main.py

import os
import io
import uuid
import re
import time
import json
import traceback
import wave
from datetime import datetime, timedelta

from flask import Flask, request, jsonify
from flask_cors import CORS
import firebase_admin
from firebase_admin import credentials, db, storage, auth
from PIL import Image
import requests

# Import and configure Google GenAI, matching the Streamlit app
from google import genai
from google.genai import types

# -----------------------------------------------------------------------------
# 1. CONFIGURATION & INITIALIZATION
# -----------------------------------------------------------------------------

# Initialize Flask app and CORS
app = Flask(__name__)
CORS(app)

# --- Firebase Initialization ---
try:
    credentials_json_string = os.environ.get("FIREBASE")
    if not credentials_json_string:
        raise ValueError("The FIREBASE environment variable is not set.")
    
    credentials_json = json.loads(credentials_json_string)
    firebase_db_url = os.environ.get("Firebase_DB")
    firebase_storage_bucket = os.environ.get("Firebase_Storage")

    if not firebase_db_url or not firebase_storage_bucket:
        raise ValueError("Firebase_DB and Firebase_Storage environment variables must be set.")

    cred = credentials.Certificate(credentials_json)
    firebase_admin.initialize_app(cred, {
        'databaseURL': firebase_db_url,
        'storageBucket': firebase_storage_bucket
    })
    print("Firebase Admin SDK initialized successfully.")
except Exception as e:
    print(f"FATAL: Error initializing Firebase: {e}")
    exit(1)

# Initialize Firebase services
bucket = storage.bucket()
db_ref = db.reference()

# --- Create Dummy Admin Account on Startup ---
# This block ensures the specified admin user exists with the correct privileges.
# It's designed to run safely on every application start.
try:
    ADMIN_EMAIL = "rairorr@gmail.com"
    print(f"Checking for admin user: {ADMIN_EMAIL}")
    try:
        # 1. Check if the user exists in Firebase Auth by email. [4]
        user = auth.get_user_by_email(ADMIN_EMAIL)
        # 2. If user exists, ensure their DB record is correct
        user_ref = db_ref.child(f'users/{user.uid}')
        user_ref.update({
            'is_admin': True,
            'credits': 9999
        })
        print(f"Admin user '{ADMIN_EMAIL}' found and privileges verified.")
    except auth.UserNotFoundError:
        # 3. If user does not exist in Auth, create them. [8]
        print(f"Admin user '{ADMIN_EMAIL}' not found, creating a new one.")
        user = auth.create_user(
            email=ADMIN_EMAIL,
            password="neo2025"
        )
        # 4. Create their record in the Realtime Database
        db_ref.child(f'users/{user.uid}').set({
            'email': ADMIN_EMAIL,
            'credits': 9999,
            'is_admin': True,
            'createdAt': datetime.utcnow().isoformat()
        })
        print(f"Successfully created admin user '{ADMIN_EMAIL}'.")
except Exception as e:
    # Catch any other exceptions during the process
    print(f"FATAL: An error occurred during admin account setup: {e}")


# --- Google GenAI Client Initialization (as per Streamlit app) ---
try:
    api_key = os.environ.get("Gemini")
    if not api_key:
        raise ValueError("The 'Gemini' environment variable for the API key is not set.")
    
    client = genai.Client(api_key=api_key)
    print("Google GenAI Client initialized successfully.")
except Exception as e:
    print(f"FATAL: Error initializing GenAI Client: {e}")
    exit(1)

# --- Model Constants (as per Streamlit app) ---
CATEGORY_MODEL = "gemini-2.0-flash-exp"
GENERATION_MODEL = "gemini-2.0-flash-exp-image-generation"
TTS_MODEL = "gemini-2.5-flash-preview-tts"


# -----------------------------------------------------------------------------
# 2. HELPER FUNCTIONS (Adapted directly from Streamlit App & Template)
# -----------------------------------------------------------------------------

def verify_token(auth_header):
    """Verifies the Firebase ID token from the Authorization header."""
    if not auth_header or not auth_header.startswith('Bearer '):
        return None
    token = auth_header.split('Bearer ')[1]
    try:
        decoded_token = auth.verify_id_token(token)
        return decoded_token['uid']
    except Exception as e:
        print(f"Token verification failed: {e}")
        return None

def verify_admin(auth_header):
    """Verifies if the user is an admin."""
    uid = verify_token(auth_header)
    if not uid:
        raise PermissionError('Invalid or missing user token')
    
    user_ref = db_ref.child(f'users/{uid}')
    user_data = user_ref.get()
    if not user_data or not user_data.get('is_admin', False):
        raise PermissionError('Admin access required')
    return uid

def upload_to_storage(data_bytes, destination_blob_name, content_type):
    """Uploads a bytes object to Firebase Storage and returns its public URL."""
    blob = bucket.blob(destination_blob_name)
    blob.upload_from_string(data_bytes, content_type=content_type)
    blob.make_public()
    return blob.public_url

def parse_numbered_steps(text):
    """Helper to parse numbered steps out of Gemini text."""
    text = "\n" + text
    steps_found = re.findall(r"\n\s*(\d+)\.\s*(.*)", text, re.MULTILINE)
    return [{"stepNumber": int(num), "text": desc.strip()} for num, desc in steps_found]

def _convert_pcm_to_wav(pcm_data, sample_rate=24000, channels=1, sample_width=2):
    """Wraps raw PCM audio data in a WAV container in memory."""
    audio_buffer = io.BytesIO()
    with wave.open(audio_buffer, 'wb') as wf:
        wf.setnchannels(channels)
        wf.setsampwidth(sample_width)
        wf.setframerate(sample_rate)
        wf.writeframes(pcm_data)
    audio_buffer.seek(0)
    return audio_buffer.getvalue()

def generate_tts_audio_and_upload(text_to_speak, uid, project_id, step_num):
    """Generates audio using the exact method from the Streamlit app and uploads it."""
    try:
        response = client.models.generate_content(
            model=TTS_MODEL,
            contents=f"Say clearly: {text_to_speak}",
            config=types.GenerateContentConfig(
                response_modalities=["AUDIO"],
                speech_config=types.SpeechConfig(
                    voice_config=types.VoiceConfig(
                        prebuilt_voice_config=types.PrebuiltVoiceConfig(voice_name='Kore')
                    )
                ),
            )
        )
        audio_part = response.candidates[0].content.parts[0]
        audio_data = audio_part.inline_data.data
        mime_type = audio_part.inline_data.mime_type
        
        final_audio_bytes = _convert_pcm_to_wav(audio_data) if 'pcm' in mime_type else audio_data
        
        audio_path = f"users/{uid}/projects/{project_id}/narrations/step_{step_num}.wav"
        return upload_to_storage(final_audio_bytes, audio_path, 'audio/wav')
    except Exception as e:
        print(f"Error during TTS generation for step {step_num}: {e}")
        return None

def send_text_request(model_name, prompt, image):
    """Helper to send requests that expect only a text response."""
    try:
        chat = client.chats.create(model=model_name)
        response = chat.send_message([prompt, image])
        response_text = "".join(part.text for part in response.candidates[0].content.parts if hasattr(part, 'text'))
        return response_text.strip()
    except Exception as e:
        print(f"Error with model {model_name}: {e}")
        return None

# -----------------------------------------------------------------------------
# 3. AUTHENTICATION & USER MANAGEMENT
# -----------------------------------------------------------------------------

@app.route('/api/auth/signup', methods=['POST'])
def signup():
    try:
        data = request.get_json()
        email, password = data.get('email'), data.get('password')
        if not email or not password: return jsonify({'error': 'Email and password are required'}), 400

        user = auth.create_user(email=email, password=password)
        user_ref = db_ref.child(f'users/{user.uid}')
        user_data = {'email': email, 'credits': 15, 'is_admin': False, 'createdAt': datetime.utcnow().isoformat()}
        user_ref.set(user_data)
        return jsonify({'success': True, 'uid': user.uid, **user_data}), 201
    except Exception as e:
        return jsonify({'error': str(e)}), 400

@app.route('/api/auth/social-signin', methods=['POST'])
def social_signin():
    """
    Ensures a user record exists in the Realtime Database after a social login
    (like Google Sign-In). The client should call this endpoint immediately after
    a successful Firebase authentication on their side, sending the
    Firebase ID Token. This creates the user's profile in our database if it's
    their first time.
    """
    uid = verify_token(request.headers.get('Authorization'))
    if not uid:
        return jsonify({'error': 'Invalid or expired token'}), 401

    user_ref = db_ref.child(f'users/{uid}')
    user_data = user_ref.get()

    if user_data:
        # User already has a profile in our DB, return it.
        return jsonify({'uid': uid, **user_data}), 200
    else:
        # This is a new user (first social login), create their profile.
        try:
            # Get user details from Firebase Auth service. [8]
            firebase_user = auth.get_user(uid)
            
            # Create the user profile in our Realtime Database
            new_user_data = {
                'email': firebase_user.email,
                'credits': 15,  # Standard starting credits
                'is_admin': False,
                'createdAt': datetime.utcnow().isoformat()
            }
            user_ref.set(new_user_data)
            
            # Return the newly created profile
            return jsonify({'success': True, 'uid': uid, **new_user_data}), 201
        except Exception as e:
            print(f"Error creating profile for new social user {uid}: {e}")
            return jsonify({'error': f'Failed to create user profile: {str(e)}'}), 500

@app.route('/api/user/profile', methods=['GET'])
def get_user_profile():
    uid = verify_token(request.headers.get('Authorization'))
    if not uid: return jsonify({'error': 'Invalid or expired token'}), 401
    
    user_data = db_ref.child(f'users/{uid}').get()
    if not user_data: return jsonify({'error': 'User not found'}), 404
    
    return jsonify({'uid': uid, **user_data})

# -----------------------------------------------------------------------------
# 4. FEEDBACK AND CREDIT REQUESTS (USER-FACING)
# -----------------------------------------------------------------------------

@app.route('/api/feedback', methods=['POST'])
def submit_feedback():
    uid = verify_token(request.headers.get('Authorization'))
    if not uid: return jsonify({'error': 'Invalid or expired token'}), 401

    try:
        data = request.get_json()
        if not data or not data.get('message'): return jsonify({'error': 'Message is required'}), 400

        user_email = (db_ref.child(f'users/{uid}').get() or {}).get('email', 'unknown')
        
        feedback_ref = db_ref.child('feedback').push()
        feedback_record = {
            "feedbackId": feedback_ref.key,
            "userId": uid,
            "userEmail": user_email,
            "type": data.get('type', 'general'),
            "message": data.get('message'),
            "createdAt": datetime.utcnow().isoformat(),
            "status": "open"
        }
        feedback_ref.set(feedback_record)
        return jsonify({"success": True, "feedbackId": feedback_ref.key}), 201
    except Exception as e:
        return jsonify({'error': str(e)}), 500

@app.route('/api/user/request-credits', methods=['POST'])
def request_credits():
    uid = verify_token(request.headers.get('Authorization'))
    if not uid: return jsonify({'error': 'Invalid or expired token'}), 401
    
    try:
        data = request.get_json()
        if not data or 'requested_credits' not in data: return jsonify({'error': 'requested_credits is required'}), 400

        request_ref = db_ref.child('credit_requests').push()
        request_ref.set({
            'requestId': request_ref.key,
            'userId': uid,
            'requested_credits': data['requested_credits'],
            'status': 'pending',
            'requestedAt': datetime.utcnow().isoformat()
        })
        return jsonify({'success': True, 'requestId': request_ref.key})
    except Exception as e:
        return jsonify({'error': str(e)}), 500

# -----------------------------------------------------------------------------
# 5. ADMIN ENDPOINTS
# -----------------------------------------------------------------------------

@app.route('/api/admin/profile', methods=['GET'])
def get_admin_profile():
    try:
        admin_uid = verify_admin(request.headers.get('Authorization'))
        
        # Fetch all necessary data from Firebase in one go
        all_users = db_ref.child('users').get() or {}
        all_projects = db_ref.child('projects').get() or {}
        all_feedback = db_ref.child('feedback').get() or {}
        all_credit_requests = db_ref.child('credit_requests').get() or {}

        # --- User Statistics Calculation ---
        total_users = len(all_users)
        admin_count = 0
        total_credits_in_system = 0
        new_users_last_7_days = 0
        seven_days_ago = datetime.utcnow() - timedelta(days=7)

        for user_data in all_users.values():
            if user_data.get('is_admin', False):
                admin_count += 1
            total_credits_in_system += user_data.get('credits', 0)
            
            # Check for new users
            try:
                created_at_str = user_data.get('createdAt')
                if created_at_str:
                    # Accommodate different possible ISO formats
                    user_created_at = datetime.fromisoformat(created_at_str.replace('Z', '+00:00'))
                    if user_created_at.replace(tzinfo=None) > seven_days_ago:
                        new_users_last_7_days += 1
            except (ValueError, TypeError):
                # Ignore if date format is invalid or missing
                pass

        # --- Project Statistics Calculation ---
        total_projects = len(all_projects)
        projects_by_status = {
            "awaiting_approval": 0,
            "awaiting_selection": 0,
            "ready": 0,
            "unknown": 0
        }
        projects_by_category = {}

        for project_data in all_projects.values():
            # Tally by status
            status = project_data.get('status', 'unknown')
            projects_by_status[status] = projects_by_status.get(status, 0) + 1
            
            # Tally by category
            category = project_data.get('category', 'N/A')
            projects_by_category[category] = projects_by_category.get(category, 0) + 1

        # --- System Health Calculation ---
        open_feedback_count = sum(1 for fb in all_feedback.values() if fb.get('status') == 'open')
        pending_requests_count = sum(1 for req in all_credit_requests.values() if req.get('status') == 'pending')

        # Assemble the final response object
        admin_personal_data = all_users.get(admin_uid, {})
        
        response_data = {
            'uid': admin_uid,
            'email': admin_personal_data.get('email'),
            'credits': admin_personal_data.get('credits'),
            'is_admin': True,
            'dashboardStats': {
                'users': {
                    'total': total_users,
                    'admins': admin_count,
                    'regular': total_users - admin_count,
                    'newLast7Days': new_users_last_7_days,
                    'totalCreditsInSystem': total_credits_in_system
                },
                'projects': {
                    'total': total_projects,
                    'byStatus': projects_by_status,
                    'byCategory': projects_by_category
                },
                'system': {
                    'openFeedback': open_feedback_count,
                    'pendingCreditRequests': pending_requests_count
                }
            }
        }
        
        return jsonify(response_data), 200

    except PermissionError as e:
        return jsonify({'error': str(e)}), 403 # Use 403 Forbidden for permission issues
    except Exception as e:
        print(traceback.format_exc())
        return jsonify({'error': f"An internal error occurred: {e}"}), 500

@app.route('/api/admin/credit_requests', methods=['GET'])
def list_credit_requests():
    try:
        verify_admin(request.headers.get('Authorization'))
        requests_data = db_ref.child('credit_requests').get() or {}
        return jsonify(list(requests_data.values()))
    except Exception as e:
        return jsonify({'error': str(e)}), 500

@app.route('/api/admin/credit_requests/<string:request_id>', methods=['PUT'])
def process_credit_request(request_id):
    try:
        admin_uid = verify_admin(request.headers.get('Authorization'))
        req_ref = db_ref.child(f'credit_requests/{request_id}')
        req_data = req_ref.get()
        if not req_data: return jsonify({'error': 'Credit request not found'}), 404

        decision = request.json.get('decision')
        if decision not in ['approved', 'declined']: return jsonify({'error': 'Decision must be "approved" or "declined"'}), 400

        if decision == 'approved':
            user_ref = db_ref.child(f'users/{req_data["userId"]}')
            user_data = user_ref.get()
            if user_data:
                new_total = user_data.get('credits', 0) + int(req_data.get('requested_credits', 0))
                user_ref.update({'credits': new_total})
        
        req_ref.update({'status': decision, 'processedBy': admin_uid, 'processedAt': datetime.utcnow().isoformat()})
        return jsonify({'success': True, 'message': f'Request {decision}.'})
    except Exception as e:
        return jsonify({'error': str(e)}), 500

@app.route('/api/admin/feedback', methods=['GET'])
def admin_view_feedback():
    try:
        verify_admin(request.headers.get('Authorization'))
        feedback_data = db_ref.child('feedback').get() or {}
        return jsonify(list(feedback_data.values()))
    except Exception as e:
        return jsonify({'error': str(e)}), 500

@app.route('/api/admin/users', methods=['GET'])
def admin_list_users():
    try:
        verify_admin(request.headers.get('Authorization'))
        all_users = db_ref.child('users').get() or {}
        user_list = [{'uid': uid, **data} for uid, data in all_users.items()]
        return jsonify(user_list)
    except Exception as e:
        return jsonify({'error': str(e)}), 500

@app.route('/api/admin/users/<string:uid>/credits', methods=['PUT'])
def admin_update_credits(uid):
    try:
        verify_admin(request.headers.get('Authorization'))
        add_credits = request.json.get('add_credits')
        if add_credits is None: return jsonify({'error': 'add_credits is required'}), 400

        user_ref = db_ref.child(f'users/{uid}')
        user_data = user_ref.get()
        if not user_data: return jsonify({'error': 'User not found'}), 404

        new_total = user_data.get('credits', 0) + float(add_credits)
        user_ref.update({'credits': new_total})
        return jsonify({'success': True, 'new_total_credits': new_total})
    except Exception as e:
        return jsonify({'error': str(e)}), 500

# -----------------------------------------------------------------------------
# 6. DIY PROJECT ENDPOINTS (Core Logic)
# -----------------------------------------------------------------------------
# (The project endpoints from the previous answer go here, unchanged)
@app.route('/api/projects', methods=['POST'])
def create_project():
    uid = verify_token(request.headers.get('Authorization'))
    if not uid: return jsonify({'error': 'Unauthorized'}), 401

    user_ref = db_ref.child(f'users/{uid}')
    user_data = user_ref.get()
    if not user_data or user_data.get('credits', 0) < 1:
        return jsonify({'error': 'Insufficient credits'}), 402

    if 'image' not in request.files:
        return jsonify({'error': 'Image file is required'}), 400
    
    image_file = request.files['image']
    context_text = request.form.get('contextText', '')
    image_bytes = image_file.read()
    pil_image = Image.open(io.BytesIO(image_bytes))

    try:
        category_prompt = (
            "You are an expert DIY assistant. Analyze the user's image and context. "
            f"Context: '{context_text}'. "
            "Categorize the project into ONE of the following: "
            "Home Appliance Repair, Automotive Maintenance, Gardening & Urban Farming, "
            "Upcycling & Sustainable Crafts, or DIY Project Creation. "
            "Reply with ONLY the category name."
        )
        category = send_text_request(CATEGORY_MODEL, category_prompt, pil_image)
        if not category: return jsonify({'error': 'Failed to get project category from AI.'}), 500

        plan_prompt = f"""
        You are an expert DIY assistant in the category: {category}.
        User Context: "{context_text if context_text else 'No context provided.'}"
        Based on the image and context, perform the following:
        1.  **Title:** Create a short, clear title for this project.
        2.  **Description:** Write a brief, one-paragraph description of the goal.
        3.  **Initial Plan:**
            - If 'Upcycling & Sustainable Crafts' AND no specific project is mentioned, propose three distinct project options as a numbered list under "UPCYCLING OPTIONS:".
            - For all other cases, briefly outline the main stages of the proposed solution.
        Structure your response EXACTLY like this:
        TITLE: [Your title]
        DESCRIPTION: [Your description]
        INITIAL PLAN:
        [Your plan or 3 options]
        """
        plan_response = send_text_request(GENERATION_MODEL, plan_prompt, pil_image)
        if not plan_response: return jsonify({'error': 'Failed to generate project plan from AI.'}), 500
        
        title = re.search(r"TITLE:\s*(.*)", plan_response).group(1).strip()
        description = re.search(r"DESCRIPTION:\s*(.*)", plan_response, re.DOTALL).group(1).strip()
        initial_plan_text = re.search(r"INITIAL PLAN:\s*(.*)", plan_response, re.DOTALL).group(1).strip()

        upcycling_options = re.findall(r"^\s*\d+\.\s*(.*)", initial_plan_text, re.MULTILINE) if "UPCYCLING OPTIONS:" in initial_plan_text else []
        initial_plan = initial_plan_text if not upcycling_options else ""
        status = "awaiting_selection" if upcycling_options else "awaiting_approval"
        
        project_id = str(uuid.uuid4())
        image_path = f"users/{uid}/projects/{project_id}/initial_image.png"
        image_url = upload_to_storage(image_bytes, image_path, content_type=image_file.content_type)

        project_data = {
            "uid": uid, "projectId": project_id, "status": status, "createdAt": datetime.utcnow().isoformat(),
            "userImageURL": image_url, "contextText": context_text, "projectTitle": title,
            "projectDescription": description, "category": category, "initialPlan": initial_plan,
            "upcyclingOptions": upcycling_options, "toolsList": [], "steps": []
        }
        db_ref.child(f'projects/{project_id}').set(project_data)

        user_ref.update({'credits': user_data.get('credits', 1) - 1})
        return jsonify(project_data), 201

    except Exception as e:
        print(traceback.format_exc())
        return jsonify({'error': f"An error occurred: {e}"}), 500

@app.route('/api/projects/<string:project_id>/approve', methods=['PUT'])
def approve_project_plan(project_id):
    uid = verify_token(request.headers.get('Authorization'))
    if not uid: return jsonify({'error': 'Unauthorized'}), 401
    
    project_ref = db_ref.child(f'projects/{project_id}')
    project_data = project_ref.get()
    if not project_data or project_data.get('uid') != uid:
        return jsonify({'error': 'Project not found or access denied'}), 404

    selected_option = request.json.get('selectedOption')
    response = requests.get(project_data['userImageURL'])
    pil_image = Image.open(io.BytesIO(response.content))

    context = f"The user chose the upcycling project: '{selected_option}'." if selected_option else f"The user has approved the plan for '{project_data['projectTitle']}'."

    detailed_prompt = f"""
    You are a DIY expert. The user wants to proceed with the project titled "{project_data['projectTitle']}".
    {context}
    Provide a detailed guide. For each step, you MUST provide a simple, clear illustrative image.
    Format your response EXACTLY like this:

    TOOLS AND MATERIALS:
    - Tool A
    - Material B

    STEPS(Maximum 7 steps):
    1. First step instructions.
    2. Second step instructions...
    """
    try:
        chat = client.chats.create(model=GENERATION_MODEL, config=types.GenerateContentConfig(response_modalities=["Text", "Image"]))
        full_resp = chat.send_message([detailed_prompt, pil_image])
        
        # Fix: Access the parts through the correct structure
        gen_parts = full_resp.candidates[0].content.parts
        
        combined_text = ""
        inline_images = []
        for part in gen_parts:
            if part.text is not None:
                combined_text += part.text + "\n"
            if part.inline_data is not None:
                img = Image.open(BytesIO(part.inline_data.data))
                inline_images.append(img)
        
        combined_text = combined_text.strip()

        tools_section = re.search(r"TOOLS AND MATERIALS:\s*(.*?)\s*STEPS:", combined_text, re.DOTALL).group(1).strip()
        steps_section = re.search(r"STEPS:\s*(.*)", combined_text, re.DOTALL).group(1).strip()
        
        tools_list = [line.strip("- ").strip() for line in tools_section.split('\n') if line.strip()]
        parsed_steps = parse_numbered_steps(steps_section)

        if len(parsed_steps) != len(inline_images): return jsonify({'error': 'AI response mismatch: Steps and images do not match.'}), 500

        final_steps = []
        for i, step_info in enumerate(parsed_steps):
            img_byte_arr = io.BytesIO()
            inline_images[i].save(img_byte_arr, format='PNG')
            img_path = f"users/{uid}/projects/{project_id}/steps/step_{i+1}_image.png"
            img_url = upload_to_storage(img_byte_arr.getvalue(), img_path, 'image/png')
            
            narration_url = generate_tts_audio_and_upload(step_info['text'], uid, project_id, i + 1)
            step_info.update({"imageUrl": img_url, "narrationUrl": narration_url, "isDone": False, "notes": ""})
            final_steps.append(step_info)
        
        update_data = {"status": "ready", "toolsList": tools_list, "steps": final_steps, "selectedOption": selected_option or ""}
        project_ref.update(update_data)
        
        return jsonify({"success": True, **update_data})

    except Exception as e:
        print(traceback.format_exc())
        return jsonify({'error': f"Failed to generate detailed guide: {e}"}), 500

@app.route('/api/projects', methods=['GET'])
def list_projects():
    uid = verify_token(request.headers.get('Authorization'))
    if not uid: return jsonify({'error': 'Unauthorized'}), 401
    projects = (db_ref.child('projects').order_by_child('uid').equal_to(uid).get() or {}).values()
    return jsonify(list(projects))

@app.route('/api/projects/<string:project_id>', methods=['GET'])
def get_project(project_id):
    uid = verify_token(request.headers.get('Authorization'))
    if not uid: return jsonify({'error': 'Unauthorized'}), 401
    project_data = db_ref.child(f'projects/{project_id}').get()
    if not project_data or project_data.get('uid') != uid:
        return jsonify({'error': 'Project not found or access denied'}), 404
    return jsonify(project_data)

@app.route('/api/projects/<string:project_id>/step/<int:step_number>', methods=['PUT'])
def update_step(project_id, step_number):
    uid = verify_token(request.headers.get('Authorization'))
    if not uid: return jsonify({'error': 'Unauthorized'}), 401
    data = request.get_json()
    if data is None: return jsonify({'error': 'JSON body is required'}), 400

    project_data = db_ref.child(f'projects/{project_id}').get()
    if not project_data or project_data.get('uid') != uid:
        return jsonify({'error': 'Project not found or access denied'}), 404

    steps = project_data.get('steps', [])
    step_index = next((i for i, s in enumerate(steps) if s.get('stepNumber') == step_number), -1)
    if step_index == -1: return jsonify({'error': f'Step number {step_number} not found'}), 404

    step_path = f'projects/{project_id}/steps/{step_index}'
    if 'isDone' in data: db_ref.child(f'{step_path}/isDone').set(bool(data['isDone']))
    if 'notes' in data: db_ref.child(f'{step_path}/notes').set(str(data['notes']))
    
    return jsonify({"success": True, "updatedStep": db_ref.child(step_path).get()})

@app.route('/api/projects/<string:project_id>', methods=['DELETE'])
def delete_project(project_id):
    uid = verify_token(request.headers.get('Authorization'))
    if not uid: return jsonify({'error': 'Unauthorized'}), 401
    
    project_ref = db_ref.child(f'projects/{project_id}')
    project_data = project_ref.get()
    if not project_data or project_data.get('uid') != uid:
        return jsonify({'error': 'Project not found or access denied'}), 404

    project_ref.delete()
    for blob in bucket.list_blobs(prefix=f"users/{uid}/projects/{project_id}/"):
        blob.delete()
    return jsonify({"success": True, "message": f"Project {project_id} deleted."})


# -----------------------------------------------------------------------------
# 7. MAIN EXECUTION
# -----------------------------------------------------------------------------
if __name__ == '__main__':
    app.run(debug=True, host="0.0.0.0", port=int(os.environ.get("PORT", 7860)))