Improve student activity registration system

requirements.txt

@@ -1,4 +1,5 @@
 fastapi
 uvicorn
 httpx
-watchfiles
+watchfiles
+pytest

src/app.py

@@ -38,6 +38,42 @@
         "schedule": "Mondays, Wednesdays, Fridays, 2:00 PM - 3:00 PM",
         "max_participants": 30,
         "participants": ["john@mergington.edu", "olivia@mergington.edu"]
+    },
+    "Basketball Team": {
+        "description": "Competitive basketball team for intramural and regional tournaments",
+        "schedule": "Mondays and Wednesdays, 4:00 PM - 5:30 PM",
+        "max_participants": 15,
+        "participants": ["alex@mergington.edu"]
+    },
+    "Tennis Club": {
+        "description": "Learn tennis skills and participate in friendly matches",
+        "schedule": "Tuesdays and Thursdays, 4:00 PM - 5:00 PM",
+        "max_participants": 12,
+        "participants": ["isabella@mergington.edu", "lucas@mergington.edu"]
+    },
+    "Art Studio": {
+        "description": "Explore painting, drawing, and mixed media techniques",
+        "schedule": "Wednesdays, 3:30 PM - 5:00 PM",
+        "max_participants": 18,
+        "participants": ["grace@mergington.edu"]
+    },
+    "Music Band": {
+        "description": "Join our school band and perform at concerts and events",
+        "schedule": "Mondays and Thursdays, 3:30 PM - 4:30 PM",
+        "max_participants": 25,
+        "participants": ["noah@mergington.edu", "ava@mergington.edu"]
+    },
+    "Debate Team": {
+        "description": "Develop critical thinking and public speaking skills through competitive debate",
+        "schedule": "Fridays, 4:00 PM - 5:30 PM",
+        "max_participants": 16,
+        "participants": ["mason@mergington.edu"]
+    },
+    "Science Club": {
+        "description": "Conduct experiments and explore scientific concepts through hands-on projects",
+        "schedule": "Tuesdays, 3:30 PM - 5:00 PM",
+        "max_participants": 20,
+        "participants": ["ethan@mergington.edu", "chloe@mergington.edu"]
     }
 }
 
@@ -62,6 +98,27 @@ def signup_for_activity(activity_name: str, email: str):
     # Get the specific activity
     activity = activities[activity_name]
 
+    # Validate student is not already signed up
+    if email in activity["participants"]:
+        raise HTTPException(status_code=400, detail="Student already signed up")
+
     # Add student
     activity["participants"].append(email)
     return {"message": f"Signed up {email} for {activity_name}"}
+
+
+@app.delete("/activities/{activity_name}/participants")
+def unregister_from_activity(activity_name: str, email: str):
+    """Unregister a student from an activity"""
+    # Validate activity exists
+    if activity_name not in activities:
+        raise HTTPException(status_code=404, detail="Activity not found")
+
+    activity = activities[activity_name]
+
+    # Validate participant exists in this activity
+    if email not in activity["participants"]:
+        raise HTTPException(status_code=404, detail="Participant not found in this activity")
+
+    activity["participants"].remove(email)
+    return {"message": f"Removed {email} from {activity_name}"}

src/static/app.js

@@ -4,27 +4,63 @@ document.addEventListener("DOMContentLoaded", () => {
   const signupForm = document.getElementById("signup-form");
   const messageDiv = document.getElementById("message");
 
+  function showMessage(message, type) {
+    messageDiv.textContent = message;
+    messageDiv.className = type;
+    messageDiv.classList.remove("hidden");
+
+    setTimeout(() => {
+      messageDiv.classList.add("hidden");
+    }, 5000);
+  }
+
   // Function to fetch activities from API
   async function fetchActivities() {
     try {
-      const response = await fetch("/activities");
+      const response = await fetch("/activities", { cache: "no-store" });
+      if (!response.ok) {
+        throw new Error(`Failed to fetch activities: ${response.status}`);
+      }
       const activities = await response.json();
 
       // Clear loading message
       activitiesList.innerHTML = "";
+      activitySelect.innerHTML = '<option value="">-- Select an activity --</option>';
 
       // Populate activities list
       Object.entries(activities).forEach(([name, details]) => {
         const activityCard = document.createElement("div");
         activityCard.className = "activity-card";
 
         const spotsLeft = details.max_participants - details.participants.length;
+        const participantsMarkup = details.participants.length
+          ? `<ul class="participant-list">${details.participants
+              .map(
+                (participant) =>
+                  `<li class="participant-item">
+                    <span class="participant-email">${participant}</span>
+                    <button
+                      type="button"
+                      class="participant-remove"
+                      data-activity="${name}"
+                      data-email="${participant}"
+                      aria-label="Remove ${participant} from ${name}"
+                      title="Unregister participant"
+                    >&times;</button>
+                  </li>`
+              )
+              .join("")}</ul>`
+          : '<p class="participant-empty">No participants yet. Be the first to sign up.</p>';
 
         activityCard.innerHTML = `
           <h4>${name}</h4>
           <p>${details.description}</p>
           <p><strong>Schedule:</strong> ${details.schedule}</p>
           <p><strong>Availability:</strong> ${spotsLeft} spots left</p>
+          <div class="participants-section">
+            <p class="participants-title">Participants</p>
+            ${participantsMarkup}
+          </div>
         `;
 
         activitiesList.appendChild(activityCard);
@@ -59,25 +95,50 @@ document.addEventListener("DOMContentLoaded", () => {
       const result = await response.json();
 
       if (response.ok) {
-        messageDiv.textContent = result.message;
-        messageDiv.className = "success";
+        showMessage(result.message, "success");
         signupForm.reset();
+        await fetchActivities();
       } else {
-        messageDiv.textContent = result.detail || "An error occurred";
-        messageDiv.className = "error";
+        showMessage(result.detail || "An error occurred", "error");
       }
+    } catch (error) {
+      showMessage("Failed to sign up. Please try again.", "error");
+      console.error("Error signing up:", error);
+    }
+  });
+
+  activitiesList.addEventListener("click", async (event) => {
+    const removeButton = event.target.closest(".participant-remove");
+    if (!removeButton) {
+      return;
+    }
+
+    const activity = removeButton.dataset.activity;
+    const email = removeButton.dataset.email;
+
+    if (!activity || !email) {
+      return;
+    }
+
+    try {
+      const response = await fetch(
+        `/activities/${encodeURIComponent(activity)}/participants?email=${encodeURIComponent(email)}`,
+        {
+          method: "DELETE",
+        }
+      );
 
-      messageDiv.classList.remove("hidden");
+      const result = await response.json();
 
-      // Hide message after 5 seconds
-      setTimeout(() => {
-        messageDiv.classList.add("hidden");
-      }, 5000);
+      if (response.ok) {
+        showMessage(result.message, "success");
+        await fetchActivities();
+      } else {
+        showMessage(result.detail || "Failed to unregister participant.", "error");
+      }
     } catch (error) {
-      messageDiv.textContent = "Failed to sign up. Please try again.";
-      messageDiv.className = "error";
-      messageDiv.classList.remove("hidden");
-      console.error("Error signing up:", error);
+      showMessage("Failed to unregister participant. Please try again.", "error");
+      console.error("Error unregistering participant:", error);
     }
   });
 

src/static/styles.css

@@ -74,6 +74,73 @@ section h3 {
   margin-bottom: 8px;
 }
 
+.participants-section {
+  margin-top: 14px;
+  padding: 12px;
+  border: 1px solid #dbe5ff;
+  border-radius: 8px;
+  background: linear-gradient(180deg, #f5f8ff 0%, #eef3ff 100%);
+}
+
+.participants-title {
+  margin-bottom: 8px;
+  font-weight: 700;
+  color: #1a237e;
+  letter-spacing: 0.2px;
+}
+
+.participant-list {
+  margin: 0;
+  padding: 0;
+  list-style: none;
+}
+
+.participant-item {
+  margin-bottom: 6px;
+  color: #24335a;
+  word-break: break-word;
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 10px;
+  padding: 8px 10px;
+  border-radius: 6px;
+  background-color: rgba(255, 255, 255, 0.75);
+  border: 1px solid #d7e2ff;
+}
+
+.participant-email {
+  overflow-wrap: anywhere;
+}
+
+.participant-remove {
+  width: 28px;
+  height: 28px;
+  border-radius: 50%;
+  border: 1px solid #f2b8b5;
+  background-color: #fff4f4;
+  color: #b42318;
+  font-size: 18px;
+  font-weight: 700;
+  line-height: 1;
+  padding: 0;
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  flex-shrink: 0;
+}
+
+.participant-remove:hover {
+  background-color: #ffe7e5;
+  border-color: #eaa6a2;
+}
+
+.participant-empty {
+  margin: 0;
+  color: #5c6d9c;
+  font-style: italic;
+}
+
 .form-group {
   margin-bottom: 15px;
 }

tests/conftest.py

@@ -0,0 +1,19 @@
+import copy
+
+import pytest
+from fastapi.testclient import TestClient
+
+from src.app import activities, app
+
+
+@pytest.fixture()
+def client():
+    return TestClient(app)
+
+
+@pytest.fixture(autouse=True)
+def restore_activities_state():
+    snapshot = copy.deepcopy(activities)
+    yield
+    activities.clear()
+    activities.update(snapshot)

tests/test_endpoints.py

@@ -0,0 +1,55 @@
+from src.app import activities
+
+
+def test_get_activities_returns_expected_structure(client):
+    # Arrange
+
+    # Act
+    response = client.get("/activities")
+
+    # Assert
+    assert response.status_code == 200
+    data = response.json()
+    assert isinstance(data, dict)
+    assert "Chess Club" in data
+    assert {
+        "description",
+        "schedule",
+        "max_participants",
+        "participants",
+    }.issubset(data["Chess Club"].keys())
+
+
+def test_signup_adds_participant_successfully(client):
+    # Arrange
+    activity_name = "Chess Club"
+    email = "new.student@mergington.edu"
+
+    # Act
+    response = client.post(
+        f"/activities/{activity_name}/signup",
+        params={"email": email},
+    )
+
+    # Assert
+    assert response.status_code == 200
+    assert response.json()["message"] == f"Signed up {email} for {activity_name}"
+    assert email in activities[activity_name]["participants"]
+
+
+def test_delete_unregisters_participant_successfully(client):
+    # Arrange
+    activity_name = "Chess Club"
+    email = "remove.me@mergington.edu"
+    activities[activity_name]["participants"].append(email)
+
+    # Act
+    response = client.delete(
+        f"/activities/{activity_name}/participants",
+        params={"email": email},
+    )
+
+    # Assert
+    assert response.status_code == 200
+    assert response.json()["message"] == f"Removed {email} from {activity_name}"
+    assert email not in activities[activity_name]["participants"]