import json
from os.path import exists
from typing import List

db_filename = "db.json"


def init_db():
    file_exists = exists(db_filename)
    if not file_exists:
        print("Initializing json file database")
        with open(db_filename, "w") as db_file:
            db_file.write("{}")


init_db()


def _load_db():
    with open(db_filename, "r") as db_file:
        db = json.loads(db_file.read())
        return db


def _save_db(db):
    with open(db_filename, "w") as db_file:
        db_file.write(json.dumps(db))


def get_latest_sync_time() -> int:
    db = _load_db()
    return db.get("latest_sync_time", 0)


def set_latest_sync_time(le_date) -> None:
    db = _load_db()
    db["latest_sync_time"] = le_date
    _save_db(db)


def add_discovered_file(file_url) -> List[str]:
    db = _load_db()
    discovered_files = set(db.get("discovered_files", []))
    discovered_files.add(file_url)
    discovered_files = list(discovered_files)
    db["discovered_files"] = discovered_files
    _save_db(db)
    return discovered_files


def get_discovered_files() -> List[str]:
    db = _load_db()
    discovered_files = set(db.get("discovered_files", []))
    return discovered_files


def add_valid_file(filename, metadata):
    db = _load_db()
    valid_files = db.get("valid_files", {})
    valid_files[filename] = metadata
    db["valid_files"] = valid_files
    _save_db(db)
    return valid_files