using System;
using System.Collections.Generic;

using NetTopologySuite.Geometries;
using NetTopologySuite.IO;

namespace Deltares.Maps
{
    /// <summary>
    ///     Reads data from ShapeFiles
    /// </summary>
    /// <remarks>
    /// </remarks>
    public class ShapeFileReader : FileReader<IFile, IFeature>, IFeatureReader
    {
        public ShapeFileReader(IFile file)
            : base(file)
        {
        }

        public ShapeFileReader(string fileName)
            : base(new ShapeFileLocation(fileName))
        {
        }

        /// <summary>
        ///     Gets or sets the value indicating geometry attribute or feature data should be read
        ///     If set to false the attribute data will be read form the .dbf file (default)
        /// </summary>
        public bool IgnoreAttributeData { get; set; }

        #region IFeatureReader Members

        public override IEnumerable<IFeature> Read()
        {
            using (var reader = new ShapefileDataReader(File.FullPath, GeometryFactory.Default))
            {
                int count = 0;

                while (reader.Read())
                {
                    var feature = new NtsFeature
                    {
                        Geometry = reader.Geometry
                    };

                    if (!IgnoreAttributeData)
                    {
                        for (int i = 0; i < reader.DbaseHeader.NumFields; i++)
                        {
                            string colName = reader.DbaseHeader.Fields[i].Name;
                            object rowValue = reader.GetValue(i);
                            if (!feature.Attributes.Exists(colName))
                            {
                                feature.Attributes.AddAttribute(colName, rowValue);
                            }
                        }
                    }

                    count++;
                    yield return feature;
                }

                if (reader.RecordCount != count)
                {
                    string message = string.Format(
                        "The shape file '{0}' contains multiple records but only one (composite) shape. " +
                        "This is not yet supported. The current implementation of the shape file reader only works " +
                        "with shape files where each shape has exactly one database record.",
                        File.FullPath);
                    throw new NotSupportedException(message);
                }
            }
        }

        #endregion
    }
}