/*
Copyright 2020 Bruno Windels <bruno@windels.cloud>

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

import {RoomTimelineStore} from "./stores/RoomTimelineStore.js";

export class Transaction {
    constructor(storeValues, writable) {
        this._storeValues = storeValues;
        this._txnStoreValues = {};
        this._writable = writable;
    }

    _store(name, mapper) {
        if (!this._txnStoreValues.hasOwnProperty(name)) {
            if (!this._storeValues.hasOwnProperty(name)) {
                throw new Error(`Transaction wasn't opened for store ${name}`);
            }
            const store = mapper(this._storeValues[name]);
            const clone = store.cloneStoreValue();
            // extra prevention for writing
            if (!this._writable) {
                Object.freeze(clone);
            }
            this._txnStoreValues[name] = clone;
        }
        return mapper(this._txnStoreValues[name]);
    }

    get session() {
        throw new Error("not yet implemented");
        // return this._store("session", storeValue => new SessionStore(storeValue));
    }

    get roomSummary() {
        throw new Error("not yet implemented");
        // return this._store("roomSummary", storeValue => new RoomSummaryStore(storeValue));
    }

    get roomTimeline() {
        return this._store("roomTimeline", storeValue => new RoomTimelineStore(storeValue));
    }

    get roomState() {
        throw new Error("not yet implemented");
        // return this._store("roomState", storeValue => new RoomStateStore(storeValue));
    }

    complete() {
        for(let name of Object.keys(this._txnStoreValues)) {
            this._storeValues[name] = this._txnStoreValues[name];
        }
        this._txnStoreValues = null;
        return Promise.resolve();
    }

    abort() {
        this._txnStoreValues = null;
        return Promise.resolve();
    }
}