"""
讀者互動資料模型（訂閱、收藏、留言、筆記）
"""
from datetime import datetime
from sqlalchemy import String, Boolean, ForeignKey, Text, UniqueConstraint, Index
from sqlalchemy.orm import Mapped, mapped_column, relationship
from typing import Optional, List, TYPE_CHECKING

from app.db.session import Base

if TYPE_CHECKING:
    from app.models.user import User
    from app.models.group import Group
    from app.models.report import Report


class Subscription(Base):
    """訂閱表"""
    __tablename__ = "subscriptions"
    __table_args__ = (
        UniqueConstraint("user_id", "group_id", name="uk_user_group"),
    )
    
    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"), nullable=False)
    group_id: Mapped[int] = mapped_column(ForeignKey("groups.id", ondelete="CASCADE"), nullable=False)
    email_notify: Mapped[bool] = mapped_column(Boolean, default=True, comment="是否Email通知")
    created_at: Mapped[datetime] = mapped_column(default=datetime.utcnow)
    
    # 關聯
    user: Mapped["User"] = relationship(back_populates="subscriptions")
    group: Mapped["Group"] = relationship(back_populates="subscriptions")


class Favorite(Base):
    """收藏表"""
    __tablename__ = "favorites"
    __table_args__ = (
        UniqueConstraint("user_id", "report_id", name="uk_user_report"),
    )
    
    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"), nullable=False)
    report_id: Mapped[int] = mapped_column(ForeignKey("reports.id", ondelete="CASCADE"), nullable=False)
    created_at: Mapped[datetime] = mapped_column(default=datetime.utcnow)
    
    # 關聯
    user: Mapped["User"] = relationship(back_populates="favorites")
    report: Mapped["Report"] = relationship(back_populates="favorites")


class Comment(Base):
    """留言表"""
    __tablename__ = "comments"
    __table_args__ = (
        Index("idx_comments_report", "report_id"),
    )
    
    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
    report_id: Mapped[int] = mapped_column(ForeignKey("reports.id", ondelete="CASCADE"), nullable=False)
    user_id: Mapped[int] = mapped_column(ForeignKey("users.id"), nullable=False)
    content: Mapped[str] = mapped_column(Text, nullable=False, comment="留言內容")
    parent_id: Mapped[Optional[int]] = mapped_column(ForeignKey("comments.id"), comment="父留言ID")
    is_deleted: Mapped[bool] = mapped_column(Boolean, default=False)
    created_at: Mapped[datetime] = mapped_column(default=datetime.utcnow)
    updated_at: Mapped[datetime] = mapped_column(default=datetime.utcnow, onupdate=datetime.utcnow)
    
    # 關聯
    report: Mapped["Report"] = relationship(back_populates="comments")
    user: Mapped["User"] = relationship(back_populates="comments")
    parent: Mapped[Optional["Comment"]] = relationship(remote_side=[id], backref="replies")


class Note(Base):
    """個人筆記表"""
    __tablename__ = "notes"
    __table_args__ = (
        Index("idx_notes_user_report", "user_id", "report_id"),
    )
    
    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"), nullable=False)
    report_id: Mapped[int] = mapped_column(ForeignKey("reports.id", ondelete="CASCADE"), nullable=False)
    content: Mapped[str] = mapped_column(Text, nullable=False, comment="筆記內容")
    created_at: Mapped[datetime] = mapped_column(default=datetime.utcnow)
    updated_at: Mapped[datetime] = mapped_column(default=datetime.utcnow, onupdate=datetime.utcnow)
    
    # 關聯
    user: Mapped["User"] = relationship(back_populates="notes")
    report: Mapped["Report"] = relationship(back_populates="notes")