from __future__ import annotations

from dataclasses import dataclass


@dataclass(frozen=True)
class CacheDependency:
    cache_key_hash: str
    point_key: str
    business_domain_uid: str | None
    generation: int


@dataclass(frozen=True)
class CacheInvalidationPlan:
    cache_key_hashes: frozenset[str]
    business_domains_to_flush: frozenset[str]


def plan_cache_invalidation(
    dependencies: list[CacheDependency],
    *,
    changed_point_keys: set[str],
    impacted_point_keys: set[str],
    dependency_metadata_complete: bool = True,
    affected_business_domains: set[str] | None = None,
) -> CacheInvalidationPlan:
    affected_points = changed_point_keys | impacted_point_keys
    cache_keys = frozenset(
        dependency.cache_key_hash
        for dependency in dependencies
        if dependency.point_key in affected_points
    )
    domains = frozenset()
    if not dependency_metadata_complete:
        domains = frozenset(affected_business_domains or ())
    return CacheInvalidationPlan(
        cache_key_hashes=cache_keys,
        business_domains_to_flush=domains,
    )