@@ -3,25 +3,13 @@ import yargs from "yargs";
33import { hideBin } from "yargs/helpers" ;
44import HDWalletProvider from "@truffle/hdwallet-provider" ;
55import CoinFlipAbi from "./CoinFlipAbi.json" ;
6- import axios from "axios" ;
76
8- const argv = yargs ( hideBin ( process . argv ) )
7+ const parser = yargs ( hideBin ( process . argv ) )
98 . option ( "private-key" , {
109 description : "Private key (as a hexadecimal string) of the sender" ,
1110 type : "string" ,
1211 required : true ,
1312 } )
14- . option ( "fortuna-url" , {
15- description : "URL of the fortuna server for your chosen provider" ,
16- type : "string" ,
17- default : "https://fortuna-staging.dourolabs.app" ,
18- } )
19- . option ( "chain-name" , {
20- description :
21- "The name of your blockchain (for accessing data from fortuna)" ,
22- type : "string" ,
23- required : true ,
24- } )
2513 . option ( "address" , {
2614 description : "The address of the CoinFlip contract" ,
2715 type : "string" ,
@@ -37,37 +25,15 @@ const argv = yargs(hideBin(process.argv))
3725 . alias ( "help" , "h" )
3826 . parserConfiguration ( {
3927 "parse-numbers" : false ,
40- } )
41- . parseSync ( ) ;
42-
43- const fortunaUrl = argv . fortunaUrl ;
44- const chainName = argv . chainName ;
45- const coinFlipContractAddress = argv . address ;
46- const rpc = argv . rpcUrl ;
47- const privateKey = argv . privateKey ;
48-
49- async function fetchWithRetry ( url : string , maxRetries : number ) : Promise < any > {
50- let retryCount = 0 ;
51-
52- async function doRequest ( ) {
53- try {
54- const response = await axios . get ( url ) ;
55- return response . data ;
56- } catch ( error ) {
57- if ( retryCount < maxRetries ) {
58- retryCount ++ ;
59- setTimeout ( doRequest , 1000 ) ;
60- } else {
61- console . error ( "Max retry attempts reached. Exiting." ) ;
62- throw error ;
63- }
64- }
65- }
66-
67- return await doRequest ( ) ; // Start the initial request
68- }
28+ } ) ;
6929
7030async function main ( ) {
31+ const argv = await parser . argv ;
32+
33+ const coinFlipContractAddress = argv . address ;
34+ const rpc = argv . rpcUrl ;
35+ const privateKey = argv . privateKey ;
36+
7137 const provider = new HDWalletProvider ( {
7238 privateKeys : [ privateKey ] ,
7339 providerOrUrl : rpc ,
@@ -84,38 +50,52 @@ async function main() {
8450
8551 console . log ( "1. Generating user's random number..." ) ;
8652 const randomNumber = web3 . utils . randomHex ( 32 ) ;
87- const commitment = web3 . utils . keccak256 ( randomNumber ) ;
8853 console . log ( ` number : ${ randomNumber } ) ;
89- console . log ( ` commitment: ${ commitment } ) ;
9054
9155 console . log ( "2. Requesting coin flip..." ) ;
9256 const flipFee = await coinFlipContract . methods . getFlipFee ( ) . call ( ) ;
9357 console . log ( ` fee : ${ flipFee } ) ;
9458
9559 const receipt = await coinFlipContract . methods
96- . requestFlip ( commitment )
60+ . requestFlip ( randomNumber )
9761 . send ( { value : flipFee , from : provider . getAddress ( 0 ) } ) ;
9862
9963 console . log ( ` tx : ${ receipt . transactionHash } ) ;
10064 const sequenceNumber = receipt . events . FlipRequest . returnValues . sequenceNumber ;
10165 console . log ( ` sequence : ${ sequenceNumber } ) ;
10266
103- console . log ( "3. Retrieving provider's random number..." ) ;
104- const url = `${ fortunaUrl } ${ chainName } ${ sequenceNumber } ;
105- console . log ( ` fetch url : ${ url } ) ;
106- // Note that there is a potential race condition here: the server may not have observed the request ^
107- // before this HTTP response. Hence, we retry fetching the url a couple of times.
108- const response = await fetchWithRetry ( url , 3 ) ;
109- const providerRandom = `0x${ response . value . data } ;
110- console . log ( ` number : ${ providerRandom } ) ;
111-
112- console . log ( "4. Revealing the result of the coin flip..." ) ;
113- const receipt2 = await coinFlipContract . methods
114- . revealFlip ( sequenceNumber , randomNumber , providerRandom )
115- . send ( { from : provider . getAddress ( 0 ) } ) ;
116- console . log ( ` tx : ${ receipt2 . transactionHash } ) ;
117- const isHeads = receipt2 . events . FlipResult . returnValues . isHeads ;
118- console . log ( ` result : ${ isHeads ? "heads" : "tails" } ) ;
67+ console . log ( "3. Waiting for result..." ) ;
68+ // Poll for new FlipResult events emitted by the CoinFlip contract. It checks if the event
69+ // has the same sequenceNumber as the request. If it does,
70+ // it logs the result and stops polling.
71+ let fromBlock = receipt . blockNumber ;
72+ const intervalId = setInterval ( async ( ) => {
73+ const currentBlock = await web3 . eth . getBlockNumber ( ) ;
74+
75+ if ( fromBlock > currentBlock ) {
76+ return ;
77+ }
78+
79+ // Get 'FlipResult' events emitted by the CoinFlip contract for given block range.
80+ const events = await coinFlipContract . getPastEvents ( "FlipResult" , {
81+ fromBlock : fromBlock ,
82+ toBlock : currentBlock ,
83+ } ) ;
84+ fromBlock = currentBlock + 1 ;
85+
86+ // Find the event with the same sequence number as the request.
87+ const event = events . find (
88+ ( event ) => event . returnValues . sequenceNumber === sequenceNumber
89+ ) ;
90+
91+ // If the event is found, log the result and stop polling.
92+ if ( event !== undefined ) {
93+ console . log (
94+ ` result : ${ event . returnValues . isHeads ? "Heads" : "Tails" }
95+ ) ;
96+ clearInterval ( intervalId ) ;
97+ }
98+ } , 1000 ) ;
11999
120100 provider . engine . stop ( ) ;
121101}
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