app.py

import os
import sys

# Hugging Face safe cache
os.environ["HF_HOME"] = "/tmp/huggingface"
os.environ["TRANSFORMERS_CACHE"] = "/tmp/huggingface/transformers"
os.environ["HUGGINGFACE_HUB_CACHE"] = "/tmp/huggingface/hub"

# Force Flask instance path to a writable temporary folder
safe_instance_path = "/tmp/flask_instance"

# Create the safe instance path after imports
os.makedirs(safe_instance_path, exist_ok=True)

from flask import Flask, render_template, redirect, url_for, flash, request
from flask_login import LoginManager, login_required, current_user
from werkzeug.utils import secure_filename
import sys
import json
from datetime import datetime

# Adjust sys.path for import flexibility
current_dir = os.path.dirname(os.path.abspath(__file__))
sys.path.append(current_dir)

# Import and initialize DB
from backend.models.database import db, Job, Application, init_db
from backend.models.user import User
from backend.routes.auth import auth_bp
from backend.routes.interview_api import interview_api
from backend.models.resume_parser.resume_to_features import extract_resume_features

# Initialize Flask app
app = Flask(
    __name__,
    static_folder='backend/static',
    static_url_path='/static',
    template_folder='backend/templates',
    instance_path=safe_instance_path  # ✅ points to writable '/tmp/flask_instance'
)

app.config['SECRET_KEY'] = 'your-secret-key'

# -----------------------------------------------------------------------------
# Cookie configuration for Hugging Face Spaces
#
# When running this app inside an iframe (as is typical on Hugging Face Spaces),
# browsers will drop cookies that have the default SameSite policy of ``Lax``.
# This prevents the Flask session cookie from being stored and means that
# ``login_user()`` will appear to have no effect – the user will be redirected
# back to the home page but remain anonymous. By explicitly setting the
# SameSite policy to ``None`` and enabling the ``Secure`` flag, we allow the
# session and remember cookies to be sent even when the app is embedded in an
# iframe. Without these settings the sign‑up and login flows work locally
# but silently fail in Spaces, causing the "redirect to home page without
# anything" behaviour reported by users.
app.config['SESSION_COOKIE_SAMESITE'] = 'None'
app.config['SESSION_COOKIE_SECURE'] = True
app.config['REMEMBER_COOKIE_SAMESITE'] = 'None'
app.config['REMEMBER_COOKIE_SECURE'] = True

# Configure the database connection
# Use /tmp directory for database in Hugging Face Spaces
# Note: Data will be lost when the space restarts
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:////tmp/codingo.db'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
from flask_wtf.csrf import CSRFProtect

# csrf = CSRFProtect(app)

# Create necessary directories in writable locations
os.makedirs('/tmp/static/audio', exist_ok=True)
os.makedirs('/tmp/temp', exist_ok=True)

# Initialize DB with app
init_db(app)

# Flask-Login setup
login_manager = LoginManager()
login_manager.login_view = 'auth.login'
login_manager.init_app(app)

@login_manager.user_loader
def load_user(user_id):
    return db.session.get(User, int(user_id))

# Register blueprints
app.register_blueprint(auth_bp)
app.register_blueprint(interview_api, url_prefix="/api")

def handle_resume_upload(file):
    """Save uploaded file temporarily, extract features, then clean up."""
    if not file or file.filename == '':
        return None, "No file uploaded", None
    
    try:
        filename = secure_filename(file.filename)
        temp_dir = '/tmp/temp'  # Use /tmp for temporary files
        os.makedirs(temp_dir, exist_ok=True)
        filepath = os.path.join(temp_dir, filename)
        
        file.save(filepath)
        features = extract_resume_features(filepath)
        
        # Clean up
        try:
            os.remove(filepath)
        except:
            pass
            
        return features, None, filename
    except Exception as e:
        print(f"Error in handle_resume_upload: {e}")
        return None, str(e), None

# Routes (keep your existing routes)
@app.route('/')
def index():
    return render_template('index.html')

@app.route('/jobs')
def jobs():
    all_jobs = Job.query.order_by(Job.date_posted.desc()).all()
    return render_template('jobs.html', jobs=all_jobs)

@app.route('/job/<int:job_id>')
def job_detail(job_id):
    job = Job.query.get_or_404(job_id)
    return render_template('job_detail.html', job=job)

@app.route('/apply/<int:job_id>', methods=['GET', 'POST'])
@login_required
def apply(job_id):
    job = Job.query.get_or_404(job_id)
    
    if request.method == 'POST':
        file = request.files.get('resume')
        features, error, _ = handle_resume_upload(file)
        
        if error or not features:
            flash("Resume parsing failed. Please try again.", "danger")
            return render_template('apply.html', job=job)
        
        application = Application(
            job_id=job_id,
            user_id=current_user.id,
            name=current_user.username,
            email=current_user.email,
            extracted_features=json.dumps(features)
        )
        
        db.session.add(application)
        db.session.commit()
        
        flash('Your application has been submitted successfully!', 'success')
        return redirect(url_for('jobs'))
    
    return render_template('apply.html', job=job)

@app.route('/my_applications')
@login_required
def my_applications():
    applications = Application.query.filter_by(
        user_id=current_user.id
    ).order_by(Application.date_applied.desc()).all()
    return render_template('my_applications.html', applications=applications)

@app.route('/parse_resume', methods=['POST'])
def parse_resume():
    file = request.files.get('resume')
    features, error, _ = handle_resume_upload(file)
    
    if error:
        return {"error": "Error parsing resume. Please try again."}, 400
    
    if not features:
        return {"error": "Failed to extract resume details."}, 400
    
    response = {
        "name": features.get('name', ''),
        "email": features.get('email', ''),
        "mobile_number": features.get('mobile_number', ''),
        "skills": features.get('skills', []),
        "experience": features.get('experience', []),
        "education": features.get('education', []),
        "summary": features.get('summary', '')
    }
    return response, 200

@app.route("/interview/<int:job_id>")
@login_required
def interview_page(job_id):
    job = Job.query.get_or_404(job_id)
    application = Application.query.filter_by(
        user_id=current_user.id, 
        job_id=job_id
    ).first()
    
    if not application or not application.extracted_features:
        flash("Please apply for this job and upload your resume first.", "warning")
        return redirect(url_for('job_detail', job_id=job_id))
    
    cv_data = json.loads(application.extracted_features)
    return render_template("interview.html", job=job, cv=cv_data)

if __name__ == '__main__':
    print("Starting Codingo application...")
    with app.app_context():
        db.create_all()
    
    # Use port from environment or default to 7860
    port = int(os.environ.get('PORT', 7860))
    app.run(debug=True, host='0.0.0.0', port=port)