package com.weEat.controllers

import java.util.Base64
import javax.inject.{Inject,Singleton}
import play.api.mvc._
import play.api.libs.json._
import com.weEat.services.OAuth2Service
import com.weEat.models.{Authorization,User}
import com.weEat.shared.models.UserRegistration
import scalaoauth2.provider._
import scala.concurrent.Future
import scala.util.{Success,Failure}
import org.mongodb.scala.ObservableImplicits
import com.weEat.services.MongoDBService
import org.mongodb.scala.model.Filters._
import org.bson.types.ObjectId

@Singleton
class UserController @Inject()(
  val controllerComponents: ControllerComponents,
  oauth: OAuth2Service,
  db: MongoDBService
) extends BaseController
    with OAuth2Provider
    with ObservableImplicits
    with OAuth2ProviderActionBuilders {

  implicit val ec = scala.concurrent.ExecutionContext.global

  import db.withCollection

  override val tokenEndpoint = new TokenEndpoint {
    override val handlers = Map(
      //OAuthGrantType.AUTHORIZATION_CODE -> new AuthorizationCode(),
      OAuthGrantType.REFRESH_TOKEN -> new RefreshToken(),
      //OAuthGrantType.CLIENT_CREDENTIALS -> new ClientCredentials(),
      //OAuthGrantType.IMPLICIT -> new Implicit(),
      OAuthGrantType.PASSWORD -> new Password()
    )
  }

  def encodeBasicAuth(email: String, pass: String) =
    s"Basic " + Base64.getEncoder().encodeToString(s"$email:$pass".getBytes())

  def decodeBasicAuth(auth: String): Option[(String, String)] = {
    val format = raw"Basic ([\d\w+/=]*)".r
    auth match {
      case format(cred) => {
        val split = new String(Base64.getDecoder().decode(cred)).split(":", 2)
        Some((split(0), split(1)))
      }
      case _ => None
    }
  }

  def accessToken = Action.async { implicit request: Request[Any] =>
    issueAccessToken(oauth)
  }

  def revokeAccessToken() =
    AuthorizedAction[Authorization](oauth).async(parse.json)
  { implicit request: AuthInfoRequest[JsValue, Authorization] =>
    val email = (request.body \ "client_id").as[String]
    val refresh = (request.body \ "refresh_token").as[String]
    oauth.revokeAccessToken(request.authInfo, email, refresh).transform {
      case Success(_) => Success(
        Ok("").withHeaders("Cache-Control" -> "no-store", "Pragma" -> "no-cache")
      )
      case Failure(e: OAuthError) => Success(
        new Status(e.statusCode)(responseOAuthErrorJson(e))
          .withHeaders(responseOAuthErrorHeader(e))
      )
      case Failure(e) => Failure(e)
    }
  }

  private val emailRegex = """(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*|"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])"""
  private def isEmail(email: String): Boolean = email.matches(emailRegex)

  // private def checkEmail(conn: Connection, email: String): Future[Boolean] = {
  //   val emailquery = "SELECT id FROM users WHERE email=? LIMIT 1"
  //   Future {
  //     TryWith(conn.prepareStatement(emailquery)) { st =>
  //       st.setString(1, email)
  //       st.executeQuery.next
  //     }
  //   }.transform(_.flatten)
  // }

  def validateRegisterRequest(body: UserRegistration) = 
    if (!isEmail(body.email))
      Some("Invalid email.")
    else if (body.password.length < 8)
      Some("Password too short (Minimum 8 characters).")
    else
      None

  // TODO: Unit test API
  def registerUser() = Action.async(parse.json)
  { implicit request: Request[JsValue] =>
    val body = request.body.as[UserRegistration]
    validateRegisterRequest(body) match {
      case Some(reason) => Future.successful(BadRequest(reason))
      case None => {
        val user = User(body)
        withCollection(User) { collection =>
          {
          collection.insertOne(user).head().map(_ =>
            {
            issueAccessToken(oauth)(Request[Map[String, Seq[String]]](
              request.withHeaders(Headers(
                "Authorization" -> encodeBasicAuth(user.email, body.password)
              )),
              Map("grant_type" -> Seq(OAuthGrantType.PASSWORD))
            ), ec)}
          ).flatten}
        }.flatten
      }
    }
  }

  def getName() = AuthorizedAction[Authorization](oauth).async
  { implicit request: AuthInfoRequest[AnyContent, Authorization] =>
    getUser(request.authInfo.user.userId).map({
      case Some(user) => Ok("%s %s".format(user.fname, user.lname))
      case None =>
        throw new IllegalStateException("Authorized user does not exist!")
    })
  }

  // TODO: Unit test API
  def getUsers() = Action.async
  { implicit request: Request[AnyContent] =>
    withCollection(User) { collection =>
      collection.find().map(res => res.email)
        .toFuture()
        .transform({
          case Success(x) => Success(Ok(Json.toJson(x)))
          case Failure(x) => throw x
      })
    }.flatten
  }

  def getUser(id: ObjectId): Future[Option[User]] = withCollection(User) { users =>
    users.find(equal("_id", id))
      .first()
      .toFutureOption()
  }.flatten

  def get(id: String) = Action.async { implicit request: Request[AnyContent] =>
    getUser(new ObjectId(id)).map({
      case Some(user) => Ok(Json.toJson(user.toShared()))
      case None => NotFound("No such user with this id")
    })
  }

  def deleteUser(id: ObjectId) = {
    withCollection(User) { (collection) =>
      collection.findOneAndDelete(equal("_id", id))
        .toFuture()
      }
  }.flatten
}