/* Copyright (C) CJ Affiliate
  *
  * You may use, distribute and modify this code under  the
  * terms of the  GNU General Public License  version 2  or
  * later.
  *
  * You should have received a copy of the license with this
  * file. If not, you will find a copy in the "LICENSE" file
  * at https://github.com/cjdev/dual-control.
  */
 
 #include "random_source.h"
 #include "sys_fstream.h"
 
 namespace
 {

 class invalid_random_source_exception : public std::exception
 {};
 

 class impl : public random_source_ifc
 {
 private:
     fstreams fstreams_;
 public:

     impl (const fstreams fstreams)

         : fstreams_ (fstreams)
     {}

     std::vector<uint8_t> get_random_bytes (int length) const override
     {

         fstreams::pstream random_source = fstreams_.open_fstream (file_path);
 
         std::vector<uint8_t> result (length);
         random_source->read (reinterpret_cast<char *> (result.data()), length);

 
         if (random_source->fail()) {
             throw invalid_random_source_exception();
         }
 

         return result;
     }
 };
 }
 

 const std::string random_source_ifc::file_path = "/dev/urandom";
 

 random_source random_source::create (const fstreams &fstreams)

 {
     return random_source (random_source::delegate (new impl (fstreams)));

 };