"""InformationSpace — the thin orchestrator entry tying the slice together (blueprint §3 L6).

A root entity / information space: shards attach to it (conformance-gated, TSD §A.2), a
coordination decision log records its canonical decisions, and a derived union resolves names to
pages. This is the L6 consumer surface for the foundation slice (attach → resolve → read);
a network API is a later workplan.
"""

from __future__ import annotations

from shard_wiki.adapters import ShardAdapter, assert_conformant
from shard_wiki.coordination import DecisionLog, EventType
from shard_wiki.model import Page
from shard_wiki.policy import DEFAULT_POLICY, Policy
from shard_wiki.union import Resolution, UnionGraph

__all__ = ["InformationSpace"]


class InformationSpace:
    def __init__(self, space_id: str, policy: Policy = DEFAULT_POLICY) -> None:
        self.space_id = space_id
        self.log = DecisionLog()
        self.union = UnionGraph(space_id, log=self.log, policy=policy)

    def attach(self, adapter: ShardAdapter) -> None:
        """Attach a shard — only if it passes conformance (verified profile, I-3/§6.6)."""
        assert_conformant(adapter)
        self.union.attach(adapter)

    def alias(self, name: str, target: str, actor: str | None = None) -> None:
        """Record a coordination-canonical alias (``name`` → ``"shard:key"``) in the log."""
        self.log.append(
            self.space_id, EventType.ALIAS_SET, {"alias": name, "target": target}, actor=actor
        )

    def resolve(self, name: str) -> Resolution:
        return self.union.resolve(name)

    def read(self, name: str) -> Page:
        """Resolve and return the page (or the canonical pick of a chorus). KeyError if red-link."""
        return self.union.resolve(name).single()