feat(event): rest api for number assessment events

#2236

Author: jo-elimu

pom-dependency-tree.txt

@@ -1,4 +1,4 @@
-ai.elimu:webapp:war:2.6.87-SNAPSHOT
+ai.elimu:webapp:war:2.6.88-SNAPSHOT
 +- ai.elimu:model:jar:model-2.0.114:compile
 |  \- com.google.code.gson:gson:jar:2.13.1:compile
 |     \- com.google.errorprone:error_prone_annotations:jar:2.38.0:compile

src/main/java/ai/elimu/rest/v2/analytics/NumberAssessmentEventsRestController.java

@@ -0,0 +1,87 @@
+package ai.elimu.rest.v2.analytics;
+
+import ai.elimu.model.v2.enums.Language;
+import ai.elimu.util.AnalyticsHelper;
+import ai.elimu.util.ConfigHelper;
+import java.io.File;
+import jakarta.servlet.http.HttpServletResponse;
+import lombok.extern.slf4j.Slf4j;
+
+import org.apache.commons.io.FileUtils;
+import org.json.JSONObject;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.multipart.MultipartFile;
+
+/**
+ * REST API endpoint for receiving number assessment events from the 
+ * <a href="https://github.com/elimu-ai/analytics">Analytics</a> application.
+ */
+@RestController
+@RequestMapping(value = "/rest/v2/analytics/number-assessment-events/csv", produces = MediaType.APPLICATION_JSON_VALUE)
+@Slf4j
+public class NumberAssessmentEventsRestController {
+    
+    @PostMapping
+    public String handleUploadCsvRequest(
+            @RequestParam("file") MultipartFile multipartFile,
+            HttpServletResponse response
+    ) {
+        log.info("handleUploadCsvRequest");
+        
+        JSONObject jsonResponseObject = new JSONObject();
+        try {
+            String contentType = multipartFile.getContentType();
+            log.info("contentType: " + contentType);
+
+            long size = multipartFile.getSize();
+            log.info("size: " + size);
+            if (size == 0) {
+                throw new IllegalArgumentException("Empty file");
+            }
+
+            // Expected format: "7161a85a0e4751cd_4000022_number-assessment-events_2025-07-01.csv"
+            String originalFilename = multipartFile.getOriginalFilename();
+            log.info("originalFilename: " + originalFilename);
+            if (originalFilename.length() != "7161a85a0e4751cd_4000022_number-assessment-events_2025-07-01.csv".length()) {
+                throw new IllegalArgumentException("Unexpected filename");
+            }
+
+            String androidIdExtractedFromFilename = AnalyticsHelper.extractAndroidIdFromCsvFilename(originalFilename);
+            log.info("androidIdExtractedFromFilename: \"" + androidIdExtractedFromFilename + "\"");
+            
+            byte[] bytes = multipartFile.getBytes();
+            log.info("bytes.length: " + bytes.length);
+            
+            // Store the original CSV file on the filesystem
+            File elimuAiDir = new File(System.getProperty("user.home"), ".elimu-ai");
+            File languageDir = new File(elimuAiDir, "lang-" + Language.valueOf(ConfigHelper.getProperty("content.language")));
+            File analyticsDir = new File(languageDir, "analytics");
+            File androidIdDir = new File(analyticsDir, "android-id-" + androidIdExtractedFromFilename);
+            File numberAssessmentEventsDir = new File(androidIdDir, "number-assessment-events");
+            numberAssessmentEventsDir.mkdirs();
+            File csvFile = new File(numberAssessmentEventsDir, originalFilename);
+            log.info("Storing CSV file at " + csvFile);
+            FileUtils.writeByteArrayToFile(csvFile, bytes);
+            log.info("csvFile.exists(): " + csvFile.exists());
+            
+            jsonResponseObject.put("result", "success");
+            jsonResponseObject.put("successMessage", "The CSV file was uploaded");
+            response.setStatus(HttpStatus.OK.value());
+        } catch (Exception ex) {
+            log.error(ex.getMessage());
+            
+            jsonResponseObject.put("result", "error");
+            jsonResponseObject.put("errorMessage", ex.getMessage());
+            response.setStatus(HttpStatus.INTERNAL_SERVER_ERROR.value());
+        }
+        
+        String jsonResponse = jsonResponseObject.toString();
+        log.info("jsonResponse: " + jsonResponse);
+        return jsonResponse;
+    }
+}