// Copyright 2017 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.

//! Values that should be shared across all modules, without necessarily
//! having to pass them all over the place, but aren't consensus values.
//! should be used sparingly.

/// An enum collecting sets of parameters used throughout the
/// code wherever mining is needed. This should allow for
/// different sets of parameters for different purposes,
/// e.g. CI, User testing, production values

use std::sync::RwLock;
use consensus::PROOFSIZE;
use consensus::DEFAULT_SIZESHIFT;
use consensus::COINBASE_MATURITY;

/// Define these here, as they should be developer-set, not really tweakable
/// by users

/// Automated testing sizeshift
pub const AUTOMATED_TESTING_SIZESHIFT: u8 = 10;

/// Automated testing proof size
pub const AUTOMATED_TESTING_PROOF_SIZE: usize = 4;

/// User testing sizeshift
pub const USER_TESTING_SIZESHIFT: u8 = 16;

/// User testing proof size
pub const USER_TESTING_PROOF_SIZE: usize = 42;

/// Automated testing coinbase maturity
pub const AUTOMATED_TESTING_COINBASE_MATURITY: u64 = 3;

/// User testing coinbase maturity
pub const USER_TESTING_COINBASE_MATURITY: u64 = 3;

/// Mining parameter modes
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum MiningParameterMode {
	/// For CI testing
	AutomatedTesting,

	/// For User testing
	UserTesting,

	/// For production, use the values in consensus.rs
	Production,
}

lazy_static!{
	/// The mining parameter mode
	pub static ref MINING_PARAMETER_MODE: RwLock<MiningParameterMode> =
			RwLock::new(MiningParameterMode::Production);
}

/// Set the mining mode
pub fn set_mining_mode(mode: MiningParameterMode) {
	let mut param_ref = MINING_PARAMETER_MODE.write().unwrap();
	*param_ref = mode;
}

/// The sizeshift
pub fn sizeshift() -> u8 {
	let param_ref = MINING_PARAMETER_MODE.read().unwrap();
	match *param_ref {
		MiningParameterMode::AutomatedTesting => AUTOMATED_TESTING_SIZESHIFT,
		MiningParameterMode::UserTesting => USER_TESTING_SIZESHIFT,
		MiningParameterMode::Production => DEFAULT_SIZESHIFT,
	}
}

/// The proofsize
pub fn proofsize() -> usize {
	let param_ref = MINING_PARAMETER_MODE.read().unwrap();
	match *param_ref {
		MiningParameterMode::AutomatedTesting => AUTOMATED_TESTING_PROOF_SIZE,
		MiningParameterMode::UserTesting => USER_TESTING_PROOF_SIZE,
		MiningParameterMode::Production => PROOFSIZE,
	}
}

/// Coinbase maturity
pub fn coinbase_maturity() -> u64 {
	let param_ref = MINING_PARAMETER_MODE.read().unwrap();
	match *param_ref {
		MiningParameterMode::AutomatedTesting => AUTOMATED_TESTING_COINBASE_MATURITY,
		MiningParameterMode::UserTesting => USER_TESTING_COINBASE_MATURITY,
		MiningParameterMode::Production => COINBASE_MATURITY,
	}
}

/// Are we in automated testing mode?
pub fn is_automated_testing_mode() -> bool {
	let param_ref = MINING_PARAMETER_MODE.read().unwrap();
	MiningParameterMode::AutomatedTesting == *param_ref
}

/// Are we in user testing mode?
pub fn is_user_testing_mode() -> bool {
	let param_ref = MINING_PARAMETER_MODE.read().unwrap();
	MiningParameterMode::UserTesting == *param_ref
}

/// Are we in production mode?
pub fn is_production_mode() -> bool {
	let param_ref = MINING_PARAMETER_MODE.read().unwrap();
	MiningParameterMode::Production == *param_ref
}


/// Helper function to get a nonce known to create a valid POW on
/// the genesis block, to prevent it taking ages. Should be fine for now
/// as the genesis block POW solution turns out to be the same for every new
/// block chain
/// at the moment

pub fn get_genesis_nonce() -> u64 {
	let param_ref = MINING_PARAMETER_MODE.read().unwrap();
	match *param_ref {
		// won't make a difference
		MiningParameterMode::AutomatedTesting => 0,
		// Magic nonce for current genesis block at cuckoo16
		MiningParameterMode::UserTesting => 27944,
		// Magic nonce for current genesis at cuckoo30
		MiningParameterMode::Production => 1429942738856787200,
	}
}

/// Returns the genesis POW for cuckoo16 (UserTesting) and cuckoo30 (Production)
pub fn get_genesis_pow() -> [u32; 42] {
	let param_ref = MINING_PARAMETER_MODE.read().unwrap();
	match *param_ref {
		// pow solution for genesis block at cuckoo16
		MiningParameterMode::UserTesting => [
			0x37f, 0x9f6, 0x136d, 0x13d3, 0x155e, 0x16dd, 0x186b, 0x1b11, 0x208e, 0x23cd,
			0x24d1, 0x278f, 0x2a1b, 0x2a28, 0x2a44, 0x2ae2, 0x2c37, 0x36af, 0x391d, 0x3c2e,
			0x3d9a, 0x3f00, 0x429f, 0x45b2, 0x47ce, 0x47f1, 0x492f, 0x4bd8, 0x4fee, 0x51f0,
			0x5207, 0x58e5, 0x5905, 0x5aca, 0x5dfb, 0x628d, 0x7310, 0x75e5, 0x76d4, 0x76df,
			0x77bd, 0x7ab9
		],
		// pow solution for genesis block at cuckoo30
		// TODO - likely this is no longer correct (block header changes)
		MiningParameterMode::Production => [
			7444824,
			11926557,
			28520390,
			30594072,
			50854023,
			52797085,
			57882033,
			59816511,
			61404804,
			84947619,
			87779345,
			115270337,
			162618676,
			166860710,
			178656003,
			178971372,
			200454733,
			209197630,
			221231015,
			228598741,
			241012783,
			245401183,
			279080304,
			295848517,
			327300943,
			329741709,
			366394532,
			382493153,
			389329248,
			404353381,
			406012911,
			418813499,
			426573907,
			452566575,
			456930760,
			463021458,
			474340589,
			476248039,
			478197093,
			487576917,
			495653489,
			501862896,
		],
		// TODO - for completeness do we provide one here for AutomatedTesting?
		_ => panic!("unexpected"),
	}
}