[Is] credit manager 구현

[vanism2091]

PR 타입

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• angular.io application / infrastructure changes
• Other... Please describe:

반영 브랜치

vanism2091/main -> 1_is

What is the current behavior?

Issue Number: N/A

추가한 기능

• 사용자 입력을 받고 검증합니다
• 학생을 추가합니다
• 학생을 삭제합니다
• 성적을 추가합니다
• 성적을 삭제합니다
• 성적의 평균을 보여줍니다
• 프로그램 실행, 종료 시 데이터를 저장하고 불러옵니다

구조

• Managers
  • CreditManager

    enum DataFile {
        static let name: String
        static let directory: String
        static let pathString: String
        static var pathUrl: URL
    }
  
    final class CreditManager {
        private var status: Status
        private var students: [Student]
        func run()
        private func parse(input: String) throws -> ParsedInput
        private func doWith(_ input: ParsedInput) throws
        private func start(_ input: ParsedInput) throws
        private func add(student input: ParsedInput) throws
        private func delete(student input: ParsedInput) throws
        private func add(score input: ParsedInput) throws
        private func delete(score input: ParsedInput) throws
        private func show(score input: ParsedInput) throws
        private func saveData()
        private func loadData()
    }

  • IOManager

    enum OutputType {
        case information
        case reaction
        case error
    }
    
    enum IOManager {
        static let nameRegex
        static func getInput(isStartStatus: Bool) throws -> String 
        static func checkValidity(of str: String) -> Bool
        static func writeMessage(_ message: String, type: OutputType = .information)
    }

• Data Struct
  • Specific
    • Score

    enum Score: Float, Codable {
        case APlus, A, BPlus, B, CPlus, C, DPlus, D, F
        
        var description: String
        init?(score: String)
    }

    • Status

    typealias ParsedInput = [Codable]
    
    enum Status: String, Codable {
        case start
        case addStudent
        case deleteStudent
        case addScore
        case deleteScore
        case showScoreAverage
        case exit
    }
    
    extension Status {
        var infoMessage: String
        func resMessage(input: ParsedInput) -> String?
        func parse(input: String) -> ParsedInput?
    }

    • Student

    final class Student: Codable {
        let name: String
        private(set) var scores: [String:Score]
        var isCourseEmpty: Bool
        var averageScore: Float 
        var allScoresDescription: String 
        init(name: String) 
        func update(course: String, score: Score) 
        func remove(course: String) -> Score?
    }
    struct StudentList: Codable {
        let students: [Student]
    }
    

  • General
    • Error

    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
    }
    enum IOError: Error {
        case wrongInput
    }

    • Info: StringLiterals

    enum Info {
        static let start: String
        enum Student {
            static let forAdd: String
            static func added(name: String) -> String
            static let forDelete: String
            static func deleted(name: String) -> String
        }
        enum Score {
            static let forAdd: String
            static func added(name:String, course: String, score: String) -> String
            static let forDelete: String
            static func deleted(name:String, course:String) -> String
            static let forAverage: String
        }
        enum Data {
            static func saved(names: [String]) -> String
            static func loaded(names: [String]) -> String
        }
        
        enum Warning {
            static let failedToLoadData: String
            static let failedToLoadReaction: String
        }
    }

Does this PR introduce a breaking change?

• Yes
• No

Test Checklist

• 저장
• 불러오기
• 입력 검증 테스트
  • 이름
  • 이름, 과목
  • 이름, 과목, 성적

Other information

구현 후 고민하는 점

• 더 좋은 저장, 불러오기 방식이 무엇일까요?
• ! 사용을 지양하기 위해 input을 검증하고 parse하는 과정에서 type downcasting 시 오류 체크를 2번 하게 된다. (Status.parse에서 한 번, CreditManager 내 method에서 한 번) 이를 해결하는 방법은 구조를 바꾸는 방법 뿐일까요?
• 에러를 CMError와 IOError로 나누었는데, 불필요한 분리일까요?