from __future__ import annotations

import uuid
from datetime import datetime
from typing import Any

from sqlalchemy import Boolean, DateTime, ForeignKey, Index, Integer, JSON, String, Text, UniqueConstraint
from sqlalchemy.orm import Mapped, mapped_column, relationship

from govoplan_core.db.base import Base, TimestampMixin


def new_uuid() -> str:
    return str(uuid.uuid4())


class NotificationMessage(Base, TimestampMixin):
    __tablename__ = "notification_messages"
    __table_args__ = (
        Index("ix_notification_messages_tenant_status", "tenant_id", "status"),
        Index("ix_notification_messages_tenant_recipient", "tenant_id", "recipient_type", "recipient_id"),
        Index(
            "ix_notification_messages_summary",
            "tenant_id",
            "recipient_id",
            "deleted_at",
            "status",
            "read_at",
        ),
        Index("ix_notification_messages_source", "tenant_id", "source_module", "source_resource_type", "source_resource_id"),
        Index("ix_notification_messages_due", "tenant_id", "status", "not_before_at"),
    )

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=new_uuid)
    tenant_id: Mapped[str] = mapped_column(String(36), nullable=False, index=True)
    source_module: Mapped[str] = mapped_column(String(100), nullable=False, index=True)
    source_resource_type: Mapped[str] = mapped_column(String(100), nullable=False, index=True)
    source_resource_id: Mapped[str | None] = mapped_column(String(255), nullable=True, index=True)
    event_kind: Mapped[str] = mapped_column(String(100), nullable=False, index=True)
    channel: Mapped[str] = mapped_column(String(40), default="inbox", nullable=False, index=True)
    recipient: Mapped[str | None] = mapped_column(String(500), nullable=True, index=True)
    recipient_type: Mapped[str | None] = mapped_column(String(40), nullable=True, index=True)
    recipient_id: Mapped[str | None] = mapped_column(String(255), nullable=True, index=True)
    recipient_label: Mapped[str | None] = mapped_column(String(500), nullable=True)
    subject: Mapped[str | None] = mapped_column(String(500), nullable=True)
    body_text: Mapped[str | None] = mapped_column(Text, nullable=True)
    body_html: Mapped[str | None] = mapped_column(Text, nullable=True)
    action_url: Mapped[str | None] = mapped_column(String(1000), nullable=True)
    priority: Mapped[int] = mapped_column(Integer, default=0, nullable=False, index=True)
    status: Mapped[str] = mapped_column(String(40), default="pending", nullable=False, index=True)
    not_before_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True, index=True)
    queued_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    sent_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    failed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    read_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    acknowledged_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    cancelled_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    attempt_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    last_error: Mapped[str | None] = mapped_column(Text, nullable=True)
    external_message_id: Mapped[str | None] = mapped_column(String(255), nullable=True, index=True)
    payload: Mapped[dict[str, Any]] = mapped_column(JSON, default=dict, nullable=False)
    metadata_: Mapped[dict[str, Any]] = mapped_column("metadata", JSON, default=dict, nullable=False)
    deleted_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True, index=True)

    attempts: Mapped[list["NotificationDeliveryAttempt"]] = relationship(
        back_populates="notification",
        cascade="all, delete-orphan",
        order_by="NotificationDeliveryAttempt.created_at",
    )


class NotificationDeliveryAttempt(Base, TimestampMixin):
    __tablename__ = "notification_delivery_attempts"
    __table_args__ = (
        Index("ix_notification_attempts_notification", "notification_id", "attempt_no"),
        Index("ix_notification_attempts_tenant_status", "tenant_id", "status"),
    )

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=new_uuid)
    tenant_id: Mapped[str] = mapped_column(String(36), nullable=False, index=True)
    notification_id: Mapped[str] = mapped_column(ForeignKey("notification_messages.id", ondelete="CASCADE"), nullable=False, index=True)
    attempt_no: Mapped[int] = mapped_column(Integer, nullable=False)
    channel: Mapped[str] = mapped_column(String(40), nullable=False, index=True)
    provider: Mapped[str | None] = mapped_column(String(100), nullable=True, index=True)
    status: Mapped[str] = mapped_column(String(40), nullable=False, index=True)
    started_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    finished_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    external_message_id: Mapped[str | None] = mapped_column(String(255), nullable=True)
    error: Mapped[str | None] = mapped_column(Text, nullable=True)
    details: Mapped[dict[str, Any]] = mapped_column(JSON, default=dict, nullable=False)

    notification: Mapped[NotificationMessage] = relationship(back_populates="attempts")


class NotificationPreference(Base, TimestampMixin):
    __tablename__ = "notification_preferences"
    __table_args__ = (
        UniqueConstraint("tenant_id", "user_id", name="uq_notification_preferences_tenant_user"),
        Index("ix_notification_preferences_tenant_user", "tenant_id", "user_id"),
    )

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=new_uuid)
    tenant_id: Mapped[str] = mapped_column(String(36), nullable=False, index=True)
    user_id: Mapped[str] = mapped_column(String(36), nullable=False, index=True)
    show_unread_badge: Mapped[bool] = mapped_column(Boolean, default=True, nullable=False)
    email_enabled: Mapped[bool] = mapped_column(Boolean, default=False, nullable=False)
    email_digest_enabled: Mapped[bool] = mapped_column(Boolean, default=False, nullable=False)
    muted_source_modules: Mapped[list[str]] = mapped_column(JSON, default=list, nullable=False)
    metadata_: Mapped[dict[str, Any]] = mapped_column("metadata", JSON, default=dict, nullable=False)


__all__ = ["NotificationDeliveryAttempt", "NotificationMessage", "NotificationPreference", "new_uuid"]