/*

 Copyright (C) 2016 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 This class manages a running buffer of Double values.

 */

import Foundation

class RunningBuffer {

    // MARK: Properties

    var buffer = [Double]()

    var size = 0

    // MARK: Initialization

    init(size: Int) {

        self.size = size

        self.buffer = [Double](repeating: 0.0, count: self.size)

    }

    // MARK: Running Buffer

    func addSample(_ sample: Double) {

        buffer.insert(sample, at:0)

        if buffer.count > size  {

            buffer.removeLast()

        }

    }

    func reset() {

        buffer.removeAll(keepingCapacity: true)

    }

    func isFull() -> Bool {

        return size == buffer.count

    }

    func sum() -> Double {

        return buffer.reduce(0.0, +)

    }

    func min() -> Double {

        var min = 0.0

        if let bufMin = buffer.min() {

            min = bufMin

        }

        return min

    }

    func max() -> Double {

        var max = 0.0

        if let bufMax = buffer.max() {

            max = bufMax

        }

        return max

    }

    func recentMean() -> Double {

        // Calculate the mean over the beginning half of the buffer.

        let recentCount = self.size / 2

        var mean = 0.0

        if (buffer.count >= recentCount) {

            let recentBuffer = buffer[0..<recentCount]

            mean = recentBuffer.reduce(0.0, +) / Double(recentBuffer.count)

        }

        return mean

    }

}