// Copyright 2018 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.

//! Definition of the genesis block. Placeholder for now.

// required for genesis replacement
//! #![allow(unused_imports)]

use chrono::prelude::{TimeZone, Utc};

use crate::core;
use crate::global;
use crate::pow::{Difficulty, Proof, ProofOfWork};
use crate::util;
use crate::util::secp::constants::SINGLE_BULLET_PROOF_SIZE;
use crate::util::secp::pedersen::{Commitment, RangeProof};
use crate::util::secp::Signature;

use crate::core::hash::Hash;
use crate::keychain::BlindingFactor;

/// Genesis block definition for development networks. The proof of work size
/// is small enough to mine it on the fly, so it does not contain its own
/// proof of work solution. Can also be easily mutated for different tests.
pub fn genesis_dev() -> core::Block {
	core::Block::with_header(core::BlockHeader {
		height: 0,
		// previous: core::hash::Hash([0xff; 32]),
		timestamp: Utc.ymd(1997, 8, 4).and_hms(0, 0, 0),
		pow: ProofOfWork {
			nonce: global::get_genesis_nonce(),
			..Default::default()
		},
		..Default::default()
	})
}

/// Placeholder for floonet genesis block, will definitely change before
/// release
pub fn genesis_floo() -> core::Block {
	let gen = core::Block::with_header(core::BlockHeader {
		height: 0,
		timestamp: Utc.ymd(2018, 12, 20).and_hms(20, 0, 0), // REPLACE
		prev_root: Hash::default(),                         // REPLACE
		output_root: Hash::default(),                       // REPLACE
		range_proof_root: Hash::default(),                  // REPLACE
		kernel_root: Hash::default(),                       // REPLACE
		total_kernel_offset: BlindingFactor::zero(),        // REPLACE
		output_mmr_size: 1,
		kernel_mmr_size: 1,
		pow: ProofOfWork {
			total_difficulty: Difficulty::from_num(10_u64.pow(6)),
			secondary_scaling: 1856,
			nonce: 1, // REPLACE
			proof: Proof {
				nonces: vec![0; 42], // REPLACE
				edge_bits: 29,
			},
		},
		..Default::default()
	});
	let kernel = core::TxKernel {
		features: core::KernelFeatures::COINBASE,
		fee: 0,
		lock_height: 0,
		excess: Commitment::from_vec(vec![]), // REPLACE
		excess_sig: Signature::from_raw_data(&[0; 64]).unwrap(), //REPLACE
	};
	let output = core::Output {
		features: core::OutputFeatures::COINBASE,
		commit: Commitment::from_vec(vec![]), // REPLACE
		proof: RangeProof {
			plen: SINGLE_BULLET_PROOF_SIZE,
			proof: [0; SINGLE_BULLET_PROOF_SIZE], // REPLACE
		},
	};
	gen.with_reward(output, kernel)
}

/// Placeholder for mainnet genesis block, will definitely change before
/// release so no use trying to pre-mine it.
pub fn genesis_main() -> core::Block {
	let gen = core::Block::with_header(core::BlockHeader {
		height: 0,
		timestamp: Utc.ymd(2019, 1, 15).and_hms(12, 0, 0), // REPLACE
		prev_root: Hash::default(),                        // REPLACE
		output_root: Hash::default(),                      // REPLACE
		range_proof_root: Hash::default(),                 // REPLACE
		kernel_root: Hash::default(),                      // REPLACE
		total_kernel_offset: BlindingFactor::zero(),       // REPLACE
		output_mmr_size: 1,
		kernel_mmr_size: 1,
		pow: ProofOfWork {
			total_difficulty: Difficulty::from_num(10_u64.pow(8)),
			secondary_scaling: 1856,
			nonce: 1, // REPLACE
			proof: Proof {
				nonces: vec![0; 42], // REPLACE
				edge_bits: 29,
			},
		},
		..Default::default()
	});
	let kernel = core::TxKernel {
		features: core::KernelFeatures::COINBASE,
		fee: 0,
		lock_height: 0,
		excess: Commitment::from_vec(vec![]), // REPLACE
		excess_sig: Signature::from_raw_data(&[0; 64]).unwrap(), //REPLACE
	};
	let output = core::Output {
		features: core::OutputFeatures::COINBASE,
		commit: Commitment::from_vec(vec![]), // REPLACE
		proof: RangeProof {
			plen: SINGLE_BULLET_PROOF_SIZE,
			proof: [0; SINGLE_BULLET_PROOF_SIZE], // REPLACE
		},
	};
	gen.with_reward(output, kernel)
}

#[cfg(test)]
mod test {
	use super::*;
	use crate::ser;
	use crate::core::hash::Hashed;

	// TODO hardcode the hashes once genesis is set
	#[test]
	fn floonet_genesis_hash() {
		let gen_hash = genesis_floo().hash();
		println!("floonet genesis hash: {}", gen_hash.to_hex());
		let gen_bin = ser::ser_vec(&genesis_floo()).unwrap();
		println!("floonet genesis full hash: {}\n", gen_bin.hash().to_hex());
		//assert_eq!(gene_hash.to_hex, "");
	}

	// TODO hardcode the hashes once genesis is set
	#[test]
	fn mainnet_genesis_hash() {
		let gen_hash = genesis_main().hash();
		println!("mainnet genesis hash: {}", gen_hash.to_hex());
		let gen_bin = ser::ser_vec(&genesis_main()).unwrap();
		println!("mainnet genesis full hash: {}\n", gen_bin.hash().to_hex());
		//assert_eq!(gene_hash.to_hex, "");
	}
}