"""Persist RegistryManager by replaying create/update events."""

from __future__ import annotations

import base64
import json
from pathlib import Path
from typing import Any

import zkac


def save_events(path: Path, events: list[dict[str, Any]]) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)
    path.write_text(json.dumps({"events": events}, indent=2), encoding="utf-8")


def load_events(path: Path) -> list[dict[str, Any]]:
    if not path.is_file():
        return []
    data = json.loads(path.read_text(encoding="utf-8"))
    return list(data.get("events", []))


def replay_manager(events: list[dict[str, Any]]) -> zkac.RegistryManager:
    """Rebuild manager from persisted events (multiple registries supported)."""
    mgr = zkac.RegistryManager()
    by_rid: dict[bytes, list[dict[str, Any]]] = {}
    for e in events:
        st = base64.b64decode(e["state_b64"])
        st_obj = zkac.RegistryState.deserialize(st)
        rid = st_obj.registry_id()
        by_rid.setdefault(rid, []).append(e)
    for rid, evs in by_rid.items():
        evs.sort(
            key=lambda e: zkac.RegistryState.deserialize(
                base64.b64decode(e["state_b64"])
            ).version()
        )
        for i, e in enumerate(evs):
            st = base64.b64decode(e["state_b64"])
            cert = base64.b64decode(e["state_cert_b64"])
            if i == 0:
                mgr.create(st, cert)
            else:
                mgr.update(rid, st, cert)
    return mgr


def append_event(path: Path, op: str, state_bytes: bytes, state_cert: bytes) -> None:
    events = load_events(path)
    events.append(
        {
            "op": op,
            "state_b64": base64.b64encode(state_bytes).decode(),
            "state_cert_b64": base64.b64encode(state_cert).decode(),
        }
    )
    save_events(path, events)