/*
 * Copyright 2019, gRPC Authors All rights reserved.
 *
 * Licensed 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 Foundation
import GRPC
import NIO
import RouteGuideModel
import Logging

// Quieten the logs.
LoggingSystem.bootstrap {
  var handler = StreamLogHandler.standardOutput(label: $0)
  handler.logLevel = .critical
  return handler
}

/// Makes a `RouteGuide` client for a service hosted on "localhost" and listening on the given port.
func makeClient(port: Int, group: EventLoopGroup) -> Routeguide_RouteGuideClient {
  let channel = ClientConnection.insecure(group: group)
    .connect(host: "localhost", port: port)

  return Routeguide_RouteGuideClient(channel: channel)
}

/// Unary call example. Calls `getFeature` and prints the response.
func getFeature(using client: Routeguide_RouteGuideClient, latitude: Int, longitude: Int) {
  print("→ GetFeature: lat=\(latitude) lon=\(longitude)")

  let point: Routeguide_Point = .with {
    $0.latitude = numericCast(latitude)
    $0.longitude = numericCast(longitude)
  }

  let call = client.getFeature(point)
  let feature: Routeguide_Feature

  do {
    feature = try call.response.wait()
  } catch {
    print("RPC failed: \(error)")
    return
  }

  let lat = feature.location.latitude
  let lon = feature.location.longitude

  if !feature.name.isEmpty {
    print("Found feature called '\(feature.name)' at \(lat), \(lon)")
  } else {
    print("Found no feature at \(lat), \(lon)")
  }
}

/// Server-streaming example. Calls `listFeatures` with a rectangle of interest. Prints each
/// response feature as it arrives.
func listFeatures(
  using client: Routeguide_RouteGuideClient,
  lowLatitude: Int,
  lowLongitude: Int,
  highLatitude: Int,
  highLongitude: Int
) {
  print("→ ListFeatures: lowLat=\(lowLatitude) lowLon=\(lowLongitude), hiLat=\(highLatitude) hiLon=\(highLongitude)")

  let rectangle: Routeguide_Rectangle = .with {
    $0.lo = .with {
      $0.latitude = numericCast(lowLatitude)
      $0.longitude = numericCast(lowLongitude)
    }
    $0.hi = .with {
      $0.latitude = numericCast(highLatitude)
      $0.longitude = numericCast(highLongitude)
    }
  }

  var resultCount = 1
  let call = client.listFeatures(rectangle) { feature in
    print("Result #\(resultCount): \(feature)")
    resultCount += 1
  }

  let status = try! call.status.recover { _ in .processingError }.wait()
  if status.code != .ok {
    print("RPC failed: \(status)")
  }
}

/// Client-streaming example. Sends `featuresToVisit` randomly chosen points from `features` with
/// a variable delay in between. Prints the statistics when they are sent from the server.
public func recordRoute(
  using client: Routeguide_RouteGuideClient,
  features: [Routeguide_Feature],
  featuresToVisit: Int
) {
  print("→ RecordRoute")
  let options = CallOptions(timeout: .minutes(rounding: 1))
  let call = client.recordRoute(callOptions: options)

  call.response.whenSuccess { summary in
    print(
      "Finished trip with \(summary.pointCount) points. Passed \(summary.featureCount) features. " +
      "Travelled \(summary.distance) meters. It took \(summary.elapsedTime) seconds."
    )
  }

  call.response.whenFailure { error in
    print("RecordRoute Failed: \(error)")
  }

  call.status.whenComplete { _ in
    print("Finished RecordRoute")
  }

  for _ in 0..<featuresToVisit {
    let index = Int.random(in: 0..<features.count)
    let point = features[index].location
    print("Visiting point \(point.latitude), \(point.longitude)")
    call.sendMessage(point, promise: nil)

    // Sleep for a bit before sending the next one.
    Thread.sleep(forTimeInterval: TimeInterval.random(in: 0.5..<1.5))
  }

  call.sendEnd(promise: nil)

  // Wait for the call to end.
  _ = try! call.status.wait()
}

/// Bidirectional example. Send some chat messages, and print any chat messages that are sent from
/// the server.
func routeChat(using client: Routeguide_RouteGuideClient) {
  print("→ RouteChat")

  let call = client.routeChat { note in
    print("Got message \"\(note.message)\" at \(note.location.latitude), \(note.location.longitude)")
  }

  call.status.whenSuccess { status in
    if status.code == .ok {
      print("Finished RouteChat")
    } else {
      print("RouteChat Failed: \(status)")
    }
  }

  let noteContent = [
    ("First message", 0, 0),
    ("Second message", 0, 1),
    ("Third message", 1, 0),
    ("Fourth message", 1, 1)
  ]

  for (message, latitude, longitude) in noteContent {
    let note: Routeguide_RouteNote = .with {
      $0.message = message
      $0.location = .with {
        $0.latitude = Int32(latitude)
        $0.longitude = Int32(longitude)
      }
    }

    print("Sending message \"\(note.message)\" at \(note.location.latitude), \(note.location.longitude)")
    call.sendMessage(note, promise: nil)
  }
  // Mark the end of the stream.
  call.sendEnd(promise: nil)

  // Wait for the call to end.
  _ = try! call.status.wait()
}

/// Loads the features from `route_guide_db.json`, assumed to be in the directory above this file.
func loadFeatures() throws -> [Routeguide_Feature] {
  let url = URL(fileURLWithPath: #file)
    .deletingLastPathComponent()  // main.swift
    .deletingLastPathComponent()  // Client/
    .appendingPathComponent("route_guide_db.json")

  let data = try Data(contentsOf: url)
  return try Routeguide_Feature.array(fromJSONUTF8Data: data)
}

func main(args: [String]) throws {
  // arg0 (dropped) is the program name. We expect arg1 to be the port.
  guard case .some(let port) = args.dropFirst(1).first.flatMap(Int.init) else {
    print("Usage: \(args[0]) PORT")
    exit(1)
  }

  // Load the features.
  let features = try loadFeatures()

  let group = MultiThreadedEventLoopGroup(numberOfThreads: 1)
  defer {
    try? group.syncShutdownGracefully()
  }

  // Make a client, make sure we close it when we're done.
  let routeGuide = makeClient(port: port, group: group)
  defer {
    try? routeGuide.channel.close().wait()
  }

  // Look for a valid feature.
  getFeature(using: routeGuide, latitude: 409146138, longitude: -746188906)

  // Look for a missing feature.
  getFeature(using: routeGuide, latitude: 0, longitude: 0)

  // Looking for features between 40, -75 and 42, -73.
  listFeatures(
    using: routeGuide,
    lowLatitude: 400000000,
    lowLongitude: -750000000,
    highLatitude: 420000000,
    highLongitude: -730000000
  )

  // Record a few randomly selected points from the features file.
  recordRoute(using: routeGuide, features: features, featuresToVisit: 10)

  // Send and receive some notes.
  routeChat(using: routeGuide)
}

try main(args: CommandLine.arguments)