from datetime import UTC, datetime
from enum import StrEnum
from uuid import uuid4

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

from app.db.session import Base


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


class InstanceRole(StrEnum):
    ADMIN = "instance_admin"
    USER = "user"


class HomeRole(StrEnum):
    OWNER = "home_owner"
    MEMBER = "home_member"
    READ_ONLY = "read_only"


class Theme(StrEnum):
    LIGHT = "light"
    DARK = "dark"
    SYSTEM = "system"


class Language(StrEnum):
    DE = "de"
    EN = "en"


class User(Base):
    __tablename__ = "users"

    id: Mapped[str] = mapped_column(UUID(as_uuid=False), primary_key=True, default=lambda: str(uuid4()))
    email: Mapped[str] = mapped_column(String(320), unique=True, index=True)
    name: Mapped[str] = mapped_column(String(160))
    password_hash: Mapped[str | None] = mapped_column(String(255), nullable=True)
    instance_role: Mapped[str] = mapped_column(String(40), default=InstanceRole.USER)
    language: Mapped[str] = mapped_column(String(8), default=Language.DE)
    theme: Mapped[str] = mapped_column(String(16), default=Theme.SYSTEM)
    timezone: Mapped[str] = mapped_column(String(80), default="Europe/Vienna")
    is_active: Mapped[bool] = mapped_column(Boolean, default=True)
    onboarding_completed: Mapped[bool] = mapped_column(Boolean, default=False)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=now_utc)
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=now_utc)

    memberships: Mapped[list["HomeMembership"]] = relationship(back_populates="user", cascade="all, delete")


class Home(Base):
    __tablename__ = "homes"

    id: Mapped[str] = mapped_column(UUID(as_uuid=False), primary_key=True, default=lambda: str(uuid4()))
    name: Mapped[str] = mapped_column(String(160))
    join_code_hash: Mapped[str | None] = mapped_column(String(128), nullable=True, index=True)
    join_code_expires_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    expiry_warning_days: Mapped[int] = mapped_column(Integer, default=5)
    daily_summary_enabled: Mapped[bool] = mapped_column(Boolean, default=True)
    daily_summary_time: Mapped[str] = mapped_column(String(5), default="08:00")
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=now_utc)

    memberships: Mapped[list["HomeMembership"]] = relationship(back_populates="home", cascade="all, delete")
    products: Mapped[list["Product"]] = relationship(back_populates="home", cascade="all, delete")


class HomeMembership(Base):
    __tablename__ = "home_memberships"
    __table_args__ = (UniqueConstraint("home_id", "user_id", name="uq_home_user"),)

    id: Mapped[str] = mapped_column(UUID(as_uuid=False), primary_key=True, default=lambda: str(uuid4()))
    home_id: Mapped[str] = mapped_column(ForeignKey("homes.id", ondelete="CASCADE"))
    user_id: Mapped[str] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"))
    role: Mapped[str] = mapped_column(String(40), default=HomeRole.MEMBER)
    notification_preferences: Mapped[dict] = mapped_column(JSONB, default=dict)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=now_utc)

    home: Mapped[Home] = relationship(back_populates="memberships")
    user: Mapped[User] = relationship(back_populates="memberships")


class Product(Base):
    __tablename__ = "products"

    id: Mapped[str] = mapped_column(UUID(as_uuid=False), primary_key=True, default=lambda: str(uuid4()))
    home_id: Mapped[str] = mapped_column(ForeignKey("homes.id", ondelete="CASCADE"), index=True)
    name: Mapped[str] = mapped_column(String(220))
    barcode: Mapped[str | None] = mapped_column(String(80), nullable=True, index=True)
    brand: Mapped[str | None] = mapped_column(String(160), nullable=True)
    category: Mapped[str] = mapped_column(String(120), default="Other")
    location: Mapped[str] = mapped_column(String(120), default="Pantry")
    quantity: Mapped[float] = mapped_column(default=1)
    unit: Mapped[str] = mapped_column(String(32), default="pcs")
    expires_at: Mapped[datetime | None] = mapped_column(Date, nullable=True)
    min_quantity: Mapped[float] = mapped_column(default=0)
    notes: Mapped[str | None] = mapped_column(Text, nullable=True)
    image_url: Mapped[str | None] = mapped_column(Text, nullable=True)
    created_by_id: Mapped[str | None] = mapped_column(ForeignKey("users.id", ondelete="SET NULL"))
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=now_utc)
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=now_utc)

    home: Mapped[Home] = relationship(back_populates="products")


class ShoppingItem(Base):
    __tablename__ = "shopping_items"

    id: Mapped[str] = mapped_column(UUID(as_uuid=False), primary_key=True, default=lambda: str(uuid4()))
    home_id: Mapped[str] = mapped_column(ForeignKey("homes.id", ondelete="CASCADE"), index=True)
    name: Mapped[str] = mapped_column(String(220))
    category: Mapped[str] = mapped_column(String(120), default="Other")
    quantity: Mapped[float] = mapped_column(default=1)
    unit: Mapped[str] = mapped_column(String(32), default="pcs")
    checked: Mapped[bool] = mapped_column(Boolean, default=False)
    product_id: Mapped[str | None] = mapped_column(ForeignKey("products.id", ondelete="SET NULL"), nullable=True)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=now_utc)


class AppSetting(Base):
    __tablename__ = "app_settings"
    key: Mapped[str] = mapped_column(String(120), primary_key=True)
    value: Mapped[dict] = mapped_column(JSONB, default=dict)
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=now_utc)


class MailSetting(Base):
    __tablename__ = "mail_settings"
    id: Mapped[int] = mapped_column(Integer, primary_key=True, default=1)
    smtp_host: Mapped[str | None] = mapped_column(String(220), nullable=True)
    smtp_port: Mapped[int] = mapped_column(Integer, default=587)
    smtp_user: Mapped[str | None] = mapped_column(String(220), nullable=True)
    smtp_password_encrypted: Mapped[str | None] = mapped_column(Text, nullable=True)
    use_tls: Mapped[bool] = mapped_column(Boolean, default=False)
    use_starttls: Mapped[bool] = mapped_column(Boolean, default=True)
    sender_address: Mapped[str | None] = mapped_column(String(320), nullable=True)
    sender_name: Mapped[str] = mapped_column(String(160), default="NexaPantry")
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=now_utc)


class InvitationToken(Base):
    __tablename__ = "invitation_tokens"
    id: Mapped[str] = mapped_column(UUID(as_uuid=False), primary_key=True, default=lambda: str(uuid4()))
    user_id: Mapped[str] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"))
    token_hash: Mapped[str] = mapped_column(String(128), unique=True, index=True)
    expires_at: Mapped[datetime] = mapped_column(DateTime(timezone=True))
    consumed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=now_utc)


class PasswordResetToken(Base):
    __tablename__ = "password_reset_tokens"
    id: Mapped[str] = mapped_column(UUID(as_uuid=False), primary_key=True, default=lambda: str(uuid4()))
    user_id: Mapped[str] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"))
    token_hash: Mapped[str] = mapped_column(String(128), unique=True, index=True)
    expires_at: Mapped[datetime] = mapped_column(DateTime(timezone=True))
    consumed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=now_utc)


class Notification(Base):
    __tablename__ = "notifications"
    id: Mapped[str] = mapped_column(UUID(as_uuid=False), primary_key=True, default=lambda: str(uuid4()))
    user_id: Mapped[str] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"), index=True)
    home_id: Mapped[str | None] = mapped_column(ForeignKey("homes.id", ondelete="CASCADE"), nullable=True)
    title: Mapped[str] = mapped_column(String(220))
    body: Mapped[str] = mapped_column(Text)
    kind: Mapped[str] = mapped_column(String(80), default="info")
    read_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=now_utc)


class AuditLog(Base):
    __tablename__ = "audit_logs"
    id: Mapped[str] = mapped_column(UUID(as_uuid=False), primary_key=True, default=lambda: str(uuid4()))
    actor_user_id: Mapped[str | None] = mapped_column(ForeignKey("users.id", ondelete="SET NULL"))
    action: Mapped[str] = mapped_column(String(160), index=True)
    target_type: Mapped[str | None] = mapped_column(String(80), nullable=True)
    target_id: Mapped[str | None] = mapped_column(String(80), nullable=True)
    metadata_json: Mapped[dict] = mapped_column(JSONB, default=dict)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=now_utc)