"""Public data shapes for the Plan layer."""

from __future__ import annotations

from dataclasses import dataclass, field
from typing import Any, Optional


@dataclass
class PlanStep:
    analysis: str
    args: dict[str, Any] = field(default_factory=dict)
    why: str = ""
    # Optional sibling step to run when the primary errors or yields no
    # finding. Lets the planner hedge between a speculative Analysis (e.g.
    # `drill_down`) and a safer one (e.g. `direct_answer`).
    fallback: Optional["PlanStep"] = None

    @classmethod
    def from_dict(cls, raw: dict[str, Any]) -> "PlanStep":
        fb_raw = raw.get("fallback")
        return cls(
            analysis=raw["analysis"],
            args=raw.get("args") or {},
            why=raw.get("why", ""),
            fallback=cls.from_dict(fb_raw) if fb_raw else None,
        )

    def to_dict(self) -> dict[str, Any]:
        out: dict[str, Any] = {
            "analysis": self.analysis,
            "args": self.args,
            "why": self.why,
        }
        if self.fallback is not None:
            out["fallback"] = self.fallback.to_dict()
        return out


@dataclass
class Plan:
    rationale: str
    steps: list[PlanStep]

    @classmethod
    def from_dict(cls, raw: dict[str, Any]) -> "Plan":
        return cls(
            rationale=raw.get("rationale", ""),
            steps=[PlanStep.from_dict(s) for s in raw.get("steps", [])],
        )