const CONTRACT_ADDR = "0xa4Dbad9463BF3B107F27649f68a64740Ed1AEC3C";

class Demo{

constructor(_web3, _account) {

this.web3 = _web3;

this.account = _account;

this.contract = new this.web3.eth.Contract(CONTRACT_ABI, CONTRACT_ADDR);

}

async index_page() {

$("#addr").text(this.account);

let result = await this.contract.methods.query_user(this.account).call();

// (users[addr].exchanged,

// users[addr].ex_date,

// users[addr].ex_amount);

this.exchanged = result[0];

if(this.exchanged == true){

$("#exchange").prop('disabled', true);

$("#exchange_result").text("已经兑换过Token，1个地址只能兑换1次");

$("#ex_date").text(new Date(Number(result[1] * 1000)).toLocaleString());

$("#ex_amount").text(Number(this.web3.utils.fromWei(result[2])));

}

}

exchange() {

let amount = $("#amount").val();

this.contract.methods.exchange().send({value: this.web3.utils.toWei(amount), from: this.account}).then((tx) => {

$("#exchange_result").text("已经提交区块链确认，交易Hash：" + tx.transactionHash);

});

}

init() {

let that = this;

this.index_page();

$("#exchange").on("click", () => {

that.exchange();

});

}

}

window.addEventListener("load", async () => {

if (window.ethereum) {

try {

// Request account access if needed

window.ethereum.enable().then(accounts => {

let web3 = new Web3(window.ethereum);

let demo = new Demo(web3, accounts[0]);

demo.init();

});

} catch (error) {

alert(error);

}

} else {

alert("need dapp browser");

}

});