import enum
import uuid
from datetime import datetime

from sqlalchemy import DateTime, Enum, ForeignKey, String, func
from sqlalchemy.dialects.postgresql import UUID
from sqlalchemy.orm import Mapped, mapped_column

from app.db.base_class import Base


class UserRole(str, enum.Enum):
    ADMIN = "ADMIN"
    PM = "PM"
    CRA = "CRA"
    PV = "PV"
    IMP = "IMP"
    QA = "QA"


class UserStatus(str, enum.Enum):
    PENDING = "PENDING"
    ACTIVE = "ACTIVE"
    REJECTED = "REJECTED"
    DISABLED = "DISABLED"


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, index=True, nullable=False)
    password_hash: Mapped[str] = mapped_column(String(255), nullable=False)
    full_name: Mapped[str] = mapped_column(String(255), nullable=False)
    role: Mapped[UserRole] = mapped_column(Enum(UserRole, name="user_role"), nullable=False)
    clinical_department: Mapped[str] = mapped_column(String(255), nullable=False)
    status: Mapped[UserStatus] = mapped_column(
        Enum(UserStatus, name="user_status"),
        nullable=False,
        server_default=UserStatus.PENDING.value,
        default=UserStatus.PENDING,
    )
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        nullable=False,
        server_default=func.now(),
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        nullable=False,
        server_default=func.now(),
        onupdate=func.now(),
    )
    approved_by: Mapped[uuid.UUID | None] = mapped_column(
        UUID(as_uuid=True),
        ForeignKey("users.id"),
        nullable=True,
    )
    approved_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    avatar_url: Mapped[str | None] = mapped_column(String(500), nullable=True)

    @property
    def is_active(self) -> bool:  # compatibility helper for existing checks
        return self.status == UserStatus.ACTIVE

    @property
    def username(self) -> str:  # backward compatibility for existing UI copy
        return self.email