from flask import Flask, render_template, redirect, url_for, flash, request
from flask_sqlalchemy import SQLAlchemy
from flask_login import LoginManager, UserMixin, login_user, login_required, logout_user, current_user
from flask_admin import Admin
from flask_admin.contrib.sqla import ModelView
from werkzeug.security import generate_password_hash, check_password_hash
import os

app = Flask(__name__)
app.config['SECRET_KEY'] = os.environ.get('SECRET_KEY', 'your-secret-key')
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///admin.db'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False

db = SQLAlchemy(app)
login_manager = LoginManager(app)
login_manager.login_view = 'login'

# 用户模型
class User(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True, nullable=False)
    password_hash = db.Column(db.String(120), nullable=False)
    is_admin = db.Column(db.Boolean, default=False)

    def set_password(self, password):
        self.password_hash = generate_password_hash(password)

    def check_password(self, password):
        return check_password_hash(self.password_hash, password)

# 管理员视图
class AdminModelView(ModelView):
    def is_accessible(self):
        return current_user.is_authenticated and current_user.is_admin

@login_manager.user_loader
def load_user(user_id):
    return User.query.get(int(user_id))

# 初始化管理员界面
admin = Admin(app, name='后台管理系统', template_mode='bootstrap3')
admin.add_view(AdminModelView(User, db.session))

@app.route('/')
def index():
    return render_template('index.html')

@app.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'POST':
        username = request.form.get('username')
        password = request.form.get('password')
        user = User.query.filter_by(username=username).first()
        
        if user and user.check_password(password):
            login_user(user)
            return redirect(url_for('admin.index'))
        flash('Invalid username or password')
    return render_template('login.html')

@app.route('/logout')
@login_required
def logout():
    logout_user()
    return redirect(url_for('index'))

def init_db():
    with app.app_context():
        db.create_all()
        # 创建默认管理员账户
        if not User.query.filter_by(username='admin').first():
            admin_user = User(username='admin', is_admin=True)
            admin_user.set_password('admin123')
            db.session.add(admin_user)
            db.session.commit()

# 初始化数据库
with app.app_context():
    init_db()

# 为 Hugging Face Spaces 配置
app.config['TEMPLATES_AUTO_RELOAD'] = True

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=7860)
else:
    # 这是为了让 Gunicorn 能够找到应用
    application = app