using Microsoft.Office.Interop.Word;
/* AutoDetect.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.Linq;
using System.Text;
using zaaReloaded2.Importer.ZaaImporter;
using zaaReloaded2.Importer.ClinicImporter;

namespace zaaReloaded2.Importer
{
    class AutoDetector
    {
        #region Public methods
        
        /// <summary>
        /// Attempts to automatically detect laboratory data in the Word
        /// document.
        /// </summary>
        /// <param name="document">Document which to parse for laboratory
        /// data.</param>
        /// <returns>True if laboratory data was detected, false if not.</returns>
        /// <exception cref="ArgumentNullException">if <paramref name="document"/>
        /// is null.</exception>
        public bool Detect(Document document)
        {
            if (document == null)
            {
                throw new ArgumentNullException(
                    "Automatic laboratory detection requires a document.");
            }

            // TODO: Try to make this algorithm more elegant.
            Paragraph start = null;
            Paragraph end = null;
            int i = 1;

            if (document.Bookmarks.Exists("Labor"))
            {
                i = GetParagraphIndex(
                    document,
                    document.Bookmarks["Labor"].Range.Paragraphs[1]);
            }

            while (i <= document.Paragraphs.Count)
            {
                // Expect the first paragraph of a Lauris block to be
                // a time stamp. This prevents erroneous detection of
                // lines such as "Tel. (09 31) 201-39432; -39126", which
                // happen to structurally resemble a paragraph with
                // laboratory items.
                if (LaurisTimePoint.IsTimeStampLine(
                    document.Paragraphs[i].Range.Text))
                {
                    start = document.Paragraphs[i];
                    break;
                }
                i++;
            }

            if (start != null)
            {
                end = start;
                while (i <= document.Paragraphs.Count - 1)
                {
                    if (!IsLabParagraph(document.Paragraphs[i+1]))
                    {
                        end = document.Paragraphs[i];
                        break;
                    }
                    i++;
                }

                document.Range(start.Range.Start, end.Range.End).Select();
                return true;
            }
            return false;
        }

        #endregion

        #region Private methods

        /// <summary>
        /// Returns true if a paragraph is a time stamp line.
        /// </summary>
        private bool IsTimeStampParagraph(Paragraph paragraph)
        {
            string text = paragraph.Range.Text;
            bool isCinicTimePoint = ClinicTimePoint.IsTimeStampLine(text);
            bool isZaaTimePoint = LaurisTimePoint.IsTimeStampLine(text);
            // If the line is a ZAA time point, but not a clinic timepoint, we can deduct that
            // the lab mode *must* be ZAA, because it will be a line in the form
            // "(17.09.2015-201710:44:00) Cyclosporin-A vor Gabe: 130 µg/l;" which does not
            // occur in the clinic format.
            if ((_mode == Mode.Undefined) && isZaaTimePoint && !isCinicTimePoint)
            {
                _mode = Mode.Zaa;
            }
            return isCinicTimePoint || isZaaTimePoint;
        }

        /// <summary>
        /// Returns true if a paragraph is either a time stamp line
        /// or a paragraph with laboratory items.
        /// </summary>
        /// <remarks>
        /// This method determines the mode: either ZAA-generated output or clinic system-generated
        /// output. ZAA is given priority over clinic. Once a mode is detected, it will stick to
        /// that mode.
        /// </remarks>
        /// <param name="paragraph"></param>
        /// <returns></returns>
        private bool IsLabParagraph(Paragraph paragraph)
        {
            string text = paragraph.Range.Text;
            bool isLabParagraph = false;
            switch (_mode)
            {
                case Mode.Undefined:
                    if (LaurisParagraph.ResemblesLaurisParagraph(text) || LaurisTimePoint.IsTimeStampLine(text))
                    {
                        _mode = Mode.Zaa;
                        isLabParagraph = true;
                    }
                    else if (ClinicLine.ResemblesClinicLine(text) || ClinicTimePoint.IsTimeStampLine(text))
                    {
                        _mode = Mode.Clinic;
                        isLabParagraph = true;
                    }
                    break;
                case Mode.Zaa:
                    isLabParagraph = LaurisParagraph.ResemblesLaurisParagraph(text) || LaurisTimePoint.IsTimeStampLine(text); 
                    break;
                case Mode.Clinic:
                    isLabParagraph = ClinicLine.ResemblesClinicLine(text) || ClinicTimePoint.IsTimeStampLine(text);
                    break;
                default:
                    break;
            }
            return isLabParagraph;
        }

        /// <summary>
        /// Returns the index of a paragraph.
        /// </summary>
        /// <remarks>
        /// http://word.mvps.org/faqs/macrosvba/GetIndexNoOfPara.htm
        /// </remarks>
        /// <param name="paragraph">Paragraph whose index to return.</param>
        /// <returns>Index of the paragraph.</returns>
        private int GetParagraphIndex(Document document, Paragraph paragraph)
        {
            return document.Range(0, paragraph.Range.Start).Paragraphs.Count;
        }
        
        #endregion

        #region Fields

        private enum Mode
        {
            Undefined,
            Zaa,
            Clinic
        }

        private Mode _mode;

        #endregion
    }
}