"""Fleet projects Node-owned sensor state and forwards SDK operations, never hardware calls."""

import json
import time
from datetime import UTC, datetime

from missioncore_plugin_sdk.v0alpha2.operations import OperationRequest
from missioncore_plugin_sdk.v0alpha2.session import DeviceSessionSnapshot

from .trust import PairingError

ACTIONS = {
    "prepare",
    "details",
    "rename",
    "verify",
    "start",
    "replay",
    "stop",
    "option",
    "offer",
    "close-peer",
    "preview.start",
    "preview.stop",
    "record.start",
    "record.stop",
    "photo.capture",
    "settings.read",
    "settings.apply",
    "files.list",
    "recovery.configure",
    "power.wake",
}
MAX_INVENTORY_ITEMS = 500
MAX_SENSOR_STATE_BYTES = 3 * 1024 * 1024
MAX_PENDING_COMMANDS = 32
MAX_COMMAND_RECEIPTS = 128


def validate_inventory(value, node_id):
    items = value.get("devices", [])
    if not isinstance(items, list) or len(items) > MAX_INVENTORY_ITEMS:
        raise ValueError("Invalid device inventory")
    seen = set()
    for item in items:
        snapshot = DeviceSessionSnapshot.model_validate(item["snapshot"])
        if (
            snapshot.context.execution.node_id != node_id
            or snapshot.context.device.device_id != item["id"]
            or item["id"] in seen
        ):
            raise ValueError("Invalid device execution binding")
        seen.add(item["id"])
    state = value.get("sensor_state", {"items": items, "operations": [], "preparation": None})
    if (
        not isinstance(state, dict)
        or state.get("items") != items
        or len(json.dumps(state, ensure_ascii=False).encode()) > MAX_SENSOR_STATE_BYTES
    ):
        raise ValueError("Invalid sensor state")
    return state


def submit(fleet, vehicle_id, value):
    command = OperationRequest.model_validate(value)
    if (
        command.action_id not in ACTIONS
        or command.idempotency_key != command.operation_id
        or len(json.dumps(value)) > 65536
    ):
        raise PairingError("Неподдерживаемая команда устройства.")
    with fleet.lock:
        row = fleet.find(vehicle_id)
        if fleet.public(row)["connectivity"] != "online":
            raise PairingError("БК недоступен. Дождитесь связи перед настройкой устройства.")
        existing = row.setdefault("sensor_commands", {}).get(command.operation_id)
        if existing:
            if existing["command"] != value:
                raise PairingError("Идентификатор операции уже использован.")
            return existing
        if (
            not datetime.now(UTC) < command.deadline_at
            or (command.deadline_at - command.requested_at).total_seconds() > 360
        ):
            raise PairingError("Срок команды истёк. Обновите устройство.")
        item = next(
            (
                item
                for item in row.get("sensor_state", {}).get("items", [])
                if item["id"] == command.session.device_id
            ),
            None,
        )
        if item is None or item["snapshot"]["context"]["session_id"] != command.session.session_id:
            raise PairingError("Сеанс устройства изменился. Обновите сведения.")
        row["sensor_commands"] = {
            k: v for k, v in row["sensor_commands"].items() if time.time() - v["updated_at"] < 600
        }
        now = datetime.now(UTC)
        # Completed viewing operations are receipts, not occupied execution
        # slots. Keep them for idempotency without blocking a later Stop.
        active = sum(
            entry["state"] in ("queued", "running")
            and datetime.fromisoformat(entry["command"]["deadline_at"]) > now
            for entry in row["sensor_commands"].values()
        )
        if active >= MAX_PENDING_COMMANDS:
            raise PairingError("Слишком много запросов к устройству. Повторите позже.")
        if len(row["sensor_commands"]) >= MAX_COMMAND_RECEIPTS:
            expired = sorted(
                (k for k, entry in row["sensor_commands"].items()
                 if entry["state"] not in ("queued", "running")
                 and datetime.fromisoformat(entry["command"]["deadline_at"]) < now),
                key=lambda k: row["sensor_commands"][k]["updated_at"],
            )
            for key in expired:
                del row["sensor_commands"][key]
                if len(row["sensor_commands"]) < MAX_COMMAND_RECEIPTS:
                    break
            if len(row["sensor_commands"]) >= MAX_COMMAND_RECEIPTS:
                raise PairingError("Слишком много запросов к устройству. Повторите позже.")
        operation = {"command": value, "state": "queued", "updated_at": time.time()}
        row["sensor_commands"][command.operation_id] = operation
        fleet.save(row)
        return operation


def operation(fleet, vehicle_id, identifier):
    with fleet.lock:
        value = fleet.find(vehicle_id).get("sensor_commands", {}).get(identifier)
        if value is None:
            raise PairingError("Операция не найдена.")
        if value["state"] in ("queued", "running") and datetime.fromisoformat(
            value["command"]["deadline_at"]
        ) < datetime.now(UTC):
            return {
                **value,
                "state": "unknown",
                "error": "Подтверждение не получено. Обновите фактическое состояние устройства.",
            }
        return value


def heartbeat(row, value):
    commands = row.setdefault("sensor_commands", {})
    acknowledgements = []
    results = value.get("sensor_results", [])
    if not isinstance(results, list) or len(results) > 64:
        raise ValueError("Invalid sensor operations")
    for result in results:
        command = result.get("command", {})
        identifier = command.get("operation_id")
        existing = commands.get(identifier)
        if (
            existing
            and existing["command"] == command
            and result.get("state") in ("running", "complete", "error", "unknown")
        ):
            commands[identifier] = {**result, "updated_at": time.time()}
            if result["state"] != "running":
                acknowledgements.append(identifier)
    pending = []
    for entry in commands.values():
        if entry["state"] == "queued" and datetime.fromisoformat(
            entry["command"]["deadline_at"]
        ) > datetime.now(UTC):
            pending.append(entry["command"])
    return {"sensor_commands": pending[:4], "sensor_acknowledgements": acknowledgements}