// Copyright 2016-2018 Cisco Systems Inc
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

import Foundation

struct ExponentialBackOffCounter {
    private var minimum: Double
    private var maximum: Double
    private var multiplier: Double
    private var current: Double?
    
    init(minimum: Double, maximum: Double, multiplier: Double) {
        self.minimum = minimum
        self.maximum = maximum
        self.multiplier = multiplier
    }
    
    mutating func next() -> Double {
        if let current = current {
            return min(current * multiplier, maximum)
        } else {
            return minimum
        }
    }
    
    mutating func reset() {
        current = nil
    }
}
