"""Freeze action identity against its decision-time observation."""

import hashlib
import json
from pathlib import Path


def observation_anchor(state, elements: list[dict] | None = None) -> dict:
    image = getattr(state, "latest_screenshot", None)
    image_name = Path(image).stem if isinstance(image, str) else None
    tree = elements if elements is not None else getattr(state, "indexed_elements", None)
    tree = tree if isinstance(tree, list) else []
    signature = json.dumps([image_name, tree], sort_keys=True, ensure_ascii=False, default=str)
    return {
        "target_image_name": image_name,
        "target_snapshot_id": hashlib.sha256(signature.encode()).hexdigest()[:24],
    }


def element_semantics(element: dict, index: int) -> dict:
    """Copy evidence; no live element/index lookup is allowed after dispatch."""
    result = {"target_index": index}
    for key in ("editable", "input_value_state", "hint", "showing_hint", "focused", "is_hint"):
        if key in element:
            result[f"target_{key}"] = element[key]
    return result