// 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;

/// 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;

/// Mining parameter modes
#[derive(Debug, Clone, Serialize, Deserialize)]
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,
	}
}

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

/// 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 {
		MiningParameterMode::AutomatedTesting => 0, //won't make a difference
		MiningParameterMode::UserTesting => 22141, //Magic nonce for current genesis block at cuckoo16
		MiningParameterMode::Production => 0, //TBD
	}
}