Step2 리뷰요청 드립니다.

src/main/java/nextstep/courses/domain/Capacity.java

@@ -0,0 +1,18 @@
+package nextstep.courses.domain;
+
+public class Capacity {
+
+    private final int max;
+    private int current;
+
+    public Capacity(int max, int current) {
+        this.max = max;
+        this.current = current;
+    }
+
+    public void validateAvailable() {
+        if (current > max) {
+            throw new IllegalStateException();
+        }
+    }
+}

src/main/java/nextstep/courses/domain/Course.java

@@ -9,25 +9,29 @@ public class Course {
 
     private Long creatorId;
 
+    private final Sessions sessions;
+
     private LocalDateTime createdAt;
 
     private LocalDateTime updatedAt;
 
-    public Course() {
-    }
-
     public Course(String title, Long creatorId) {
-        this(0L, title, creatorId, LocalDateTime.now(), null);
+        this(0L, title, creatorId, new Sessions(), LocalDateTime.now(), null);
     }
 
-    public Course(Long id, String title, Long creatorId, LocalDateTime createdAt, LocalDateTime updatedAt) {
+    public Course(Long id, String title, Long creatorId, Sessions sessions, LocalDateTime createdAt, LocalDateTime updatedAt) {
         this.id = id;
         this.title = title;
         this.creatorId = creatorId;
+        this.sessions = sessions;
         this.createdAt = createdAt;
         this.updatedAt = updatedAt;
     }
 
+    public void addSession(Session session) {
+        sessions.add(session);
+    }
+
     public String getTitle() {
         return title;
     }

src/main/java/nextstep/courses/domain/CoverImage.java

@@ -0,0 +1,17 @@
+package nextstep.courses.domain;
+
+public class CoverImage {
+    private ImageSize imageSize;
+    private ImageType imageType;
+    private ImageDimension imageDimension;
+
+    public CoverImage(int size, String fileName, int width, int height) {
+        this(new ImageSize(size), ImageType.fromFileName(fileName), new ImageDimension(width, height));
+    }
+
+    private CoverImage(ImageSize imageSize, ImageType imageType, ImageDimension imageDimension) {
+        this.imageSize = imageSize;
+        this.imageType = imageType;
+        this.imageDimension = imageDimension;
+    }
+}

src/main/java/nextstep/courses/domain/Enrollment.java

@@ -0,0 +1,15 @@
+package nextstep.courses.domain;
+
+import java.time.LocalDateTime;
+
+public class Enrollment {
+    private final Long sessionId;
+    private final Long userId;
+    private final LocalDateTime enrollmentDate;
+
+    public Enrollment(Long sessionId, Long userId) {
+        this.sessionId = sessionId;
+        this.userId = userId;
+        this.enrollmentDate = LocalDateTime.now();
+    }
+}

src/main/java/nextstep/courses/domain/EnrollmentPolicy.java

@@ -0,0 +1,7 @@
+package nextstep.courses.domain;
+
+import nextstep.payments.domain.Payment;
+
+public interface EnrollmentPolicy {
+    void validateEnrollment(Payment payment);
+}

src/main/java/nextstep/courses/domain/FreeEnrollmentPolicy.java

@@ -0,0 +1,10 @@
+package nextstep.courses.domain;
+
+import nextstep.payments.domain.Payment;
+
+public class FreeEnrollmentPolicy implements EnrollmentPolicy{
+    @Override
+    public void validateEnrollment(Payment payment) {
+        // 무료강의는 검증하지 않는다
+    }
+}

src/main/java/nextstep/courses/domain/ImageDimension.java

@@ -0,0 +1,30 @@
+package nextstep.courses.domain;
+
+public class ImageDimension {
+
+    public static final int HEIGHT_RATIO = 2;
+    public static final int WIDTH_RATIO = 3;
+    public static final int MIN_WIDTH = 300;
+    public static final int MIN_HEIGHT = 200;
+    private int width;
+    private int height;
+
+    public ImageDimension(int width, int height) {
+        validateMinimumSize(width, height);
+        validateRatio(width, height);
+        this.width = width;
+        this.height = height;
+    }
+
+    private static void validateMinimumSize(int width, int height) {
+        if (width < MIN_WIDTH || height < MIN_HEIGHT) {
+            throw new IllegalArgumentException();
+        }
+    }
+
+    private static void validateRatio(int width, int height) {
+        if (!(HEIGHT_RATIO * width == WIDTH_RATIO * height)) {
+            throw new IllegalArgumentException();
+        }
+    }
+}

src/main/java/nextstep/courses/domain/ImageSize.java

@@ -0,0 +1,29 @@
+package nextstep.courses.domain;
+
+import java.util.Objects;
+
+public class ImageSize {
+
+    public static final int MAX_SIZE = 1_048_576;
+    private int imageSize;
+
+    public ImageSize(int imageSize) {
+        if (imageSize > MAX_SIZE) {
+            throw new IllegalArgumentException();
+        }
+        this.imageSize = imageSize;
+    }
+
+    @Override
+    public boolean equals(Object object) {
+        if (this == object) return true;
+        if (object == null || getClass() != object.getClass()) return false;
+        ImageSize imageSize1 = (ImageSize) object;
+        return imageSize == imageSize1.imageSize;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hashCode(imageSize);
+    }
+}

src/main/java/nextstep/courses/domain/ImageType.java

@@ -0,0 +1,43 @@
+package nextstep.courses.domain;
+
+import java.util.Arrays;
+
+public enum ImageType {
+
+    GIF("gif"),
+    JPG("jpg", "jpeg"),
+    PNG("png"),
+    SVG("svg");
+
+    private final String[] extensions;
+
+    ImageType(String... extensions) {
+        this.extensions = extensions;
+    }
+
+    private boolean matches(String extension) {
+        return Arrays.stream(extensions)
+                .anyMatch(ext -> ext.equalsIgnoreCase(extension));
+    }
+
+    private static ImageType from(String extension) {
+        return Arrays.stream(values())
+                .filter(type -> type.matches(extension))
+                .findFirst()
+                .orElseThrow(() -> new IllegalArgumentException());
+    }
+
+    public static ImageType fromFileName(String fileName) {
+        String extension = extractExtension(fileName);
+        return from(extension);
+    }
+
+    private static String extractExtension(String fileName) {
+        int index = fileName.lastIndexOf(".");
+        if (index == -1 || index == fileName.length() - 1) {
+            throw new IllegalArgumentException();
+        }
+        return fileName.substring(index + 1);
+    }
+
+}

src/main/java/nextstep/courses/domain/Money.java

@@ -0,0 +1,28 @@
+package nextstep.courses.domain;
+
+import java.util.Objects;
+
+public class Money {
+    private final long amount;
+
+    public Money(long amount) {
+        this.amount = amount;
+    }
+
+    public boolean isEqualTo(Money other) {
+        return this.equals(other);
+    }
+
+    @Override
+    public boolean equals(Object object) {
+        if (this == object) return true;
+        if (object == null || getClass() != object.getClass()) return false;
+        Money money = (Money) object;
+        return amount == money.amount;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hashCode(amount);
+    }
+}

src/main/java/nextstep/courses/domain/PaidEnrollmentPolicy.java

@@ -0,0 +1,26 @@
+package nextstep.courses.domain;
+
+import nextstep.payments.domain.Payment;
+
+public class PaidEnrollmentPolicy implements EnrollmentPolicy {
+
+    private final Money money;
+    private final Capacity capacity;
+
+    public PaidEnrollmentPolicy(Money money, Capacity capacity) {
+        this.money = money;
+        this.capacity = capacity;
+    }
+
+    @Override
+    public void validateEnrollment(Payment payment) {
+        capacity.validateAvailable();
+        validatePayment(payment);
+    }
+
+    private void validatePayment(Payment payment) {
+        if (!payment.isSameAmount(money)) {
+            throw new IllegalArgumentException();
+        }
+    }
+}

src/main/java/nextstep/courses/domain/Session.java

@@ -0,0 +1,41 @@
+package nextstep.courses.domain;
+
+import nextstep.payments.domain.Payment;
+
+import java.time.LocalDateTime;
+
+public class Session {
+    private final long id;
+    private final SessionDuration sessionDuration;
+    private final CoverImage coverImage;
+    private final EnrollmentPolicy enrollmentPolicy;
+    private final SessionState sessionState;
+
+    public Session(long id
+            , LocalDateTime startDate
+            , LocalDateTime endDate
+            , int size
+            , String fileName
+            , int width
+            , int height
+            , EnrollmentPolicy enrollmentPolicy
+            , SessionState sessionState) {
+        this(id, new SessionDuration(startDate, endDate), new CoverImage(size, fileName, width, height)
+                , enrollmentPolicy, sessionState);
+    }
+
+    public Session(long id, SessionDuration sessionDuration, CoverImage coverImage
+            , EnrollmentPolicy enrollmentPolicy, SessionState sessionState) {
+        this.id = id;
+        this.sessionDuration = sessionDuration;
+        this.coverImage = coverImage;
+        this.enrollmentPolicy = enrollmentPolicy;
+        this.sessionState = sessionState;
+    }
+
+    public Enrollment enroll(Long userId, Payment payment) {
+        sessionState.validateEnroll();
+        enrollmentPolicy.validateEnrollment(payment);
+        return new Enrollment(this.id, userId);
+    }
+}

src/main/java/nextstep/courses/domain/SessionDuration.java

@@ -0,0 +1,20 @@
+package nextstep.courses.domain;
+
+import java.time.LocalDateTime;
+
+public class SessionDuration {
+    private LocalDateTime startDate;
+    private LocalDateTime endDate;
+
+    public SessionDuration(LocalDateTime startDate, LocalDateTime endDate) {
+        validateDate(startDate, endDate);
+        this.startDate = startDate;
+        this.endDate = endDate;
+    }
+
+    private void validateDate(LocalDateTime startDate, LocalDateTime endDate) {
+        if (!startDate.isBefore(endDate)) {
+            throw new IllegalArgumentException();
+        }
+    }
+}

src/main/java/nextstep/courses/domain/SessionState.java

@@ -0,0 +1,13 @@
+package nextstep.courses.domain;
+
+public enum SessionState {
+    READY,
+    OPEN,
+    CLOSED;
+
+    public void validateEnroll() {
+        if (this != OPEN) {
+            throw new IllegalStateException();
+        }
+    }
+}

src/main/java/nextstep/courses/domain/Sessions.java

@@ -0,0 +1,20 @@
+package nextstep.courses.domain;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Sessions {
+    private final List<Session> sessions;
+
+    public Sessions() {
+        this(new ArrayList<>());
+    }
+
+    public Sessions(List<Session> sessions) {
+        this.sessions = new ArrayList<>(sessions);
+    }
+
+    public void add(Session session) {
+        this.sessions.add(session);
+    }
+}

src/main/java/nextstep/courses/infrastructure/JdbcCourseRepository.java

@@ -30,6 +30,7 @@ public Course findById(Long id) {
                 rs.getLong(1),
                 rs.getString(2),
                 rs.getLong(3),
+                null,
                 toLocalDateTime(rs.getTimestamp(4)),
                 toLocalDateTime(rs.getTimestamp(5)));
         return jdbcTemplate.queryForObject(sql, rowMapper, id);