef GRN_STATIC
# define GRN_DAT_API
#else
# ifndef GRN_DAT_API
#  ifdef WIN32
#   ifdef GRN_DAT_EXPORT
#    define GRN_DAT_API __declspec(dllexport)
#   else  // GRN_DAT_EXPORT
#    define GRN_DAT_API __declspec(dllimport)
#   endif  // GRN_DAT_EXPORT
#  else  // WIN32
#   define GRN_DAT_API
#  endif  // WIN32
# endif  // GRN_DAT_API
#endif

namespace grn {
namespace dat {

#ifdef _MSC_VER
typedef unsigned __int8  UInt8;
typedef unsigned __int16 UInt16;
typedef unsigned __int32 UInt32;
typedef unsigned __int64 UInt64;
#else  // _MSC_VER
typedef ::uint8_t UInt8;
typedef ::uint16_t UInt16;
typedef ::uint32_t UInt32;
typedef ::uint64_t UInt64;
#endif  // _MSC_VER

const UInt8  MAX_UINT8  = static_cast<UInt8>(0xFFU);
const UInt16 MAX_UINT16 = static_cast<UInt16>(0xFFFFU);
const UInt32 MAX_UINT32 = static_cast<UInt32>(0xFFFFFFFFU);
const UInt64 MAX_UINT64 = static_cast<UInt64>(0xFFFFFFFFFFFFFFFFULL);

// If a key is a prefix of another key, such a key is associated with a special
// terminal node which has TERMINAL_LABEL.
const UInt16 TERMINAL_LABEL  = 0x100;
const UInt16 MIN_LABEL       = '\0';
const UInt16 MAX_LABEL       = TERMINAL_LABEL;
const UInt32 INVALID_LABEL   = 0x1FF;
const UInt32 LABEL_MASK      = 0x1FF;

// The MSB of BASE is used to represent whether the node is a linker node or
// not and the other 31 bits represent the offset to its child nodes. So, the
// number of nodes is limited to 2^31.
const UInt32 ROOT_NODE_ID    = 0;
const UInt32 MAX_NODE_ID     = 0x7FFFFFFF;
const UInt32 MAX_NUM_NODES   = MAX_NODE_ID + 1;
const UInt32 INVALID_NODE_ID = MAX_NODE_ID + 1;

// 0 is reserved for non-linker leaf nodes. For example, the root node of an
// initial double-array is a non-linker leaf node.
const UInt32 MAX_OFFSET      = MAX_NODE_ID;
const UInt32 INVALID_OFFSET  = 0;

// Phantom nodes are managed in each block because siblings are always put in
// the same block.
const UInt32 BLOCK_SIZE      = 0x200;
const UInt32 BLOCK_MASK      = 0x1FF;
const UInt32 MAX_BLOCK_ID    = MAX_NODE_ID / BLOCK_SIZE;
const UInt32 MAX_NUM_BLOCKS  = MAX_BLOCK_ID + 1;

// Blocks are divided by their levels, which indicate how easily update
// operations can find a good offset in them. The level of a block rises when
// find_offset() fails in that block many times. MAX_FAILURE_COUNT is the
// threshold. Also, in order to limit the time cost, find_offset() scans at
// most MAX_BLOCK_COUNT blocks.
// Larger parameters bring more chances of finding good offsets but it leads to
// more node renumberings, which are costly operations, and thus results in
// a degradation of space/time efficiencies.
const UInt32 MAX_FAILURE_COUNT  = 4;
const UInt32 MAX_BLOCK_COUNT    = 16;
const UInt32 MAX_BLOCK_LEVEL    = 5;

// Blocks in the same level compose a doubly linked list. The entry block of
// a linked list is called a leader. INVALID_LEADER means that a linked list is
// empty and there exists no leader.
const UInt32 INVALID_LEADER     = 0x7FFFFFFF;

const UInt32 MIN_KEY_ID      = 1;
const UInt32 MAX_KEY_ID      = MAX_NODE_ID;
const UInt32 INVALID_KEY_ID  = 0;

// A key length is represented as a 12-bit unsigned integer in Key.
// A key ID is represented as a 28-bit unsigned integer in Key.
const UInt32 MAX_KEY_LENGTH  = (1U << 12) - 1;
const UInt32 MAX_NUM_KEYS    = (1U << 28) - 1;

const UInt64 MIN_FILE_SIZE              = 1 << 16;
const UInt64 DEFAULT_FILE_SIZE          = 1 << 20;
const UInt64 MAX_FILE_SIZE              = (UInt64)1 << 40;
const double DEFAULT_NUM_NODES_PER_KEY  = 4.0;
const double MAX_NUM_NODES_PER_KEY      = 16.0;
const double DEFAULT_AVERAGE_KEY_LENGTH = 16.0;
const UInt32 MAX_KEY_BUF_SIZE           = 0x80000000U;
const UInt32 MAX_TOTAL_KEY_LENGTH       = 0xFFFFFFFFU;

const UInt32 ID_RANGE_CURSOR      = 0x00001;
const UInt32 KEY_RANGE_CURSOR     = 0x00002;
const UInt32 PREFIX_CURSOR        = 0x00004;
const UInt32 PREDICTIVE_CURSOR    = 0x00008;
const UInt32 CURSOR_TYPE_MASK     = 0x000FF;

const UInt32 ASCENDING_CURSOR     = 0x00100;
const UInt32 DESCENDING_CURSOR    = 0x00200;
const UInt32 CURSOR_ORDER_MASK    = 0x00F00;

const UInt32 EXCEPT_LOWER_BOUND   = 0x01000;
const UInt32 EXCEPT_UPPER_BOUND   = 0x02000;
const UInt32 EXCEPT_EXACT_MATCH   = 0x04000;
const UInt32 CURSOR_OPTIONS_MASK  = 0xFF000;

const UInt32 REMOVING_FLAG  = 1U << 0;
const UInt32 INSERTING_FLAG = 1U << 1;
const UInt32 UPDATING_FLAG  = 1U << 2;
const UInt32 CHANGING_MASK  = REMOVING_FLAG | INSERTING_FLAG | UPDATING_FLAG;

const UInt32 MKQ_SORT_THRESHOLD = 10;

enum ErrorCode {
  PARAM_ERROR      = -1,
  IO_ERROR         = -2,
  FORMAT_ERROR     = -3,
  MEMORY_ERROR     = -4,
  SIZE_ERROR       = -5,
  UNEXPECTED_ERROR = -6,
  STATUS_ERROR     = -7
};

class Exception : public std::exception {
 public:
  Exception() throw()
      : std::exception(),
        file_(""),
        line_(-1),
        what_("") {}
  Exception(const char *file, int line, const char *what) throw()
      : std::exception(),
        file_(file),
        line_(line),
        what_((what != NULL) ? what : "") {}
  Exception(const Exception &ex) throw()
      : std::exception(ex),
        file_(ex.file_),
        line_(ex.line_),
        what_(ex.what_) {}
  virtual ~Exception() throw() {}

  virtual ErrorCode code() const throw() = 0;
  virtual const char *file() const throw() {
    return file_;
  }
  virtual int line() const throw() {
    return line_;
  }
  virtual const char *what() const throw() {
    return what_;
  }

 private:
  const char *file_;
  int line_;
  const char *what_;
};

template <ErrorCode T>
class Error : public Exception {
 public:
  Error() throw()
      : Exception() {}
  Error(const char *file, int line, const char *what) throw()
      : Exception(file, line, what) {}
  Error(const Error &ex) throw()
      : Exception(ex) {}
  virtual ~Error() throw() {}

  virtual ErrorCode code() const throw() {
    return T;
  }
};

typedef Error<PARAM_ERROR> ParamError;
typedef Error<IO_ERROR> IOError;
typedef Error<FORMAT_ERROR> FormatError;
typedef Error<MEMORY_ERROR> MemoryError;
typedef Error<SIZE_ERROR> SizeError;
typedef Error<UNEXPECTED_ERROR> UnexpectedError;
typedef Error<STATUS_ERROR> StatusError;

#define GRN_DAT_INT_TO_STR(value) #value
#define GRN_DAT_LINE_TO_STR(line) GRN_DAT_INT_TO_STR(line)
#define GRN_DAT_LINE_STR GRN_DAT_LINE_TO_STR(__LINE__)

#define GRN_DAT_THROW(code, msg)\
  (throw grn::dat::Error<code>(__FILE__, __LINE__,\
   __FILE__ ":" GRN_DAT_LINE_STR ": " #code ": " msg))
#define GRN_DAT_THROW_IF(code, cond)\
  (void)((!(cond)) || (GRN_DAT_THROW(code, #cond), 0))

#ifdef _DEBUG
 #define GRN_DAT_DEBUG_THROW_IF(cond)\
   GRN_DAT_THROW_IF(grn::dat::UNEXPECTED_ERROR, cond)
 #define GRN_DAT_DEBUG_LOG(var)\
   (std::clog << __FILE__ ":" GRN_DAT_LINE_STR ": " #var ": "\
              << (var) << std::endl)
#else  // _DEBUG
 #define GRN_DAT_DEBUG_THROW_IF(cond)
 #define GRN_DAT_DEBUG_LOG(var)
#endif  // _DEBUG

}  // namespace dat
}  // namespace grn