"""Local session state. No passwords."""

from __future__ import annotations

import json
from dataclasses import asdict, dataclass, field
from datetime import datetime, timezone
from pathlib import Path
from typing import Any

from gpu_rent.paths import runtime_dir, state_path

CURRENT_VERSION = 1


@dataclass
class SessionState:
    version: int = CURRENT_VERSION
    phase: str = "idle"
    server_id: str | None = None
    server_name: str | None = None
    flavor_id: str | None = None
    flavor_name: str | None = None
    boot_volume_id: str | None = None
    data_volume_id: str | None = None
    floating_ip: str | None = None
    keypair_name: str | None = None
    created_at: str | None = None
    unshelved_at: str | None = None
    notes: dict[str, Any] = field(default_factory=dict)
    floating_ip_id: str | None = None
    network_id: str | None = None
    security_group_id: str | None = None
    image_id: str | None = None
    availability_zone: str | None = None
    spot: bool = True
    bootstrapped: bool = False

    def to_dict(self) -> dict[str, Any]:
        return asdict(self)

    @classmethod
    def from_dict(cls, data: dict[str, Any]) -> SessionState:
        known = {k: v for k, v in data.items() if k in cls.__dataclass_fields__}
        return cls(**known)


def utc_now() -> str:
    return datetime.now(timezone.utc).replace(microsecond=0).isoformat()


def load_state() -> SessionState:
    path = state_path()
    if not path.is_file():
        return SessionState()
    raw = json.loads(path.read_text(encoding="utf-8"))
    if not isinstance(raw, dict):
        return SessionState()
    return SessionState.from_dict(raw)


def save_state(state: SessionState) -> None:
    runtime_dir().mkdir(parents=True, exist_ok=True)
    path = state_path()
    path.write_text(json.dumps(state.to_dict(), indent=2) + "\n", encoding="utf-8")


def preempt_window_end(state: SessionState) -> datetime | None:
    stamp = state.unshelved_at or state.created_at
    if not stamp:
        return None
    try:
        start = datetime.fromisoformat(stamp)
    except ValueError:
        return None
    if start.tzinfo is None:
        start = start.replace(tzinfo=timezone.utc)
    from datetime import timedelta

    return start + timedelta(hours=24)