# 🧠 HALE API Integration Guide (Next.js, Flutter, React, Mobile)

Welcome! This guide outlines how to integrate the HALE (Adaptive Learning Engine) backend into any frontend application. The HALE backend is a production-grade FastAPI app with a Reinforcement Learning engine that dynamically customizes study plans.

---

## 🌐 Server Details
- **Production API URL**: `https://raunak211006-hale-api.hf.space`
- **Swagger Documentation**: `https://raunak211006-hale-api.hf.space/docs`
- **Response Format**: JSON only.
- **Authentication**: JWT Bearer token in headers: `Authorization: Bearer <token>`

---

## 🔄 The Complete Lifecycle Flow
To build a seamless interface, your frontend should follow this logical flow:

```mermaid
graph TD
    A[1. Auth: Login/Register] -->|JWT Token| B[2. Setup: Create Goals & Timetable]
    B --> C[3. Daily Plan: Fetch Today's Tasks]
    C -->|If tasks pending| D[4. Work: Complete Tasks & Update State]
    D -->|Award XP + RL Reward| C
    C -->|If all tasks done| E[5. Day Close: Done for Today]
    E -->|Unlock Next Day Preview| F[6. Next Day Preview]
```

---

## 🛠️ Step-by-Step Implementation

### 1. Authentication (Login & JWT Store)
Save the `access_token` and `refresh_token` in `localStorage`, `secure_store`, or cookies.

#### Request Example (Javascript/Typescript):
```typescript
const API_URL = "https://raunak211006-hale-api.hf.space";

// 1. Register User
async function registerUser(userId: string, password: string, email?: string) {
  const res = await fetch(`${API_URL}/api/auth/register`, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ user_id: userId, password, email })
  });
  return res.json();
}

// 2. Login User
async function loginUser(userId: string, password: string) {
  const res = await fetch(`${API_URL}/api/auth/login`, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ user_id: userId, password })
  });
  const data = await res.json(); // returns { access_token, refresh_token }
  
  if (data.access_token) {
    localStorage.setItem("access_token", data.access_token);
    localStorage.setItem("refresh_token", data.refresh_token);
  }
  return data;
}
```

---

### 2. Authenticated Fetch Helper
Use this helper to automatically inject the Bearer token into all headers:

```typescript
async function fetchWithAuth(endpoint: string, options: RequestInit = {}) {
  const token = localStorage.getItem("access_token");
  const headers = {
    "Content-Type": "application/json",
    ...(token ? { "Authorization": `Bearer ${token}` } : {}),
    ...options.headers,
  };

  const response = await fetch(`${API_URL}${endpoint}`, { ...options, headers });
  
  if (response.status === 401) {
     // Handle expired token: refresh token logic goes here
     console.error("Session expired. Redirect to login.");
  }
  
  return response.json();
}
```

---

### 3. Create a Learning Goal
Curriculum plans are generated by Gemini AI instantly based on the prompt.

```typescript
async function createGoal(goalText: string, days = 30, priority = 1) {
  return fetchWithAuth("/api/goals/", {
    method: "POST",
    body: JSON.stringify({
      goal: goalText,             // e.g. "Master React and Typescript"
      duration_days: days,
      priority: priority          // Higher priority (1) gets more study allocation
    })
  });
}
```

---

### 4. Fetch the Daily Plan
This returns today's tasks and the Reinforcement Learning behavior engine's state parameters.

```typescript
async function getDailyPlan() {
  return fetchWithAuth("/api/plan");
}
```

#### JSON Response Schema:
```json
{
  "date": "2026-05-21",
  "tasks": [
    "Core: Learn JSX Syntax (~40 min)"
  ],
  "tasks_detail": [
    {
      "type": "core",
      "title": "Learn JSX Syntax",
      "est_min": 40,
      "deliverable": "Build static portfolio header",
      "goal_id": 1,
      "goal_label": "React.js Mastery",
      "date": "2026-05-21"
    }
  ],
  "behavior": {
    "action_label": "Normal",
    "intensity": 0.65,
    "mood": 0.8,
    "fatigue": 0.1,
    "cold_start": false,
    "plateau_detected": false
  },
  "coach_message": "Awesome energy today! Let's conquer this first React building block.",
  "streak": 5,
  "total_minutes": 40,
  "goals_count": 1,
  "next_day_preview": null
}
```

---

### 5. Mark a Task Complete (Triggers RL reward)
When completing a task, the RL engine modifies user parameters (`alpha`/`beta` parameters) based on task duration and subjective satisfaction.

```typescript
async function completeTask(date: string, goalId: number, durationMin: number, satisfaction: number) {
  return fetchWithAuth("/api/complete-task", {
    method: "POST",
    body: JSON.stringify({
      date: date,                    // YYYY-MM-DD from tasks_detail
      goal_id: goalId,               // goal_id from tasks_detail
      actual_duration_min: durationMin,
      satisfaction: satisfaction,    // Float between 0.0 (hated it) to 1.0 (loved it)
      notes: "Completed all code challenges!"
    })
  });
}
```
*Note: If `all_completed` is returned as `true` in the response, you can immediately notify the user and transition them to the next day's preview.*

---

### 6. Done For Today (Close Day Manually)
Forces manual closure of the day. All remaining tasks are completed, streak counts are updated, and the **Next Day's Preview** is generated.

```typescript
async function closeDay() {
  return fetchWithAuth("/api/day/complete", { method: "POST" });
}
```

#### Day Close Response Sample:
```json
{
  "closed": 1,
  "message": "Day closed. 1 task(s) marked as done.",
  "date": "2026-05-21",
  "streak": 6,
  "xp_gained": 15,
  "total_xp": 450,
  "level": 3,
  "leveled_up": false,
  "next_day_preview": {
    "action_label": "Deep Work",
    "intensity": 0.85,
    "preview": true
  }
}
```

---

### 7. Get Tomorrow's Preview Explicitly
Fetch a preview of tomorrow's focus and adaptive intensity without actually progressing the current state.

```typescript
async function getNextDayPreview() {
  return fetchWithAuth("/api/plan/next");
}
```

---

## ⚡ Real-Time Adaptive Feedback State

You should allow the user to input their behavioral metrics periodically (e.g., mood, fatigue, sleep quality). This recalibrates the Reinforcement Learning engine instantly:

```typescript
async function updateBehaviorState(mood: number, fatigue: number, stress: number, sleepQuality: number) {
  return fetchWithAuth("/api/update-state", {
    method: "POST",
    body: JSON.stringify({
      mood: mood,                 // 0.0 to 1.0
      fatigue: fatigue,           // 0.0 to 1.0
      stress: stress,             // 0.0 to 1.0
      sleep_quality: sleepQuality // 0.0 to 1.0
    })
  });
}
```
*Call this when a user changes their status slider. The next call to `/api/plan` will return adapted durations based on these metrics.*

---

## 📊 Summary Table of API Endpoints

| Resource | HTTP Method | Endpoint | Description |
|---|---|---|---|
| **Auth** | `POST` | `/api/auth/register` | Register new user |
| **Auth** | `POST` | `/api/auth/login` | Login and get tokens |
| **Goals** | `POST` | `/api/goals/` | Create a goal with AI syllabus |
| **Goals** | `GET` | `/api/goals/` | List user goals |
| **Daily Plan** | `GET` | `/api/plan` | Fetch current adaptive daily tasks |
| **Tasks** | `POST` | `/api/complete-task` | Mark task completed (awards XP/RL) |
| **Tasks** | `POST` | `/api/skip-task` | Skip a task |
| **Lifecycle** | `POST` | `/api/day/complete` | Complete day & generate next preview |
| **Lifecycle** | `GET` | `/api/plan/next` | Preview tomorrow's focus |
| **Lifecycle** | `GET` | `/api/day/status` | Today's completion details |
| **Analytics** | `GET` | `/api/stats` | Gamification stats (level, XP, streaks) |
| **Behavior** | `POST` | `/api/update-state` | Update mood/fatigue to adapt engine |

---

## 🛡️ Production Security Checklist
1. Always keep the Hugging Face `SECRET_KEY` secret.
2. In production, always set the connection string `DATABASE_URL` to the Neon PostgreSQL cluster.
3. CORS configuration allows `*` by default for testing. You can restrict it in Space Settings to only allow your domain (e.g. `https://my-lifeos-app.vercel.app`).