import uuid
from datetime import datetime, timezone
from typing import Optional, TYPE_CHECKING
from sqlalchemy import String, DateTime, ForeignKey, Boolean
from sqlalchemy.orm import Mapped, mapped_column, relationship
from sqlalchemy.dialects.postgresql import UUID
from app.core.database import Base

if TYPE_CHECKING:
    from app.models.team import Team
    from app.models.tree import Tree
    from app.models.session import Session
    from app.models.folder import UserFolder


class User(Base):
    __tablename__ = "users"

    id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True),
        primary_key=True,
        default=uuid.uuid4
    )
    email: Mapped[str] = mapped_column(String(255), unique=True, nullable=False, index=True)
    password_hash: Mapped[str] = mapped_column(String(255), nullable=False)
    name: Mapped[str] = mapped_column(String(255), nullable=False)
    role: Mapped[str] = mapped_column(String(50), nullable=False, default="engineer")
    is_team_admin: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)
    team_id: Mapped[Optional[uuid.UUID]] = mapped_column(
        UUID(as_uuid=True),
        ForeignKey("teams.id"),
        nullable=True
    )
    invite_code_id: Mapped[Optional[uuid.UUID]] = mapped_column(
        UUID(as_uuid=True),
        ForeignKey("invite_codes.id"),
        nullable=True
    )
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=lambda: datetime.now(timezone.utc)
    )
    last_login: Mapped[Optional[datetime]] = mapped_column(DateTime(timezone=True), nullable=True)

    # Relationships
    team: Mapped[Optional["Team"]] = relationship("Team", back_populates="users")
    trees: Mapped[list["Tree"]] = relationship("Tree", back_populates="author")
    sessions: Mapped[list["Session"]] = relationship("Session", back_populates="user")
    folders: Mapped[list["UserFolder"]] = relationship("UserFolder", back_populates="user")

    @property
    def is_admin(self) -> bool:
        """Returns True if user is a global (ResolutionFlow) admin."""
        return self.role == "admin"

    @property
    def can_manage_team(self) -> bool:
        """Returns True if user can manage their team (team admin or global admin)."""
        return self.is_admin or (self.is_team_admin and self.team_id is not None)