✨ feat: Calendar | write slices: StartDay and FinishDay (#6)

Author: MateuszNaKodach

src/main/java/com/dddheroes/heroesofddd/calendar/write/Calendar.java

@@ -0,0 +1,68 @@
+package com.dddheroes.heroesofddd.calendar.write;
+
+import com.dddheroes.heroesofddd.calendar.write.finishday.CanOnlyFinishCurrentDay;
+import com.dddheroes.heroesofddd.calendar.write.finishday.DayFinished;
+import com.dddheroes.heroesofddd.calendar.write.finishday.FinishDay;
+import com.dddheroes.heroesofddd.calendar.write.startday.CannotSkipDays;
+import com.dddheroes.heroesofddd.calendar.write.startday.DayStarted;
+import com.dddheroes.heroesofddd.calendar.write.startday.StartDay;
+import org.axonframework.commandhandling.CommandHandler;
+import org.axonframework.eventsourcing.EventSourcingHandler;
+import org.axonframework.modelling.command.AggregateCreationPolicy;
+import org.axonframework.modelling.command.AggregateIdentifier;
+import org.axonframework.modelling.command.CreationPolicy;
+import org.axonframework.spring.stereotype.Aggregate;
+
+import static org.axonframework.modelling.command.AggregateLifecycle.apply;
+
+@Aggregate
+class Calendar {
+
+    @AggregateIdentifier
+    private CalendarId calendarId;
+    private Month currentMonth;
+    private Week currentWeek;
+    private Day currentDay;
+
+    @CommandHandler
+    @CreationPolicy(AggregateCreationPolicy.CREATE_IF_MISSING)
+        // performance downside in comparison to constructor
+    void handle(StartDay command) {
+        new CannotSkipDays(command, currentMonth, currentWeek, currentDay).verify();
+
+        apply(
+                DayStarted.event(
+                        command.calendarId(),
+                        command.month(),
+                        command.week(),
+                        command.day()
+                )
+        );
+    }
+
+    @EventSourcingHandler
+    void on(DayStarted event) {
+        calendarId = new CalendarId(event.calendarId());
+        currentMonth = new Month(event.month());
+        currentWeek = new Week(event.week());
+        currentDay = new Day(event.day());
+    }
+
+    @CommandHandler
+    void handle(FinishDay command) {
+        new CanOnlyFinishCurrentDay(command, currentMonth, currentWeek, currentDay).verify();
+
+        apply(
+                DayFinished.event(
+                        command.calendarId(),
+                        command.month(),
+                        command.week(),
+                        command.day()
+                )
+        );
+    }
+
+    Calendar() {
+        // required by Axon
+    }
+}

src/main/java/com/dddheroes/heroesofddd/calendar/write/CalendarCommand.java

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+package com.dddheroes.heroesofddd.calendar.write;
+
+public interface CalendarCommand {
+
+    CalendarId calendarId();
+}

src/main/java/com/dddheroes/heroesofddd/calendar/write/CalendarEvent.java

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+package com.dddheroes.heroesofddd.calendar.write;
+
+public interface CalendarEvent {
+
+    String calendarId();
+
+}

src/main/java/com/dddheroes/heroesofddd/calendar/write/CalendarId.java

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+package com.dddheroes.heroesofddd.calendar.write;
+
+import java.util.UUID;
+
+public record CalendarId(String raw) {
+
+    public CalendarId {
+        if (raw == null || raw.isBlank()) {
+            throw new IllegalArgumentException("Calendar id cannot be null or empty");
+        }
+    }
+
+    public static CalendarId of(String raw) {
+        return new CalendarId(raw);
+    }
+
+    public static CalendarId random() {
+        return new CalendarId(UUID.randomUUID().toString());
+    }
+
+    @Override
+    public String toString() {
+        return raw;
+    }
+}

src/main/java/com/dddheroes/heroesofddd/calendar/write/Day.java

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+package com.dddheroes.heroesofddd.calendar.write;
+
+public record Day(Integer raw) {
+
+    public Day {
+        if (raw == null || raw < 1 || raw > 7) {
+            throw new IllegalArgumentException("Day must be between 1 and 7");
+        }
+    }
+
+    public static Day of(Integer raw) {
+        return new Day(raw);
+    }
+
+}

src/main/java/com/dddheroes/heroesofddd/calendar/write/Month.java

@@ -0,0 +1,15 @@
+package com.dddheroes.heroesofddd.calendar.write;
+
+public record Month(Integer raw) {
+
+    public Month {
+        if (raw == null || raw < 1) {
+            throw new IllegalArgumentException("Month must be greater than 0");
+        }
+    }
+
+    public static Month of(Integer raw) {
+        return new Month(raw);
+    }
+
+}

src/main/java/com/dddheroes/heroesofddd/calendar/write/Week.java

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+package com.dddheroes.heroesofddd.calendar.write;
+
+public record Week(Integer raw) {
+
+    public Week {
+        if (raw == null || raw < 1 || raw > 4) {
+            throw new IllegalArgumentException("Week must be between 1 and 4");
+        }
+    }
+
+    public static Week of(Integer raw) {
+        return new Week(raw);
+    }
+
+}

src/main/java/com/dddheroes/heroesofddd/calendar/write/finishday/CanOnlyFinishCurrentDay.java

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+package com.dddheroes.heroesofddd.calendar.write.finishday;
+
+import com.dddheroes.heroesofddd.calendar.write.Day;
+import com.dddheroes.heroesofddd.calendar.write.Month;
+import com.dddheroes.heroesofddd.calendar.write.Week;
+import com.dddheroes.heroesofddd.shared.DomainRule;
+
+public record CanOnlyFinishCurrentDay(
+        FinishDay command,
+        Month currentMonth,
+        Week currentWeek,
+        Day currentDay
+) implements DomainRule {
+
+    @Override
+    public boolean isViolated() {
+        boolean isCurrentDay = command.month().equals(currentMonth)
+                && command.week().equals(currentWeek)
+                && command.day().equals(currentDay);
+        return !isCurrentDay;
+    }
+
+    @Override
+    public String message() {
+        return "Can only finish current day";
+    }
+}

src/main/java/com/dddheroes/heroesofddd/calendar/write/finishday/DayFinished.java

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+package com.dddheroes.heroesofddd.calendar.write.finishday;
+
+import com.dddheroes.heroesofddd.calendar.write.CalendarEvent;
+import com.dddheroes.heroesofddd.calendar.write.CalendarId;
+import com.dddheroes.heroesofddd.calendar.write.Day;
+import com.dddheroes.heroesofddd.calendar.write.Month;
+import com.dddheroes.heroesofddd.calendar.write.Week;
+
+public record DayFinished(
+        String calendarId,
+        Integer month,
+        Integer week,
+        Integer day
+) implements CalendarEvent {
+
+    public static DayFinished event(CalendarId calendarId, Month month, Week week, Day day) {
+        return new DayFinished(calendarId.raw(), month.raw(), week.raw(), day.raw());
+    }
+}

src/main/java/com/dddheroes/heroesofddd/calendar/write/finishday/FinishDay.java

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+package com.dddheroes.heroesofddd.calendar.write.finishday;
+
+import com.dddheroes.heroesofddd.calendar.write.CalendarCommand;
+import com.dddheroes.heroesofddd.calendar.write.CalendarId;
+import com.dddheroes.heroesofddd.calendar.write.Day;
+import com.dddheroes.heroesofddd.calendar.write.Month;
+import com.dddheroes.heroesofddd.calendar.write.Week;
+import org.axonframework.modelling.command.TargetAggregateIdentifier;
+
+public record FinishDay(
+        @TargetAggregateIdentifier
+        CalendarId calendarId,
+        Month month,
+        Week week,
+        Day day
+) implements CalendarCommand {
+
+    public static FinishDay command(String calendarId, Integer month, Integer week, Integer day) {
+        return new FinishDay(CalendarId.of(calendarId), Month.of(month), Week.of(week), Day.of(day));
+    }
+}