from __future__ import annotations
import enum
import uuid
from datetime import datetime, timezone
from sqlalchemy import JSON, Boolean, DateTime, Enum, Float, ForeignKey, Integer, String, Text
from sqlalchemy.orm import Mapped, mapped_column
from .base import Base


class AlertOperator(str, enum.Enum):
    gt = ">"
    lt = "<"
    gte = ">="
    lte = "<="
    eq = "=="
    ne = "!="


class AlertStateEnum(str, enum.Enum):
    inactive = "inactive"
    pending = "pending"
    firing = "firing"
    acknowledged = "acknowledged"
    resolved = "resolved"


class AlertRule(Base):
    __tablename__ = "alert_rules"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
    name: Mapped[str] = mapped_column(String(128), nullable=False)
    source_module: Mapped[str] = mapped_column(String(64), nullable=False)
    resource_name: Mapped[str] = mapped_column(String(255), nullable=False)
    metric_name: Mapped[str] = mapped_column(String(128), nullable=False)
    # The DB enum (migration 0002) stores the operator VALUES (">", "<", …), so
    # persist values rather than SQLAlchemy's default enum-member NAMES ("gt"…).
    operator: Mapped[AlertOperator] = mapped_column(
        Enum(AlertOperator, name="alertoperator",
             values_callable=lambda e: [m.value for m in e]),
        nullable=False,
    )
    threshold: Mapped[float] = mapped_column(Float, nullable=False)
    consecutive_failures_required: Mapped[int] = mapped_column(Integer, nullable=False, default=1)
    enabled: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True)
    # Optional admin-only action: run an Ansible playbook on transition-to-firing.
    # Shape: {source, playbook, inventory, extra_vars, limit, tags, check}. NULL = none.
    ansible_action: Mapped[dict | None] = mapped_column(JSON, nullable=True)
    created_by: Mapped[str] = mapped_column(String(36), ForeignKey("users.id", ondelete="RESTRICT"), nullable=False)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, default=lambda: datetime.now(timezone.utc)
    )


class AlertState(Base):
    __tablename__ = "alert_states"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
    rule_id: Mapped[str] = mapped_column(
        String(36), ForeignKey("alert_rules.id", ondelete="CASCADE"), nullable=False, unique=True
    )
    state: Mapped[AlertStateEnum] = mapped_column(
        Enum(AlertStateEnum), nullable=False, default=AlertStateEnum.inactive
    )
    consecutive_failure_count: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    last_transition_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, default=lambda: datetime.now(timezone.utc)
    )
    acknowledged_by: Mapped[str | None] = mapped_column(
        String(36), ForeignKey("users.id", ondelete="SET NULL"), nullable=True
    )
    acknowledged_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)


class MaintenanceWindow(Base):
    __tablename__ = "maintenance_windows"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
    name: Mapped[str] = mapped_column(String(128), nullable=False)
    start_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
    end_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
    # Scope — null means "all". scope_resource requires scope_source to be set.
    scope_source: Mapped[str | None] = mapped_column(String(64), nullable=True)
    scope_resource: Mapped[str | None] = mapped_column(String(255), nullable=True)
    created_by: Mapped[str] = mapped_column(
        String(36), ForeignKey("users.id", ondelete="RESTRICT"), nullable=False
    )
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, default=lambda: datetime.now(timezone.utc)
    )


class AlertEvent(Base):
    __tablename__ = "alert_events"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
    rule_id: Mapped[str] = mapped_column(
        String(36), ForeignKey("alert_rules.id", ondelete="CASCADE"), nullable=False
    )
    from_state: Mapped[str] = mapped_column(String(32), nullable=False)
    to_state: Mapped[str] = mapped_column(String(32), nullable=False)
    metric_value: Mapped[float] = mapped_column(Float, nullable=False)
    transitioned_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, default=lambda: datetime.now(timezone.utc)
    )
    email_sent: Mapped[bool | None] = mapped_column(Boolean, nullable=True)
    email_error: Mapped[str | None] = mapped_column(Text, nullable=True)
    webhook_sent: Mapped[bool | None] = mapped_column(Boolean, nullable=True)
    webhook_error: Mapped[str | None] = mapped_column(Text, nullable=True)
    # Set when this firing event triggered an Ansible action run (audit link).
    ansible_run_id: Mapped[str | None] = mapped_column(
        String(36), ForeignKey("ansible_runs.id", ondelete="SET NULL"), nullable=True
    )