/*
 * 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.
 */

package org.apache.texera.amber.operator.source.fetcher

import org.apache.texera.amber.core.executor.SourceOperatorExecutor
import org.apache.texera.amber.core.tuple.TupleLike
import org.apache.texera.amber.operator.source.fetcher.URLFetchUtil.getInputStreamFromURL
import org.apache.texera.amber.util.JSONUtils.objectMapper
import org.apache.commons.io.IOUtils

import java.net.URL

class URLFetcherOpExec(descString: String) extends SourceOperatorExecutor {
  private val desc: URLFetcherOpDesc = objectMapper.readValue(descString, classOf[URLFetcherOpDesc])
  override def produceTuple(): Iterator[TupleLike] = {

    val urlObj = new URL(desc.url)
    val input = getInputStreamFromURL(urlObj)
    val contentInputStream = input match {
      case Some(value) => value
      case None        => IOUtils.toInputStream(s"Fetch failed for URL: $desc.url", "UTF-8")
    }
    Iterator(if (desc.decodingMethod == DecodingMethod.UTF_8) {
      TupleLike(IOUtils.toString(contentInputStream, "UTF-8"))
    } else {
      TupleLike(IOUtils.toByteArray(contentInputStream))
    })
  }
}
