/*
 * Copyright (c) 2003-2012, John Wiegley.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of New Artisans LLC nor the names of its
 *   contributors may be used to endorse or promote products derived from
 *   this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @defgroup util General utilities
 */

/**
 * @file   utils.h
 * @author John Wiegley
 *
 * @ingroup util
 *
 * @brief General utility facilities used by Ledger
 */
#ifndef _UTILS_H
#define _UTILS_H

/**
 * @name Default values
 */
/*@{*/

#define TIMERS_ON   1

#if defined(DEBUG_MODE)
#define VERIFY_ON   1
#define TRACING_ON  1
#define DEBUG_ON    1
#elif defined(NDEBUG)
#define NO_ASSERTS  1
//#define NO_LOGGING  1
#else
#define TRACING_ON  1           // use --trace X to enable
#endif

/*@}*/

/**
 * @name Forward declarations
 */
/*@{*/

namespace ledger {
  using namespace boost;

#if defined(VERIFY_ON) || defined(HAVE_BOOST_PYTHON)
  class string;
#else
  typedef std::string string;
#endif

  typedef std::list<string> strings_list;

  typedef posix_time::ptime         ptime;
  typedef ptime::time_duration_type time_duration;
  typedef gregorian::date           date;
  typedef gregorian::date_duration  date_duration;
  typedef posix_time::seconds       seconds;

  typedef boost::filesystem::path             path;
  typedef boost::filesystem::ifstream         ifstream;
  typedef boost::filesystem::ofstream         ofstream;
  typedef boost::filesystem::filesystem_error filesystem_error;
}

#if BOOST_FILESYSTEM_VERSION == 3
#if defined(VERIFY_ON) || defined(HAVE_BOOST_PYTHON)
namespace boost { namespace filesystem3 { namespace path_traits {
template<> struct is_pathable<ledger::string> { static const bool value = true; };
}}}
#endif // defined(VERIFY_ON) || defined(HAVE_BOOST_PYTHON)
#endif // BOOST_FILESYSTEM_VERSION == 3

/*@}*/

/**
 * @name Assertions
 */
/*@{*/

#ifdef assert
#undef assert
#endif

#if ! defined(NO_ASSERTS)
#define ASSERTS_ON 1
#endif
#if defined(ASSERTS_ON)

namespace ledger {
  void debug_assert(const string& reason, const string& func,
                    const string& file, std::size_t line);
}

#define assert(x)                                               \
  ((x) ? ((void)0) : debug_assert(#x, BOOST_CURRENT_FUNCTION,   \
                                  __FILE__, __LINE__))

#else // ! ASSERTS_ON

#define assert(x)

#endif // ASSERTS_ON

/*@}*/

/**
 * @name Verification (i.e., heavy asserts)
 */
/*@{*/

#if defined(VERIFY_ON)

namespace ledger {

extern bool verify_enabled;

#define VERIFY(x)   (ledger::verify_enabled ? assert(x) : ((void)0))
#define DO_VERIFY() ledger::verify_enabled

void initialize_memory_tracing();
void shutdown_memory_tracing();

std::size_t current_memory_size();
std::size_t current_objects_size();

void trace_ctor_func(void * ptr, const char * cls_name, const char * args,
                     std::size_t cls_size);
void trace_dtor_func(void * ptr, const char * cls_name, std::size_t cls_size);

#define TRACE_CTOR(cls, args) \
  (DO_VERIFY() ? \
   ledger::trace_ctor_func(this, #cls, args, sizeof(cls)) : ((void)0))
#define TRACE_DTOR(cls) \
  (DO_VERIFY() ? \
   ledger::trace_dtor_func(this, #cls, sizeof(cls)) : ((void)0))

void report_memory(std::ostream& out, bool report_all = false);

} // namespace ledger

#else // ! VERIFY_ON

#define VERIFY(x)
#define DO_VERIFY() true
#define TRACE_CTOR(cls, args)
#define TRACE_DTOR(cls)

#endif // VERIFY_ON

#define IF_VERIFY() if (DO_VERIFY())

/*@}*/

/**
 * @name String wrapper
 *
 * This string type is a wrapper around std::string that allows us to trace
 * constructor and destructor calls.  It also makes ledger's use of strings a
 * unique type, that the Boost.Python code can use as the basis for
 * transparent Unicode conversions.
 */
/*@{*/

namespace ledger {

#if defined(VERIFY_ON) || defined(HAVE_BOOST_PYTHON)

class string : public std::string
{
public:
  string();
  string(const string& str);
  string(const std::string& str);
  string(size_type len, char x);
  template<class _InputIterator>
  string(_InputIterator __beg, _InputIterator __end)
    : std::string(__beg, __end) {
    TRACE_CTOR(string, "InputIterator, InputIterator");
  }
  string(const char * str);
  string(const char * str, const char * end);
  string(const string& str, size_type x);
  string(const string& str, size_type x, size_type y);
  string(const char * str, size_type x);
  string(const char * str, size_type x, size_type y);
  ~string() throw();

#if defined(HAVE_BOOST_SERIALIZATION)
private:
  /** Serialization. */

  friend class boost::serialization::access;

  template<class Archive>
  void serialize(Archive& ar, const unsigned int /* version */) {
    ar & boost::serialization::base_object<std::string>(*this);
  }
#endif // HAVE_BOOST_SERIALIZATION
};

inline string operator+(const string& __lhs, const string& __rhs)
{
  string __str(__lhs);
  __str.append(__rhs);
  return __str;
}

string operator+(const char* __lhs, const string& __rhs);
string operator+(char __lhs, const string& __rhs);

inline string operator+(const string& __lhs, const char* __rhs)
{
  string __str(__lhs);
  __str.append(__rhs);
  return __str;
}

inline string operator+(const string& __lhs, char __rhs)
{
  typedef string                __string_type;
  typedef string::size_type     __size_type;
  __string_type __str(__lhs);
  __str.append(__size_type(1), __rhs);
  return __str;
}

inline bool operator==(const string& __lhs, const string& __rhs)
{ return __lhs.compare(__rhs) == 0; }

inline bool operator==(const char* __lhs, const string& __rhs)
{ return __rhs.compare(__lhs) == 0; }

inline bool operator==(const string& __lhs, const char* __rhs)
{ return __lhs.compare(__rhs) == 0; }

inline bool operator!=(const string& __lhs, const string& __rhs)
{ return __rhs.compare(__lhs) != 0; }

inline bool operator!=(const char* __lhs, const string& __rhs)
{ return __rhs.compare(__lhs) != 0; }

inline bool operator!=(const string& __lhs, const char* __rhs)
{ return __lhs.compare(__rhs) != 0; }

#endif // defined(VERIFY_ON) || defined(HAVE_BOOST_PYTHON)

extern string empty_string;

strings_list split_arguments(const char * line);

} // namespace ledger

/*@}*/

/**
 * @name Tracing and logging
 */
/*@{*/

#if ! defined(NO_LOGGING)
#define LOGGING_ON 1
#endif
#if defined(LOGGING_ON)

namespace ledger {

enum log_level_t {
  LOG_OFF = 0,
  LOG_CRIT,
  LOG_FATAL,
  LOG_ASSERT,
  LOG_ERROR,
  LOG_VERIFY,
  LOG_WARN,
  LOG_INFO,
  LOG_EXCEPT,
  LOG_DEBUG,
  LOG_TRACE,
  LOG_ALL
};

extern log_level_t        _log_level;
extern std::ostream *     _log_stream;
extern std::ostringstream _log_buffer;

void logger_func(log_level_t level);

#define LOGGER(cat) \
    static const char * const _this_category = cat

#if defined(TRACING_ON)

extern uint8_t _trace_level;

#define SHOW_TRACE(lvl) \
  (ledger::_log_level >= ledger::LOG_TRACE && lvl <= ledger::_trace_level)
#define TRACE(lvl, msg) \
  (SHOW_TRACE(lvl) ? \
   ((ledger::_log_buffer << msg), \
    ledger::logger_func(ledger::LOG_TRACE)) : (void)0)

#else // TRACING_ON

#define SHOW_TRACE(lvl) false
#define TRACE(lvl, msg)

#endif // TRACING_ON

#if defined(DEBUG_ON)

extern optional<std::string>       _log_category;
#if defined(HAVE_BOOST_REGEX_UNICODE)
  extern optional<boost::u32regex> _log_category_re;
#else
  extern optional<boost::regex>    _log_category_re;
#endif

inline bool category_matches(const char * cat) {
  if (_log_category) {
    if (! _log_category_re) {
      _log_category_re =
#if defined(HAVE_BOOST_REGEX_UNICODE)
        boost::make_u32regex(_log_category->c_str(),
                             boost::regex::perl | boost::regex::icase);
#else
        boost::regex(_log_category->c_str(),
                     boost::regex::perl | boost::regex::icase);
#endif
    }
#if defined(HAVE_BOOST_REGEX_UNICODE)
    return boost::u32regex_search(cat, *_log_category_re);
#else
    return boost::regex_search(cat, *_log_category_re);
#endif
  }
  return false;
}

#define SHOW_DEBUG(cat) \
  (ledger::_log_level >= ledger::LOG_DEBUG && ledger::category_matches(cat))
#define SHOW_DEBUG_() SHOW_DEBUG(_this_category)

#define DEBUG(cat, msg) \
  (SHOW_DEBUG(cat) ? \
   ((ledger::_log_buffer << msg), \
    ledger::logger_func(ledger::LOG_DEBUG)) : (void)0)
#define DEBUG_(msg) DEBUG(_this_category, msg)

#else // DEBUG_ON

#define SHOW_DEBUG(cat) false
#define SHOW_DEBUG_()   false
#define DEBUG(cat, msg)
#define DEBUG_(msg)

#endif // DEBUG_ON

#define LOG_MACRO(level, msg) \
  (ledger::_log_level >= level ? \
   ((ledger::_log_buffer << msg), ledger::logger_func(level)) : (void)0)

#define SHOW_INFO()     (ledger::_log_level >= ledger::LOG_INFO)
#define SHOW_WARN()     (ledger::_log_level >= ledger::LOG_WARN)
#define SHOW_ERROR()    (ledger::_log_level >= ledger::LOG_ERROR)
#define SHOW_FATAL()    (ledger::_log_level >= ledger::LOG_FATAL)
#define SHOW_CRITICAL() (ledger::_log_level >= ledger::LOG_CRIT)

#define INFO(msg)      LOG_MACRO(ledger::LOG_INFO, msg)
#define WARN(msg)      LOG_MACRO(ledger::LOG_WARN, msg)
#define ERROR(msg)     LOG_MACRO(ledger::LOG_ERROR, msg)
#define FATAL(msg)     LOG_MACRO(ledger::LOG_FATAL, msg)
#define CRITICAL(msg)  LOG_MACRO(ledger::LOG_CRIT, msg)
#define EXCEPTION(msg) LOG_MACRO(ledger::LOG_EXCEPT, msg)

} // namespace ledger

#else // ! LOGGING_ON

#define LOGGER(cat)

#define SHOW_TRACE(lvl) false
#define SHOW_DEBUG(cat) false
#define SHOW_DEBUG_()   false
#define SHOW_INFO()     false
#define SHOW_WARN()     false
#define SHOW_ERROR()    false
#define SHOW_FATAL()    false
#define SHOW_CRITICAL() false

#define TRACE(lvl, msg)
#define DEBUG(cat, msg)
#define DEBUG_(msg)
#define INFO(msg)
#define WARN(msg)
#define ERROR(msg)
#define FATAL(msg)
#define CRITICAL(msg)

#endif // LOGGING_ON

#define IF_TRACE(lvl) if (SHOW_TRACE(lvl))
#define IF_DEBUG(cat) if (SHOW_DEBUG(cat))
#define IF_DEBUG_()   if (SHOW_DEBUG_())
#define IF_INFO()     if (SHOW_INFO())
#define IF_WARN()     if (SHOW_WARN())
#define IF_ERROR()    if (SHOW_ERROR())
#define IF_FATAL()    if (SHOW_FATAL())
#define IF_CRITICAL() if (SHOW_CRITICAL())

/*@}*/

/**
 * @name Timers
 * This allows log xacts to specify cumulative time spent.
 */
/*@{*/

#if defined(LOGGING_ON) && defined(TIMERS_ON)

namespace ledger {

void start_timer(const char * name, log_level_t lvl);
void stop_timer(const char * name);
void finish_timer(const char * name);

#if defined(TRACING_ON)
#define TRACE_START(name, lvl, msg) \
  (SHOW_TRACE(lvl) ? \
   ((ledger::_log_buffer << msg), \
    ledger::start_timer(#name, ledger::LOG_TRACE)) : ((void)0))
#define TRACE_STOP(name, lvl) \
  (SHOW_TRACE(lvl) ? ledger::stop_timer(#name) : ((void)0))
#define TRACE_FINISH(name, lvl) \
  (SHOW_TRACE(lvl) ? ledger::finish_timer(#name) : ((void)0))
#else
#define TRACE_START(name, lvl, msg)
#define TRACE_STOP(name, lvl)
#define TRACE_FINISH(name, lvl)
#endif

#if defined(DEBUG_ON)
#define DEBUG_START(name, cat, msg) \
  (SHOW_DEBUG(cat) ? \
   ((ledger::_log_buffer << msg), \
    ledger::start_timer(#name, ledger::LOG_DEBUG)) : ((void)0))
#define DEBUG_START_(name, msg) \
  DEBUG_START_(name, _this_category, msg)
#define DEBUG_STOP(name, cat) \
  (SHOW_DEBUG(cat) ? ledger::stop_timer(#name) : ((void)0))
#define DEBUG_STOP_(name) \
  DEBUG_STOP_(name, _this_category)
#define DEBUG_FINISH(name, cat) \
  (SHOW_DEBUG(cat) ? ledger::finish_timer(#name) : ((void)0))
#define DEBUG_FINISH_(name) \
  DEBUG_FINISH_(name, _this_category)
#else
#define DEBUG_START(name, cat, msg)
#define DEBUG_START_(name, msg)
#define DEBUG_STOP(name)
#define DEBUG_FINISH(name)
#endif

#define INFO_START(name, msg) \
  (SHOW_INFO() ? \
   ((ledger::_log_buffer << msg), \
    ledger::start_timer(#name, ledger::LOG_INFO)) : ((void)0))
#define INFO_STOP(name) \
  (SHOW_INFO() ? stop_timer(#name) : ((void)0))
#define INFO_FINISH(name) \
  (SHOW_INFO() ? finish_timer(#name) : ((void)0))

} // namespace ledger

#else // ! (LOGGING_ON && TIMERS_ON)

#define TRACE_START(lvl, msg, name)
#define TRACE_STOP(name, lvl)
#define TRACE_FINISH(name, lvl)

#define DEBUG_START(name, msg)
#define DEBUG_START_(name, cat, msg)
#define DEBUG_STOP(name)
#define DEBUG_FINISH(name)

#define INFO_START(name, msg)
#define INFO_STOP(name)
#define INFO_FINISH(name)

#endif // TIMERS_ON

/*@}*/

/*
 * These files define the other internal facilities.
 */

#include "error.h"

enum caught_signal_t {
  NONE_CAUGHT,
  INTERRUPTED,
  PIPE_CLOSED
};

extern caught_signal_t caught_signal;

void sigint_handler(int sig);
void sigpipe_handler(int sig);

inline void check_for_signal() {
  switch (caught_signal) {
  case NONE_CAUGHT:
    break;
  case INTERRUPTED:
    throw std::runtime_error(_("Interrupted by user (use Control-D to quit)"));
  case PIPE_CLOSED:
    throw std::runtime_error(_("Pipe terminated"));
  }
}

/**
 * @name General utility functions
 */
/*@{*/

#if defined(__GXX_EXPERIMENTAL_CXX0X__) && __GXX_EXPERIMENTAL_CXX0X__
#define foreach(x, y) for (x : y)
#define unique_ptr std::unique_ptr
#else
#define foreach BOOST_FOREACH
#define unique_ptr std::auto_ptr
#endif

namespace ledger {

template <typename T, typename U>
inline T& downcast(U& object) {
  return *polymorphic_downcast<T *>(&object);
}

path resolve_path(const path& pathname);

#ifdef HAVE_REALPATH
extern "C" char * realpath(const char *, char resolved_path[]);
#endif

inline const string& either_or(const string& first,
                               const string& second) {
  return first.empty() ? second : first;
}

inline char * skip_ws(char * ptr) {
  while (*ptr == ' ' || *ptr == '\t' || *ptr == '\n')
    ptr++;
  return ptr;
}

inline char * trim_ws(char * ptr) {
  std::size_t len = std::strlen(ptr);
  int i = int(len) - 1;
  while (i >= 0 && (ptr[i] == ' ' || ptr[i] == '\t' || ptr[i] == '\n'))
    ptr[i--] = '\0';
  return skip_ws(ptr);
}

inline char * next_element(char * buf, bool variable = false) {
  for (char * p = buf; *p; p++) {
    if (! (*p == ' ' || *p == '\t'))
      continue;

    if (! variable) {
      *p = '\0';
      return skip_ws(p + 1);
    }
    else if (*p == '\t') {
      *p = '\0';
      return skip_ws(p + 1);
    }
    else if (*(p + 1) == ' ') {
      *p = '\0';
      return skip_ws(p + 2);
    }
  }
  return NULL;
}

inline char peek_next_nonws(std::istream& in) {
  char c = static_cast<char>(in.peek());
  while (in.good() && ! in.eof() && std::isspace(c)) {
    in.get(c);
    c = static_cast<char>(in.peek());
  }
  return c;
}

#define READ_INTO(str, targ, size, var, cond) {         \
    char * _p = targ;                                   \
    var = static_cast<char>(str.peek());                \
    while (str.good() && ! str.eof() && var != '\n' &&  \
           (cond) && _p - targ < size) {                \
      str.get(var);                                     \
      if (str.eof())                                    \
        break;                                          \
      if (var == '\\') {                                \
        str.get(var);                                   \
        if (in.eof())                                   \
          break;                                        \
        switch (var) {                                  \
        case 'b': var = '\b'; break;                    \
        case 'f': var = '\f'; break;                    \
        case 'n': var = '\n'; break;                    \
        case 'r': var = '\r'; break;                    \
        case 't': var = '\t'; break;                    \
        case 'v': var = '\v'; break;                    \
        default: break;                                 \
        }                                               \
      }                                                 \
      *_p++ = var;                                      \
      var = static_cast<char>(str.peek());              \
    }                                                   \
    *_p = '\0';                                         \
  }

#define READ_INTO_(str, targ, size, var, idx, cond) {   \
    char * _p = targ;                                   \
    var = static_cast<char>(str.peek());                \
    while (str.good() && ! str.eof() && var != '\n' &&  \
           (cond) && _p - targ < size) {                \
      str.get(var);                                     \
      if (str.eof())                                    \
        break;                                          \
      idx++;                                            \
      if (var == '\\') {                                \
        str.get(var);                                   \
        if (in.eof())                                   \
          break;                                        \
        switch (var) {                                  \
        case 'b': var = '\b'; break;                    \
        case 'f': var = '\f'; break;                    \
        case 'n': var = '\n'; break;                    \
        case 'r': var = '\r'; break;                    \
        case 't': var = '\t'; break;                    \
        case 'v': var = '\v'; break;                    \
        default: break;                                 \
        }                                               \
        idx++;                                          \
      }                                                 \
      *_p++ = var;                                      \
      var = static_cast<char>(str.peek());              \
    }                                                   \
    *_p = '\0';                                         \
  }

inline string to_hex(unsigned int * message_digest, const int len = 1)
{
  std::ostringstream buf;

  for(int i = 0; i < 5 ; i++) {
    buf.width(8);
    buf.fill('0');
    buf << std::hex << message_digest[i];
    if (i + 1 >= len)
      break;                    // only output the first LEN dwords
  }
  return buf.str();
}

inline string sha1sum(const string& str)
{
  SHA1 sha;
  sha.Reset();
  sha << str.c_str();
  unsigned int message_digest[5];
  sha.Result(message_digest);
  return to_hex(message_digest, 5);
}

class push_xml
{
  std::ostream& out;
  string        tag;
  bool          leave_open;

public:
  push_xml(std::ostream& _out, const string& _tag, bool has_attrs = false,
           bool _leave_open = false)
    : out(_out), tag(_tag), leave_open(_leave_open) {
    out << '<' << tag;
    if (! has_attrs)
      out << '>';
  }
  ~push_xml() {
    if (! leave_open)
      out << "</" << tag << '>';
  }

  void close_attrs() {
    out << '>';
  }

  static string guard(const string& str) {
    std::ostringstream buf;
    foreach (const char& ch, str) {
      switch (ch) {
      case '<':
        buf << "&lt;";
        break;
      case '>':
        buf << "&gt;";
        break;
      case '&':
        buf << "&amp;";
        break;
      default:
        buf << ch;
        break;
      }
    }
    return buf.str();
  }
};

extern const string version;

} // namespace ledger

/*@}*/

#endif // _UTILS_H