from datetime import UTC, datetime
from uuid import UUID

from sqlalchemy import Boolean, DateTime, ForeignKey, Integer, String, Text
from sqlalchemy.orm import Mapped, mapped_column
from uuid_utils import uuid7

from .db import Base


def new_id() -> UUID:
    return UUID(str(uuid7()))


def utcnow() -> datetime:
    return datetime.now(UTC)


class AppState(Base):
    __tablename__ = "app_state"
    key: Mapped[str] = mapped_column(String(64), primary_key=True)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)


class User(Base):
    __tablename__ = "users"
    id: Mapped[UUID] = mapped_column(primary_key=True, default=new_id)
    username: Mapped[str] = mapped_column(String(64), unique=True, index=True)
    password_hash: Mapped[str] = mapped_column(Text)
    timezone: Mapped[str] = mapped_column(String(64), default="Asia/Shanghai")
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)


class Session(Base):
    __tablename__ = "sessions"
    id: Mapped[UUID] = mapped_column(primary_key=True, default=new_id)
    token_hash: Mapped[str] = mapped_column(String(64), unique=True, index=True)
    user_id: Mapped[UUID] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"), index=True)
    expires_at: Mapped[datetime] = mapped_column(DateTime(timezone=True))
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)


class Folder(Base):
    __tablename__ = "folders"
    id: Mapped[UUID] = mapped_column(primary_key=True, default=new_id)
    user_id: Mapped[UUID] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"), index=True)
    name: Mapped[str] = mapped_column(String(120))
    position: Mapped[int] = mapped_column(Integer, default=0)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)


class TaskList(Base):
    __tablename__ = "task_lists"
    id: Mapped[UUID] = mapped_column(primary_key=True, default=new_id)
    user_id: Mapped[UUID] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"), index=True)
    folder_id: Mapped[UUID | None] = mapped_column(ForeignKey("folders.id", ondelete="SET NULL"), nullable=True)
    name: Mapped[str] = mapped_column(String(120))
    is_inbox: Mapped[bool] = mapped_column(Boolean, default=False)
    position: Mapped[int] = mapped_column(Integer, default=0)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)


class Task(Base):
    __tablename__ = "tasks"
    id: Mapped[UUID] = mapped_column(primary_key=True, default=new_id)
    user_id: Mapped[UUID] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"), index=True)
    list_id: Mapped[UUID] = mapped_column(ForeignKey("task_lists.id", ondelete="CASCADE"), index=True)
    parent_id: Mapped[UUID | None] = mapped_column(ForeignKey("tasks.id", ondelete="CASCADE"), nullable=True)
    title: Mapped[str] = mapped_column(String(500))
    description: Mapped[str] = mapped_column(Text, default="")
    priority: Mapped[int] = mapped_column(Integer, default=0)
    completed: Mapped[bool] = mapped_column(Boolean, default=False, index=True)
    due_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    version: Mapped[int] = mapped_column(Integer, default=1)
    position: Mapped[int] = mapped_column(Integer, default=0)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, onupdate=utcnow)
    deleted_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)