import uuid
from datetime import datetime
from typing import Optional

from sqlalchemy import DateTime, ForeignKey, Index, String, Text, JSON, func
from sqlalchemy import Uuid
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.models.base import Base, UUIDMixin


class AuditLog(Base, UUIDMixin):
    """Immutable record of member activity and application errors."""

    __tablename__ = "audit_logs"
    __table_args__ = (
        Index("ix_audit_logs_timestamp", "timestamp"),
        Index("ix_audit_logs_member_id", "member_id"),
        Index("ix_audit_logs_action_type", "action_type"),
        Index("ix_audit_logs_status", "status"),
    )

    timestamp: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), server_default=func.now(), nullable=False
    )
    # Nullable FK — SET NULL if member is deleted so the log is preserved.
    member_id: Mapped[Optional[uuid.UUID]] = mapped_column(
        Uuid(as_uuid=True),
        ForeignKey("members.id", ondelete="SET NULL"),
        nullable=True,
    )
    # Denormalised for readability after member deletion.
    member_email: Mapped[Optional[str]] = mapped_column(String(255), nullable=True)

    # One of: login, logout, page_visit, booking_created, booking_cancelled,
    #         profile_updated, onboarding_updated, contract_signed,
    #         account_claimed, message_read, error
    action_type: Mapped[str] = mapped_column(String(64), nullable=False)

    # Identifies the page / feature area, e.g. "members/dashboard"
    area: Mapped[str] = mapped_column(String(255), nullable=False)

    # Human-readable one-liner
    description: Mapped[str] = mapped_column(String(500), nullable=False)

    # success | warning | error
    status: Mapped[str] = mapped_column(String(16), nullable=False, default="success")

    # Optional related booking — SET NULL if booking is deleted.
    booking_id: Mapped[Optional[uuid.UUID]] = mapped_column(
        Uuid(as_uuid=True),
        ForeignKey("bookings.id", ondelete="SET NULL"),
        nullable=True,
    )

    # Error detail — populated for action_type='error' records.
    error_message: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
    error_detail: Mapped[Optional[str]] = mapped_column(Text, nullable=True)

    # Request metadata
    ip_address: Mapped[Optional[str]] = mapped_column(String(64), nullable=True)
    user_agent: Mapped[Optional[str]] = mapped_column(String(512), nullable=True)

    # Catch-all JSON for any extra context (e.g. booking service_type)
    extra: Mapped[Optional[dict]] = mapped_column(JSON, nullable=True)

    member: Mapped[Optional["Member"]] = relationship(  # type: ignore[name-defined]
        "Member", foreign_keys=[member_id]
    )