/**
  * The MIT License (MIT)
  *
  * Copyright (c) 2013-2015 Andrew Snare, Age Mooij
  *
  * 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 gh
import spray.json._

/**
  * A custom version of the Spray DefaultJsonProtocol with a modified field naming strategy
  */
trait SnakifiedSprayJsonSupport extends DefaultJsonProtocol {
  import reflect._

  /**
    * This is the most important piece of code in this object!
    * It overrides the default naming scheme used by spray-json and replaces it with a scheme that turns camelcased
    * names into snakified names (i.e. using underscores as word separators).
    */
  override protected def extractFieldNames(classTag: ClassTag[_]) = {
    import java.util.Locale

    def snakify(name: String) = {
      val pass1 = """([A-Z]+)([A-Z][a-z])""".r.replaceAllIn(name, "$1_$2")
      val pass2 = """([a-z\d])([A-Z])""".r.replaceAllIn(pass1, "$1_$2")

      pass2.toLowerCase(Locale.US)
    }

    super.extractFieldNames(classTag).map{ snakify(_) }
  }
}

object SnakifiedSprayJsonSupport extends SnakifiedSprayJsonSupport