SD/feat/#59 Added getById, update and delete

online-book-store/src/main/java/com/amigoscode/cohort2d/onlinebookstore/author/AuthorController.java

@@ -20,11 +20,33 @@ public List<AuthorDTO> getAuthors(){
         return authorService.getAllAuthors();
     }
 
+    @GetMapping("{id}")
+    public AuthorDTO getAuthorById(@PathVariable("id") Long id){
+        return authorService.getAuthorById(id);
+    }
+
     @PostMapping
     public ResponseEntity<?> addAuthor(@Valid @RequestBody AuthorDTO authorDTO){
         authorService.addAuthor(authorDTO);
 
         return ResponseEntity.ok()
                 .build();
     }
+
+
+    @PutMapping("{id}")
+    public ResponseEntity<?> updateAuthor(
+            @PathVariable("id") Long id,
+            @RequestBody AuthorDTO authorDTO
+    ){
+        authorService.updateAuthor(id, authorDTO);
+
+        return ResponseEntity.ok()
+                .build();
+    }
+
+    @DeleteMapping("{id}")
+    public void deleteAuthorById(@PathVariable("id") Long id){
+        authorService.deleteAuthorById(id);
+    }
 }

online-book-store/src/main/java/com/amigoscode/cohort2d/onlinebookstore/author/AuthorDAO.java

@@ -12,4 +12,10 @@ public interface AuthorDAO {
     boolean existsAuthorByName(String s, String s1);
 
     void addAuthor(Author author);
+
+    boolean existsAuthorById(Long id);
+
+    void updateAuthor(Author existingAuthor);
+
+    void deleteAuthorById(Long id);
 }

online-book-store/src/main/java/com/amigoscode/cohort2d/onlinebookstore/author/AuthorJPAService.java

@@ -19,16 +19,31 @@ public List<Author> findAllAuthors() {
 
     @Override
     public Optional<Author> findById(long id) {
-        return Optional.empty();
+        return authorRepository.findById(id);
     }
 
     @Override
     public boolean existsAuthorByName(String firstName, String lastName) {
         return authorRepository.existsAuthorByFirstNameAndLastName(firstName, lastName);
     }
 
+    @Override
+    public boolean existsAuthorById(Long id) {
+        return authorRepository.existsById(id);
+    }
+
     @Override
     public void addAuthor(Author author) {
         authorRepository.save(author);
     }
+
+    @Override
+    public void updateAuthor(Author author) {
+        authorRepository.save(author);
+    }
+
+    @Override
+    public void deleteAuthorById(Long id) {
+        authorRepository.deleteById(id);
+    }
 }

online-book-store/src/main/java/com/amigoscode/cohort2d/onlinebookstore/author/AuthorService.java

@@ -1,6 +1,8 @@
 package com.amigoscode.cohort2d.onlinebookstore.author;
 
 import com.amigoscode.cohort2d.onlinebookstore.exceptions.DuplicateResourceException;
+import com.amigoscode.cohort2d.onlinebookstore.exceptions.RequestValidationException;
+import com.amigoscode.cohort2d.onlinebookstore.exceptions.ResourceNotFoundException;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 
@@ -29,4 +31,49 @@ public void addAuthor(AuthorDTO authorDTO) {
         //save
         authorDAO.addAuthor(AuthorDTOMapper.INSTANCE.dtoToModel(authorDTO));
     }
+
+    public AuthorDTO getAuthorById(Long id) {
+        return AuthorDTOMapper.INSTANCE.modelToDTO(
+                authorDAO.findById(id)
+                .orElseThrow(
+                        () -> new ResourceNotFoundException("Author with id [%s] not found.".formatted(id))));
+    }
+
+    public void updateAuthor(Long id, AuthorDTO updateRequest) {
+
+        // find book - check exists
+        Author existingAuthor = authorDAO.findById(id)
+                .orElseThrow(() -> new ResourceNotFoundException(
+                        "Author with id [%s] not found.".formatted(id)
+                ));
+
+        // check if there are any changes
+        if(AuthorDTOMapper.INSTANCE.modelToDTO(existingAuthor).equals(updateRequest)){
+            throw new RequestValidationException("No data changes found.");
+        }
+
+        // first name
+        if(!updateRequest.firstName().equals(existingAuthor.getFirstName())){
+            existingAuthor.setFirstName(updateRequest.firstName());
+        }
+
+        // last name
+        if(!updateRequest.lastName().equals(existingAuthor.getLastName())){
+            existingAuthor.setLastName(updateRequest.lastName());
+        }
+
+        authorDAO.updateAuthor(existingAuthor);
+
+    }
+
+    public void deleteAuthorById(Long id) {
+
+        // if author does not exist throw
+        if(!authorDAO.existsAuthorById(id)){
+            throw new ResourceNotFoundException("Author with id [%s] not found.".formatted(id));
+        }
+
+        //delete
+        authorDAO.deleteAuthorById(id);
+    }
 }

online-book-store/src/test/java/com/amigoscode/cohort2d/onlinebookstore/author/AuthorJPAServiceTest.java

@@ -43,6 +43,18 @@ void shouldCheckAuthorExistsByName() {
         verify(authorRepository).existsAuthorByFirstNameAndLastName(firstName,lastName);
     }
 
+    @Test
+    void shouldCheckAuthorExistsById() {
+        // Given
+        Long id = 1L;
+
+        // When
+        underTest.existsAuthorById(id);
+
+        // Then
+        verify(authorRepository).existsById(id);
+    }
+
     @Test
     void shouldAddAuthor() {
         // Given
@@ -54,4 +66,43 @@ void shouldAddAuthor() {
         // Then
         verify(authorRepository).save(author);
     }
+
+    @Test
+    void shouldGetAuthorById() {
+        // Given
+        Long id = 10L;
+
+        // When
+        underTest.findById(id);
+
+        // Then
+        verify(authorRepository).findById(id);
+
+    }
+
+    @Test
+    void shouldUpdateAuthor() {
+        // Given
+        Author author = new Author(1L, "Susan", "Doyle");
+
+        // When
+        underTest.updateAuthor(author);
+
+        // Then
+        verify(authorRepository).save(author);
+
+    }
+
+    @Test
+    void shouldDeleteAuthorById() {
+        // Given
+        Long id = 1L;
+
+        // When
+        underTest.deleteAuthorById(id);
+
+        // Then
+        verify(authorRepository).deleteById(id);
+
+    }
 }

online-book-store/src/test/java/com/amigoscode/cohort2d/onlinebookstore/author/AuthorServiceTest.java

@@ -1,6 +1,8 @@
 package com.amigoscode.cohort2d.onlinebookstore.author;
 
 import com.amigoscode.cohort2d.onlinebookstore.exceptions.DuplicateResourceException;
+import com.amigoscode.cohort2d.onlinebookstore.exceptions.RequestValidationException;
+import com.amigoscode.cohort2d.onlinebookstore.exceptions.ResourceNotFoundException;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
@@ -9,6 +11,7 @@
 import org.mockito.junit.jupiter.MockitoExtension;
 
 import java.util.List;
+import java.util.Optional;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
@@ -69,6 +72,117 @@ void shouldAddAuthor() {
 
     }
 
+    @Test
+    void shouldGetAuthorById() {
+        // Given
+        Long id = 1L;
+        Author author = new Author(id, "Jane", "Austin");
+        given(authorDAO.findById(id)).willReturn(Optional.of(author));
+
+        AuthorDTO expected = AuthorDTOMapper.INSTANCE.modelToDTO(author);
+
+        // When
+        AuthorDTO actual = underTest.getAuthorById(id);
+
+        // Then
+        assertThat(actual.id()).isEqualTo(expected.id());
+        assertThat(actual.firstName()).isEqualTo(expected.firstName());
+        assertThat(actual.lastName()).isEqualTo(expected.lastName());
+    }
+
+    @Test
+    void shouldUpdateAuthorById() {
+        // Given
+        Long id = 1L;
+        Author author = new Author(id, "John", "Doe");
+        given(authorDAO.findById(id)).willReturn(Optional.of(author));
+
+        AuthorDTO request = new AuthorDTO(id, "Jane", "Dawson");
+
+        // When
+        underTest.updateAuthor(id, request);
+
+        // Then
+        ArgumentCaptor<Author> authorArgumentCaptor = ArgumentCaptor.forClass(Author.class);
+        verify(authorDAO).updateAuthor(authorArgumentCaptor.capture());
+
+        Author capturedAuthor = authorArgumentCaptor.getValue();
+
+        assertThat(capturedAuthor.getId()).isEqualTo(request.id());
+        assertThat(capturedAuthor.getFirstName()).isEqualTo(request.firstName());
+        assertThat(capturedAuthor.getLastName()).isEqualTo(request.lastName());
+
+    }
+
+    @Test
+    void shouldDeleteAuthorById() {
+        // Given
+        Long id = 10L;
+        given(authorDAO.existsAuthorById(id)).willReturn(true);
+
+        // When
+        underTest.deleteAuthorById(id);
+
+        // Then
+        verify(authorDAO).deleteAuthorById(id);
+    }
+
+    @Test
+    void shouldThrowWhenGetByIdNonExistentAuthor() {
+        // Given
+        Long id = 10L;
+
+        // When && Then
+        assertThatThrownBy(() -> underTest.getAuthorById(id))
+                .isInstanceOf(ResourceNotFoundException.class)
+                .hasMessage("Author with id [%s] not found.".formatted(id));
+
+    }
+
+    @Test
+    void shouldThrowWhenDeletingNonExistentAuthor() {
+        // Given
+        Long id = 10L;
+
+        // When && Then
+        assertThatThrownBy(() -> underTest.deleteAuthorById(id))
+                .isInstanceOf(ResourceNotFoundException.class)
+                .hasMessage("Author with id [%s] not found.".formatted(id));
+
+        verify(authorDAO, never()).deleteAuthorById(id);
+    }
+
+    @Test
+    void shouldThrowWhenUpdatingNonExistentAuthor() {
+        // Given
+        Long id = 1L;
+        AuthorDTO request = new AuthorDTO(id, "Jane", "Doe");
+
+        // When && Then
+        assertThatThrownBy(() -> underTest.updateAuthor(id, request))
+                .isInstanceOf(ResourceNotFoundException.class)
+                .hasMessage("Author with id [%s] not found.".formatted(id));
+
+        verify(authorDAO, never()).updateAuthor(any());
+    }
+
+    @Test
+    void shouldThrowWhenUpdatingWhenNoChangesFound() {
+        // Given
+        Long id = 1L;
+        AuthorDTO request = new AuthorDTO(id, "Jane", "Doe");
+        Author existingAuthor = new Author(id, "Jane", "Doe");
+
+        when(authorDAO.findById(id)).thenReturn(Optional.of(existingAuthor));
+
+
+        // When && Then
+        assertThatThrownBy(() -> underTest.updateAuthor(id, request))
+                .isInstanceOf(RequestValidationException.class)
+                .hasMessage("No data changes found.");
+
+        verify(authorDAO, never()).updateAuthor(any());
+    }
 
     @Test
     void shouldThrowWhenAddingAuthorWithExistingFirstNameLastName() {