"""Approval-mode state shared by the Textual client and agent server."""

from __future__ import annotations

import contextlib
import inspect
import json
import logging
import os
import tempfile
from collections.abc import Mapping
from enum import StrEnum
from hashlib import sha256
from pathlib import Path
from typing import TypedDict

logger = logging.getLogger(__name__)

APPROVAL_MODE_NAMESPACE: tuple[str, str] = ("deepagents_code", "approval_mode")
"""Store namespace for per-thread approval-mode control records."""

YOLO_ACKNOWLEDGEMENT_POLICY_VERSION = "2026-07-14"
"""Version of the unrestricted-mode warning that must be acknowledged."""


class ApprovalMode(StrEnum):
    """Tool-approval policy selected for an interactive thread."""

    MANUAL = "manual"
    AUTO = "auto"
    YOLO = "yolo"


class ApprovalModePayload(TypedDict):
    """Stored approval-mode control payload."""

    mode: str


def coerce_approval_mode(value: object) -> ApprovalMode:
    """Return a validated mode, failing closed to `manual`.

    Args:
        value: Untrusted mode value from config, context, or storage.

    Returns:
        A validated `ApprovalMode`; invalid values become `ApprovalMode.MANUAL`.
    """
    try:
        return ApprovalMode(value) if isinstance(value, str) else ApprovalMode.MANUAL
    except ValueError:
        return ApprovalMode.MANUAL


def approval_mode_key(thread_id: str) -> str:
    """Return the store key for a thread's live approval mode.

    Args:
        thread_id: LangGraph thread id for the active session.

    Returns:
        Deterministic store key that does not expose the raw thread id.
    """
    return sha256(thread_id.encode("utf-8")).hexdigest()


def approval_mode_payload(
    *,
    mode: ApprovalMode | str | None = None,
    auto_approve: bool | None = None,
) -> ApprovalModePayload:
    """Return the stored approval-mode payload.

    Args:
        mode: Explicit approval mode.
        auto_approve: Compatibility input for callers using the previous Boolean
            API. `True` maps to unrestricted `yolo`, and `False` maps to `manual`.

    Returns:
        JSON-serializable store value.

    Raises:
        ValueError: If neither or both inputs are supplied, or `mode` is invalid.
    """
    if (mode is None) == (auto_approve is None):
        msg = "Provide exactly one of mode or auto_approve"
        raise ValueError(msg)
    if auto_approve is not None:
        resolved = ApprovalMode.YOLO if auto_approve else ApprovalMode.MANUAL
    else:
        try:
            resolved = ApprovalMode(mode)
        except (TypeError, ValueError) as exc:
            msg = f"Invalid approval mode: {mode!r}"
            raise ValueError(msg) from exc
    return {"mode": resolved.value}


def _item_value(item: object) -> object:
    """Extract a store item's value.

    Args:
        item: SDK or runtime store-item shape.

    Returns:
        The stored value, or `None` when the shape is unrecognized.
    """
    if isinstance(item, Mapping):
        return item.get("value")
    return getattr(item, "value", None)


def _approval_mode_from_item(item: object) -> ApprovalMode | None:
    """Extract a validated approval mode from a Store item.

    Args:
        item: SDK or runtime store-item shape.

    Returns:
        The stored mode, or `None` when the item is missing or malformed.
    """
    if item is None:
        logger.debug("Approval-mode store item is missing")
        return None

    value = _item_value(item)
    raw_mode = value.get("mode") if isinstance(value, Mapping) else None
    if isinstance(raw_mode, str):
        try:
            return ApprovalMode(raw_mode)
        except ValueError:
            pass

    logger.warning("Approval-mode store item has invalid contents")
    return None


def read_approval_mode_from_store(
    store: object, key: str | None
) -> ApprovalMode | None:
    """Read a live approval mode from the server-side LangGraph Store.

    Args:
        store: `request.runtime.store` from the graph server.
        key: Store key produced by `approval_mode_key`.

    Returns:
        A validated mode, or `None` when the record cannot be trusted. Callers
        must interpret `None` as `manual`.
    """
    if store is None:
        logger.debug("Approval-mode store is unavailable")
        return None
    if not isinstance(key, str) or not key:
        logger.debug("Approval-mode store key is missing or invalid")
        return None

    get = getattr(store, "get", None)
    if get is None:
        logger.debug("Approval-mode store does not expose get()")
        return None

    try:
        item = get(APPROVAL_MODE_NAMESPACE, key)
    except Exception:
        logger.warning("Could not read approval-mode store item", exc_info=True)
        return None
    return _approval_mode_from_item(item)


async def aread_approval_mode_from_store(
    store: object, key: str | None
) -> ApprovalMode | None:
    """Asynchronously read a live approval mode from a LangGraph Store.

    The graph server supplies an async batched Store whose synchronous methods
    reject calls from the event-loop thread. Prefer `aget()` for that runtime,
    while retaining a synchronous fallback for lightweight local test stores.

    Args:
        store: `request.runtime.store` from the graph server.
        key: Store key produced by `approval_mode_key`.

    Returns:
        A validated mode, or `None` when the record cannot be trusted. Callers
        must interpret `None` as `manual`.
    """
    if store is None:
        logger.debug("Approval-mode store is unavailable")
        return None
    if not isinstance(key, str) or not key:
        logger.debug("Approval-mode store key is missing or invalid")
        return None

    aget = getattr(store, "aget", None)
    get = getattr(store, "get", None)
    try:
        if callable(aget):
            result = aget(APPROVAL_MODE_NAMESPACE, key)
            item = await result if inspect.isawaitable(result) else result
        elif callable(get):
            item = get(APPROVAL_MODE_NAMESPACE, key)
        else:
            logger.debug("Approval-mode store does not expose get() or aget()")
            return None
    except Exception:
        logger.warning("Could not read approval-mode store item", exc_info=True)
        return None
    return _approval_mode_from_item(item)


async def awrite_approval_mode(
    agent: object,
    thread_id: str,
    *,
    mode: ApprovalMode | str | None = None,
    auto_approve: bool | None = None,
) -> str | None:
    """Persist approval mode through an agent's remote store client.

    Args:
        agent: Agent object. Remote agents expose `aput_store_item`.
        thread_id: LangGraph thread id for the active session.
        mode: Explicit approval mode.
        auto_approve: Compatibility input for the previous Boolean API.

    Returns:
        Store key written, or `None` when the agent has no store writer.
    """
    put = getattr(agent, "aput_store_item", None)
    if put is None:
        return None

    key = approval_mode_key(thread_id)
    await put(
        APPROVAL_MODE_NAMESPACE,
        key,
        approval_mode_payload(mode=mode, auto_approve=auto_approve),
    )
    return key


def yolo_acknowledgement_path() -> Path:
    """Return the installation-local acknowledgement file path.

    Returns:
        Path under the private dcode state directory.
    """
    from deepagents_code.model_config import DEFAULT_STATE_DIR

    return DEFAULT_STATE_DIR / "approval.json"


def has_yolo_acknowledgement(path: Path | None = None) -> bool:
    """Return whether the current unrestricted-mode warning was accepted.

    Args:
        path: Alternate acknowledgement path for tests.

    Returns:
        `True` only for a valid record matching the current policy version.
    """
    target = path or yolo_acknowledgement_path()
    try:
        data = json.loads(target.read_text(encoding="utf-8"))
    except (FileNotFoundError, OSError, UnicodeDecodeError, json.JSONDecodeError):
        return False
    return (
        isinstance(data, dict)
        and data.get("version") == 1
        and data.get("policy_version") == YOLO_ACKNOWLEDGEMENT_POLICY_VERSION
        and data.get("acknowledged") is True
    )


def save_yolo_acknowledgement(path: Path | None = None) -> bool:
    """Persist the current unrestricted-mode warning acknowledgement.

    Args:
        path: Alternate acknowledgement path for tests.

    Returns:
        `True` when the private atomic write succeeds, otherwise `False`.
    """
    target = path or yolo_acknowledgement_path()
    payload = {
        "version": 1,
        "policy_version": YOLO_ACKNOWLEDGEMENT_POLICY_VERSION,
        "acknowledged": True,
    }
    tmp_path: Path | None = None
    try:
        target.parent.mkdir(parents=True, exist_ok=True, mode=0o700)
        if os.name != "nt":
            target.parent.chmod(0o700)
        fd, raw_tmp_path = tempfile.mkstemp(dir=target.parent, suffix=".tmp")
        tmp_path = Path(raw_tmp_path)
        with os.fdopen(fd, "w", encoding="utf-8") as handle:
            json.dump(payload, handle, separators=(",", ":"))
            handle.write("\n")
        if os.name != "nt":
            tmp_path.chmod(0o600)
        tmp_path.replace(target)
        if os.name != "nt":
            target.chmod(0o600)
    except OSError:
        logger.warning("Could not persist YOLO acknowledgement", exc_info=True)
        if tmp_path is not None:
            with contextlib.suppress(OSError):
                tmp_path.unlink()
        return False
    return True