from __future__ import annotations
import json
import os
from functools import lru_cache
from jsonschema import Draft202012Validator, RefResolver

SCHEMAS_DIR = os.getenv("SCHEMAS_DIR", os.path.join(os.path.dirname(os.path.dirname(__file__)), "..", "schemas"))

@lru_cache(maxsize=16)
def load_schema(name: str) -> dict:
    # name: "note.schema.json" | "chunk.schema.json" | "edge.schema.json"
    path = os.path.join(SCHEMAS_DIR, name)
    if not os.path.isfile(path):
        raise FileNotFoundError(f"Schema not found: {path}")
    with open(path, "r", encoding="utf-8") as f:
        return json.load(f)

@lru_cache(maxsize=16)
def get_validator(name: str) -> Draft202012Validator:
    schema = load_schema(name)
    resolver = RefResolver.from_schema(schema)
    return Draft202012Validator(schema, resolver=resolver)