package com.github.davidmoten.rx.jdbc;
   
   import java.sql.Connection;
   import java.sql.SQLException;
   import java.util.concurrent.atomic.AtomicBoolean;
   
   import com.github.davidmoten.rx.jdbc.exceptions.SQLRuntimeException;
   import com.zaxxer.hikari.HikariDataSource;
   
  /**
   * Provides database connection pooling using HikariCP.
   */
  public final class ConnectionProviderPooled implements ConnectionProvider {
  
      /**
       * HikariCP connection pool.
       */
      private final HikariDataSource pool;
  
      /**
       * Ensure idempotency of this.close() method.
       */
      private final AtomicBoolean isOpen = new AtomicBoolean(true);
  
      /**
       * Constructor.
       * 
       * @param url
       * @param minPoolSize
       * @param maxPoolSize
       */
      public ConnectionProviderPooled(String url, int minPoolSize, int maxPoolSize) {
          this(createPool(url, null, null, minPoolSize, maxPoolSize));
      }
  
      // Visible for testing
      ConnectionProviderPooled(HikariDataSource pool) {
          this.pool = pool;
      }
  
      /**
       * Constructor.
       * 
       * @param url jdbc url
       * @param username database login username
       * @param password database login password
       * @param minPoolSize minimum size of the connection pool
       * @param maxPoolSize maximum size of the connection pool
       */
      public ConnectionProviderPooled(String url, String username, String password, int minPoolSize,
              int maxPoolSize) {
          this(createPool(url, username, password, minPoolSize, maxPoolSize));
      }
  
      /**
       * Returns a new pooled data source based on jdbc url.
       * 
       * @param url jdbc url
       * @param username login username
       * @param password login password
       * @param minPoolSize minimum database connection pool size
       * @param maxPoolSize maximum database connection pool size
       * @return
       */
      private static HikariDataSource createPool(String url, String username, String password,
              int minPoolSize, int maxPoolSize) {
  
          HikariDataSource ds = new HikariDataSource();
          ds.setJdbcUrl(url);
          ds.setUsername(username);
          ds.setPassword(password);
          ds.setMinimumIdle(minPoolSize);
          ds.setMaximumPoolSize(maxPoolSize);
          return ds;
      }
  
      @Override
      public Connection get() {
          try {
              return pool.getConnection();
          } catch (SQLException e) {
              throw new SQLRuntimeException(e);
          }
      }
  
      @Override
      public void close() {
          if (isOpen.getAndSet(false))
              pool.close();
      }
  
  }