/* LaurisParagraph.cs
 * part of zaaReloaded2
 * 
 * Copyright 2015-2017 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.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using zaaReloaded2.Thesaurus;
using zaaReloaded2.LabModel;
using Bovender.Extensions;

namespace zaaReloaded2.Importer.ZaaImporter
{
    /// <summary>
    /// Parses an entire Lauris paragraph (such as "Klinische Chemie: ...")
    /// and creates a list of <see cref="LabItem"/>s.
    /// </summary>
    public class LaurisParagraph
    {
        #region Static methods

        /// <summary>
        /// Investigates a paragraph and determines whether it looks
        /// like a Lauris laboratory items paragraph.
        /// </summary>
        public static bool ResemblesLaurisParagraph(string paragraph)
        {
            return _expectedFormat.IsMatch(paragraph);
        }

        #endregion

        #region Public properties

        /// <summary>
        /// Gets a collection of <see cref="LabItem"/>s found in this paragraph.
        /// </summary>
        public IItemDictionary Items { get; private set; }

        /// <summary>
        /// Gets the caption that was extracted from the <see cref="OriginalParagraph"/>,
        /// e.g. "Klin. Chemie" in "Klin. Chemie: Natrium ...".
        /// </summary>
        public string Caption { get; private set; }

        /// <summary>
        /// Gets the original paragraph that this object was constructed from.
        /// </summary>
        public string OriginalParagraph { get; private set; }

        /// <summary>
        /// Is true if the <see cref="OriginalParagraph"/> matches the expected
        /// format and contains <see cref="LabItem"/>s.
        /// </summary>
        public bool IsLaurisParagraph { get; private set; }

        #endregion

        #region Constructor

        public LaurisParagraph(string paragraph)
        {
            OriginalParagraph = paragraph;
            Parse();
        }

        /// <summary>
        /// Constructs a <see cref="LaurisParagraph"/> object from a given
        /// Lauris paragraph, using a <paramref name="parameterDictionary"/>
        /// and a <paramref name="unitDictionary"/> to translate the individual
        /// items' properties.
        /// </summary>
        /// <param name="paragraph">lauris paragraph to parse.</param>
        /// <param name="parameterDictionary">ParameterDictionary that contains
        /// canonical names and material types.</param>
        /// <param name="unitDictionary">Unit dictionary that contains canonical
        /// unit names.</param>
        public LaurisParagraph(string paragraph,
            Thesaurus.Parameters parameterDictionary,
            Thesaurus.Units unitDictionary)
        {
            OriginalParagraph = paragraph;
            _parameterDictionary = parameterDictionary;
            _unitDictionary = unitDictionary;
            Parse();
        }

        #endregion

        #region Private methods

        /// <summary>
        /// Attempts to parse a Lauris paragraph.
        /// </summary>
        void Parse()
        {
            Logger.Info("Parse: \"{0}\"", OriginalParagraph.TruncateWithEllipsis(40));
            Match m = _expectedFormat.Match(OriginalParagraph);
            if (m.Success)
            {
                Logger.Info("Parse: Matches Lauris paragraph format");
                Items = new ItemDictionary();
                if (m.Groups["caption"].Success)
                {
                    Caption = m.Groups["caption"].Value.Trim(new char[] {' ', ':'});
                }

                foreach (Capture itemCapture in m.Groups["items"].Captures)
                {
                    LaurisItem i = new LaurisItem(itemCapture.Value, _parameterDictionary, _unitDictionary);
                    Items[i.QualifiedName] = i;
                }
                IsLaurisParagraph = Items.Count > 0;
            }
            else
            {
                Logger.Info("Parse: Does not match Lauris paragraph format");
                IsLaurisParagraph = false;
            }
        }

        #endregion

        #region Fields

        static readonly Regex _expectedFormat = new Regex(@"(?<caption>[^:]+:\s*)?(?<items>[^:]+:\s*[^;]+;)+");
        Thesaurus.Parameters _parameterDictionary;
        Thesaurus.Units _unitDictionary;

        #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
    }
}