from datetime import datetime
from flask_sqlalchemy import SQLAlchemy
from flask_login import UserMixin
from werkzeug.security import generate_password_hash, check_password_hash

db = SQLAlchemy()

class User(UserMixin, db.Model):
    __tablename__ = 'users'
    
    id = db.Column(db.Integer, primary_key=True)
    nickname = db.Column(db.String(80), unique=True, nullable=False)
    email = db.Column(db.String(120), unique=True, nullable=False)
    password_hash = db.Column(db.String(255), nullable=False)
    is_active = db.Column(db.Boolean, default=True, nullable=False)
    is_admin = db.Column(db.Boolean, default=False, nullable=False)
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    updated_at = db.Column(db.DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
    
    # Relationships
    posts = db.relationship('Post', backref='author', lazy='dynamic', cascade='all, delete-orphan')
    comments = db.relationship('Comment', backref='author', lazy='dynamic', cascade='all, delete-orphan')
    likes = db.relationship('Like', backref='user', lazy='dynamic', cascade='all, delete-orphan')
    
    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)
    
    def __repr__(self):
        return f'<User {self.nickname}>'

class Post(db.Model):
    __tablename__ = 'posts'
    
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(200), nullable=False)
    subtitle = db.Column(db.String(300))
    content = db.Column(db.Text, nullable=False)
    difficulty = db.Column(db.Integer, default=3, nullable=False)  # 1-5 scale
    published = db.Column(db.Boolean, default=False, nullable=False)
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    updated_at = db.Column(db.DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
    
    # Foreign Keys
    author_id = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=False)
    
    # Relationships
    images = db.relationship('PostImage', backref='post', lazy='dynamic', cascade='all, delete-orphan')
    gpx_files = db.relationship('GPXFile', backref='post', lazy='dynamic', cascade='all, delete-orphan')
    comments = db.relationship('Comment', backref='post', lazy='dynamic', cascade='all, delete-orphan')
    likes = db.relationship('Like', backref='post', lazy='dynamic', cascade='all, delete-orphan')
    
    def get_difficulty_label(self):
        labels = ['Very Easy', 'Easy', 'Moderate', 'Hard', 'Very Hard']
        return labels[self.difficulty - 1] if 1 <= self.difficulty <= 5 else 'Unknown'
    
    def get_like_count(self):
        return self.likes.count()
    
    def __repr__(self):
        return f'<Post {self.title}>'

class PostImage(db.Model):
    __tablename__ = 'post_images'
    
    id = db.Column(db.Integer, primary_key=True)
    filename = db.Column(db.String(255), nullable=False)
    original_name = db.Column(db.String(255), nullable=False)
    description = db.Column(db.Text)
    size = db.Column(db.Integer, nullable=False)
    mime_type = db.Column(db.String(100), nullable=False)
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    
    # Foreign Keys
    post_id = db.Column(db.Integer, db.ForeignKey('posts.id'), nullable=False)
    
    def __repr__(self):
        return f'<PostImage {self.filename}>'

class GPXFile(db.Model):
    __tablename__ = 'gpx_files'
    
    id = db.Column(db.Integer, primary_key=True)
    filename = db.Column(db.String(255), nullable=False)
    original_name = db.Column(db.String(255), nullable=False)
    size = db.Column(db.Integer, nullable=False)
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    
    # Foreign Keys
    post_id = db.Column(db.Integer, db.ForeignKey('posts.id'), nullable=False)
    
    def __repr__(self):
        return f'<GPXFile {self.filename}>'

class Comment(db.Model):
    __tablename__ = 'comments'
    
    id = db.Column(db.Integer, primary_key=True)
    content = db.Column(db.Text, nullable=False)
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    updated_at = db.Column(db.DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
    
    # Foreign Keys
    author_id = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=False)
    post_id = db.Column(db.Integer, db.ForeignKey('posts.id'), nullable=False)
    
    def __repr__(self):
        return f'<Comment {self.id}>'

class Like(db.Model):
    __tablename__ = 'likes'
    
    id = db.Column(db.Integer, primary_key=True)
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    
    # Foreign Keys
    user_id = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=False)
    post_id = db.Column(db.Integer, db.ForeignKey('posts.id'), nullable=False)
    
    # Unique constraint
    __table_args__ = (db.UniqueConstraint('user_id', 'post_id', name='unique_user_post_like'),)
    
    def __repr__(self):
        return f'<Like {self.user_id}-{self.post_id}>'