Configuration.scala

package play.api

import java.io._

import com.typesafe.config._

import scala.collection.JavaConverters._
import scala.util.control.NonFatal

/**
 * This object provides a set of operations to create `Configuration` values.
 *
 * For example, to load a `Configuration` in a running application:
 * {{{
 * val config = Configuration.load()
 * val foo = config.getString("foo").getOrElse("boo")
 * }}}
 *
 * The underlying implementation is provided by https://github.com/typesafehub/config.
 */
object Configuration {

  private[this] lazy val dontAllowMissingConfigOptions = ConfigParseOptions.defaults().setAllowMissing(false)

  private[this] lazy val dontAllowMissingConfig = ConfigFactory.load(dontAllowMissingConfigOptions)
  /**
   * loads `Configuration` from 'conf/application.conf' in Dev mode
   * @return  configuration to be used
   */
  private[play] def loadDev(appPath: File, devSettings: Map[String, String]): Config = {
    try {
      val file = {
        devSettings.get("config.file").orElse(Option(System.getProperty("config.file")))
          .map(f => new File(f)).getOrElse(new File(appPath, "conf/application.conf"))
      }
      ConfigFactory.parseMap(devSettings.asJava).withFallback(
        ConfigFactory.load(ConfigFactory.parseFileAnySyntax(file))
      )
    } catch {
      case e: ConfigException => throw configError(e.origin, e.getMessage, Some(e))
    }
  }

  /**
   * Loads a new `Configuration` either from the classpath or from
   * `conf/application.conf` depending on the application's Mode.
   *
   * The provided mode is used if the application is not ready
   * yet, just like when calling this method from `play.api.Application`.
   *
   * Defaults to Mode.Dev
   *
   * @param mode Application mode.
   * @return a `Configuration` instance
   */
  def load(appPath: File, mode: Mode.Mode = Mode.Dev, devSettings: Map[String, String] = Map.empty) = {
    try {
      val currentMode = Play.maybeApplication.map(_.mode).getOrElse(mode)
      if (currentMode == Mode.Prod) Configuration(dontAllowMissingConfig) else Configuration(loadDev(appPath, devSettings))
    } catch {
      case e: ConfigException => throw configError(e.origin, e.getMessage, Some(e))
      case e: Throwable => throw e
    }
  }

  /**
   * Returns an empty Configuration object.
   */
  def empty = Configuration(ConfigFactory.empty())

  /**
   * Create a ConfigFactory object from the data passed as a Map.
   */
  def from(data: Map[String, Any]) = {

    def asJavaRecursively[A](data: Map[A, Any]): Map[A, Any] = {
      data.mapValues { value =>
        value match {
          case v: Map[_, _] => asJavaRecursively(v).asJava
          case v: Iterable[_] => v.asJava
          case v => v
        }
      }
    }

    Configuration(ConfigFactory.parseMap(asJavaRecursively[String](data).asJava))
  }

  private def configError(origin: ConfigOrigin, message: String, e: Option[Throwable] = None): PlayException = {
    import scalax.io.JavaConverters._
    new PlayException.ExceptionSource("Configuration error", message, e.orNull) {
      def line = Option(origin.lineNumber: java.lang.Integer).orNull
      def position = null
      def input = Option(origin.url).map(_.asInput.string).orNull
      def sourceName = Option(origin.filename).orNull
      override def toString = "Configuration error: " + getMessage
    }
  }

}

/**
 * A full configuration set.
 *
 * The underlying implementation is provided by https://github.com/typesafehub/config.
 *
 * @param underlying the underlying Config implementation
 */
case class Configuration(underlying: Config) {

  /**
   * Merge 2 configurations.
   */
  def ++(other: Configuration): Configuration = {
    Configuration(other.underlying.withFallback(underlying))
  }

  /**
   * Read a value from the underlying implementation,
   * catching Errors and wrapping it in an Option value.
   */
  private def readValue[T](path: String, v: => T): Option[T] = {
    try {
      Option(v)
    } catch {
      case e: ConfigException.Missing => None
      case NonFatal(e) => throw reportError(path, e.getMessage, Some(e))
    }
  }

  /**
   * Retrieves a configuration value as a `String`.
   *
   * This method supports an optional set of valid values:
   * {{{
   * val config = Configuration.load()
   * val mode = config.getString("engine.mode", Some(Set("dev","prod")))
   * }}}
   *
   * A configuration error will be thrown if the configuration value does not match any of the required values.
   *
   * @param path the configuration key, relative to configuration root key
   * @param validValues valid values for this configuration
   * @return a configuration value
   */
  def getString(path: String, validValues: Option[Set[String]] = None): Option[String] = readValue(path, underlying.getString(path)).map { value =>
    validValues match {
      case Some(values) if values.contains(value) => value
      case Some(values) if values.isEmpty => value
      case Some(values) => throw reportError(path, "Incorrect value, one of " + (values.reduceLeft(_ + ", " + _)) + " was expected.")
      case None => value
    }
  }

  /**
   * Retrieves a configuration value as an `Int`.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val poolSize = configuration.getInt("engine.pool.size")
   * }}}
   *
   * A configuration error will be thrown if the configuration value is not a valid `Int`.
   *
   * @param path the configuration key, relative to the configuration root key
   * @return a configuration value
   */
  def getInt(path: String): Option[Int] = readValue(path, underlying.getInt(path))

  /**
   * Retrieves a configuration value as a `Boolean`.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val isEnabled = configuration.getBoolean("engine.isEnabled")
   * }}}
   *
   * A configuration error will be thrown if the configuration value is not a valid `Boolean`.
   * Authorized vales are `yes/no or true/false.
   *
   * @param path the configuration key, relative to the configuration root key
   * @return a configuration value
   */
  def getBoolean(path: String): Option[Boolean] = readValue(path, underlying.getBoolean(path))

  /**
   * Retrieves a configuration value as `Milliseconds`.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val timeout = configuration.getMilliseconds("engine.timeout")
   * }}}
   *
   * The configuration must be provided as:
   *
   * {{{
   * engine.timeout = 1 second
   * }}}
   */
  def getMilliseconds(path: String): Option[Long] = readValue(path, underlying.getMilliseconds(path))

  /**
   * Retrieves a configuration value as `Nanoseconds`.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val timeout = configuration.getNanoseconds("engine.timeout")
   * }}}
   *
   * The configuration must be provided as:
   *
   * {{{
   * engine.timeout = 1 second
   * }}}
   */
  def getNanoseconds(path: String): Option[Long] = readValue(path, underlying.getNanoseconds(path))

  /**
   * Retrieves a configuration value as `Bytes`.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val maxSize = configuration.getString("engine.maxSize")
   * }}}
   *
   * The configuration must be provided as:
   *
   * {{{
   * engine.maxSize = 512k
   * }}}
   */
  def getBytes(path: String): Option[Long] = readValue(path, underlying.getBytes(path))

  /**
   * Retrieves a sub-configuration, i.e. a configuration instance containing all keys starting with a given prefix.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val engineConfig = configuration.getSub("engine")
   * }}}
   *
   * The root key of this new configuration will be ‘engine’, and you can access any sub-keys relatively.
   *
   * @param path the root prefix for this sub-configuration
   * @return a new configuration
   */
  def getConfig(path: String): Option[Configuration] = readValue(path, underlying.getConfig(path)).map(Configuration(_))

  /**
   * Retrieves a configuration value as a `Double`.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val population = configuration.getDouble("world.population")
   * }}}
   *
   * A configuration error will be thrown if the configuration value is not a valid `Double`.
   *
   * @param path the configuration key, relative to the configuration root key
   * @return a configuration value
   */
  def getDouble(path: String): Option[Double] = readValue(path, underlying.getDouble(path))

  /**
   * Retrieves a configuration value as a `Long`.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val duration = configuration.getLong("timeout.duration")
   * }}}
   *
   * A configuration error will be thrown if the configuration value is not a valid `Long`.
   *
   * @param path the configuration key, relative to the configuration root key
   * @return a configuration value
   */
  def getLong(path: String): Option[Long] = readValue(path, underlying.getLong(path))

  /**
   * Retrieves a configuration value as a `Number`.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val counter = configuration.getNumber("foo.counter")
   * }}}
   *
   * A configuration error will be thrown if the configuration value is not a valid `Number`.
   *
   * @param path the configuration key, relative to the configuration root key
   * @return a configuration value
   */
  def getNumber(path: String): Option[Number] = readValue(path, underlying.getNumber(path))

  /**
   * Retrieves a configuration value as a List of `Boolean`.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val switches = configuration.getBooleanList("board.switches")
   * }}}
   *
   * The configuration must be provided as:
   *
   * {{{
   * board.switches = [true, true, false]
   * }}}
   *
   * A configuration error will be thrown if the configuration value is not a valid `Boolean`.
   * Authorized vales are `yes/no or true/false.
   */
  def getBooleanList(path: String): Option[java.util.List[java.lang.Boolean]] = readValue(path, underlying.getBooleanList(path))

  /**
   * Retrieves a configuration value as a List of `Bytes`.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val maxSizes = configuration.getBytesList("engine.maxSizes")
   * }}}
   *
   * The configuration must be provided as:
   *
   * {{{
   * engine.maxSizes = [512k, 256k, 256k]
   * }}}
   */
  def getBytesList(path: String): Option[java.util.List[java.lang.Long]] = readValue(path, underlying.getBytesList(path))

  /**
   * Retrieves a List of sub-configurations, i.e. a configuration instance for each key that matches the path.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val engineConfigs = configuration.getConfigList("engine")
   * }}}
   *
   * The root key of this new configuration will be "engine", and you can access any sub-keys relatively.
   */
  def getConfigList(path: String): Option[java.util.List[Configuration]] = readValue[java.util.List[_ <: Config]](path, underlying.getConfigList(path)).map { configs => configs.asScala.map(Configuration(_)).asJava }

  /**
   * Retrieves a configuration value as a List of `Double`.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val maxSizes = configuration.getDoubleList("engine.maxSizes")
   * }}}
   *
   * The configuration must be provided as:
   *
   * {{{
   * engine.maxSizes = [5.0, 3.34, 2.6]
   * }}}
   */
  def getDoubleList(path: String): Option[java.util.List[java.lang.Double]] = readValue(path, underlying.getDoubleList(path))

  /**
   * Retrieves a configuration value as a List of `Integer`.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val maxSizes = configuration.getIntList("engine.maxSizes")
   * }}}
   *
   * The configuration must be provided as:
   *
   * {{{
   * engine.maxSizes = [100, 500, 2]
   * }}}
   */
  def getIntList(path: String): Option[java.util.List[java.lang.Integer]] = readValue(path, underlying.getIntList(path))

  /**
   * Gets a list value (with any element type) as a ConfigList, which implements java.util.List<ConfigValue>.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val maxSizes = configuration.getList("engine.maxSizes")
   * }}}
   *
   * The configuration must be provided as:
   *
   * {{{
   * engine.maxSizes = ["foo", "bar"]
   * }}}
   */
  def getList(path: String): Option[ConfigList] = readValue(path, underlying.getList(path))

  /**
   * Retrieves a configuration value as a List of `Long`.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val maxSizes = configuration.getLongList("engine.maxSizes")
   * }}}
   *
   * The configuration must be provided as:
   *
   * {{{
   * engine.maxSizes = [10000000000000, 500, 2000]
   * }}}
   */
  def getLongList(path: String): Option[java.util.List[java.lang.Long]] = readValue(path, underlying.getLongList(path))

  /**
   * Retrieves a configuration value as List of `Milliseconds`.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val timeouts = configuration.getMillisecondsList("engine.timeouts")
   * }}}
   *
   * The configuration must be provided as:
   *
   * {{{
   * engine.timeouts = [1 second, 1 second]
   * }}}
   */
  def getMillisecondsList(path: String): Option[java.util.List[java.lang.Long]] = readValue(path, underlying.getMillisecondsList(path))

  /**
   * Retrieves a configuration value as List of `Nanoseconds`.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val timeouts = configuration.getNanosecondsList("engine.timeouts")
   * }}}
   *
   * The configuration must be provided as:
   *
   * {{{
   * engine.timeouts = [1 second, 1 second]
   * }}}
   */
  def getNanosecondsList(path: String): Option[java.util.List[java.lang.Long]] = readValue(path, underlying.getNanosecondsList(path))

  /**
   * Retrieves a configuration value as a List of `Number`.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val maxSizes = configuration.getNumberList("engine.maxSizes")
   * }}}
   *
   * The configuration must be provided as:
   *
   * {{{
   * engine.maxSizes = [50, 500, 5000]
   * }}}
   */
  def getNumberList(path: String): Option[java.util.List[java.lang.Number]] = readValue(path, underlying.getNumberList(path))

  /**
   * Retrieves a configuration value as a List of `ConfigObject`.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val engineProperties = configuration.getObjectList("engine.properties")
   * }}}
   *
   * The configuration must be provided as:
   *
   * {{{
   * engine.properties = [{id: 5, power: 3}, {id: 6, power: 20}]
   * }}}
   */
  def getObjectList(path: String): Option[java.util.List[_ <: ConfigObject]] = readValue[java.util.List[_ <: ConfigObject]](path, underlying.getObjectList(path))

  /**
   * Retrieves a configuration value as a List of `String`.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val names = configuration.getStringList("names")
   * }}}
   *
   * The configuration must be provided as:
   *
   * {{{
   * names = ["Jim", "Bob", "Steve"]
   * }}}
   */
  def getStringList(path: String): Option[java.util.List[java.lang.String]] = readValue(path, underlying.getStringList(path))

  /**
   * Retrieves a ConfigObject for this path, which implements Map<String,ConfigValue>
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val engineProperties = configuration.getObject("engine.properties")
   * }}}
   *
   * The configuration must be provided as:
   *
   * {{{
   * engine.properties = {id: 1, power: 5}
   * }}}
   */
  def getObject(path: String): Option[ConfigObject] = readValue(path, underlying.getObject(path))

  /**
   * Returns available keys.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val keys = configuration.keys
   * }}}
   *
   * @return the set of keys available in this configuration
   */
  def keys: Set[String] = underlying.entrySet.asScala.map(_.getKey).toSet

  /**
   * Returns sub-keys.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * val subKeys = configuration.subKeys
   * }}}
   * @return the set of direct sub-keys available in this configuration
   */
  def subKeys: Set[String] = underlying.root().keySet().asScala.toSet

  /**
   * Returns every path as a set of key to value pairs, by recursively iterating through the
   * config objects.
   */
  def entrySet: Set[(String, ConfigValue)] = underlying.entrySet().asScala.map(e => e.getKey -> e.getValue).toSet

  /**
   * Creates a configuration error for a specific configuration key.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * throw configuration.reportError("engine.connectionUrl", "Cannot connect!")
   * }}}
   *
   * @param path the configuration key, related to this error
   * @param message the error message
   * @param e the related exception
   * @return a configuration exception
   */
  def reportError(path: String, message: String, e: Option[Throwable] = None): PlayException = {
    Configuration.configError(if (underlying.hasPath(path)) underlying.getValue(path).origin else underlying.root.origin, message, e)
  }

  /**
   * Creates a configuration error for this configuration.
   *
   * For example:
   * {{{
   * val configuration = Configuration.load()
   * throw configuration.globalError("Missing configuration key: [yop.url]")
   * }}}
   *
   * @param message the error message
   * @param e the related exception
   * @return a configuration exception
   */
  def globalError(message: String, e: Option[Throwable] = None): PlayException = {
    Configuration.configError(underlying.root.origin, message, e)
  }

}