from sqlalchemy import Column, Integer, String, Text, DateTime, JSON, ForeignKey, Enum as SAEnum, UniqueConstraint
from sqlalchemy.orm import relationship
from sqlalchemy.sql import func
from database import Base


class Resource(Base):
    __tablename__ = "resources"

    id = Column(Integer, primary_key=True, index=True)
    user_id = Column(Integer, ForeignKey("users.id"), nullable=False)
    resource_type = Column(
        SAEnum("courseware", "animation", "exercise", "lesson_plan", "exam", "other", name="res_type"),
        default="other",
    )
    title = Column(String(200), nullable=False)
    description = Column(Text, default="")
    content_ref = Column(String(500), default="")
    file_url = Column(String(500), default="")
    cover_image = Column(String(500), default="")
    tags = Column(JSON, default=list)
    subject = Column(String(50), default="")
    grade = Column(String(50), default="")
    downloads = Column(Integer, default=0)
    likes = Column(Integer, default=0)
    views = Column(Integer, default=0)
    is_public = Column(Integer, default=1)
    status = Column(SAEnum("active", "archived", name="res_status"), default="active")
    created_at = Column(DateTime, server_default=func.now())
    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now())

    author = relationship("User", back_populates="resources")
    favorites = relationship("ResourceFavorite", back_populates="resource", cascade="all, delete-orphan")


class ResourceFavorite(Base):
    __tablename__ = "resource_favorites"
    __table_args__ = (UniqueConstraint("user_id", "resource_id", name="uq_resource_favorite_user_resource"),)

    id = Column(Integer, primary_key=True, index=True)
    user_id = Column(Integer, ForeignKey("users.id"), nullable=False, index=True)
    resource_id = Column(Integer, ForeignKey("resources.id"), nullable=False, index=True)
    created_at = Column(DateTime, server_default=func.now())

    user = relationship("User", back_populates="resource_favorites")
    resource = relationship("Resource", back_populates="favorites")