#include "libstore/derivations.hh"
#include "libstore/fs-accessor.hh"
#include "libstore/globals.hh"
#include "libstore/store-api.hh"
#include "libutil/archive.hh"
#include "libutil/compression.hh"

namespace nix {

LocalFSStore::LocalFSStore(const Params& params) : Store(params) {}

struct LocalStoreAccessor : public FSAccessor {
  ref<LocalFSStore> store;

  explicit LocalStoreAccessor(const ref<LocalFSStore>& store) : store(store) {}

  Path toRealPath(const Path& path) {
    Path storePath = store->toStorePath(path);
    if (!store->isValidPath(storePath)) {
      throw InvalidPath(format("path '%1%' is not a valid store path") %
                        storePath);
    }
    return store->getRealStoreDir() + std::string(path, store->storeDir.size());
  }

  FSAccessor::Stat stat(const Path& path) override {
    auto realPath = toRealPath(path);

    struct stat st;
    if (lstat(realPath.c_str(), &st) != 0) {
      if (errno == ENOENT || errno == ENOTDIR) {
        return {Type::tMissing, 0, false};
      }
      throw SysError(format("getting status of '%1%'") % path);
    }

    if (!S_ISREG(st.st_mode) && !S_ISDIR(st.st_mode) && !S_ISLNK(st.st_mode)) {
      throw Error(format("file '%1%' has unsupported type") % path);
    }

    return {S_ISREG(st.st_mode)
                ? Type::tRegular
                : S_ISLNK(st.st_mode) ? Type::tSymlink : Type::tDirectory,
            S_ISREG(st.st_mode) ? (uint64_t)st.st_size : 0,
            S_ISREG(st.st_mode) && ((st.st_mode & S_IXUSR) != 0u)};
  }

  StringSet readDirectory(const Path& path) override {
    auto realPath = toRealPath(path);

    auto entries = nix::readDirectory(realPath);

    StringSet res;
    for (auto& entry : entries) {
      res.insert(entry.name);
    }

    return res;
  }

  std::string readFile(const Path& path) override {
    return nix::readFile(toRealPath(path));
  }

  std::string readLink(const Path& path) override {
    return nix::readLink(toRealPath(path));
  }
};

ref<FSAccessor> LocalFSStore::getFSAccessor() {
  return make_ref<LocalStoreAccessor>(ref<LocalFSStore>(
      std::dynamic_pointer_cast<LocalFSStore>(shared_from_this())));
}

void LocalFSStore::narFromPath(const Path& path, Sink& sink) {
  if (!isValidPath(path)) {
    throw Error(format("path '%s' is not valid") % path);
  }
  dumpPath(getRealStoreDir() + std::string(path, storeDir.size()), sink);
}

const std::string LocalFSStore::drvsLogDir = "drvs";

std::shared_ptr<std::string> LocalFSStore::getBuildLog(const Path& path_) {
  auto path(path_);

  assertStorePath(path);

  if (!isDerivation(path)) {
    try {
      path = queryPathInfo(path)->deriver;
    } catch (InvalidPath&) {
      return nullptr;
    }
    if (path.empty()) {
      return nullptr;
    }
  }

  std::string baseName = baseNameOf(path);

  for (int j = 0; j < 2; j++) {
    Path logPath =
        j == 0 ? fmt("%s/%s/%s/%s", logDir, drvsLogDir,
                     std::string(baseName, 0, 2), std::string(baseName, 2))
               : fmt("%s/%s/%s", logDir, drvsLogDir, baseName);
    Path logBz2Path = logPath + ".bz2";

    if (pathExists(logPath)) {
      return std::make_shared<std::string>(readFile(logPath));
    }
    if (pathExists(logBz2Path)) {
      try {
        return decompress("bzip2", readFile(logBz2Path));
      } catch (Error&) {
      }
    }
  }

  return nullptr;
}

}  // namespace nix