#ifndef   UTILITY_H_
#define   UTILITY_H_

#include <string>
#include <stack>
#include <cctype>

namespace meow{
  inline std::string stringPrintf(char const * fmt, ...);
  inline std::string stringReplace(std::string str,
                                   std::string const& from,
                                   std::string const& to);
  inline bool cstringEndWith(char const* str, int n, ...);
#define debugPrintf(...) \
  meow::debugPrintf_(\
                     __FILE__,\
                     __PRETTY_FUNCTION__,\
                     __LINE__,\
                     meow::stringPrintf(__VA_ARGS__).c_str())
  inline void debugPrintf_(char const* file,
                           char const* func,
                           size_t      line,
                           char const* msg);
  inline void messagePrintf(int level_change, char const* fmt, ...);

  static const double PI = 3.14159265358979323846264338327950288;

  inline double noEPS(double value, double eps = 1e-9);
  inline double   normalize(double lower, double upper, double value);
  inline double denormalize(double lower, double upper, double ratio);
  inline double ratioMapping(double l1, double u1, double m1,
                             double l2, double u2);
  template<class T>
  inline T inRange(T const& mn, T const& mx, T const& v);
  template<class T>
  inline T squ(T const& x);

  template<class T>
  inline double average(T const& beg, T const& end, double sigs);
  template<class T>
  inline double average(T const& beg, T const& end, T const& p, double sigs);

  //# === meow:: *Functios* in utility.h
  //# [options="header",width="100%",cols="1>s,5<,1<,10<",grid="rows"]
  //# |==============================================================
  //# |Name             | Parameters                | Return_Type | Description
  //# |stringPrintf     |(char const * `fmt`, ...)  | std::string
  //# |Format print to C++ string and return it
  
  
  //# |stringReplace  |(std::string `str`,\
  //#                   std::string const& `from`,\
  //#                   std::string const& `to`)    | std::string
  //# |Return a string like `str`, but all `from` be replaced by `to`
  
  
  //# |cstringEndWith |(char const* `str`,\int `n`, ...) | bool 
  //# |Return whether `str` is end with one of the c-string you specify in
  //#  the parameters or not
  
  
  //# |debugPrintf    |(char const* `fmt`, ...)     | void
  //# |Print debug message (file name, line number, ...etc) when `DEBUG` is
  //#  defined
  
  
  //# |messagePrintf  |(int `level_change`,\char const* `fmt`, ...) | void
  //# |階層式的訊息輸出
  
  
  //# |noEPS          |(double `value`, double `eps` = 1e-9) | double |
  //# 如果abs(輸入的數值) < eps, 則回傳0, 否則回傳輸入的數值
  
  
  //# |normalize      |(double `lower`, double `upper`, \ double value)
  //# | double | `(value - lower) / (upper - lower)`
  
  
  //# |denormalize    |(double `lower`, double `upper`,
  //# \ double `ratio`) | double | `lower + (upper - lower) * ratio`
  
  
  //# |ratioMapping   |(double `l1`, double `u1`,
  //# \double `m1`, double `l2`,\double `u2`)
  //# | double | `denormalize(l2, u2, normalize(l1, u1, m1))`
  
  
  //# |inRange<T>     |(T const& `mn`, T const& `mx`, \ T const& `v`) | T | 
  //# `std::max(mn, std::min(mx, v))`
  
  
  //# |squ<T>  |(T const& `x`) | T| `x * x`
  
  
  //# |average<T>|(T const& `beg`, T const& `end`, \ double `sigs`)| T|
  //# 只將 `sigs` 個標準差以內的數據拿來取平均
  
  
  //# |average<T>|(T const& `beg`, T const& `end`,
  //# \ T const& `p`, double `sigs`)| T| 同上, 不過這次用 `p` 來加權平均
  //# |==============================================================
  //# 
  //# [NOTE]
  //# ====================================
  //#  * `stringReplace()` 不是用什麼好方法寫的因此執行效率很低請別虐待它. 
  //#  * 額外附贈一個 `const double PI = 3.141592653589......`
  //# ====================================
  //#
  //# '''
  //#
}

#include "utility.hpp"

#endif // UTILITY_H_