Statistics

Statistics.swift

class Statistics {
    let minimum: Int
    let maximum: Int
    let average: Int

    init(minimum: Int, maximum: Int, average: Int) {
        self.minimum = minimum
        self.maximum = maximum
        self.average = average
    }
}

protocol MinimumCalculator {
    func calculate(input: [Int]) -> Int
}

protocol MaximumCalculator {
    func calculate(input: [Int]) -> Int
}

protocol AverageCalculator {
    func calculate(input: [Int]) -> Int
}

class Stats {
    let minimumCalculator: MinimumCalculator
    let maximumCalculator: MaximumCalculator
    let averageCalculator: AverageCalculator

    init(minimumCalculator: MinimumCalculator, maximumCalculator: MaximumCalculator, averageCalculator: AverageCalculator) {
        self.minimumCalculator = minimumCalculator
        self.maximumCalculator = maximumCalculator
        self.averageCalculator = averageCalculator
    }

    func calculate(input: [Int]) -> Statistics {
        return Statistics(
            minimum: self.minimumCalculator.calculate(input),
            maximum: self.maximumCalculator.calculate(input),
            average: self.averageCalculator.calculate(input)
        )
    }
}