from flask_sqlalchemy import SQLAlchemy
from datetime import datetime
import json

db = SQLAlchemy()

# ✅ Import User model here, before Job and Application use it
from backend.models.user import User

class Job(db.Model):
    __tablename__ = 'jobs'

    id = db.Column(db.Integer, primary_key=True)
    role = db.Column(db.String(100), nullable=False)
    description = db.Column(db.Text, nullable=False)
    seniority = db.Column(db.String(50), nullable=False)
    skills = db.Column(db.Text, nullable=False)
    company = db.Column(db.String(100), nullable=False)
    date_posted = db.Column(db.DateTime, default=datetime.utcnow)

    recruiter_id = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=True)
    recruiter = db.relationship('User', backref='posted_jobs')

    def __repr__(self):
        return f"<Job {self.role} at {self.company}>"

class Application(db.Model):
    __tablename__ = 'applications'

    id = db.Column(db.Integer, primary_key=True)
    job_id = db.Column(db.Integer, db.ForeignKey('jobs.id'), nullable=False)
    user_id = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=False)

    name = db.Column(db.String(100), nullable=False)
    email = db.Column(db.String(100), nullable=False)
    resume_path = db.Column(db.String(255), nullable=True)
    cover_letter = db.Column(db.Text, nullable=True)
    extracted_features = db.Column(db.Text, nullable=True)
    status = db.Column(db.String(50), default='applied')
    date_applied = db.Column(db.DateTime, default=datetime.utcnow)

    user = db.relationship('User', backref='applications')

    def __repr__(self):
        return f"Application('{self.name}', '{self.email}', Job ID: {self.job_id})"

    def get_profile_data(self):
        try:
            return json.loads(self.extracted_features) if self.extracted_features else {}
        except:
            return {}

def init_db(app):
    db.init_app(app)
    with app.app_context():
        db.create_all()
        # Add sample data...


        # Add sample data if jobs table is empty
        if Job.query.count() == 0:
            sample_jobs = [
                Job(
                    role='Senior Python Developer',
                    description='Experienced developer needed for backend systems.',
                    seniority='Senior',
                    skills=json.dumps(['Python', 'Flask', 'SQL', 'AWS']),
                    company='TechCorp'
                ),
                Job(
                    role='Data Scientist',
                    description='ML model development and statistical analysis.',
                    seniority='Mid',
                    skills=json.dumps(['Python', 'scikit-learn', 'Pandas', 'Spark']),
                    company='DataInsights'
                ),
                Job(
                    role='Frontend Developer',
                    description='Modern web frontend development with React.',
                    seniority='Junior',
                    skills=json.dumps(['HTML', 'CSS', 'JavaScript', 'React']),
                    company='WebSolutions'
                ),
            ]

            for job in sample_jobs:
                db.session.add(job)

            db.session.commit()
            print("✅ Sample jobs added to database.")