feat: added image endpoint basic functionality

src/main/java/cat/siesta/twochi_verifier_be/Controller.java

@@ -0,0 +1,23 @@
+package cat.siesta.twochi_verifier_be;
+
+import java.util.Map;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.bind.annotation.RestController;
+
+import lombok.AllArgsConstructor;
+
+@RestController
+@AllArgsConstructor
+public class Controller {
+    private ImageRetrieverService imageRetrieverService;
+
+    @GetMapping("/image")
+    @ResponseStatus(HttpStatus.OK)
+    public Map<String, Object> image() {
+        var imageAndToken = imageRetrieverService.getImage();
+        return Map.of("url", imageAndToken.getLeft(), "token", imageAndToken.getRight());
+    }
+}

src/main/java/cat/siesta/twochi_verifier_be/ImageRepository.java

@@ -0,0 +1,7 @@
+package cat.siesta.twochi_verifier_be;
+
+import java.net.URL;
+
+public interface ImageRepository {
+    public URL getImage();
+}

src/main/java/cat/siesta/twochi_verifier_be/ImageRetrieverService.java

@@ -0,0 +1,21 @@
+package cat.siesta.twochi_verifier_be;
+
+import java.net.URL;
+
+import org.apache.commons.lang3.tuple.Pair;
+import org.springframework.stereotype.Service;
+
+import lombok.AllArgsConstructor;
+
+@Service
+@AllArgsConstructor
+public class ImageRetrieverService {
+    private final TokenGenerator tokenGenerator;
+    private final ImageRepository imageRepository;
+
+    public Pair<URL, String> getImage() {
+        var url = imageRepository.getImage();
+        return Pair.of(url, tokenGenerator.generate(url.toString()));
+    }
+
+}

src/main/java/cat/siesta/twochi_verifier_be/TokenGenerator.java

@@ -0,0 +1,24 @@
+package cat.siesta.twochi_verifier_be;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.ToString;
+
+@EqualsAndHashCode
+@ToString
+@Getter
+@Component
+public class TokenGenerator {
+    private final String secret;
+
+    public TokenGenerator(@Value("${twochi.secret}") String secret) {
+        this.secret = secret;
+    }
+
+    public String generate(String url) {
+        return url + "\n" + secret;
+    }
+}

src/main/java/cat/siesta/twochi_verifier_be/rest/HomeResource.java

@@ -1,15 +0,0 @@
-package cat.siesta.twochi_verifier_be.rest;
-
-import org.springframework.web.bind.annotation.GetMapping;
-import org.springframework.web.bind.annotation.RestController;
-
-
-@RestController
-public class HomeResource {
-
-    @GetMapping("/")
-    public String index() {
-        return "\"Hello World!\"";
-    }
-
-}

src/main/resources/application.yml

@@ -11,3 +11,5 @@ spring:
       lifecycle-management: start-only
 springdoc:
   pathsToMatch: /
+twochi:
+  secret: ${TWOCHI_SECRET}

src/test/java/cat/siesta/twochi_verifier_be/ImageRetrieverTest.java

@@ -0,0 +1,55 @@
+package cat.siesta.twochi_verifier_be;
+
+import static org.mockito.Mockito.when;
+
+import java.net.URI;
+import java.net.URL;
+
+import org.apache.commons.lang3.RandomStringUtils;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.http.MediaType;
+import org.springframework.test.context.bean.override.mockito.MockitoBean;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
+import org.springframework.test.web.servlet.result.MockMvcResultMatchers;
+
+@SpringBootTest(properties = {
+        "twochi.secret = mysecret"
+})
+@AutoConfigureMockMvc
+public class ImageRetrieverTest {
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @Autowired
+    private TokenGenerator tokenGenerator;
+
+    @MockitoBean
+    private ImageRepository imageRepository;
+
+    @Test
+    void retrieves_image_with_valid_token() throws Exception {
+        var url = randomUrl();
+        var expectedToken = tokenGenerator.generate(url.toString());
+        var expectedJson = String.format("{'url': '%s', 'token': '%s'}", url, expectedToken);
+        when(imageRepository.getImage()).thenReturn(url);
+
+        this.mockMvc.perform(MockMvcRequestBuilders.get("/image"))
+                .andExpect(MockMvcResultMatchers.status().isOk())
+                .andExpect(MockMvcResultMatchers.content().contentType(MediaType.APPLICATION_JSON))
+                .andExpect(MockMvcResultMatchers.content().json(expectedJson));
+    }
+
+    private URL randomUrl() {
+        try {
+            return URI
+                    .create(String.format("https://%s.com", RandomStringUtils.insecure().nextAlphabetic(10))).toURL();
+        } catch (Exception e) {
+            throw new RuntimeException("failed to create random url");
+        }
+    }
+}