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.jdbc.service;
  
  import java.util.Date;
  import lombok.Data;
  import lombok.extern.slf4j.Slf4j;
  import org.springframework.dao.DuplicateKeyException;
  import org.springframework.jdbc.core.JdbcTemplate;
  import org.springframework.transaction.annotation.Isolation;
  import org.springframework.transaction.annotation.Propagation;
  import org.springframework.transaction.annotation.Transactional;
  
  @Data
  @Slf4j
  @Transactional(isolation = Isolation.READ_COMMITTED, propagation = Propagation.REQUIRES_NEW)
  public class SimpleJdbcLockSingleKeyService implements JdbcLockSingleKeyService {
  
    public static final String ACQUIRE_FORMATTED_QUERY = "INSERT INTO %s (lock_key, token, expireAt) VALUES (?, ?, ?)";
    public static final String RELEASE_FORMATTED_QUERY = "DELETE FROM %s WHERE lock_key = ? AND token = ?";
    public static final String DELETE_EXPIRED_FORMATTED_QUERY = "DELETE FROM %s WHERE expireAt < ?";
    public static final String REFRESH_FORMATTED_QUERY = "UPDATE %s SET expireAt = ? WHERE lock_key = ? AND token = ?";
  
    private final JdbcTemplate jdbcTemplate;
  
    @Override
    public String acquire(final String key, final String storeId, final String token, final long expiration) {
      final Date now = new Date();
      final int expired = jdbcTemplate.update(String.format(DELETE_EXPIRED_FORMATTED_QUERY, storeId), now);
      log.debug("Expired {} locks", expired);
  
      try {
        final Date expireAt = new Date(now.getTime() + expiration);
        final int created = jdbcTemplate.update(String.format(ACQUIRE_FORMATTED_QUERY, storeId), key, token, expireAt);
        return created == 1 ? token : null;
      } catch (final DuplicateKeyException e) {
        return null;
      }
    }
  
    @Override
    public boolean release(final String key, final String storeId, final String token) {
      final int deleted = jdbcTemplate.update(String.format(RELEASE_FORMATTED_QUERY, storeId), key, token);
  
      final boolean released = deleted == 1;
      if (released) {
        log.debug("Release query successfully affected 1 record for key {} with token {} in store {}", key, token, storeId);
      } else if (deleted > 0) {
        log.error("Unexpected result from release for key {} with token {} in store {}, released {}", key, token, storeId, deleted);
      } else {
        log.error("Release query did not affect any records for key {} with token {} in store {}", key, token, storeId);
      }
  
      return released;
    }
  
    @Override
    public boolean refresh(final String key, final String storeId, final String token, final long expiration) {
      final Date now = new Date();
      final Date expireAt = new Date(now.getTime() + expiration);
  
      final int updated = jdbcTemplate.update(String.format(REFRESH_FORMATTED_QUERY, storeId), expireAt, key, token);
      final boolean refreshed = updated == 1;
      if (refreshed) {
        log.debug("Refresh query successfully affected 1 record for key {} with token {} in store {}", key, token, storeId);
      } else if (updated > 0) {
        log.error("Unexpected result from refresh for key {} with token {} in store {}, refreshed {}", key, token, storeId, updated);
      } else {
        log.error("Refresh query did not affect any records for key {} with token {} in store {}", key, token, storeId);
      }
  
      return refreshed;
    }
  }
  