from app import db
from datetime import datetime
from flask import url_for
import json

# Association table for document-tag many-to-many relationship
document_tags = db.Table('document_tags',
    db.Column('document_id', db.Integer, db.ForeignKey('document.id'), primary_key=True),
    db.Column('tag_id', db.Integer, db.ForeignKey('tag.id'), primary_key=True)
)

class Document(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(200), nullable=False)
    content = db.Column(db.Text, nullable=False, default='')
    created_date = db.Column(db.DateTime, default=datetime.utcnow)
    updated_date = db.Column(db.DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
    category_id = db.Column(db.Integer, db.ForeignKey('category.id'))
    user_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)
    tags = db.relationship('Tag', secondary=document_tags, backref=db.backref('documents', lazy='dynamic'))
    
    def __repr__(self):
        return f'<Document {self.title}>'
    
    def to_dict(self):
        return {
            'id': self.id,
            'title': self.title,
            'content': self.content,
            'created_date': self.created_date.isoformat(),
            'updated_date': self.updated_date.isoformat(),
            'category_id': self.category_id,
            'user_id': self.user_id,
            'tags': [tag.name for tag in self.tags]
        }

class Category(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(100), nullable=False)
    icon = db.Column(db.String(100), default='mdi-folder-outline')  # Material Design Icons
    description = db.Column(db.String(200))
    parent_id = db.Column(db.Integer, db.ForeignKey('category.id'))
    user_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)
    is_root = db.Column(db.Boolean, default=False)
    documents = db.relationship('Document', backref='category', lazy='dynamic')
    children = db.relationship('Category', backref=db.backref('parent', remote_side=[id]), lazy='dynamic')
    
    def __repr__(self):
        return f'<Category {self.name}>'
    
    def to_dict(self):
        return {
            'id': self.id,
            'name': self.name,
            'icon': self.icon,
            'description': self.description,
            'parent_id': self.parent_id,
            'user_id': self.user_id,
            'is_root': self.is_root,
            'children': [child.to_dict() for child in self.children],
            'documents': [doc.id for doc in self.documents]
        }

class Tag(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(50), nullable=False)
    user_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)
    color = db.Column(db.String(20), default='#50fa7b')
    
    __table_args__ = (
        db.UniqueConstraint('name', 'user_id', name='_tag_user_uc'),
    )
    
    def __repr__(self):
        return f'<Tag {self.name}>'
    
    def to_dict(self):
        return {
            'id': self.id,
            'name': self.name,
            'user_id': self.user_id,
            'color': self.color,
            'document_count': self.documents.count()
        }