"""Controller run state model and persistence."""
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, Optional


def _now() -> str:
    return datetime.now(timezone.utc).isoformat()


@dataclass
class ControllerState:
    controller_run_id: str
    original_goal: str
    decision_mode: str                              # "real" | "stub"
    iteration_count: int = 0
    decisions: list[dict[str, Any]] = field(default_factory=list)
    linked_bridge_run_ids: list[str] = field(default_factory=list)
    bridge_run_results: list[dict[str, Any]] = field(default_factory=list)
    final_status: str = "running"                   # running | done | failed | stopped
    recovery_attempted: bool = False                # True after rewrite rule applied
    recovery_reason: Optional[str] = None           # rewrite_explain() text or skip reason
    rewritten_goal: Optional[str] = None            # goal after rewrite (if recovery applied)
    created_at: str = field(default_factory=_now)
    updated_at: str = field(default_factory=_now)

    @property
    def trace_id(self) -> str:
        """trace_id == controller_run_id by definition."""
        return self.controller_run_id

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

    def touch(self) -> None:
        self.updated_at = _now()


# ---------------------------------------------------------------------------
# Persistence helpers
# ---------------------------------------------------------------------------

def state_path(runs_dir: Path, ctrl_id: str) -> Path:
    return runs_dir / ctrl_id / "controller_state.json"


def save(state: ControllerState, runs_dir: Path) -> None:
    p = state_path(runs_dir, state.controller_run_id)
    p.parent.mkdir(parents=True, exist_ok=True)
    p.write_text(json.dumps(state.to_dict(), indent=2), encoding="utf-8")


def load(runs_dir: Path, ctrl_id: str) -> Optional[ControllerState]:
    p = state_path(runs_dir, ctrl_id)
    if not p.exists():
        return None
    data = json.loads(p.read_text(encoding="utf-8"))
    return ControllerState(**data)