1 files changed, 227 insertions, 0 deletions
diff --git a/Scala/example/project/CourseraHttp.scala b/Scala/example/project/CourseraHttp.scala
new file mode 100644
index 0000000..792c2bf
--- /dev/null
+++ b/Scala/example/project/CourseraHttp.scala
@@ -0,0 +1,227 @@
+import dispatch.{Request, Http, NoLogging, StatusCode, url}
+import cc.spray.json.{JsNull, JsonParser, DefaultJsonProtocol, JsValue}
+import RichJsValue._
+import org.apache.commons.codec.digest.DigestUtils
+import org.apache.commons.codec.binary.{Hex, Base64}
+import java.io.{IOException, File, FileInputStream}
+import scalaz.Scalaz.{mkIdentity, ValidationNEL}
+
+import Settings._
+
+case class JsonSubmission(api_state: String, user_info: JsValue, submission_metadata: JsValue, solutions: JsValue, submission_encoding: String, submission: String)
+//case class JsonQueueResult(submission: JsonSubmission)
+object SubmitJsonProtocol extends DefaultJsonProtocol {
+  implicit val jsonSubmissionFormat = jsonFormat6(JsonSubmission)
+//  implicit val jsonQueueResultFormat = jsonFormat1(JsonQueueResult)
+}
+
+object CourseraHttp {
+  private lazy val http = new Http with NoLogging
+
+  private def executeRequest[T](req: Request)(parse: String => ValidationNEL[String, T]): ValidationNEL[String, T] = {
+    try {
+      http(req >- { res =>
+        parse(res)
+      })
+    } catch {
+      case ex: IOException =>
+        ("Connection failed\n"+ ex.toString()).failNel
+      case StatusCode(code, message) =>
+        ("HTTP failed with status "+ code +"\n"+ message).failNel
+    }
+  }
+
+
+  /******************************
+   * SUBMITTING
+   */
+
+  def getChallenge(email: String, submitProject: ProjectDetails): ValidationNEL[String, Challenge] = {
+    val baseReq = url(challengeUrl(submitProject.courseId))
+    val withArgs = baseReq << Map("email_address" -> email,
+                                  "assignment_part_sid" -> submitProject.assignmentPartId,
+                                  "response_encoding" -> "delim")
+
+    executeRequest(withArgs) { res =>
+      // example result. there might be an `aux_data` value at the end.
+      // |email_address|a@b.com|challenge_key|XXYYXXYYXXYY|state|XXYYXXYYXXYY|challenge_aux_data|
+      val parts = res.split('|').filterNot(_.isEmpty)
+      if (parts.length < 7)
+        ("Unexpected challenge format: \n"+ res).failNel
+      else
+        Challenge(parts(1), parts(3), parts(5)).successNel
+    }
+  }
+
+  def submitSolution(sourcesJar: File, submitProject: ProjectDetails, challenge: Challenge, chResponse: String): ValidationNEL[String, String] = {
+    val fileLength = sourcesJar.length()
+    if (!sourcesJar.exists()) {
+      ("Sources jar archive does not exist\n"+ sourcesJar.getAbsolutePath).failNel
+    } else if (fileLength == 0l) {
+      ("Sources jar archive is empty\n"+ sourcesJar.getAbsolutePath).failNel
+    } else if (fileLength > maxSubmitFileSize) {
+      ("Sources jar archive is too big. Allowed size: "+
+        maxSubmitFileSize +" bytes, found "+ fileLength +" bytes.\n"+
+        sourcesJar.getAbsolutePath).failNel
+    } else {
+      val bytes = new Array[Byte](fileLength.toInt)
+      val sizeRead = try {
+        val is = new FileInputStream(sourcesJar)
+        val read = is.read(bytes)
+        is.close()
+        read
+      } catch {
+        case ex: IOException =>
+          ("Failed to read sources jar archive\n"+ ex.toString()).failNel
+      }
+      if (sizeRead != bytes.length) {
+        ("Failed to read the sources jar archive, size read: "+ sizeRead).failNel
+      } else {
+        val fileData = encodeBase64(bytes)
+        val surl = submitUrl(submitProject.courseId)
+        println("courseId: " + submitProject.courseId)
+        println("submitUrl: " + surl)
+        val baseReq = url(submitUrl(submitProject.courseId))
+        println(baseReq)
+        val withArgs = baseReq << Map("assignment_part_sid" -> submitProject.assignmentPartId,
+                                      "email_address" -> challenge.email,
+                                      "submission" -> fileData,
+                                      "submission_aux" -> "",
+                                      "challenge_response" -> chResponse,
+                                      "state" -> challenge.state)
+        executeRequest(withArgs) { res =>
+          // the API returns HTTP 200 even if there are failures, how impolite...
+          if (res.contains("Your submission has been accepted"))
+            res.successNel
+          else
+            res.failNel
+        }
+      }
+    }
+  }
+
+  def challengeResponse(challenge: Challenge, otPassword: String): String =
+    shaHexDigest(challenge.challengeKey + otPassword)
+
+
+  /********************************
+   * DOWNLOADING SUBMISSIONS
+   */
+
+  // def downloadFromQueue(queue: String, targetJar: File, apiKey: String): ValidationNEL[String, QueueResult] = {
+  //   val baseReq = url(Settings.submitQueueUrl)
+  //   val withArgsAndHeader = baseReq << Map("queue" -> queue) <:< Map("X-api-key" -> apiKey)
+
+  //   executeRequest(withArgsAndHeader) { res =>
+  //     extractJson(res, targetJar)
+  //   }
+  // }
+
+  def readJsonFile(jsonFile: File, targetJar: File): ValidationNEL[String, QueueResult] = {
+    extractJson(sbt.IO.read(jsonFile), targetJar)
+  }
+
+  def extractJson(jsonData: String, targetJar: File): ValidationNEL[String, QueueResult] = {
+    import SubmitJsonProtocol._
+    for {
+      jsonSubmission <- {
+        try {
+          val parsed = JsonParser(jsonData)
+          val submission = parsed \ "submission"
+          if (submission == JsNull) {
+            ("Nothing to grade, queue is empty.").failNel
+          } else {
+            submission.convertTo[JsonSubmission].successNel
+          }
+        } catch {
+          case e: Exception =>
+            ("Could not parse submission\n"+ jsonData +"\n"+ fullExceptionString(e)).failNel
+        }
+      }
+      queueResult <- {
+        val encodedFile = jsonSubmission.submission
+        val jarContent = decodeBase64(encodedFile)
+        try {
+          sbt.IO.write(targetJar, jarContent)
+          QueueResult(jsonSubmission.api_state).successNel
+        } catch {
+          case e: IOException =>
+            ("Failed to write jar file to "+ targetJar.getAbsolutePath +"\n"+ e.toString).failNel
+        }
+      }
+    } yield queueResult
+  }
+
+  def unpackJar(file: File, targetDirectory: File): ValidationNEL[String, Unit] = {
+    try {
+      val files = sbt.IO.unzip(file, targetDirectory)
+      if (files.isEmpty)
+        ("No files found when unpacking jar file "+ file.getAbsolutePath).failNel
+      else
+        ().successNel
+    } catch {
+      case e: IOException =>
+        val msg = "Error while unpacking the jar file "+ file.getAbsolutePath +" to "+ targetDirectory.getAbsolutePath +"\n"+ e.toString
+        if (Settings.offlineMode) {
+          println("[offline mode] "+ msg)
+          ().successNel
+        } else {
+          msg.failNel
+        }
+    }
+  }
+
+
+  /********************************
+   * SUBMITTING GRADES
+   */
+
+  def submitGrade(feedback: String, score: String, apiState: String, apiKey: String, gradeProject: ProjectDetails): ValidationNEL[String, Unit] = {
+    import DefaultJsonProtocol._
+    val baseReq = url(Settings.uploadFeedbackUrl(gradeProject.courseId))
+    val withArgs = baseReq << Map("api_state" -> apiState, "score" -> score, "feedback" -> feedback) <:< Map("X-api-key" -> apiKey)
+    executeRequest(withArgs) { res =>
+      try {
+        val js = JsonParser(res)
+        val status = (js \ "status").convertTo[String]
+        if (status == "202")
+          ().successNel
+        else
+          ("Unexpected result from submit request: "+ status).failNel
+      } catch {
+        case e: Exception =>
+          ("Failed to parse response while submitting grade\n"+ res +"\n"+ fullExceptionString(e)).failNel
+      }
+    }
+  }
+
+
+  /*********************************
+   * TOOLS AND STUFF
+   */
+
+  def shaHexDigest(s: String): String = {
+    val chars = Hex.encodeHex(DigestUtils.sha(s))
+    new String(chars)
+  }
+
+
+  def fullExceptionString(e: Throwable) =
+    e.toString +"\n"+ e.getStackTrace.map(_.toString).mkString("\n")
+
+
+  /* Base 64 tools */
+
+  def encodeBase64(bytes: Array[Byte]): String =
+    new String(Base64.encodeBase64(bytes))
+
+  def decodeBase64(str: String): Array[Byte] = {
+    // codecs 1.4 has a version accepting a string, but not 1.2; jar hell.
+    Base64.decodeBase64(str.getBytes)
+  }
+}
+
+case class Challenge(email: String, challengeKey: String, state: String)
+
+case class QueueResult(apiState: String)
+