Merge pull request #35 from nastiausenko/link-controller

added link controller and create link method

src/main/java/com/linkurlshorter/urlshortener/link/CreateLinkRequest.java

@@ -0,0 +1,29 @@
+package com.linkurlshorter.urlshortener.link;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+/**
+ * Represents a request object for creating a link.
+ * <p>
+ * This class encapsulates the data required to create a link, including the long URL.
+ * </p>
+ *
+ * <p>
+ * An instance of this class is typically used as a parameter in methods that create links.
+ * </p>
+ *
+ * <p>
+ * The long URL provided in the request is validated using the {@link UrlLongFormatValidator} annotation.
+ * </p>
+ *
+ * @author Artem Poliakov
+ * @version 1.0
+ */
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+public class CreateLinkRequest {
+    @UrlLongFormatValidator
+    private String longLink;
+}

src/main/java/com/linkurlshorter/urlshortener/link/CreateLinkResponse.java

@@ -0,0 +1,20 @@
+package com.linkurlshorter.urlshortener.link;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+/**
+ * A response class representing the result of a link creation request.
+ * It contains information about any error that occurred during the creation process
+ * and the generated short link if the creation was successful.
+ *
+ * @author Artem Poliakov
+ * @version 1.0
+ */
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+public class CreateLinkResponse {
+    private String error;
+    private String shortLink;
+}

src/main/java/com/linkurlshorter/urlshortener/link/InternalServerLinkException.java

@@ -0,0 +1,17 @@
+package com.linkurlshorter.urlshortener.link;
+/**
+ * Indicating unexpected exceptions which do not depend on user
+ * @author Artem Poliakov
+ * @version 1.0
+ * */
+public class InternalServerLinkException extends RuntimeException{
+    private static final String DEFAULT_MSG = "Unexpected server error occurred";
+
+    public InternalServerLinkException() {
+        super(DEFAULT_MSG);
+    }
+
+    public InternalServerLinkException(String msg) {
+        super(msg);
+    }
+}

src/main/java/com/linkurlshorter/urlshortener/link/LinkController.java

@@ -1,7 +1,67 @@
 package com.linkurlshorter.urlshortener.link;
 
-import org.springframework.stereotype.Controller;
+import com.linkurlshorter.urlshortener.user.User;
+import com.linkurlshorter.urlshortener.user.UserService;
+import jakarta.persistence.EntityManager;
+import jakarta.validation.Valid;
+import lombok.RequiredArgsConstructor;
+import org.apache.commons.lang3.RandomStringUtils;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.core.context.SecurityContextHolder;
+import org.springframework.web.bind.annotation.*;
 
-@Controller
+import java.time.LocalDateTime;
+import java.util.UUID;
+/**
+ * Controller for Link-related operations such as create, delete, update and get info + statistics
+ * @version 1.0
+ * @author Artem Poliakov
+ * */
+@RestController
+@RequiredArgsConstructor
+@RequestMapping("/link")
 public class LinkController {
+    private static final int SHORT_LINK_LIFETIME_IN_DAYS = 30;
+
+    private final LinkService linkService;
+    private final UserService userService;
+    private final EntityManager entityManager;
+    /**
+     * Controller method for creating a new link.
+     * <p>
+     * This method handles POST requests to create a new link. It accepts a valid {@link CreateLinkRequest}
+     * in the request body and generates a new short URL for the provided long URL. The short URL is then
+     * associated with the authenticated user and stored in the database. Upon successful creation of the link,
+     * a {@link CreateLinkResponse} containing the newly generated short URL is returned with a status of 200 (OK).
+     * If any errors occur during the process, an {@link InternalServerLinkException} is thrown.
+     * </p>
+     *
+     * @param createRequest the request object containing the long URL to be shortened
+     * @return a ResponseEntity containing the response object indicating the success or failure of the link creation,
+     * along with the generated short URL
+     * @throws InternalServerLinkException if an error occurs during the link creation process
+     * @see CreateLinkRequest
+     * @see CreateLinkResponse
+     * @see InternalServerLinkException
+     */
+    @PostMapping("/create")
+    public ResponseEntity<CreateLinkResponse> createLink(@RequestBody @Valid CreateLinkRequest createRequest){
+        Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
+        UUID userId = userService.findByEmail(authentication.getName()).getId();
+        String newShortUrl = RandomStringUtils.randomAlphanumeric(8);
+        try {
+            linkService.save(
+                    Link.builder()
+                            .longLink(createRequest.getLongLink())
+                            .shortLink(newShortUrl)
+                            .expirationTime(LocalDateTime.now().plusDays(SHORT_LINK_LIFETIME_IN_DAYS))
+                            .user(entityManager.getReference(User.class, userId))
+                            .build()  //TODO: add validations (short link being unique etc)
+            );
+        } catch(Exception e){
+            throw new InternalServerLinkException();
+        }
+        return ResponseEntity.ok(new CreateLinkResponse("ok", newShortUrl));
+    }
 }

src/main/java/com/linkurlshorter/urlshortener/link/LinkModifyingResponse.java

@@ -0,0 +1,30 @@
+package com.linkurlshorter.urlshortener.link;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+/**
+ * Represents a response object for modifying a link.
+ * <p>
+ * This class encapsulates the response data after attempting to modify a link,
+ * including any error messages that may occur during the process.
+ * </p>
+ *
+ * <p>
+ * An instance of this class is typically returned from methods that modify links,
+ * providing information about the success or failure of the operation.
+ * </p>
+ *
+ * <p>
+ * The {@code error} field contains any error message that occurred during the modification process.
+ * </p>
+ *
+ * @author [Author Name]
+ * @version 1.0
+ */
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+public class LinkModifyingResponse {
+    private String error;
+}