// Copyright (c) 2017-today Informatikbüro Daniel Schick
// Base class excel (writer not yet implemented but eventually..)   

using System;
using System.Collections.Generic;
using Microsoft.Office.Interop.Excel;
using System.Runtime.InteropServices;
using log4net;

namespace ENI2.Excel
{
    internal class ExcelBase : IDisposable
    {

        #region Fields

        internal enum CountryMode { NONE, DE, DK };

        protected CountryMode _countryMode = CountryMode.DE;

        protected Workbooks _excelWorkbooks;
        protected Workbook _workBook;
        protected Application _excelApp;
        protected Dictionary<string, Name> _nameDict;
        protected ILog _log;

        #endregion

        #region Construction

        public ExcelBase(string filePath)
        {

            _log = LogManager.GetLogger(this.GetType().Name);

            this._excelApp = new Application();
            this._excelApp.DisplayAlerts = false;
            this._excelWorkbooks = _excelApp.Workbooks;
        }

        #endregion

        #region Properties

        internal CountryMode Mode { get { return _countryMode; } }

        #endregion

        #region protected methods

        protected void InitNameFields()
        {
            _nameDict = new Dictionary<string, Name>();
            int bookCnt = 0;
            foreach (Name name in _workBook.Names)
            {
                string theValue = name.Value;
                // Namensbezug: =SheetZelle. Leere Referenzen überspringen (kommt immer mal wieder vor!)

                string nameKey = name.Name;

                try
                {
                    if (nameKey.Contains("!"))
                        nameKey = nameKey.Substring(nameKey.IndexOf('!') + 1);
                }
                catch (Exception)
                {
                    _log.DebugFormat("Strange name in Sheet: {0}", nameKey);
                    continue;
                }

                if ((theValue != "=#REF!#REF!") && (theValue != "=#BEZUG!#BEZUG!"))
                {
                    _nameDict[nameKey] = name;
                    bookCnt++;
                }
            }
            _log.DebugFormat("{0} named ranges found at Workbook level", bookCnt);


            foreach (Worksheet ws in _workBook.Worksheets)
            {
                int wsCnt = 0;
                foreach (Name name in ws.Names)
                {
                    string theValue = name.Value;
                    // Namensbezug: =SheetZelle. Leere Referenzen überspringen (kommt immer mal wieder vor!)
                    if (!_nameDict.ContainsKey(name.Name))
                    {
                        if ((theValue != "=#REF!#REF!") && (theValue != "=#BEZUG!#BEZUG!"))
                        {
                            _nameDict[name.Name] = name;
                            wsCnt++;
                        }
                    }
                }
                if (wsCnt > 0)
                    _log.DebugFormat("{0} named ranges found in Worksheet {1}", wsCnt, ws.Name);
            }
        }

        #endregion

        #region Dispose

        public void Dispose()
        {
            try
            {
                if (this._workBook != null)
                {
                    this._workBook.Close(0);
                    _log.Debug("Close Worksheet");
                    Marshal.ReleaseComObject(this._workBook);
                }

                if (this._excelWorkbooks != null)
                {
                    this._excelWorkbooks.Close();
                    _log.Debug("Close Workbooks");
                    Marshal.ReleaseComObject(this._excelWorkbooks);                
                }
                if (this._excelApp != null)
                {
                    _log.Debug("Quit Excel");
                    this._excelApp.Quit();
                    Marshal.ReleaseComObject(this._excelApp);
                }
            }
            catch(Exception ex)
            {
                _log.ErrorFormat("Exception disposing ExcelReader: {0}", ex.Message);
            }
        }

        #endregion

    }
}