const EventEmitter = require('events')
const ObservableStore = require('obs-store')
const ethUtil = require('ethereumjs-util')
const createId = require('./random-id')
/**
* Represents, and contains data about, an 'eth_sign' type signature request. These are created when a signature for
* an eth_sign call is requested.
*
* @see {@link https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_sign}
*
* @typedef {Object} Message
* @property {number} id An id to track and identify the message object
* @property {Object} msgParams The parameters to pass to the eth_sign method once the signature request is approved.
* @property {Object} msgParams.metamaskId Added to msgParams for tracking and identification within MetaMask.
* @property {string} msgParams.data A hex string conversion of the raw buffer data of the signature request
* @property {number} time The epoch time at which the this message was created
* @property {string} status Indicates whether the signature request is 'unapproved', 'approved', 'signed' or 'rejected'
* @property {string} type The json-prc signing method for which a signature request has been made. A 'Message' with
* always have a 'eth_sign' type.
*
*/
module.exports = class MessageManager extends EventEmitter {
/**
* Controller in charge of managing - storing, adding, removing, updating - Messages.
*
* @typedef {Object} MessageManager
* @param {Object} opts @deprecated
* @property {Object} memStore The observable store where Messages are saved.
* @property {Object} memStore.unapprovedMsgs A collection of all Messages in the 'unapproved' state
* @property {number} memStore.unapprovedMsgCount The count of all Messages in this.memStore.unapprobedMsgs
* @property {array} messages Holds all messages that have been created by this MessageManager
*
*/
constructor (opts) {
super()
this.memStore = new ObservableStore({
unapprovedMsgs: {},
unapprovedMsgCount: 0,
})
this.messages = []
}
/**
* A getter for the number of 'unapproved' Messages in this.messages
*
* @returns {number} The number of 'unapproved' Messages in this.messages
*
*/
get unapprovedMsgCount () {
return Object.keys(this.getUnapprovedMsgs()).length
}
/**
* A getter for the 'unapproved' Messages in this.messages
*
* @returns {Object} An index of Message ids to Messages, for all 'unapproved' Messages in this.messages
*
*/
getUnapprovedMsgs () {
return this.messages.filter(msg => msg.status === 'unapproved')
.reduce((result, msg) => { result[msg.id] = msg; return result }, {})
}
/**
* Creates a new Message with an 'unapproved' status using the passed msgParams. this.addMsg is called to add the
* new Message to this.messages, and to save the unapproved Messages from that list to this.memStore.
*
* @param {Object} msgParams The params for the eth_sign call to be made after the message is approved.
* @returns {number} The id of the newly created message.
*
*/
addUnapprovedMessage (msgParams) {
msgParams.data = normalizeMsgData(msgParams.data)
// create txData obj with parameters and meta data
var time = (new Date()).getTime()
var msgId = createId()
var msgData = {
id: msgId,
msgParams: msgParams,
time: time,
status: 'unapproved',
type: 'eth_sign',
}
this.addMsg(msgData)
// signal update
this.emit('update')
return msgId
}
/**
* Adds a passed Message to this.messages, and calls this._saveMsgList() to save the unapproved Messages from that
* list to this.memStore.
*
* @param {Message} msg The Message to add to this.messages
*
*/
addMsg (msg) {
this.messages.push(msg)
this._saveMsgList()
}
/**
* Returns a specified Message.
*
* @param {number} msgId The id of the Message to get
* @returns {Message|undefined} The Message with the id that matches the passed msgId, or undefined if no Message has that id.
*
*/
getMsg (msgId) {
return this.messages.find(msg => msg.id === msgId)
}
/**
* Approves a Message. Sets the message status via a call to this.setMsgStatusApproved, and returns a promise with
* any the message params modified for proper signing.
*
* @param {Object} msgParams The msgParams to be used when eth_sign is called, plus data added by MetaMask.
* @param {Object} msgParams.metamaskId Added to msgParams for tracking and identification within MetaMask.
* @returns {Promise<object>} Promises the msgParams object with metamaskId removed.
*
*/
approveMessage (msgParams) {
this.setMsgStatusApproved(msgParams.metamaskId)
return this.prepMsgForSigning(msgParams)
}
/**
* Sets a Message status to 'approved' via a call to this._setMsgStatus.
*
* @param {number} msgId The id of the Message to approve.
*
*/
setMsgStatusApproved (msgId) {
this._setMsgStatus(msgId, 'approved')
}
/**
* Sets a Message status to 'signed' via a call to this._setMsgStatus and updates that Message in this.messages by
* adding the raw signature data of the signature request to the Message
*
* @param {number} msgId The id of the Message to sign.
* @param {buffer} rawSig The raw data of the signature request
*
*/
setMsgStatusSigned (msgId, rawSig) {
const msg = this.getMsg(msgId)
msg.rawSig = rawSig
this._updateMsg(msg)
this._setMsgStatus(msgId, 'signed')
}
/**
* Removes the metamaskId property from passed msgParams and returns a promise which resolves the updated msgParams
*
* @param {Object} msgParams The msgParams to modify
* @returns {Promise<object>} Promises the msgParams with the metamaskId property removed
*
*/
prepMsgForSigning (msgParams) {
delete msgParams.metamaskId
return Promise.resolve(msgParams)
}
/**
* Sets a Message status to 'rejected' via a call to this._setMsgStatus.
*
* @param {number} msgId The id of the Message to reject.
*
*/
rejectMsg (msgId) {
this._setMsgStatus(msgId, 'rejected')
}
/**
* Updates the status of a Message in this.messages via a call to this._updateMsg
*
* @private
* @param {number} msgId The id of the Message to update.
* @param {string} status The new status of the Message.
* @throws A 'MessageManager - Message not found for id: "${msgId}".' if there is no Message in this.messages with an
* id equal to the passed msgId
* @fires An event with a name equal to `${msgId}:${status}`. The Message is also fired.
* @fires If status is 'rejected' or 'signed', an event with a name equal to `${msgId}:finished` is fired along with the message
*
*/
_setMsgStatus (msgId, status) {
const msg = this.getMsg(msgId)
if (!msg) throw new Error('MessageManager - Message not found for id: "${msgId}".')
msg.status = status
this._updateMsg(msg)
this.emit(`${msgId}:${status}`, msg)
if (status === 'rejected' || status === 'signed') {
this.emit(`${msgId}:finished`, msg)
}
}
/**
* Sets a Message in this.messages to the passed Message if the ids are equal. Then saves the unapprovedMsg list to
* storage via this._saveMsgList
*
* @private
* @param {msg} Message A Message that will replace an existing Message (with the same id) in this.messages
*
*/
_updateMsg (msg) {
const index = this.messages.findIndex((message) => message.id === msg.id)
if (index !== -1) {
this.messages[index] = msg
}
this._saveMsgList()
}
/**
* Saves the unapproved messages, and their count, to this.memStore
*
* @private
* @fires 'updateBadge'
*
*/
_saveMsgList () {
const unapprovedMsgs = this.getUnapprovedMsgs()
const unapprovedMsgCount = Object.keys(unapprovedMsgs).length
this.memStore.updateState({ unapprovedMsgs, unapprovedMsgCount })
this.emit('updateBadge')
}
}
/**
* A helper function that converts raw buffer data to a hex, or just returns the data if it is already formatted as a hex.
*
* @param {any} data The buffer data to convert to a hex
* @returns {string} A hex string conversion of the buffer data
*
*/
function normalizeMsgData (data) {
if (data.slice(0, 2) === '0x') {
// data is already hex
return data
} else {
// data is unicode, convert to hex
return ethUtil.bufferToHex(new Buffer(data, 'utf8'))
}
}