// Copyright 2016 The Grin Developers
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

extern crate grin_core;
extern crate grin_chain;
extern crate rand;
extern crate time;
extern crate secp256k1zkp as secp;

use std::sync::Arc;
use rand::os::OsRng;

use grin_chain::types::*;
use grin_core::core::hash::Hashed;
use grin_core::pow;
use grin_core::core;
use grin_core::consensus;

#[test]
fn mine_empty_chain() {
	let mut rng = OsRng::new().unwrap();
	let store = grin_chain::store::ChainKVStore::new(".grin".to_string()).unwrap();

	// save a genesis block
	let mut gen = grin_core::genesis::genesis();
	gen.header.cuckoo_len = 16;
	let diff = gen.header.difficulty.clone();
	pow::pow(&mut gen, diff).unwrap();
	store.save_block(&gen).unwrap();

	// setup a new head tip
	let tip = Tip::new(gen.hash());
	store.save_head(&tip).unwrap();

	// mine and add a few blocks
	let mut prev = gen;
	let secp = secp::Secp256k1::with_caps(secp::ContextFlag::Commit);
	let reward_key = secp::key::SecretKey::new(&secp, &mut rng);
	let arc_store = Arc::new(store);
	let adapter = Arc::new(NoopAdapter {});

	for n in 1..4 {
		let mut b = core::Block::new(&prev.header, vec![], reward_key).unwrap();
		b.header.timestamp = prev.header.timestamp + time::Duration::seconds(60);

		let (difficulty, _) = consensus::next_target(b.header.timestamp.to_timespec().sec,
		                                             prev.header.timestamp.to_timespec().sec,
		                                             prev.header.difficulty.clone(),
		                                             prev.header.cuckoo_len);
		b.header.difficulty = difficulty.clone();

		pow::pow(&mut b, difficulty).unwrap();
		grin_chain::pipe::process_block(&b,
		                                arc_store.clone(),
		                                adapter.clone(),
		                                grin_chain::pipe::EASY_POW)
			.unwrap();

		// checking our new head
		let head = arc_store.clone().head().unwrap();
		assert_eq!(head.height, n);
		assert_eq!(head.last_block_h, b.hash());

		prev = b;
	}
}