content: /*
   * MIT License
   *
   * Copyright (c) 2020 Alen Turkovic
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in all
   * copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   */
  
  package com.github.alturkovic.lock.mongo.impl;
  
  import com.github.alturkovic.lock.AbstractSimpleLock;
  import com.github.alturkovic.lock.mongo.model.LockDocument;
  import com.mongodb.client.result.DeleteResult;
  import com.mongodb.client.result.UpdateResult;
  import java.time.LocalDateTime;
  import java.time.temporal.ChronoUnit;
  import java.util.function.Supplier;
  import lombok.extern.slf4j.Slf4j;
  import org.springframework.data.mongodb.core.FindAndModifyOptions;
  import org.springframework.data.mongodb.core.MongoTemplate;
  import org.springframework.data.mongodb.core.query.Criteria;
  import org.springframework.data.mongodb.core.query.Query;
  import org.springframework.data.mongodb.core.query.Update;
  
  @Slf4j
  public class SimpleMongoLock extends AbstractSimpleLock {
    private final MongoTemplate mongoTemplate;
  
    public SimpleMongoLock(final Supplier<String> tokenSupplier, final MongoTemplate mongoTemplate) {
      super(tokenSupplier);
      this.mongoTemplate = mongoTemplate;
    }
  
    @Override
    protected String acquire(final String key, final String storeId, final String token, final long expiration) {
      final Query query = Query.query(Criteria.where("_id").is(key));
      final Update update = new Update()
        .setOnInsert("_id", key)
        .setOnInsert("expireAt", LocalDateTime.now().plus(expiration, ChronoUnit.MILLIS))
        .setOnInsert("token", token);
  
      final FindAndModifyOptions options = new FindAndModifyOptions().upsert(true).returnNew(true);
      final LockDocument doc = mongoTemplate.findAndModify(query, update, options, LockDocument.class, storeId);
  
      final boolean locked = doc.getToken().equals(token);
      log.debug("Tried to acquire lock for key {} with token {} in store {}. Locked: {}", key, token, storeId, locked);
      return locked ? token : null;
    }
  
    @Override
    protected boolean release(final String key, final String storeId, final String token) {
      final DeleteResult deleted = mongoTemplate.remove(Query.query(Criteria.where("_id").is(key).and("token").is(token)), storeId);
      final boolean released = deleted.getDeletedCount() == 1;
      if (released) {
        log.debug("Remove query successfully affected 1 record for key {} with token {} in store {}", key, token, storeId);
      } else if (deleted.getDeletedCount() > 0) {
        log.error("Unexpected result from release for key {} with token {} in store {}, released {}", key, token, storeId, deleted);
      } else {
        log.error("Remove query did not affect any records for key {} with token {} in store {}", key, token, storeId);
      }
  
      return released;
    }
  
    @Override
    protected boolean refresh(final String key, final String storeId, final String token, final long expiration) {
      final UpdateResult updated = mongoTemplate.updateFirst(Query.query(Criteria.where("_id").is(key).and("token").is(token)),
        Update.update("expireAt", LocalDateTime.now().plus(expiration, ChronoUnit.MILLIS)),
        storeId);
  
      final boolean refreshed = updated.getModifiedCount() == 1;
      if (refreshed) {
        log.debug("Refresh query successfully affected 1 record for key {} with token {} in store {}", key, token, storeId);
      } else if (updated.getModifiedCount() > 0) {
        log.error("Unexpected result from refresh for key {} with token {} in store {}, released {}", key, token, storeId, updated);
      } else {
        log.warn("Refresh query did not affect any records for key {} with token {} in store {}. This is possible when refresh interval fires for the final time after the lock has been released",
          key, token, storeId);
      }
  
      return refreshed;
    }
  }