import uuid
from datetime import datetime, timezone

from sqlalchemy import Boolean, DateTime, ForeignKey, Integer, String, Text
from sqlalchemy.dialects.postgresql import UUID
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.database import Base


def utcnow():
    return datetime.now(timezone.utc)


class Department(Base):
    __tablename__ = "departments"

    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    name: Mapped[str] = mapped_column(String(100), unique=True, nullable=False)
    description: Mapped[str | None] = mapped_column(Text)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, onupdate=utcnow)

    users: Mapped[list["User"]] = relationship(back_populates="department")


class User(Base):
    __tablename__ = "users"

    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    employee_id: Mapped[str | None] = mapped_column(String(50), unique=True)
    email: Mapped[str] = mapped_column(String(255), unique=True, nullable=False)
    full_name: Mapped[str] = mapped_column(String(200), nullable=False)
    department_id: Mapped[uuid.UUID | None] = mapped_column(UUID(as_uuid=True), ForeignKey("departments.id"))
    role: Mapped[str] = mapped_column(String(20), default="employee")  # employee | team_lead | admin
    avatar_url: Mapped[str | None] = mapped_column(Text)
    is_active: Mapped[bool] = mapped_column(Boolean, default=True)
    total_xp: Mapped[int] = mapped_column(Integer, default=0)
    verified_xp: Mapped[int] = mapped_column(Integer, default=0)  # XP from Tier 1+2 only
    current_level: Mapped[str] = mapped_column(String(50), default="Novice")
    password_hash: Mapped[str | None] = mapped_column(String(255))  # Demo auth only
    azure_ad_oid: Mapped[str | None] = mapped_column(String(255))  # Future: Azure AD
    github_username: Mapped[str | None] = mapped_column(String(100))  # GitHub Copilot mapping
    udemy_email: Mapped[str | None] = mapped_column(String(255))  # If different from primary
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, onupdate=utcnow)

    department: Mapped[Department | None] = relationship(back_populates="users")
    completions: Mapped[list["ActivityCompletion"]] = relationship(back_populates="user", foreign_keys="[ActivityCompletion.user_id]")
    badges: Mapped[list["UserBadge"]] = relationship(back_populates="user")