// Copyright (c) Microsoft Corporation. All rights reserved.

// Licensed under the MIT License.

'use strict';

import { inject, injectable, named } from 'inversify';

import { Memento } from 'vscode';

import { GLOBAL_MEMENTO, IMemento, IPersistentState, IPersistentStateFactory, WORKSPACE_MEMENTO } from './types';

class PersistentState<T> implements IPersistentState<T>{

constructor(private storage: Memento, private key: string, private defaultValue?: T, private expiryDurationMs?: number) { }

public get value(): T {

if (this.expiryDurationMs) {

const cachedData = this.storage.get<{ data?: T; expiry?: number }>(this.key, { data: this.defaultValue! });

if (!cachedData || !cachedData.expiry || cachedData.expiry < Date.now()) {

return this.defaultValue!;

} else {

return cachedData.data!;

}

} else {

return this.storage.get<T>(this.key, this.defaultValue!);

}

}

public async updateValue(newValue: T): Promise<void> {

if (this.expiryDurationMs) {

await this.storage.update(this.key, { data: newValue, expiry: Date.now() + this.expiryDurationMs });

} else {

await this.storage.update(this.key, newValue);

}

}

}

@injectable()

export class PersistentStateFactory implements IPersistentStateFactory {

constructor(@inject(IMemento) @named(GLOBAL_MEMENTO) private globalState: Memento,

@inject(IMemento) @named(WORKSPACE_MEMENTO) private workspaceState: Memento) { }

public createGlobalPersistentState<T>(key: string, defaultValue?: T, expiryDurationMs?: number): IPersistentState<T> {

return new PersistentState<T>(this.globalState, key, defaultValue, expiryDurationMs);

}

public createWorkspacePersistentState<T>(key: string, defaultValue?: T, expiryDurationMs?: number): IPersistentState<T> {

return new PersistentState<T>(this.workspaceState, key, defaultValue, expiryDurationMs);

}

}