from pathlib import Path

from controllers.base import CONTROLLERS
from controllers.notices import Notices
from engine.offline import queue
from engine.outbox import Outbox, Request
from engine.record import Record
from resources.base import SYSTEM, Refused


def scope_of(asked: Request) -> str:
    return CONTROLLERS[asked.type].resource.scope


def held_here(root: Path, asked: Request) -> bool:
    return Record(root, asked.env).holds(scope_of(asked))


def run(root: Path, asked: Request) -> None:
    getattr(CONTROLLERS[asked.type](Record(root, asked.env), actor=asked.actor), asked.word)(*asked.args, **asked.named)


def request(root: Path, asked: Request) -> None:
    """Runs a write into another scope now when this machine holds that scope, and otherwise queues it for the machine that does."""
    if held_here(root, asked):
        run(root, asked)
        return
    queue(Record(root, asked.env), scope_of(asked), asked)


def deliver(root: Path) -> int:
    """Runs every waiting request whose scope this machine holds now; the rest wait, and a refused one becomes a notice where it was meant."""
    taken = Outbox(root).take(lambda asked: held_here(root, asked))
    for asked in taken:
        try:
            run(root, asked)
        except Refused as error:
            Notices(Record(root, asked.env), actor=SYSTEM).create("A change sent from another machine was refused", brief=f"{asked.type} {asked.word}: {error}", tone="warn")
    return len(taken)