// Copyright 2019 Parity Technologies (UK) Ltd.
// This file is part of substrate-subxt.
//
// subxt 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.
//
// subxt 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 substrate-subxt.  If not, see <http://www.gnu.org/licenses/>.

use sp_keyring::AccountKeyring;
use substrate_subxt::{
    balances,
    system::System,
    DefaultNodeRuntime as Runtime,
    ExtrinsicSuccess,
};

type AccountId = <Runtime as System>::AccountId;
type Balance = <Runtime as balances::Balances>::Balance;

fn main() {
    let result: Result<ExtrinsicSuccess<_>, Box<dyn std::error::Error + 'static>> =
        async_std::task::block_on(async move {
            env_logger::init();

            let signer = AccountKeyring::Alice.pair();

            let dest = AccountKeyring::Bob.to_account_id();

            let cli = substrate_subxt::ClientBuilder::<Runtime>::new()
                .build()
                .await?;
            let xt = cli.xt(signer, None).await?;
            let xt_result = xt
                .watch()
                .events_decoder(|decoder| {
                    // for any primitive event with no type size registered
                    decoder.register_type_size::<(u64, u64)>("IdentificationTuple")
                })
                .submit(balances::transfer::<Runtime>(dest.clone().into(), 10_000))
                .await?;
            Ok(xt_result)
        });
    match result {
        Ok(extrinsic_success) => {
            match extrinsic_success
                .find_event::<(AccountId, AccountId, Balance, Balance)>(
                    "Balances", "Transfer",
                ) {
                Some(Ok((_from, _to, value, _fees))) => {
                    println!("Balance transfer success: value: {:?}", value)
                }
                Some(Err(err)) => println!("Failed to decode code hash: {}", err),
                None => println!("Failed to find Contracts::CodeStored Event"),
            }
        }
        Err(err) => println!("Error: {:?}", err),
    }
}