package org.apache.esme.external

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.text._
import java.util.Locale.US

import org.apache.esme.model.User

object AtomFeed{
  val dateFormats = List(new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ", US),
                                  new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", US),
                                  new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ", US),
                                  new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", US))
}

class AtomFeed(user: User, atomURL: String, source: String, truncateChars: Int, tags: List[String])
  extends Feed(user, atomURL, source, truncateChars, tags) {
  import scala.xml._
  
  override def dateFormats = AtomFeed.dateFormats
  
  override def getEntries(xml: NodeSeq) = xml \ "entry"
  
  override def getText(node: Node) = {
    // a title element is mandatory
    node \ "title" text
  }
  
  override def getLink(node: Node) = {
    // there must be either a link with @rel="alternate"
    // or a link without @rel or content
    val link = node \ "link"
    if (link isEmpty)
      node \ "content" text
    else {
      val alternate = link find(_ \ "@rel" xml_== "alternate")
      val anyLink = alternate getOrElse((link find(_ \ "@rel" isEmpty)).get)
      anyLink \ "@href" text
    }
  }
  
  override def getDate(node: Node) = {
    // parseInternetDate(node \ "published" text).getTime
    val published = node \ "published"
    val date = if (published isEmpty)
      node \ "updated"
      else published
    parseInternetDate(date text).map(_.getTime).getOrElse(System.currentTimeMillis)
  }
}