from flask import Flask, render_template, request, redirect, url_for, session, flash, send_from_directory
from werkzeug.utils import secure_filename
from werkzeug.security import generate_password_hash, check_password_hash
import os
from datetime import datetime
from models import db, User, Resource

app = Flask(__name__)
app.config['SECRET_KEY'] = 'your_secret_key_here'
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///resource_management.db'
app.config['UPLOAD_FOLDER'] = 'uploads'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False

db.init_app(app)

# Ensure uploads folder exists
if not os.path.exists(app.config['UPLOAD_FOLDER']):
    os.makedirs(app.config['UPLOAD_FOLDER'])

# Create database tables automatically
with app.app_context():
    db.create_all()

@app.route('/')
def index():
    if 'username' not in session:
        return redirect(url_for('login'))
    username = session['username']
    user_type = session['user_type']
    resource_count = Resource.query.count()
    last_login = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    return render_template('index.html', username=username, user_type=user_type, resource_count=resource_count, last_login=last_login)

@app.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'POST':
        username = request.form['username']
        password = request.form['password']
        user_type = request.form['user_type']

        user = User.query.filter_by(username=username, user_type=user_type).first()
        if user and check_password_hash(user.password, password):
            session['username'] = user.username
            session['user_type'] = user.user_type
            return redirect(url_for('index'))
        else:
            flash('Invalid username, password, or user type.', 'error')
    return render_template('login.html')

@app.route('/signup', methods=['GET', 'POST'])
def signup():
    if request.method == 'POST':
        username = request.form['username']
        password = request.form['password']
        confirm_password = request.form['confirm_password']
        user_type = request.form['user_type']

        if password != confirm_password:
            flash('Passwords do not match!', 'error')
            return redirect(url_for('signup'))

        existing_user = User.query.filter_by(username=username).first()
        if existing_user:
            flash('Username already exists.', 'error')
            return redirect(url_for('signup'))

        hashed_password = generate_password_hash(password)
        new_user = User(username=username, password=hashed_password, user_type=user_type)
        db.session.add(new_user)
        db.session.commit()
        flash('Account created successfully. Please log in.', 'success')
        return redirect(url_for('login'))
    return render_template('signup.html')

@app.route('/logout')
def logout():
    session.clear()
    return redirect(url_for('login'))

@app.route('/view_resources', methods=['GET', 'POST'])
def view_resources():
    if 'username' not in session:
        return redirect(url_for('login'))
    user_type = session['user_type']

    institutions = db.session.query(Resource.institution).distinct()
    resource_types = db.session.query(Resource.type).distinct()

    filters = {}
    if request.method == 'POST':
        if 'delete_resource' in request.form and user_type == 'admin':
            resource_id = request.form['delete_resource']
            resource = Resource.query.get(resource_id)
            if resource:
                try:
                    os.remove(os.path.join(app.config['UPLOAD_FOLDER'], resource.resource_file))
                except FileNotFoundError:
                    pass
                db.session.delete(resource)
                db.session.commit()
                flash('Resource deleted successfully.', 'success')
            else:
                flash('Resource not found.', 'error')
            return redirect(url_for('view_resources'))

        filters['institution'] = request.form.get('institution')
        filters['department'] = request.form.get('department')
        filters['resource_type'] = request.form.get('resource_type')

    query = Resource.query
    if filters.get('institution'):
        query = query.filter_by(institution=filters['institution'])
    if filters.get('department'):
        query = query.filter_by(department=filters['department'])
    if filters.get('resource_type'):
        query = query.filter_by(type=filters['resource_type'])

    resources = query.all()

    departments = []
    if filters.get('institution'):
        departments = db.session.query(Resource.department).filter_by(institution=filters['institution']).distinct()

    return render_template('view_resources.html', resources=resources, institutions=institutions, departments=departments, resource_types=resource_types, user_type=user_type, filters=filters)

@app.route('/add_resource', methods=['GET', 'POST'])
def add_resource():
    if 'username' not in session or session['user_type'] != 'admin':
        return redirect(url_for('login'))
    if request.method == 'POST':
        name = request.form['name']
        type = request.form['type']
        institution = request.form['institution']
        department = request.form['department']
        resource_file = request.files['resource_file']

        if resource_file:
            filename = secure_filename(resource_file.filename)
            resource_file.save(os.path.join(app.config['UPLOAD_FOLDER'], filename))

            new_resource = Resource(name=name, type=type, institution=institution, department=department, resource_file=filename)
            db.session.add(new_resource)
            db.session.commit()
            flash('Resource added successfully!', 'success')
            return redirect(url_for('view_resources'))
    return render_template('add_resource.html')

@app.route('/uploads/<filename>')
def uploaded_file(filename):
    return send_from_directory(app.config['UPLOAD_FOLDER'], filename)

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=7860, debug=True)