#include <llarp/nodedb.h>
#include <llarp/router_contact.h>
#include <map>
#include "crypto.hpp"
#include "fs.hpp"
#include "mem.hpp"

static const char skiplist_subdirs[] = "0123456789ABCDEF";

struct llarp_nodedb
{
  llarp_nodedb(llarp_alloc *m, llarp_crypto *c) : mem(m), crypto(c)
  {
  }

  llarp_alloc *mem;
  llarp_crypto *crypto;
  std::map< llarp::pubkey, llarp_rc * > entries;

  void
  Clear()
  {
    auto itr = entries.begin();
    while(itr != entries.end())
    {
      mem->free(mem, itr->second);
      itr = entries.erase(itr);
    }
  }

  ssize_t
  Load(const fs::path &path)
  {
    std::error_code ec;
    if(!fs::exists(path, ec))
    {
      return -1;
    }
    ssize_t loaded = 0;

    for(const char &ch : skiplist_subdirs)
    {
      fs::path sub = path / std::string(ch, 1);
      for(auto &f : fs::directory_iterator(sub))
      {
        ssize_t l = loadSubdir(f);
        if(l > 0)
          loaded += l;
      }
    }
    return loaded;
  }

  bool
  loadfile(const fs::path &fpath)
  {
    llarp_buffer_t buff;
    FILE *f = fopen(fpath.c_str(), "rb");
    if(!f)
      return false;
    if(!llarp_buffer_readfile(&buff, f, mem))
    {
      fclose(f);
      return false;
    }
    fclose(f);
    llarp_rc *rc = llarp::Alloc< llarp_rc >(mem);
    llarp::Zero(rc, sizeof(llarp_rc));
    if(llarp_rc_bdecode(mem, rc, &buff))
    {
      if(llarp_rc_verify_sig(crypto, rc))
      {
        llarp::pubkey pk;
        memcpy(pk.data(), rc->pubkey, pk.size());
        entries[pk] = rc;
        return true;
      }
    }
    llarp_rc_free(rc);
    mem->free(mem, rc);
    return false;
  }

  ssize_t
  loadSubdir(const fs::path &dir)
  {
    ssize_t sz = 0;
    for(auto &path : fs::directory_iterator(dir))
    {
      if(loadfile(path))
        sz++;
    }
    return sz;
  }
};

extern "C" {

struct llarp_nodedb *
llarp_nodedb_new(struct llarp_alloc *mem, struct llarp_crypto *crypto)
{
  void *ptr =
      mem->alloc(mem, sizeof(llarp_nodedb), llarp::alignment< llarp_nodedb >());
  if(!ptr)
    return nullptr;
  return new(ptr) llarp_nodedb(mem, crypto);
}

void
llarp_nodedb_free(struct llarp_nodedb **n)
{
  if(*n)
  {
    struct llarp_alloc *mem = (*n)->mem;
    (*n)->Clear();
    (*n)->~llarp_nodedb();
    mem->free(mem, *n);
  }
  *n = nullptr;
}

bool
llarp_nodedb_ensure_dir(const char *dir)
{
  fs::path path(dir);
  std::error_code ec;
  if(!fs::exists(dir, ec))
    fs::create_directories(path, ec);

  if(ec)
    return false;

  if(!fs::is_directory(path))
    return false;

  for(const char &ch : skiplist_subdirs)
  {
    fs::path sub = path / std::string(ch, 1);
    fs::create_directory(sub, ec);
    if(ec)
      return false;
  }
  return true;
}

ssize_t
llarp_nodedb_load_dir(struct llarp_nodedb *n, const char *dir)
{
  return n->Load(dir);
}
}