Add find course endpoint

apps/main/tv/codely/apps/backoffice/backend/controller/courses/CoursesGetController.java

@@ -1,8 +1,10 @@
 package tv.codely.apps.backoffice.backend.controller.courses;
 
+import org.springframework.http.HttpStatus;
 import org.springframework.web.bind.annotation.*;
 import tv.codely.backoffice.courses.application.BackofficeCoursesResponse;
 import tv.codely.backoffice.courses.application.search_by_criteria.SearchBackofficeCoursesByCriteriaQuery;
+import tv.codely.shared.domain.DomainError;
 import tv.codely.shared.domain.bus.command.CommandBus;
 import tv.codely.shared.domain.bus.query.QueryBus;
 import tv.codely.shared.domain.bus.query.QueryHandlerExecutionError;
@@ -44,6 +46,11 @@ public List<HashMap<String, String>> index(
         }}).collect(Collectors.toList());
     }
 
+    @Override
+    protected HashMap<Class<? extends DomainError>, HttpStatus> errorMapping() {
+        return null;
+    }
+
     private List<HashMap<String, String>> parseFilters(HashMap<String, Serializable> params) {
         int maxParams = params.size();
 

apps/main/tv/codely/apps/backoffice/backend/controller/health_check/HealthCheckGetController.java

@@ -1,7 +1,9 @@
 package tv.codely.apps.backoffice.backend.controller.health_check;
 
+import org.springframework.http.HttpStatus;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RestController;
+import tv.codely.shared.domain.DomainError;
 import tv.codely.shared.domain.bus.command.CommandBus;
 import tv.codely.shared.domain.bus.query.QueryBus;
 import tv.codely.shared.infrastructure.spring.ApiController;
@@ -25,4 +27,9 @@ public HashMap<String, String> index() {
 
         return status;
     }
+
+    @Override
+    protected HashMap<Class<? extends DomainError>, HttpStatus> errorMapping() {
+        return null;
+    }
 }

apps/main/tv/codely/apps/mooc/backend/controller/courses/CourseGetController.java

@@ -0,0 +1,44 @@
+package tv.codely.apps.mooc.backend.controller.courses;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RestController;
+import tv.codely.mooc.courses.application.CourseResponse;
+import tv.codely.mooc.courses.application.find.FindCourseQuery;
+import tv.codely.shared.domain.DomainError;
+import tv.codely.shared.domain.bus.command.CommandBus;
+import tv.codely.shared.domain.bus.query.QueryBus;
+import tv.codely.shared.domain.bus.query.QueryHandlerExecutionError;
+import tv.codely.shared.domain.bus.query.QueryNotRegisteredError;
+import tv.codely.shared.infrastructure.spring.ApiController;
+
+import java.io.Serializable;
+import java.util.HashMap;
+
+@RestController
+public final class CourseGetController extends ApiController {
+    public CourseGetController(
+        QueryBus queryBus,
+        CommandBus commandBus
+    ) {
+        super(queryBus, commandBus);
+    }
+
+    @GetMapping("/courses/{id}")
+    public ResponseEntity<HashMap<String, Serializable>> index(@PathVariable String id) throws QueryHandlerExecutionError, QueryNotRegisteredError {
+        CourseResponse course = ask(new FindCourseQuery(id));
+
+        return ResponseEntity.ok().body(new HashMap<String, Serializable>() {{
+            put("id", course.id());
+            put("name", course.name());
+            put("duration", course.duration());
+        }});
+    }
+
+    @Override
+    protected HashMap<Class<? extends DomainError>, HttpStatus> errorMapping() {
+        return null;
+    }
+}

apps/main/tv/codely/apps/mooc/backend/controller/courses/CoursesPutController.java

@@ -7,12 +7,15 @@
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RestController;
 import tv.codely.mooc.courses.application.create.CreateCourseCommand;
+import tv.codely.shared.domain.DomainError;
 import tv.codely.shared.domain.bus.command.CommandBus;
 import tv.codely.shared.domain.bus.command.CommandHandlerExecutionError;
 import tv.codely.shared.domain.bus.command.CommandNotRegisteredError;
 import tv.codely.shared.domain.bus.query.QueryBus;
 import tv.codely.shared.infrastructure.spring.ApiController;
 
+import java.util.HashMap;
+
 @RestController
 public final class CoursesPutController extends ApiController {
     public CoursesPutController(
@@ -31,6 +34,11 @@ public ResponseEntity<String> index(
 
         return new ResponseEntity<>(HttpStatus.CREATED);
     }
+
+    @Override
+    protected HashMap<Class<? extends DomainError>, HttpStatus> errorMapping() {
+        return null;
+    }
 }
 
 final class Request {

apps/main/tv/codely/apps/mooc/backend/controller/courses_counter/CoursesCounterGetController.java

@@ -1,9 +1,11 @@
 package tv.codely.apps.mooc.backend.controller.courses_counter;
 
+import org.springframework.http.HttpStatus;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RestController;
 import tv.codely.mooc.courses_counter.application.find.CoursesCounterResponse;
 import tv.codely.mooc.courses_counter.application.find.FindCoursesCounterQuery;
+import tv.codely.shared.domain.DomainError;
 import tv.codely.shared.domain.bus.command.CommandBus;
 import tv.codely.shared.domain.bus.query.QueryBus;
 import tv.codely.shared.domain.bus.query.QueryHandlerExecutionError;
@@ -26,4 +28,9 @@ public HashMap<String, Integer> index() throws QueryNotRegisteredError, QueryHan
             put("total", response.total());
         }};
     }
+
+    @Override
+    protected HashMap<Class<? extends DomainError>, HttpStatus> errorMapping() {
+        return null;
+    }
 }

apps/main/tv/codely/apps/mooc/backend/controller/health_check/HealthCheckGetController.java

@@ -1,7 +1,9 @@
 package tv.codely.apps.mooc.backend.controller.health_check;
 
+import org.springframework.http.HttpStatus;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RestController;
+import tv.codely.shared.domain.DomainError;
 import tv.codely.shared.domain.bus.command.CommandBus;
 import tv.codely.shared.domain.bus.query.QueryBus;
 import tv.codely.shared.infrastructure.spring.ApiController;
@@ -25,4 +27,9 @@ public HashMap<String, String> index() {
 
         return status;
     }
+
+    @Override
+    protected HashMap<Class<? extends DomainError>, HttpStatus> errorMapping() {
+        return null;
+    }
 }

apps/main/tv/codely/apps/mooc/backend/controller/notifications/NewsletterNotificationPutController.java

@@ -6,12 +6,15 @@
 import org.springframework.web.bind.annotation.PutMapping;
 import org.springframework.web.bind.annotation.RestController;
 import tv.codely.mooc.notifications.application.send_new_courses_newsletter.SendNewCoursesNewsletterCommand;
+import tv.codely.shared.domain.DomainError;
 import tv.codely.shared.domain.bus.command.CommandBus;
 import tv.codely.shared.domain.bus.command.CommandHandlerExecutionError;
 import tv.codely.shared.domain.bus.command.CommandNotRegisteredError;
 import tv.codely.shared.domain.bus.query.QueryBus;
 import tv.codely.shared.infrastructure.spring.ApiController;
 
+import java.util.HashMap;
+
 @RestController
 public final class NewsletterNotificationPutController extends ApiController {
     public NewsletterNotificationPutController(
@@ -29,4 +32,9 @@ public ResponseEntity<String> index(
 
         return new ResponseEntity<>(HttpStatus.CREATED);
     }
+
+    @Override
+    protected HashMap<Class<? extends DomainError>, HttpStatus> errorMapping() {
+        return null;
+    }
 }

apps/test/tv/codely/apps/mooc/backend/controller/courses/CourseGetControllerShould.java

@@ -0,0 +1,20 @@
+package tv.codely.apps.mooc.backend.controller.courses;
+
+import org.junit.jupiter.api.Test;
+import tv.codely.apps.mooc.MoocApplicationTestCase;
+
+final class CourseGetControllerShould extends MoocApplicationTestCase {
+    @Test
+    void find_an_existing_course() throws Exception {
+        String id   = "99ad55f5-6eab-4d73-b383-c63268e251e8";
+        String body = "{\"name\": \"The best course\", \"duration\": \"5 hours\"}";
+
+        givenThereIsACourse(id, body);
+
+        assertResponse(String.format("/courses/%s", id), 200, body);
+    }
+
+    private void givenThereIsACourse(String id, String body) throws Exception {
+        assertRequestWithBody("PUT", String.format("/courses/%s", id), body, 201);
+    }
+}

src/mooc/main/tv/codely/mooc/courses/application/CourseResponse.java

@@ -17,4 +17,16 @@ public CourseResponse(String id, String name, String duration) {
     public static CourseResponse fromAggregate(Course course) {
         return new CourseResponse(course.id().value(), course.name().value(), course.duration().value());
     }
+
+    public String id() {
+        return id;
+    }
+
+    public String name() {
+        return name;
+    }
+
+    public String duration() {
+        return duration;
+    }
 }

src/mooc/main/tv/codely/mooc/courses/application/find/CourseFinder.java

@@ -0,0 +1,22 @@
+package tv.codely.mooc.courses.application.find;
+
+import tv.codely.mooc.courses.application.CourseResponse;
+import tv.codely.mooc.courses.domain.CourseId;
+import tv.codely.mooc.courses.domain.CourseNotExist;
+import tv.codely.mooc.courses.domain.CourseRepository;
+import tv.codely.shared.domain.Service;
+
+@Service
+public final class CourseFinder {
+    private final CourseRepository repository;
+
+    public CourseFinder(CourseRepository repository) {
+        this.repository = repository;
+    }
+
+    public CourseResponse find(CourseId id) throws CourseNotExist {
+        return repository.search(id)
+                         .map(CourseResponse::fromAggregate)
+                         .orElseThrow(() -> new CourseNotExist(id));
+    }
+}

src/mooc/main/tv/codely/mooc/courses/application/find/FindCourseQuery.java

@@ -0,0 +1,15 @@
+package tv.codely.mooc.courses.application.find;
+
+import tv.codely.shared.domain.bus.query.Query;
+
+public final class FindCourseQuery implements Query {
+    private final String id;
+
+    public FindCourseQuery(String id) {
+        this.id = id;
+    }
+
+    public String id() {
+        return id;
+    }
+}

src/mooc/main/tv/codely/mooc/courses/application/find/FindCourseQueryHandler.java

@@ -0,0 +1,25 @@
+package tv.codely.mooc.courses.application.find;
+
+import tv.codely.mooc.courses.application.CourseResponse;
+import tv.codely.mooc.courses.domain.CourseId;
+import tv.codely.mooc.courses.domain.CourseNotExist;
+import tv.codely.shared.domain.Service;
+import tv.codely.shared.domain.bus.query.QueryHandler;
+
+@Service
+public final class FindCourseQueryHandler implements QueryHandler<FindCourseQuery, CourseResponse> {
+    private final CourseFinder finder;
+
+    public FindCourseQueryHandler(CourseFinder finder) {
+        this.finder = finder;
+    }
+
+    @Override
+    public CourseResponse handle(FindCourseQuery query) {
+        try {
+            return finder.find(new CourseId(query.id()));
+        } catch (CourseNotExist error) {
+            return null;
+        }
+    }
+}

src/mooc/main/tv/codely/mooc/courses/domain/CourseNotExist.java

@@ -0,0 +1,9 @@
+package tv.codely.mooc.courses.domain;
+
+import tv.codely.shared.domain.DomainError;
+
+public final class CourseNotExist extends DomainError {
+    public CourseNotExist(CourseId id) {
+        super("course_not_exist", String.format("The course <%s> doesn't exist", id.value()));
+    }
+}

src/shared/main/tv/codely/shared/domain/DomainError.java

@@ -0,0 +1,21 @@
+package tv.codely.shared.domain;
+
+public abstract class DomainError extends Throwable {
+    private final String errorCode;
+    private final String errorMessage;
+
+    public DomainError(String errorCode, String errorMessage) {
+        super(errorMessage);
+
+        this.errorCode    = errorCode;
+        this.errorMessage = errorMessage;
+    }
+
+    public String getErrorCode() {
+        return errorCode;
+    }
+
+    public String getErrorMessage() {
+        return errorMessage;
+    }
+}

src/shared/main/tv/codely/shared/infrastructure/spring/ApiController.java

@@ -1,5 +1,7 @@
 package tv.codely.shared.infrastructure.spring;
 
+import org.springframework.http.HttpStatus;
+import tv.codely.shared.domain.DomainError;
 import tv.codely.shared.domain.bus.command.Command;
 import tv.codely.shared.domain.bus.command.CommandBus;
 import tv.codely.shared.domain.bus.command.CommandHandlerExecutionError;
@@ -9,8 +11,10 @@
 import tv.codely.shared.domain.bus.query.QueryHandlerExecutionError;
 import tv.codely.shared.domain.bus.query.QueryNotRegisteredError;
 
+import java.util.HashMap;
+
 public abstract class ApiController {
-    private final QueryBus queryBus;
+    private final QueryBus   queryBus;
     private final CommandBus commandBus;
 
     public ApiController(QueryBus queryBus, CommandBus commandBus) {
@@ -25,4 +29,6 @@ protected void dispatch(Command command) throws CommandNotRegisteredError, Comma
     protected <R> R ask(Query query) throws QueryNotRegisteredError, QueryHandlerExecutionError {
         return queryBus.ask(query);
     }
+
+    abstract protected HashMap<Class<? extends DomainError>, HttpStatus> errorMapping();
 }