/* ZaaImporter.cs
 * part of zaaReloaded2
 * 
 * Copyright 2017 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.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using Bovender.Extensions;
using zaaReloaded2.LabModel;
using zaaReloaded2.Thesaurus;

namespace zaaReloaded2.Importer
{
    /// <summary>
    /// Base class for certain importers such as ZaaImporter, ClinicImporter.
    /// </summary>
    public class BaseImporter : IImporter
    {
        #region IImporter implementation

        public Laboratory Laboratory
        {
            [DebuggerStepThrough]
            get
            {
                if (_laboratory == null)
                {
                    _laboratory = new Laboratory();
                }
                return _laboratory;
            }
            [DebuggerStepThrough]
            set
            {
                _laboratory = value;
            }
        }

        public bool Success
        {
            get
            {
                return Laboratory.TimePoints.Count > 0;
            }
        }

        /// <summary>
        /// Splits the <paramref name="text"/> into individual time points
        /// and creates <see cref="TimePoint"/> objects from them.
        /// </summary>
        public void Import(string text)
        {
            Logger.Info("Import: \"{0}\"", text.TruncateWithEllipsis(120));
            string[] paragraphs = Helpers.SplitParagraphs(text);
            Logger.Info("Import: {0} paragraph(s)", paragraphs.Length);
            TimePoint timePoint = null;

            foreach (string paragraph in paragraphs)
            {
                Logger.Info("Import: \"{0}\"", paragraph.TruncateWithEllipsis(40));
                // If the current paragraph looks like a time stamp,
                // create a new time point.
                if (IsTimeStamp(paragraph))
                {
                    Logger.Info("Import: Time stamp detected", paragraph);
                    timePoint = CreateTimePoint(paragraph, _parameters, _units);
                    // Add the time point to the laboratory only if none
                    // with the same time stamp exists yet.
                    TimePoint existing = null;
                    if (Laboratory.TryGetTimePoint(timePoint.TimeStamp, ref existing))
                    {
                        timePoint = existing;
                    }
                    else
                    {
                        Laboratory.AddTimePoint(timePoint);
                    }
                }
                // If the current paragraph looks like a paragraph with
                // laboratory items, add it to the current time point;
                // if no time point exists yet, create one.
                else if (IsItemsParagraph(paragraph))
                {
                    Logger.Info("Import: Paragraph with lab items detected");
                    if (timePoint == null)
                    {
                        timePoint = CreateTimePoint(paragraph, _parameters, _units);
                        Laboratory.AddTimePoint(timePoint);
                    }
                    else
                    {
                        timePoint.Parse(paragraph);
                    }
                }
                else
                {
                    Logger.Debug("Import: Neither time stamp, nor Lauris paragraph");
                }
            }
        }

        #endregion

        #region Constructor

        public BaseImporter()
        {
            _parameters = Parameters.Default;
            _units = Units.Default;
        }

        #endregion

        #region Virtual methods

        protected virtual TimePoint CreateTimePoint(string paragraph, Parameters parameters, Units units)
        {
            NotImplementedException e = new NotImplementedException("Cannot create TimePoint in base class - derived class must override CreateTimePoint");
            Logger.Fatal(e);
            throw e;
        }

        protected virtual bool IsTimeStamp(string paragraph)
        {
            NotImplementedException e = new NotImplementedException("Cannot test time stamp in base class - derived class must override IsTimeStamp");
            Logger.Fatal(e);
            throw e;
        }

        protected virtual bool IsItemsParagraph(string paragraph)
        {
            NotImplementedException e = new NotImplementedException("Cannot test items in base class - derived class must override IsItemsParagraph");
            Logger.Fatal(e);
            throw e;
        }

        #endregion

        #region Fields

        Laboratory _laboratory;
        Parameters _parameters;
        Units _units;

        #endregion

        #region Class logger

        private static NLog.Logger Logger { get { return _logger.Value; } }

        private static readonly Lazy<NLog.Logger> _logger = new Lazy<NLog.Logger>(() => NLog.LogManager.GetCurrentClassLogger());

        #endregion
    }
}