"""Data models for the autoscaler daemon."""

from __future__ import annotations

from datetime import datetime
from enum import StrEnum
from typing import Any

from pydantic import BaseModel, Field


class SlotState(StrEnum):
    """Exhaustive slot states."""

    EMPTY = "empty"
    LAUNCHING = "launching"
    BOOTING = "booting"
    BINDING = "binding"
    READY = "ready"
    DRAINING = "draining"
    TERMINATING = "terminating"
    ERROR = "error"


class ReservationPhase(StrEnum):
    """Exhaustive reservation phases."""

    PENDING = "pending"
    READY = "ready"
    FAILED = "failed"
    RELEASED = "released"
    EXPIRED = "expired"


# ---------------------------------------------------------------------------
# API request models
# ---------------------------------------------------------------------------


class ReservationRequest(BaseModel):
    """POST /v1/reservations request body."""

    system: str
    reason: str
    build_id: int | None = None


class CapacityHint(BaseModel):
    """POST /v1/hints/capacity request body."""

    builder: str
    queued: int
    running: int
    system: str
    timestamp: datetime


# ---------------------------------------------------------------------------
# API response models
# ---------------------------------------------------------------------------


class ReservationResponse(BaseModel):
    """Reservation representation returned by the API."""

    reservation_id: str
    phase: ReservationPhase
    slot: str | None = None
    instance_id: str | None = None
    system: str
    created_at: datetime
    updated_at: datetime
    expires_at: datetime
    released_at: datetime | None = None


class SlotInfo(BaseModel):
    """Slot representation returned by the API."""

    slot_id: str
    system: str
    state: SlotState
    instance_id: str | None = None
    instance_ip: str | None = None
    lease_count: int
    last_state_change: datetime


class SlotsSummary(BaseModel):
    """Aggregate slot counts by state."""

    total: int = 0
    ready: int = 0
    launching: int = 0
    booting: int = 0
    binding: int = 0
    draining: int = 0
    terminating: int = 0
    empty: int = 0
    error: int = 0


class ReservationsSummary(BaseModel):
    """Aggregate reservation counts by phase."""

    pending: int = 0
    ready: int = 0
    failed: int = 0


class Ec2Summary(BaseModel):
    """EC2 subsystem health."""

    api_ok: bool = True
    last_reconcile_at: datetime | None = None


class HaproxySummary(BaseModel):
    """HAProxy subsystem health."""

    socket_ok: bool = True
    last_stat_poll_at: datetime | None = None


class StateSummary(BaseModel):
    """GET /v1/state/summary response."""

    slots: SlotsSummary = Field(default_factory=SlotsSummary)
    reservations: ReservationsSummary = Field(default_factory=ReservationsSummary)
    ec2: Ec2Summary = Field(default_factory=Ec2Summary)
    haproxy: HaproxySummary = Field(default_factory=HaproxySummary)


class ErrorDetail(BaseModel):
    """Structured error detail."""

    code: str
    message: str
    retryable: bool = False
    details: dict[str, Any] | None = None


class ErrorResponse(BaseModel):
    """Standard error response envelope."""

    error: ErrorDetail
    request_id: str


class HealthResponse(BaseModel):
    """Health check response."""

    status: str