[Is] credit manager 구현

CreditManager.swift

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+//
+//  CreditManager.swift
+//  Git_ Exercise
+//
+//  Created by sei_dev on 12/19/22.
+//
+
+import Foundation
+
+/// creditManager의 DataFile 관련 정보들
+enum DataFile {
+    /// 데이터가 저장되고 로드하는 json 파일 이름
+    static let name = "data.json"
+    /// 파일이 저장될 Directory
+    static let directory: String = FileManager.default.currentDirectoryPath
+    static let pathString = DataFile.directory.appending(DataFile.name)
+    static var pathUrl: URL {
+        if #available(macOS 13.0, *) {
+            return URL(filePath: DataFile.directory.appending(DataFile.name))
+        } else {
+            return URL(fileURLWithPath: DataFile.directory.appending(DataFile.name))
+        }
+    }
+}
+
+final class CreditManager {
+    /// CreditManager - singleton
+    static let shared = CreditManager()
+    private init() { }
+
+    /// CreditManager의 현재 status
+    private var status: Status = .start
+    /// CreditManager에 등록된 Student의 List
+    private var students = [Student]()
+
+    /// 1. 저장된 데이터 로드
+    /// 2. 프로그램 상태에 맞는 info 메세지 출력
+    /// 3. input 처리 및 실행
+    /// 4. error발생 시 설명 출력
+    ///     - 종료 error 시 데이터 저장 및 프로그램 종료
+    func run() {
+        loadData()
+        while true {
+            do {
+                IOManager.writeMessage(status.infoMessage)
+                let input = try IOManager.getInput(isStartStatus: status == .start)
+                let parsedInput = try parse(input: input)
+                try doWith(parsedInput)
+            } catch {
+                IOManager.writeMessage(error.localizedDescription, type: .error)
+                switch error {
+                case CMError.quitProgram:
+                    saveData()
+                    return
+                default:
+                    status = .start
+                }
+            }
+        }
+    }
+
+    /// status 별 input parse
+    private func parse(input: String) throws -> ParsedInput {
+        guard let parsedInput = status.parse(input: input) else {
+            throw status == .start ? CMError.invalidStartInput : IOError.wrongInput
+        }
+        return parsedInput
+    }
+
+
+    /// 입력과 상태에 따라 CreditManager 작동 분기
+    ///
+    /// - result Infomation이 있다면 출력한다
+    /// - 실행 후 credit manager의 status는 start로 변경
+    private func doWith(_ input: ParsedInput) throws {
+        do {
+            switch self.status {
+            case .start:
+                try start(input)
+                return
+            case .addStudent:
+                try add(student: input)
+            case .deleteStudent:
+                try delete(student: input)
+            case .addScore:
+                try add(score: input)
+            case .deleteScore:
+                try delete(score: input)
+            case .showScoreAverage:
+                try show(score: input)
+            case .exit:
+                return
+            }
+        } catch {
+            throw error
+        }
+        if let resInfo = status.resMessage(input: input) {
+            IOManager.writeMessage(resInfo, type: .reaction)
+        }
+        status = .start
+    }
+}
+
+//MARK: - Start
+
+extension CreditManager {
+    /// 입력에 따라 credit manager의 status 변경
+    private func start(_ input: ParsedInput) throws {
+        guard let nextStatus = input[0] as? Status else {
+            throw CMError.invalidStartInput
+        }
+        guard nextStatus != .exit else {
+            throw CMError.quitProgram
+        }
+        guard [Status.start, Status.addStudent].contains(nextStatus) || false == students.isEmpty else {
+            throw CMError.emptyStudents
+        }
+        self.status = nextStatus
+    }
+}
+
+//MARK: - AddStudent
+
+extension CreditManager {
+    /// 입력받은 학생을 students에 추가
+    ///
+    /// Error occurs when
+    /// - 입력받은 학생이 이미 존재
+    private func add(student input: ParsedInput) throws {
+        guard let name = input[0] as? String else {
+            throw IOError.wrongInput
+        }
+        guard false == exists(student: name) else {
+            throw CMError.studentAleadyExists(name: name)
+        }
+        let student = Student(name: name)
+        students.append(student)
+    }
+
+    /// 학생이 등록되어 있다면 true
+    private func exists(student name: String) -> Bool {
+        return students.contains { $0.name == name }
+    }
+}
+
+//MARK: - Delete Student
+
+extension CreditManager {
+    /// 입력받은 학생을 students에서 삭제
+    ///
+    /// Error occurs when
+    /// - 등록된 학생이 0명
+    /// - 입력받은 학생이 존재하지 않음
+    private func delete(student input: ParsedInput) throws {
+        guard false == students.isEmpty  else {
+            throw CMError.emptyStudents
+        }
+        guard let name = input[0] as? String else {
+            throw IOError.wrongInput
+        }
+        guard exists(student: name) else {
+            throw CMError.studentNotFound(name: name)
+        }
+        students.removeAll { $0.name == name }
+    }
+}
+
+
+//MARK: - Add Score
+
+extension CreditManager {
+    /// 등록된 학생에 course, score 정보 추가
+    ///
+    /// Error occurs when
+    /// - 입력받은 학생이 존재하지 않음
+    private func add(score input: ParsedInput) throws {
+        guard let name = input[0] as? String,
+              let course = input[1] as? String,
+              let score = input[2] as? Score else {
+            throw IOError.wrongInput
+        }
+        guard let student = students.first(where: { $0.name == name}) else {
+            throw CMError.studentNotFound(name: name)
+        }
+        student.update(course: course, score: score)
+    }
+}
+
+//MARK: - Delete Score
+
+extension CreditManager {
+    /// 등록된 학생의 course 정보 삭제
+    ///
+    /// Error occurs when
+    /// - 입력받은 학생이 존재하지 않음
+    /// - 학생 정보에 해당 과목이 등록되어 있지 않음
+    private func delete(score input: ParsedInput) throws {
+        guard let name = input[0] as? String,
+              let course = input[1] as? String else {
+            throw IOError.wrongInput
+        }
+        guard let student = students.first(where: { $0.name == name}) else {
+            throw CMError.studentNotFound(name: name)
+        }
+        guard student.remove(course: course) != nil else {
+            throw CMError.courseNotFound(name: name, course: course)
+        }
+    }
+}
+
+//MARK: - Show Average Score
+
+extension CreditManager {
+    /// 등록된 학생의 전체 과목과 평점 확인
+    ///
+    /// Error occurs when
+    /// - 입력받은 학생이 존재하지 않음
+    /// - 학생 정보에 등록된 과목이 없음
+    private func show(score input: ParsedInput) throws {
+        guard let name = input[0] as? String else {
+            throw IOError.wrongInput
+        }
+        guard let student = students.first(where: { $0.name == name}) else {
+            throw CMError.studentNotFound(name: name)
+        }
+        guard false == student.scores.isEmpty else {
+            throw CMError.emptyCourse(name: name)
+        }
+        IOManager.writeMessage(student.allScoresDescription)
+    }
+}
+
+
+extension CreditManager {
+    /// students property를 json 파일에 저장
+    private func saveData() {
+        let encoder = JSONEncoder()
+        encoder.outputFormatting = .prettyPrinted
+        do {
+            let data = try encoder.encode(StudentList(students: students))
+
+            if false == FileManager.default.fileExists(atPath: DataFile.pathString) {
+                FileManager.default.createFile(atPath: DataFile.pathString, contents: nil)
+            }
+
+            try data.write(to: DataFile.pathUrl)
+            let names = students.map {$0.name}
+
+            IOManager.writeMessage(Info.Data.saved(names: names), type: .reaction)
+        } catch {
+            IOManager.writeMessage(error.localizedDescription, type: .error)
+        }
+    }
+
+    /// json 파일 데이터를 students property에 불러오기
+    private func loadData() {
+        guard let data = try? Data(contentsOf: DataFile.pathUrl),
+              let studentList = try? JSONDecoder().decode(StudentList.self, from: data) else {
+            IOManager.writeMessage(Info.Warning.failedToLoadData, type: .error)
+            return
+        }
+        students = studentList.students
+
+        let names = students.map {$0.name}
+        IOManager.writeMessage(Info.Data.loaded(names: names), type: .reaction)
+    }
+}

Error.swift

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+//
+//  Error.swift
+//  Git_ Exercise
+//
+//  Created by sei_dev on 12/19/22.
+//
+
+import Foundation
+
+//MARK: - CMError
+
+enum CMError: Error {
+    case invalidStartInput
+    case studentAleadyExists(name: String)
+    case studentNotFound(name: String)
+    case emptyCourse(name: String)
+    case courseNotFound(name: String, course:String)
+    case emptyStudents
+    case quitProgram
+}
+
+extension CMError: LocalizedError {
+    public var errorDescription: String? {
+        switch self {
+        case .invalidStartInput:
+            return "입력이 잘못되었습니다. 1~5 사이의 숫자 혹은 X를 입력해주세요."
+        case let .studentAleadyExists(name):
+            return "\(name): 이미 존재하는 학생입니다. 추가하지 않습니다."
+        case let .studentNotFound(name):
+            return "\(name) 학생을 찾지 못했습니다."
+        case let .courseNotFound(name, course):
+            return "\(name) - \(course): 등록되지 않은 과목입니다."
+        case let .emptyCourse(name):
+            return "\(name): 등록된 과목이 없습니다."
+        case .emptyStudents:
+            return "등록된 학생이 존재하지 않습니다."
+        case .quitProgram:
+            return "프로그램을 종료합니다..."
+        }
+    }
+}
+
+//MARK: - IOError
+
+enum IOError: Error {
+    case wrongInput
+}
+
+extension IOError: LocalizedError {
+    public var errorDescription: String? {
+        switch self {
+        case .wrongInput:
+            return "입력이 잘못되었습니다. 다시 확인해주세요."
+        }
+    }
+}

IOManager.swift

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+//
+//  IOManager.swift
+//  Git_ Exercise
+//
+//  Created by sei_dev on 12/19/22.
+//
+
+import Foundation
+
+/// Console output type
+enum OutputType {
+    case information
+    case reaction
+    case error
+}
+
+enum IOManager {
+    static let nameRegex = "^[A-Za-z0-9_]+$"
+
+    /// 사용자 입력 받기
+    static func getInput(isStartStatus: Bool) throws -> String {
+        guard let input = readLine(),
+              input != "" else {
+            throw isStartStatus ? CMError.invalidStartInput : IOError.wrongInput
+        }
+        return input
+    }
+
+    static func checkValidity(of str: String) -> Bool {
+        return str.range(of: Self.nameRegex, options: .regularExpression, range: nil, locale: nil) != nil
+    }
+
+    /// message 콘솔에 출력
+    static func writeMessage(_ message: String, type: OutputType = .information) {
+        switch type {
+        case .information:
+            print("> \(message)")
+        case .reaction:
+            print("< \(message)")
+        case .error:
+            fputs("⚠️ \(message)\n", stderr)
+        }
+    }
+}