from datetime import datetime
from app import db
from flask_login import UserMixin
from werkzeug.security import generate_password_hash, check_password_hash
from sqlalchemy.ext.associationproxy import association_proxy

# User roles
class Role:
    MEMBER = 'member'
    MODERATOR = 'moderator'
    ADMIN = 'admin'

# Association table for topics and tags
topic_tag = db.Table('topic_tag',
    db.Column('topic_id', db.Integer, db.ForeignKey('topic.id'), primary_key=True),
    db.Column('tag_id', db.Integer, db.ForeignKey('tag.id'), primary_key=True)
)

# User model
class User(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(64), unique=True, nullable=False, index=True)
    email = db.Column(db.String(120), unique=True, nullable=False, index=True)
    password_hash = db.Column(db.String(256), nullable=False)
    role = db.Column(db.String(20), nullable=False, default=Role.MEMBER)
    avatar = db.Column(db.String(120), nullable=True, default='default.png')
    signature = db.Column(db.String(200), nullable=True)
    location = db.Column(db.String(100), nullable=True)
    website = db.Column(db.String(120), nullable=True)
    bio = db.Column(db.Text, nullable=True)
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    last_seen = db.Column(db.DateTime, default=datetime.utcnow)
    is_active = db.Column(db.Boolean, default=True)
    is_banned = db.Column(db.Boolean, default=False)
    ban_reason = db.Column(db.Text, nullable=True)
    
    # Relationships
    topics = db.relationship('Topic', backref='author', lazy='dynamic')
    posts = db.relationship('Post', backref='author', lazy='dynamic', foreign_keys='Post.author_id')
    reactions = db.relationship('Reaction', backref='user', lazy='dynamic')
    reports = db.relationship('Report', backref='reporter', lazy='dynamic', foreign_keys='Report.reporter_id')
    
    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 is_admin(self):
        return self.role == Role.ADMIN
    
    def is_moderator(self):
        return self.role == Role.MODERATOR or self.role == Role.ADMIN
    
    def update_last_seen(self):
        self.last_seen = datetime.utcnow()
        db.session.commit()
    
    def __repr__(self):
        return f'<User {self.username}>'

# Category model
class Category(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(100), nullable=False)
    description = db.Column(db.Text, nullable=True)
    order = db.Column(db.Integer, default=0)
    
    # Relationships
    topics = db.relationship('Topic', backref='category', lazy='dynamic')
    
    def topic_count(self):
        return self.topics.count()
    
    def post_count(self):
        count = 0
        for topic in self.topics:
            count += topic.posts.count()
        return count
    
    def __repr__(self):
        return f'<Category {self.name}>'

# Topic model
class Topic(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(200), nullable=False)
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    updated_at = db.Column(db.DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
    views = db.Column(db.Integer, default=0)
    is_locked = db.Column(db.Boolean, default=False)
    is_pinned = db.Column(db.Boolean, default=False)
    
    # Foreign keys
    category_id = db.Column(db.Integer, db.ForeignKey('category.id'), nullable=False)
    author_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)
    
    # Relationships
    posts = db.relationship('Post', backref='topic', lazy='dynamic', cascade='all, delete-orphan')
    tags = db.relationship('Tag', secondary=topic_tag, backref=db.backref('topics', lazy='dynamic'))
    reports = db.relationship('Report', backref='topic', lazy='dynamic', 
                             primaryjoin="and_(Report.topic_id==Topic.id, Report.post_id==None)")
    
    def reply_count(self):
        return self.posts.count() - 1  # Subtract first post
    
    def last_post(self):
        return self.posts.order_by(Post.created_at.desc()).first()
    
    def increment_view(self):
        self.views += 1
        db.session.commit()
    
    def __repr__(self):
        return f'<Topic {self.title}>'

# Post model
class Post(db.Model):
    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)
    edited_by_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=True)
    
    # Foreign keys
    topic_id = db.Column(db.Integer, db.ForeignKey('topic.id'), nullable=False)
    author_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)
    
    # Relationships
    reactions = db.relationship('Reaction', backref='post', lazy='dynamic', cascade='all, delete-orphan')
    reports = db.relationship('Report', backref='post', lazy='dynamic', 
                             primaryjoin="Report.post_id==Post.id")
    
    edited_by = db.relationship('User', foreign_keys=[edited_by_id])
    
    def get_reaction_count(self, reaction_type=None):
        if reaction_type:
            return self.reactions.filter_by(reaction_type=reaction_type).count()
        return self.reactions.count()
    
    def __repr__(self):
        return f'<Post {self.id}>'

# Tag model
class Tag(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(50), nullable=False, unique=True)
    
    def __repr__(self):
        return f'<Tag {self.name}>'

# Reaction model
class Reaction(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    reaction_type = db.Column(db.String(20), nullable=False, default='like')
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    
    # Foreign keys
    user_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)
    post_id = db.Column(db.Integer, db.ForeignKey('post.id'), nullable=False)
    
    # Enforce unique reaction per user per post
    __table_args__ = (
        db.UniqueConstraint('user_id', 'post_id', name='_user_post_reaction_uc'),
    )
    
    def __repr__(self):
        return f'<Reaction {self.reaction_type}>'

# Report model
class Report(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    reason = db.Column(db.Text, nullable=False)
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    is_resolved = db.Column(db.Boolean, default=False)
    resolved_at = db.Column(db.DateTime, nullable=True)
    resolved_by_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=True)
    
    # Foreign keys
    reporter_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)
    topic_id = db.Column(db.Integer, db.ForeignKey('topic.id'), nullable=True)
    post_id = db.Column(db.Integer, db.ForeignKey('post.id'), nullable=True)
    
    # Relationships
    resolved_by = db.relationship('User', foreign_keys=[resolved_by_id])
    
    def __repr__(self):
        return f'<Report {self.id}>'