let request: IDBOpenDBRequest;
let db: IDBDatabase;
let version = 1;

export enum Stores {
    Departure = 'departure',
    Arrival = 'arrival'
}

export const initDB = (): Promise<boolean | IDBDatabase> => {
    return new Promise((resolve) => {
        request = indexedDB.open('myDB');

        request.onupgradeneeded = (e) => {
            let req = (e.target as IDBOpenDBRequest)
            db = req.result;

            if (!db.objectStoreNames.contains(Stores.Arrival)) {
                db.createObjectStore(Stores.Arrival, { keyPath: 'id' });
            }
            if (!db.objectStoreNames.contains(Stores.Departure)) {
                db.createObjectStore(Stores.Departure, { keyPath: 'id' });
            }
        };

        request.onsuccess = (e) => {
            let req = (e.target as IDBOpenDBRequest)
            db = req.result;
            version = db.version;
            resolve(req.result);
        };

        request.onerror = (e) => {
            resolve(false);
        };
    });
};

export const addData = <T>(storeName: string, data: T): Promise<T | string | null> => {
    return new Promise((resolve) => {
        const tx = db.transaction(storeName, 'readwrite');
        const store = tx.objectStore(storeName);
        store.add(data);
        resolve(data);
    });
};

export const deleteData = (storeName: string, key: number): Promise<boolean> => {
    return new Promise((resolve) => {
        const tx = db.transaction(storeName, 'readwrite');
        const store = tx.objectStore(storeName);
        const res = store.delete(key);
        console.log("removing" + key)
        res.onsuccess = () => {
            console.log("success")
            resolve(true);
        };
        res.onerror = () => {
            console.log("error")
            resolve(false);
        }
    });
};

export const updateData = <T>(storeName: string, key: number, data: T): Promise<T | string | null> => {
    return new Promise((resolve) => {
        const tx = db.transaction(storeName, 'readwrite');
        const store = tx.objectStore(storeName);
        const res = store.get(key);
        res.onsuccess = () => {
            const newData = { ...res.result, ...data };
            store.put(newData);
            resolve(newData);
        };
        res.onerror = () => {
            resolve(null);
        }
    });
};

export const getStoreData = <T>(storeName: Stores): Promise<T[] | null> => {
    return new Promise((resolve) => {
        const tx = db.transaction(storeName, 'readonly');
        const store = tx.objectStore(storeName);
        const res = store.getAll();
        res.onsuccess = () => {
            resolve(res.result);
        };
    });
};

export { };