fetcher.scala

package com.swipr.lib

import dispatch._
import net.liftweb.json._
import java.net.URL

package Google.ImageSearch {
  case class Result(url: String)
  case class SearchResponse(results: List[Result])
  case class SearchEnvelope(responseData: SearchResponse,
                            responseDetails: Option[Map[String,Any]],
                            responseStatus: Int)
}                            
  
object GoogleImageFetcher {
  import Google.ImageSearch._
  lazy val http = new Http
  val endpoint = :/("ajax.googleapis.com") / 
                 "ajax" / 
                 "services" /
                 "search" /
                 "images"

  def requestForImages(q: String) = 
    endpoint <<? Map("v" -> "1.0",
                     "q" -> q) secure

  def queryResults(q: String): Option[SearchEnvelope] = {
    implicit val formats = DefaultFormats
    http(requestForImages(q) >- 
         { (body) => 
           JsonParser.parse(body).extractOpt[Google.ImageSearch.SearchEnvelope]
         })
  }

  def apply(q: String): List[URL] = {
    queryResults(q) match {
      case None => List()
      case Some(x) => x.responseData.results.map( (r) => new URL(r.url) )
    }
  }
}