using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading;
using Deltares.Standard.IO;
using Deltares.Standard.Language;
using LumenWorks.Framework.IO.Csv;

namespace Deltares.Dam.Data.CsvImporters
{
    public class CsvImporterSurfaceLinesException : Exception
    {
        public CsvImporterSurfaceLinesException(string message) : base(message)
        {
        }
    }

    public class CsvImporterSurfaceLines
    {
        private readonly List<SurfaceLineRecord> surfaceLineRecords = new List<SurfaceLineRecord>();
        private List<string> errorMessages = new List<string>();

        public class SurfaceLineRecord
        {
            private IList<double> xcoors = new List<double>();
            private IList<double> ycoors = new List<double>();
            private IList<double> zcoors = new List<double>();

            public string SurfaceLineId { get; set; }
            public int SurfaceLineRecordId { get; set; }

            public IList<double> Xcoors
            {
                get { return xcoors; }
                set { xcoors = value; }
            }

            public IList<double> Ycoors
            {
                get { return ycoors; }
                set { ycoors = value; }
            }

            public IList<double> Zcoors
            {
                get { return zcoors; }
                set { zcoors = value; }
            }
        }

        private void CheckColumn(int index, string fileName, string fieldName)
        {
            if (index < 0)
            {
                var csvHeaderFieldError = LocalizationManager.GetTranslatedText(GetType(), "csvHeaderFieldError");
                throw new CsvImporterSurfaceLinesException(String.Format("{0} : {1} {2}", fileName, csvHeaderFieldError, fieldName));
            }
        }

        /// <summary>
        /// Copies to temporary file.
        /// </summary>
        /// <param name="fileName">Name of the file.</param>
        /// <returns>the name of the temporary file</returns>
        private string CopyToTemporaryFile(string fileName)
        {
            string newFilename = Path.GetTempFileName();
            File.Delete(newFilename);
            File.Copy(fileName, newFilename);
            return newFilename;
        }

        public CsvImporterSurfaceLines(string filename)
        {
            errorMessages.Clear();
            ThrowHelper.ThrowIfStringArgumentNullOrEmpty(filename, StringResourceNames.CsvFileNotValid);
            ThrowHelper.ThrowIfFileNotExist(filename, StringResourceNames.CsvFileNotFound);

            // This is a 'dynamic' csv file, i.e. the number of columns is not known and can vary per row. So make sure of a 
            // proper header (i.e. a header with the maximum number of fields
            // because the file will be changed we copy it to a temporary file and perform the action on the temporary file
            string tempFilename = CopyToTemporaryFile(filename);
            CsvReaderUtilities.EnsureProperHeaderForDynamicRecordLengthInCsvFile(tempFilename);
            var oldcur = Thread.CurrentThread.CurrentCulture;
            try
            {
                Thread.CurrentThread.CurrentCulture = CsvReaderUtilities.DetermineCultureForFile(tempFilename);
                using (CsvReader csv = new CsvReader(new StreamReader(tempFilename), true, ';'){ MissingFieldAction = MissingFieldAction.ReplaceByNull })
                {
                    string[] headers = CsvImporterHelper.GetFieldHeaders(this, csv);
                    int colIndexSurfaceLineId = CsvReaderUtilities.GetHeaderIndexByString(headers, SurfaceLineCsvColumnNames.LocationColumnName);
                    if (colIndexSurfaceLineId < 0)
                    {
                        // colIndexSurfaceLineId can be defined with 2 identifiers (ProfileNameColumnName is deprecated, LocationColumnName is the new one)
                        colIndexSurfaceLineId = CsvReaderUtilities.GetHeaderIndexByString(headers, SurfaceLineCsvColumnNames.LocationColumnName);
                        if (colIndexSurfaceLineId < 0)
                        {
                            colIndexSurfaceLineId = CsvReaderUtilities.GetHeaderIndexByString(headers, SurfaceLineCsvColumnNames.ProfileNameColumnName);
                        }
                    }
                    CheckColumn(colIndexSurfaceLineId, tempFilename, SurfaceLineCsvColumnNames.LocationColumnName);
                    int colIndexFirstX = CsvReaderUtilities.GetHeaderIndexByString(headers, SurfaceLineCsvColumnNames.FirstXColumnName);
                    CheckColumn(colIndexFirstX, tempFilename, SurfaceLineCsvColumnNames.FirstXColumnName);
                    int maxColumns = headers.Count();
                    var end = Math.Floor((maxColumns - colIndexFirstX + 1) / 3.0);
                    var surflineIndex = 1;
                    while (csv.ReadNextRecord())
                    {
                        var recordReadError = false;
                        SurfaceLineRecord surfaceLine = new SurfaceLineRecord
                        {
                            SurfaceLineRecordId = surflineIndex
                        };
                        surflineIndex++;
                        surfaceLine.SurfaceLineId = csv[colIndexSurfaceLineId];
                        var colIndex = colIndexFirstX;
                        for (int i = 0; i < end; i++)
                        {
                            // if the first value = null the end of this surfaceline is reached, so break and it. Checking on null can only be done this way,
                            // a csv[index] == null does not work as that throws an exception itself.
                            try
                            {
                                var dum = csv[colIndex];
                                if (String.IsNullOrEmpty(dum))
                                    break;
                            }
                            catch (Exception)
                            {
                                break;
                            }
                            // other "errors" are real errors so trap them.
                            try
                            {                                
                                surfaceLine.Xcoors.Add(Convert.ToDouble(csv[colIndex]));
                                colIndex++;
                                surfaceLine.Ycoors.Add(Convert.ToDouble(csv[colIndex]));
                                colIndex++;
                                surfaceLine.Zcoors.Add(Convert.ToDouble(csv[colIndex]));
                                colIndex++;
                            }
                            catch (Exception e)
                            {
                                var csvSurfaceLineError = String.Format(LocalizationManager.GetTranslatedText(GetType(), "csvSurfaceLineError"), surfaceLine.SurfaceLineRecordId, colIndex + 1);
                                errorMessages.Add(csvSurfaceLineError + e.Message);
                                recordReadError = true;
                                break;
                            }                                                        
                        }
                        if (!recordReadError)
                        {
                            surfaceLineRecords.Add(surfaceLine);
                        }
                    }
                }
            }
            finally
            {
                File.Delete(tempFilename);
                Thread.CurrentThread.CurrentCulture = oldcur;
            }
        }

        public List<SurfaceLineRecord> ImportedItems
        {
            get { return surfaceLineRecords; }
        }

        public List<string> ErrorMessages
        {
            get { return errorMessages; }
            set { errorMessages = value; }
        }
    }
}