Show topic lessons (#332)

* Update launch screen

* Create lessons service

* Display lessons

* Handle lesson selection

* Create CourseService

* Create EnrollmentService

* Join courses

* Support cache in LessonsService

ExamEGERussian/Resources/Assets/Assets.xcassets/logo.imageset/Contents.json

@@ -0,0 +1,21 @@
+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "filename" : "logo.png",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}

ExamEGERussian/Sources/ApplicationLayer/AppDelegate/AppDelegate.swift

@@ -27,6 +27,9 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
             authAPI: AuthAPI(),
             stepicsAPI: StepicsAPI(),
             profilesAPI: ProfilesAPI(),
+            coursesAPI: CoursesAPI(),
+            enrollmentsAPI: EnrollmentsAPI(),
+            lessonsAPI: LessonsAPI(),
             defaultsStorageManager: DefaultsStorageManager(),
             randomCredentialsGenerator: RandomCredentialsGeneratorImplementation()
         )

ExamEGERussian/Sources/ApplicationLayer/RootNavigationManager/RootNavigationManager.swift

@@ -8,13 +8,13 @@
 
 import UIKit
 
-// MARK: RootNavigationManager
-
 final class RootNavigationManager {
 
-    // MARK: - Instance Variables
+    // MARK: - Instance Properties
 
     private unowned let serviceComponents: ServiceComponents
+    private weak var navigationController: UINavigationController?
+    private let knowledgeGraph = KnowledgeGraph()
 
     // MARK: Init
 
@@ -28,14 +28,44 @@ final class RootNavigationManager {
         let controller = TopicsTableViewController()
         controller.presenter = TopicsPresenterImpl(
             view: controller,
-            model: KnowledgeGraph(),
+            knowledgeGraph: knowledgeGraph,
+            router: self,
             userRegistrationService: serviceComponents.userRegistrationService,
             graphService: serviceComponents.graphService
         )
-        let navigationController = UINavigationController(rootViewController: controller)
+        navigationController = UINavigationController(rootViewController: controller)
 
         window.rootViewController = navigationController
         window.makeKeyAndVisible()
     }
 
 }
+
+// MARK: - RootNavigationManager: TopicsRouter -
+
+extension RootNavigationManager: TopicsRouter {
+    func showLessonsForTopicWithId(_ id: String) {
+        let controller = LessonsTableViewController()
+        let presenter = LessonsPresenterImpl(
+            view: controller,
+            router: self,
+            topicId: id,
+            knowledgeGraph: knowledgeGraph,
+            lessonsService: serviceComponents.lessonsService,
+            courseService: serviceComponents.courseService,
+            enrollmentService: serviceComponents.enrollmentService
+        )
+        controller.presenter = presenter
+        controller.title = knowledgeGraph[id]?.key.title
+
+        navigationController?.pushViewController(controller, animated: true)
+    }
+}
+
+// MARK: - RootNavigationManager: LessonsRouter -
+
+extension RootNavigationManager: LessonsRouter {
+    func showStepsForLessonWith(_ id: Int) {
+        print("\(#function) \(id)")
+    }
+}

ExamEGERussian/Sources/BusinessLogicLayer/Assemblies/ServiceComponentsAssembly/ServiceComponents.swift

@@ -11,4 +11,7 @@ import Foundation
 protocol ServiceComponents: class {
     var userRegistrationService: UserRegistrationService { get }
     var graphService: GraphService { get }
+    var lessonsService: LessonsService { get }
+    var courseService: CourseService { get }
+    var enrollmentService: EnrollmentService { get }
 }

ExamEGERussian/Sources/BusinessLogicLayer/Assemblies/ServiceComponentsAssembly/ServiceComponentsAssembly.swift

@@ -12,18 +12,27 @@ final class ServiceComponentsAssembly: ServiceComponents {
     private let authAPI: AuthAPI
     private let stepicsAPI: StepicsAPI
     private let profilesAPI: ProfilesAPI
+    private let coursesAPI: CoursesAPI
+    private let enrollmentsAPI: EnrollmentsAPI
+    private let lessonsAPI: LessonsAPI
     private let defaultsStorageManager: DefaultsStorageManager
     private let randomCredentialsGenerator: RandomCredentialsGenerator
 
     init(authAPI: AuthAPI,
          stepicsAPI: StepicsAPI,
          profilesAPI: ProfilesAPI,
+         coursesAPI: CoursesAPI,
+         enrollmentsAPI: EnrollmentsAPI,
+         lessonsAPI: LessonsAPI,
          defaultsStorageManager: DefaultsStorageManager,
          randomCredentialsGenerator: RandomCredentialsGenerator
         ) {
         self.authAPI = authAPI
         self.stepicsAPI = stepicsAPI
         self.profilesAPI = profilesAPI
+        self.coursesAPI = coursesAPI
+        self.enrollmentsAPI = enrollmentsAPI
+        self.lessonsAPI = lessonsAPI
         self.defaultsStorageManager = defaultsStorageManager
         self.randomCredentialsGenerator = randomCredentialsGenerator
     }
@@ -41,4 +50,16 @@ final class ServiceComponentsAssembly: ServiceComponents {
     var graphService: GraphService {
         return GraphServiceImpl()
     }
+
+    var lessonsService: LessonsService {
+        return LessonsServiceImpl(lessonsAPI: lessonsAPI)
+    }
+
+    var courseService: CourseService {
+        return CourseServiceImpl(coursesAPI: coursesAPI)
+    }
+
+    var enrollmentService: EnrollmentService {
+        return EnrollmentServiceImpl(enrollmentsAPI: enrollmentsAPI)
+    }
 }

ExamEGERussian/Sources/BusinessLogicLayer/Services/CourseService/CourseService.swift

@@ -0,0 +1,23 @@
+//
+//  CourseService.swift
+//  ExamEGERussian
+//
+//  Created by Ivan Magda on 26/07/2018.
+//  Copyright © 2018 Alex Karpov. All rights reserved.
+//
+
+import Foundation
+import PromiseKit
+
+protocol CourseService: class {
+    /// Method is used to fetch Course objects from Stepik API
+    ///
+    /// - Parameter ids: Ids Course objects
+    /// - Returns: Promise with a result of an array of Course objects from API.
+    func fetchCourses(with ids: [Int]) -> Promise<[Course]>
+    /// Method is used to obtain Course objects from cache with ids
+    ///
+    /// - Parameter ids: Ids Course objects
+    /// - Returns: Promise with a result of an array of Course objects from cache.
+    func obtainCourses(with ids: [Int]) -> Promise<[Course]>
+}

ExamEGERussian/Sources/BusinessLogicLayer/Services/CourseService/CourseServiceImpl.swift

@@ -0,0 +1,28 @@
+//
+//  CourseServiceImpl.swift
+//  ExamEGERussian
+//
+//  Created by Ivan Magda on 26/07/2018.
+//  Copyright © 2018 Alex Karpov. All rights reserved.
+//
+
+import Foundation
+import PromiseKit
+
+final class CourseServiceImpl: CourseService {
+    private let coursesAPI: CoursesAPI
+
+    init(coursesAPI: CoursesAPI) {
+        self.coursesAPI = coursesAPI
+    }
+
+    func fetchCourses(with ids: [Int]) -> Promise<[Course]> {
+        return obtainCourses(with: ids).then { courses in
+            self.coursesAPI.retrieve(ids: ids, existing: courses)
+        }
+    }
+
+    func obtainCourses(with ids: [Int]) -> Promise<[Course]> {
+        return Course.fetchAsync(ids)
+    }
+}

ExamEGERussian/Sources/BusinessLogicLayer/Services/EnrollmentService/EnrollmentService.swift

@@ -0,0 +1,18 @@
+//
+//  EnrollmentService.swift
+//  ExamEGERussian
+//
+//  Created by Ivan Magda on 26/07/2018.
+//  Copyright © 2018 Alex Karpov. All rights reserved.
+//
+
+import Foundation
+import PromiseKit
+
+protocol EnrollmentService: class {
+    /// Method is used to joining Course object with specified id.
+    ///
+    /// - Parameter course: Course to join.
+    /// - Returns: Promise when fullfilled.
+    func joinCourse(_ course: Course) -> Promise<Course>
+}

ExamEGERussian/Sources/BusinessLogicLayer/Services/EnrollmentService/EnrollmentServiceImpl.swift

@@ -0,0 +1,24 @@
+//
+//  EnrollmentServiceImpl.swift
+//  ExamEGERussian
+//
+//  Created by Ivan Magda on 26/07/2018.
+//  Copyright © 2018 Alex Karpov. All rights reserved.
+//
+
+import Foundation
+import PromiseKit
+
+final class EnrollmentServiceImpl: EnrollmentService {
+    private let enrollmentsAPI: EnrollmentsAPI
+
+    init(enrollmentsAPI: EnrollmentsAPI) {
+        self.enrollmentsAPI = enrollmentsAPI
+    }
+
+    func joinCourse(_ course: Course) -> Promise<Course> {
+        return enrollmentsAPI.joinCourse(course).then { _ -> Promise<Course> in
+            .value(course)
+        }
+    }
+}

ExamEGERussian/Sources/BusinessLogicLayer/Services/GraphService/GraphService.swift

@@ -10,5 +10,8 @@ import Foundation
 import PromiseKit
 
 protocol GraphService: class {
-    func obtainGraph() -> Promise<KnowledgeGraphPlainObject>
+    /// Method is used to fetch KnowledgeGraphPlainObject object from API.
+    ///
+    /// - Returns: Promise with a result of KnowledgeGraphPlainObject.
+    func fetchGraph() -> Promise<KnowledgeGraphPlainObject>
 }

ExamEGERussian/Sources/BusinessLogicLayer/Services/GraphService/GraphServiceImpl.swift

@@ -13,7 +13,7 @@ import Alamofire
 final class GraphServiceImpl: GraphService {
     private static let url = URL(string: "https://www.dropbox.com/s/l8n1wny8qu0gbqt/example.json?dl=1")!
 
-    func obtainGraph() -> Promise<KnowledgeGraphPlainObject> {
+    func fetchGraph() -> Promise<KnowledgeGraphPlainObject> {
         return Alamofire
             .request(GraphServiceImpl.url)
             .responseDecodable(KnowledgeGraphPlainObject.self)

ExamEGERussian/Sources/BusinessLogicLayer/Services/LessonsService/LessonsService.swift

@@ -0,0 +1,23 @@
+//
+//  LessonsService.swift
+//  ExamEGERussian
+//
+//  Created by Ivan Magda on 24/07/2018.
+//  Copyright © 2018 Alex Karpov. All rights reserved.
+//
+
+import Foundation
+import PromiseKit
+
+protocol LessonsService: class {
+    /// Method is used to fetch lessons from Stepik API.
+    ///
+    /// - Parameter ids: Lessons ids.
+    /// - Returns: Promise with an array of LessonPlainObjects.
+    func fetchLessons(with ids: [Int]) -> Promise<[LessonPlainObject]>
+    /// Method is used to obtain lessons from cache.
+    ///
+    /// - Parameter ids: Lessons ids.
+    /// - Returns: Promise with an array of cached LessonPlainObjects.
+    func obtainLessons(with ids: [Int]) -> Promise<[LessonPlainObject]>
+}

ExamEGERussian/Sources/BusinessLogicLayer/Services/LessonsService/LessonsServiceImpl.swift

@@ -0,0 +1,56 @@
+//
+//  LessonsServiceImpl.swift
+//  ExamEGERussian
+//
+//  Created by Ivan Magda on 24/07/2018.
+//  Copyright © 2018 Alex Karpov. All rights reserved.
+//
+
+import Foundation
+import CoreData
+import PromiseKit
+
+final class LessonsServiceImpl: LessonsService {
+    private let lessonsAPI: LessonsAPI
+
+    init(lessonsAPI: LessonsAPI) {
+        self.lessonsAPI = lessonsAPI
+    }
+
+    func fetchLessons(with ids: [Int]) -> Promise<[LessonPlainObject]> {
+        return executeFetchRequest(ids: ids)
+            .then { self.lessonsAPI.retrieve(ids: ids, existing: $0) }
+            .mapValues { self.toPlainObject($0) }
+    }
+
+    func obtainLessons(with ids: [Int]) -> Promise<[LessonPlainObject]> {
+        return executeFetchRequest(ids: ids).mapValues { self.toPlainObject($0) }
+    }
+
+    // MARK: - Private API
+
+    private func executeFetchRequest(ids: [Int]) -> Promise<[Lesson]> {
+        let request = NSFetchRequest<NSFetchRequestResult>(entityName: String(describing: Lesson.self))
+        let descriptor = NSSortDescriptor(key: "managedId", ascending: true)
+
+        let idPredicates = ids.map { NSPredicate(format: "managedId == %@", $0 as NSNumber) }
+        let predicate = NSCompoundPredicate(type: NSCompoundPredicate.LogicalType.or, subpredicates: idPredicates)
+        request.predicate = predicate
+        request.sortDescriptors = [descriptor]
+
+        return Promise<[Lesson]> { seal in
+            let asyncRequest = NSAsynchronousFetchRequest(fetchRequest: request, completionBlock: { results in
+                guard let lessons = results.finalResult as? [Lesson] else {
+                    seal.fulfill([])
+                    return
+                }
+                seal.fulfill(lessons)
+            })
+            _ = try? CoreDataHelper.instance.context.execute(asyncRequest)
+        }
+    }
+
+    private func toPlainObject(_ lesson: Lesson) -> LessonPlainObject {
+        return LessonPlainObject(id: lesson.id, steps: lesson.steps.map { $0.id }, title: lesson.title)
+    }
+}

ExamEGERussian/Sources/Model/PlainObjects/KnowledgeGraph/GoalPlainObject.swift → ExamEGERussian/Sources/Model/PlainObjects/KnowledgeGraph/KnowledgeGraphGoalPlainObject.swift

@@ -8,7 +8,7 @@
 
 import Foundation
 
-struct GoalPlainObject: Codable {
+struct KnowledgeGraphGoalPlainObject: Codable {
     let title: String
     let id: String
     let requiredTopics: [String]

ExamEGERussian/Sources/Model/PlainObjects/KnowledgeGraph/LessonPlainObject.swift → ExamEGERussian/Sources/Model/PlainObjects/KnowledgeGraph/KnowledgeGraphLessonPlainObject.swift

@@ -8,7 +8,7 @@
 
 import Foundation
 
-struct LessonPlainObject: Codable {
+struct KnowledgeGraphLessonPlainObject: Codable {
     let id: Int
     let type: String
     let course: String

ExamEGERussian/Sources/Model/PlainObjects/KnowledgeGraph/KnowledgeGraphPlainObject.swift

@@ -9,26 +9,26 @@
 import Foundation
 
 struct KnowledgeGraphPlainObject: Codable {
-    let goals: [GoalPlainObject]
-    let topics: [TopicPlainObject]
-    let topicsMap: [TopicsMapPlainObject]
+    let goals: [KnowledgeGraphGoalPlainObject]
+    let topics: [KnowledgeGraphTopicPlainObject]
+    let topicsMap: [KnowledgeGraphTopicsMapPlainObject]
 
     enum CodingKeys: String, CodingKey {
         case goals
         case topics
         case topicsMap = "topics-map"
     }
 
-    init(goals: [GoalPlainObject], topics: [TopicPlainObject], topicsMap: [TopicsMapPlainObject]) {
+    init(goals: [KnowledgeGraphGoalPlainObject], topics: [KnowledgeGraphTopicPlainObject], topicsMap: [KnowledgeGraphTopicsMapPlainObject]) {
         self.goals = goals
         self.topics = topics
         self.topicsMap = topicsMap
     }
 
     init(from decoder: Decoder) throws {
         let container = try decoder.container(keyedBy: CodingKeys.self)
-        goals = try container.decode([GoalPlainObject].self, forKey: .goals)
-        topics = try container.decode([TopicPlainObject].self, forKey: .topics)
-        topicsMap = try container.decode([TopicsMapPlainObject].self, forKey: .topicsMap)
+        goals = try container.decode([KnowledgeGraphGoalPlainObject].self, forKey: .goals)
+        topics = try container.decode([KnowledgeGraphTopicPlainObject].self, forKey: .topics)
+        topicsMap = try container.decode([KnowledgeGraphTopicsMapPlainObject].self, forKey: .topicsMap)
     }
 }