// Copyright (C) 2025 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.google.gerrit.server.account;

import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.collect.ImmutableList;
import com.google.common.flogger.FluentLogger;
import com.google.gerrit.entities.Account;
import com.google.gerrit.exceptions.StorageException;
import com.google.gerrit.server.cache.CacheModule;
import com.google.inject.Inject;
import com.google.inject.Module;
import com.google.inject.Singleton;
import com.google.inject.TypeLiteral;
import com.google.inject.name.Named;
import java.util.List;
import java.util.concurrent.ExecutionException;

@Singleton
public class AuthTokenCache {
  private static final FluentLogger logger = FluentLogger.forEnclosingClass();

  private static final String CACHE_NAME = "tokens";

  private final LoadingCache<Account.Id, List<AuthToken>> cache;

  public static Module module() {
    return new CacheModule() {
      @Override
      protected void configure() {
        cache(CACHE_NAME, Account.Id.class, new TypeLiteral<List<AuthToken>>() {})
            .loader(Loader.class);
        bind(AuthTokenCache.class);
      }
    };
  }

  @Inject
  AuthTokenCache(@Named(CACHE_NAME) LoadingCache<Account.Id, List<AuthToken>> cache) {
    this.cache = cache;
  }

  public List<AuthToken> get(Account.Id accountId) {
    try {
      return cache.get(accountId);
    } catch (ExecutionException e) {
      logger.atWarning().withCause(e).log(
          "Cannot load authentication tokens for %d", accountId.get());
      throw new StorageException(e);
    }
  }

  public void evict(Account.Id accountId) {
    if (accountId != null) {
      logger.atFine().log("Evict authentication token for username %d", accountId.get());
      cache.invalidate(accountId);
    }
  }

  static class Loader extends CacheLoader<Account.Id, List<AuthToken>> {
    private final DirectAuthTokenAccessor directAccessor;

    @Inject
    Loader(DirectAuthTokenAccessor directAccessor) {
      this.directAccessor = directAccessor;
    }

    @Override
    public ImmutableList<AuthToken> load(Account.Id accountId) throws Exception {
      return directAccessor.getTokens(accountId);
    }
  }
}