/*
* (C) 2015,2017 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/

#include <botan/ffi.h>

#include <botan/hash.h>
#include <botan/internal/ffi_util.h>

extern "C" {

using namespace Botan_FFI;

BOTAN_FFI_DECLARE_STRUCT(botan_hash_struct, Botan::HashFunction, 0x1F0A4F84);

int botan_hash_init(botan_hash_t* hash, const char* hash_name, uint32_t flags) {
   return ffi_guard_thunk(__func__, [=]() -> int {
      if(hash == nullptr || hash_name == nullptr || *hash_name == 0) {
         return BOTAN_FFI_ERROR_NULL_POINTER;
      }
      if(flags != 0) {
         return BOTAN_FFI_ERROR_BAD_FLAG;
      }

      auto h = Botan::HashFunction::create(hash_name);
      if(h == nullptr) {
         return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
      }

      *hash = new botan_hash_struct(std::move(h));
      return BOTAN_FFI_SUCCESS;
   });
}

int botan_hash_destroy(botan_hash_t hash) {
   return BOTAN_FFI_CHECKED_DELETE(hash);
}

int botan_hash_output_length(botan_hash_t hash, size_t* out) {
   if(out == nullptr) {
      return BOTAN_FFI_ERROR_NULL_POINTER;
   }
   return BOTAN_FFI_VISIT(hash, [=](const auto& h) { *out = h.output_length(); });
}

int botan_hash_block_size(botan_hash_t hash, size_t* out) {
   if(out == nullptr) {
      return BOTAN_FFI_ERROR_NULL_POINTER;
   }
   return BOTAN_FFI_VISIT(hash, [=](const auto& h) { *out = h.hash_block_size(); });
}

int botan_hash_clear(botan_hash_t hash) {
   return BOTAN_FFI_VISIT(hash, [](auto& h) { h.clear(); });
}

int botan_hash_update(botan_hash_t hash, const uint8_t* buf, size_t len) {
   if(len == 0) {
      return 0;
   }

   if(buf == nullptr) {
      return BOTAN_FFI_ERROR_NULL_POINTER;
   }

   return BOTAN_FFI_VISIT(hash, [=](auto& h) { h.update(buf, len); });
}

int botan_hash_final(botan_hash_t hash, uint8_t out[]) {
   if(out == nullptr) {
      return BOTAN_FFI_ERROR_NULL_POINTER;
   }
   return BOTAN_FFI_VISIT(hash, [=](auto& h) { h.final(out); });
}

int botan_hash_copy_state(botan_hash_t* dest, const botan_hash_t source) {
   return BOTAN_FFI_VISIT(source, [=](const auto& src) { *dest = new botan_hash_struct(src.copy_state()); });
}

int botan_hash_name(botan_hash_t hash, char* name, size_t* name_len) {
   if(name_len == nullptr) {
      return BOTAN_FFI_ERROR_NULL_POINTER;
   }

   return BOTAN_FFI_VISIT(hash, [=](const auto& h) { return write_str_output(name, name_len, h.name()); });
}
}
