zaaReloaded2/zaaReloaded2/Models/LabItem.cs

/* LabItem.cs
 * part of zaaReloaded2
 * 
 * Copyright 2015 Daniel Kraus
 * 
 * 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.
 */
using System;
using System.Globalization;
using System.Text.RegularExpressions;

namespace zaaReloaded2.Models
{
    /// <summary>
    /// Represents a single laboratory item (e.g., sodium or creatinine).
    /// </summary>
    public class LabItem
    {
        #region Properties

        /// <summary>
        /// Gets or sets the original name of the item (as known by Lauris).
        /// </summary>
        public string Name { get; set; }

        /// <summary>
        /// Gets or sets the unit of the item (as known by Lauris).
        /// </summary>
        public string Unit { get; set; }

        /// <summary>
        /// Gets or sets the value of the item. This may be a number or a string.
        /// </summary>
        public string Value { get; set; }

        public double NumericalValue
        {
            get
            {
                if (IsNumerical)
                {
                    return _numericalValue;
                }
                else
                {
                    throw new InvalidOperationException(
                        String.Format("Value '{0}' is not numerical.", Value));
                }
            }
            private set
            {
                _numericalValue = value;
            }
        }

        public bool IsNumerical
        {
            get
            {
                return (Double.TryParse(Value,
                    NumberStyles.Any,
                    CultureInfo.InvariantCulture,
                    out _numericalValue));
            }
        }

        /// <summary>
        /// Gets or sets the normal value of the item. Need not be set. This is
        /// used for items with nominal values (as opposed to numbers).
        /// </summary>
        public string Normal { get; set; }

        /// <summary>
        /// Gets or sets the lower limit of normal.
        /// </summary>
        public double LowerLimit
        {
            get
            {
                return _lowerLimit;
            }
            set
            {
                _lowerLimit = value;
                HasLowerLimit = true;
            }
        }

        /// <summary>
        /// Is true if the item has a lower limit of normal.
        /// </summary>
        public bool HasLowerLimit { get; private set; }

        /// <summary>
        /// Gets or sets the upper limit of normal.
        /// </summary>
        public double UpperLimit
        {
            get
            {
                return _upperLimit;
            }
            set
            {
                _upperLimit = value;
                HasUpperLimit = true;
            }
        }

        /// <summary>
        /// Is true if the item has an upper limit of normal.
        /// </summary>
        public bool HasUpperLimit { get; private set; }

        /// <summary>
        /// Is true if <see cref="Value"/> is normal.
        /// </summary>
        public bool IsNormal
        {
            get
            {
                if (HasLimits)
                {
                    if (HasLowerLimit && HasUpperLimit)
                    {
                        return (LowerLimit <= NumericalValue &&
                            NumericalValue <= UpperLimit);
                    }
                    else
                    {
                        if (HasLowerLimit)
                        {
                            return (LowerLimit <= NumericalValue);
                        }
                        return (NumericalValue <= UpperLimit);
                    }
                }
                else
                {
                    return (Value == Normal);
                }
            }
        }

        /// <summary>
        /// Is true if the item has lower and/or upper limits. Is false if the
        /// item does not have limits but a <see cref="Normal"/> value.
        /// </summary>
        public bool HasLimits
        {
            get { return (HasLowerLimit || HasUpperLimit); }
        }

        /// <summary>
        /// The original Lauris string from which this lab item was created.
        /// </summary>
        public string Lauris { get; private set; }

        /// <summary>
        /// The canonical name of this item, or the Lauris <see cref="Name"/>
        /// of the item if no canonical name is known.
        /// </summary>
        public string CanonicalName
        {
            get
            {
                if (!string.IsNullOrEmpty(_canonicalName))
                {
                    return _canonicalName;
                }
                else
                {
                    return Name;
                }
            }
        }

        #endregion

        #region Constructors

        /// <summary>
        /// Creates an empty LabItem object.
        /// </summary>
        public LabItem() { }

        /// <summary>
        /// Creates a LabItem object from a given Lauris output.
        /// </summary>
        /// <param name="laurisString">Lauris output to parse.</param>
        public LabItem(string laurisString)
            :this()
        {
            Lauris = laurisString;
            ParseLauris();
        }

        #endregion

        #region Private methods

        /// <summary>
        /// Parses the original Lauris string contained in
        /// <see cref="Lauris"/>.
        /// </summary>
        private void ParseLauris()
        {
            // Examples of Lauris output strings:
            // "Natrium: 139 [135 - 145] mmol/l"
            // "HDL - Cholesterin: 45 [>= 35] mg/dl"
            // "GOT (ASAT): 303.0 [<= 50] U/l; "
            // "Niedermol. Heparin (Anti-Xa): 0.99 U/ml;"
            // "HBs-Antigen: neg. ;"
            // "Erythrozyten (U): + [negativ]"
            Match match;
            Regex numericalRegex = new Regex(
                @"(?<name>[^:]+):\s*(?<value>[\d.]+)\s*(?<limits>\[[^\]]+])?\s*(?<unit>[^;]+)?");
            Regex categoricalRegex = new Regex(
                @"(?<name>[^:]+):\s*(?<value>[^[;]+)\s*(\[(?<normal>[^\]]+)])?");
            if (numericalRegex.IsMatch(Lauris))
            {
                match = numericalRegex.Match(Lauris);
                ParseLimits(match);
            }
            else
            {
                match = categoricalRegex.Match(Lauris);
                Normal = match.Groups["normal"].Value.Trim();
            }
            if (match != null)
            {
                Name = match.Groups["name"].Value.Trim();
                Value = match.Groups["value"].Value.Trim();
                Unit = match.Groups["unit"].Value.Trim();
            }
        }

        /// <summary>
        /// Parses a string containing value limits. The string must be like
        /// "[3.5 - 5]", "[>= 50]", or "[&lt;= 100]".
        /// </summary>
        /// <param name="match">Match object that should contain a group "limits".</param>
        void ParseLimits(Match match)
        {
            if (match.Groups["limits"].Success)
            {
                Regex limitRegex = new Regex(@"\[(?<limit1>[\d.]+)?\s*(?<operator>\S+)\s*(?<limit2>[\d.]+)?]");
                Match limitMatch = limitRegex.Match(match.Groups["limits"].Value);
                if (limitMatch.Groups["limit1"].Success && limitMatch.Groups["limit2"].Success)
                {
                    // Use InvariantCulture because Lauris always outputs dots as decimal separator
                    LowerLimit = Double.Parse(limitMatch.Groups["limit1"].Value,
                        CultureInfo.InvariantCulture);
                    UpperLimit = Double.Parse(limitMatch.Groups["limit2"].Value,
                        CultureInfo.InvariantCulture);
                }
                else
                {
                    switch (limitMatch.Groups["operator"].Value.Trim())
                    {
                        case "<=":
                            UpperLimit = Double.Parse(limitMatch.Groups["limit2"].Value,
                                CultureInfo.InvariantCulture);
                            break;
                        case ">=":
                            LowerLimit = Double.Parse(limitMatch.Groups["limit2"].Value,
                                CultureInfo.InvariantCulture);
                            break;
                        default:
                            throw new InvalidOperationException(
                                String.Format("Unknown operator in {0}",
                                    match.Groups["limits"].Value));
                    }
                }
            }
        }

        #endregion

        #region Fields

        string _canonicalName;
        double _numericalValue;
        double _lowerLimit;
        double _upperLimit;

        #endregion
    }
}