// Abstract interface for an ADC input

// Copyright (C)2017-2018-2023, Philip Munts dba Munts Technologies.
//
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namespace IO.Interfaces.ADC
{
    /// <summary>
    /// Abstract interface for ADC inputs returning an integer sample value.
    /// </summary>
    public interface Sample
    {
        /// <summary>
        /// Read-only property returning an integer analog sample value.
        /// </summary>
        int sample
        {
            get;
        }

        /// <summary>
        /// Read-only property returning the number of bits of resolution.
        /// </summary>
        int resolution
        {
            get;
        }
    }

    /// <summary>
    /// Abstract interface for ADC inputs returning a floating point voltage
    /// value.
    /// </summary>
    public interface Voltage
    {
        /// <summary>
        /// Read-only property returning a floating point analog voltage value.
        /// </summary>
        double voltage
        {
            get;
        }
    }

    /// <summary>
    /// Encapsulates ADC voltage inputs.
    /// </summary>
    public class Input: Voltage
    {
        private readonly Sample input;
        private readonly double stepsize;

        /// <summary>
        /// Create an ADC voltage input.
        /// </summary>
        /// <param name="input">ADC sample object.</param>
        /// <param name="reference">ADC reference in volts.</param>
        /// <param name="gain">ADC input gain in volts per volt.</param>
        public Input(Sample input, double reference, double gain = 1.0)
        {
            if (reference == 0.0)
            {
                throw new System.Exception("reference parameter is invalid");
            }

            if (gain == 0.0)
            {
                throw new System.Exception("gain parameter is invalid");
            }

            this.input = input;

            this.stepsize =
                reference / System.Math.Pow(2, input.resolution) / gain;
        }

        /// <summary>
        /// Read-only property returning the analog input voltage.
        /// </summary>
        public double voltage
        {
            get
            {
                return this.input.sample * this.stepsize;
            }
        }
    }
}