func retrieveSelfServiceData (completion: @escaping (Bool) -> ()) {
        database.collection(SelfServiceKeys.collectionKey).getDocuments { (querySnapshot, error) in
            if let error = error {
                print("Error getting documents: \(error)")
                completion(false)
            } else {
                self.courses.removeAll()
                for document in querySnapshot!.documents {
                    if let documentData = document.data() as? [String : Any] {
                        let newAdmins = documentData[SelfServiceKeys.adminsKey] as? [String]
                        let newCourses = documentData[SelfServiceKeys.coursesKey] as? [Any]
                        for course in newCourses! {
                            let dictCourse = course as! [String: Any]
                            let newCicles = dictCourse[SelfServiceKeys.CoursesKeys.cicles] as? Int
                            let newDescription = dictCourse[SelfServiceKeys.CoursesKeys.description] as? String
                            let newEmphasis = dictCourse[SelfServiceKeys.CoursesKeys.emphasis] as? [String]
                            let newImage = dictCourse[SelfServiceKeys.CoursesKeys.image] as? String
                            let newMissions = dictCourse[SelfServiceKeys.CoursesKeys.missions] as? Int
                            let newSeasons = dictCourse[SelfServiceKeys.CoursesKeys.seasons] as? Int
                            self.courses.append(Course(cicles: newCicles, description: newDescription, emphasis: newEmphasis, image: newImage, missions: newMissions, seasons: newSeasons))
                        }
                    }
                }
                completion(true)
            }
        }
    }

func retrieveSubjectsByCourseCicleEmphasis (completion: @escaping (Bool) -> ()) {
        let cicleFirestoreString = String(format: "Ciclo %d", (self.selectedCicle! + 1))
        print(cicleFirestoreString)
        database.collection(SubjectsKeys.collectionKey).whereField(SubjectsKeys.formation, isEqualTo: self.selectedCourse!).whereField(SubjectsKeys.cicleKey, isEqualTo: cicleFirestoreString).whereField(SubjectsKeys.emphasis, isEqualTo: self.selectedEmphasis!).getDocuments { (querySnapshot, error) in
            if let error = error {
                print("Error getting documents: \(error)")
                completion(false)
            } else {
                self.subjects.removeAll()
                for document in querySnapshot!.documents {
                    let newArrayLearningObject = document[SubjectsKeys.learningObjectKey] as? [Any]
                    let newImage = document[SubjectsKeys.image] as? String
                    let newName = document[SubjectsKeys.name] as? String
                    let newSubject = Subject.init(arrayLearningObject: newArrayLearningObject!, image: newImage!, name: newName!)
                    self.subjects.append(newSubject)
                }
                completion(true)
            }
        }
    }

func retrieveTeamMembers (completion: @escaping (Bool) -> ()) {
        database.collection(TeamMemberKeys.collectionKey).whereField(TeamMemberKeys.teamIDKey, isEqualTo: team!.reference!).getDocuments() { (querySnapshot, error) in
            if let error = error {
                print("Error getting documents: \(error)")
                completion(false)
            } else {
                self.members.removeAll()
                for document in querySnapshot!.documents {
                    if let documentData = document.data() as? [String : Any] {
                        let newCourse = documentData[TeamMemberKeys.courseKey] as? String
                        let newEmail = documentData[TeamMemberKeys.emailKey] as? String
                        let newTeamID = documentData[TeamMemberKeys.teamIDKey] as? DocumentReference
                        let newName = documentData[TeamMemberKeys.nameKey] as? String
                        let ID = document.documentID
                        let newTeamMember = TeamMember.init(course: newCourse, email: newEmail, teamID: newTeamID, name: newName, ID: ID)
                        self.members.append(newTeamMember)
                    }
                }
                completion(true)
            }
        }
    }

struct SelfServiceKeys {
    static let collectionKey = "meta-info"
    static let adminsKey = "admins"
    static let coursesKey = "cursos"
    struct CoursesKeys {
        static let cicles = "ciclos"
        static let description = "desc"
        static let emphasis = "enfases"
        static let image = "img"
        static let missions = "missoes"
        static let seasons = "temporadas"
    }
}

struct SubjectsKeys {
    static let collectionKey = "self"
    static let learningObjectKey = "arrayObjAprendizagem"
    static let cicleKey = "ciclo"
    static let emphasis = "enfase"
    static let formation = "formacao"
    static let image = "img"
    static let name = "nome"
    struct LearningObjectKeys {
        static let format = "formato"
        static let link = "link"
        static let name = "nome"
        static let type = "tipo"
    }
}