// Copyright 2015-2017 Parity Technologies (UK) Ltd.
// This file is part of Parity.

// Parity is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// Parity is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with Parity.  If not, see <http://www.gnu.org/licenses/>.

import { action, observable } from 'mobx';
import store from 'store';

import { sha3 } from '@parity/api/util/sha3';

import filteredRequests from '../DappRequests/filteredRequests';

const LS_PERMISSIONS = '_parity::dapps::methods';

export default class Store {
  @observable filteredRequests = Object.keys(filteredRequests);
  @observable modalOpen = false;
  @observable permissions = {};
  @observable tokens = {};

  constructor () {
    this.permissions = store.get(LS_PERMISSIONS) || {};
  }

  @action closeModal = () => {
    this.modalOpen = false;
  }

  @action openModal = () => {
    this.modalOpen = true;
  }

  @action createToken = (appId) => {
    const token = sha3(`${appId}:${Date.now()}`);

    this.tokens = Object.assign({}, this.tokens, {
      [token]: appId
    });

    return token;
  }

  @action addTokenPermission = (method, token) => {
    const id = `${method}:${this.tokens[token]}`;

    this.permissions = Object.assign({}, this.permissions, {
      [id]: true
    });
    this.savePermissions();
  }

  @action toggleAppPermission = (method, appId) => {
    const id = `${method}:${appId}`;

    this.permissions = Object.assign({}, this.permissions, {
      [id]: !this.permissions[id]
    });
    this.savePermissions();
  }

  hasTokenPermission = (method, token) => {
    return this.hasAppPermission(method, this.tokens[token]);
  }

  hasAppPermission = (method, appId) => {
    return this.permissions[`${method}:${appId}`] || false;
  }

  savePermissions = () => {
    store.set(LS_PERMISSIONS, this.permissions);
  }

  static instance = null;

  static get () {
    if (!Store.instance) {
      Store.instance = new Store();
    }

    return Store.instance;
  }
}