import os, json
from tinydb import TinyDB
from tinydb.storages import Storage

# Paths
OLD_FILE = "orders.json"
ARCHIVE_FILE = "orders_old.json"
NEW_FILE = "orders_new.json"  # final TinyDB JSON file
TABLE_NAME = "orders"


class PrettyJSONStorage(Storage):
    """Custom TinyDB storage that pretty-prints JSON."""
    def __init__(self, path):
        self.path = path

    def read(self):
        try:
            with open(self.path, "r", encoding="utf-8") as f:
                return json.load(f)
        except FileNotFoundError:
            return None

    def write(self, data):
        with open(self.path, "w", encoding="utf-8") as f:
            json.dump(data, f, ensure_ascii=False, indent=2)


def migrate():
    if not os.path.isfile(OLD_FILE):
        print("No old JSON file found. Nothing to migrate.")
        return

    # Load old orders
    with open(OLD_FILE, "r", encoding="utf-8") as f:
        orders = json.load(f) or []

    if not orders:
        print("No orders found in the old JSON.")
        return
    
    print(orders)

    # Open TinyDB and insert into table
    db = TinyDB(NEW_FILE, storage=PrettyJSONStorage)
    orders_table = db.table(TABLE_NAME)
    for order in orders:
        orders_table.insert(order)

    # Rename old file to archive
    os.rename(OLD_FILE, ARCHIVE_FILE)
    os.rename(NEW_FILE, OLD_FILE)
    print(f"Migrated {len(orders)} orders into table '{TABLE_NAME}'.")
    print(f"Old JSON file renamed to '{ARCHIVE_FILE}'.")
    print(f"New TinyDB JSON file is '{OLD_FILE}'.")


if __name__ == "__main__":
    migrate()