feat(admin): add Admin Dashboard GUI portal at /admin for managing email subscribers

backend/src/main/java/com/rit/portal/controller/AdminController.java

@@ -0,0 +1,162 @@
+package com.rit.portal.controller;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.StandardOpenOption;
+import java.util.*;
+
+@RestController
+@RequestMapping("/api/admin")
+@CrossOrigin(origins = "*")
+public class AdminController {
+
+    @Value("${admin.username:ritadmin}")
+    private String adminUsername;
+
+    @Value("${admin.password:ritadmin2026!}")
+    private String adminPassword;
+
+    private Path getRecipientsFilePath() {
+        // Try VPS deployment path first, fallback to workspace relative path
+        Path vpsPath = Paths.get("/var/www/freshers-hub/scripts/recipients.txt");
+        if (Files.exists(vpsPath.getParent())) {
+            return vpsPath;
+        }
+        Path localPath = Paths.get("scripts/recipients.txt").toAbsolutePath();
+        if (!Files.exists(localPath.getParent())) {
+            try {
+                Files.createDirectories(localPath.getParent());
+            } catch (IOException ignored) {}
+        }
+        return localPath;
+    }
+
+    @PostMapping("/login")
+    public ResponseEntity<Map<String, Object>> login(@RequestBody Map<String, String> payload) {
+        String username = payload.get("username");
+        String password = payload.get("password");
+
+        Map<String, Object> response = new HashMap<>();
+        if (adminUsername.equals(username) && adminPassword.equals(password)) {
+            response.put("success", true);
+            response.put("message", "Admin login successful");
+            response.put("token", "ADMIN_SESSION_TOKEN_RIT_2026");
+            return ResponseEntity.ok(response);
+        } else {
+            response.put("success", false);
+            response.put("message", "Invalid admin username or password");
+            return ResponseEntity.status(401).body(response);
+        }
+    }
+
+    @GetMapping("/recipients")
+    public ResponseEntity<List<String>> getRecipients() {
+        Path path = getRecipientsFilePath();
+        List<String> recipients = new ArrayList<>();
+        if (Files.exists(path)) {
+            try {
+                List<String> lines = Files.readAllLines(path);
+                for (String line : lines) {
+                    String trimmed = line.trim();
+                    if (!trimmed.isEmpty() && !trimmed.startsWith("#")) {
+                        recipients.add(trimmed);
+                    }
+                }
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+        return ResponseEntity.ok(recipients);
+    }
+
+    @PostMapping("/recipients")
+    public ResponseEntity<Map<String, Object>> addRecipient(@RequestBody Map<String, String> payload) {
+        String email = payload.get("email");
+        Map<String, Object> response = new HashMap<>();
+
+        if (email == null || !email.contains("@")) {
+            response.put("success", false);
+            response.put("message", "Please enter a valid email address");
+            return ResponseEntity.badRequest().body(response);
+        }
+
+        email = email.trim().toLowerCase();
+        Path path = getRecipientsFilePath();
+        List<String> existing = getRecipientsList(path);
+
+        if (existing.contains(email)) {
+            response.put("success", false);
+            response.put("message", "Email is already subscribed to notifications");
+            return ResponseEntity.badRequest().body(response);
+        }
+
+        existing.add(email);
+        saveRecipientsList(path, existing);
+
+        response.put("success", true);
+        response.put("message", "Added recipient: " + email);
+        response.put("recipients", existing);
+        return ResponseEntity.ok(response);
+    }
+
+    @DeleteMapping("/recipients")
+    public ResponseEntity<Map<String, Object>> removeRecipient(@RequestParam String email) {
+        Map<String, Object> response = new HashMap<>();
+        if (email == null) {
+            response.put("success", false);
+            response.put("message", "Email parameter is required");
+            return ResponseEntity.badRequest().body(response);
+        }
+
+        String target = email.trim().toLowerCase();
+        Path path = getRecipientsFilePath();
+        List<String> existing = getRecipientsList(path);
+
+        boolean removed = existing.removeIf(e -> e.equalsIgnoreCase(target));
+        if (removed) {
+            saveRecipientsList(path, existing);
+            response.put("success", true);
+            response.put("message", "Removed recipient: " + target);
+            response.put("recipients", existing);
+            return ResponseEntity.ok(response);
+        } else {
+            response.put("success", false);
+            response.put("message", "Email not found in recipient list");
+            return ResponseEntity.badRequest().body(response);
+        }
+    }
+
+    private List<String> getRecipientsList(Path path) {
+        List<String> recipients = new ArrayList<>();
+        if (Files.exists(path)) {
+            try {
+                List<String> lines = Files.readAllLines(path);
+                for (String line : lines) {
+                    String trimmed = line.trim();
+                    if (!trimmed.isEmpty() && !trimmed.startsWith("#")) {
+                        recipients.add(trimmed);
+                    }
+                }
+            } catch (IOException ignored) {}
+        }
+        return recipients;
+    }
+
+    private void saveRecipientsList(Path path, List<String> recipients) {
+        try {
+            if (path.getParent() != null && !Files.exists(path.getParent())) {
+                Files.createDirectories(path.getParent());
+            }
+            Files.write(path, recipients, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}

backend/src/main/resources/application.properties

@@ -14,3 +14,7 @@ server.port=8085
 
 # ─── GOOGLE OAUTH2 CONFIGURATION ───
 google.client.id=${GOOGLE_CLIENT_ID:81935488244-vmab5t8fipfof1n6l7di7eg4fve6k8lf.apps.googleusercontent.com}
+
+# ─── ADMIN PORTAL CREDENTIALS ───
+admin.username=${ADMIN_USERNAME:ritadmin}
+admin.password=${ADMIN_PASSWORD:ritadmin2026!}