import { openDB } from 'indexed-pdb'

export const DB_NAME = "/com.nesbox.tic/TIC-80";
export const DB_STORE = "FILE_DATA";

export function filename_from_key (key) {
    if (key.startsWith(DB_NAME+"/")) { return key.substr((DB_NAME+"/").length); }
}

export async function load_key (key) {
    const db = await openDB(DB_NAME),
          objectStore = db.transaction([DB_STORE], "readonly").objectStore(DB_STORE);
    return await objectStore.get(key);
}    

export async function save_key (key, item) {
    const db = await openDB(DB_NAME),
          objectStore = db.transaction([DB_STORE], "readwrite").objectStore(DB_STORE);
    return await objectStore.put(item, key);
}    

export async function save_cart(filename, cart, mode) {
    return await save_key(DB_NAME+"/"+filename, {timestamp: new Date(), contents: cart.tobuffer(), mode: mode});
}

export function compareBuffers (a, b) {
    var ad = new DataView(a.buffer),
        bd = new DataView(b.buffer);
    if (ad.byteLength != bd.byteLength) { return false; }
    for (var i=0; i<ad.byteLength; i++) {
        if (ad.getUint8(i, 1) != bd.getUint8(i, 1)) { return false;}
    }
    return true;
}