using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Deltares.Standard;
using System.Reflection;
using System.Xml.Linq;
using System.Xml.Schema;
using System.IO;
using System.Xml;
using System.Globalization;
using Deltares.Standard.IO.DtoAssembler;


namespace Deltares.Dam.Data.Assemblers
{
    using Standard.Extensions;

    public class TimeSeriesAssembler : DtoAssembler<TimeSerieCollection>
    {
        #region Constant declarations

        /// <summary>
        /// Holds the xml element name
        /// </summary>
        private const string XmlElementName = "TimeSeries";

        /// <summary>
        /// Holds the name of the xml schema
        /// </summary>
        private const string XmlSchemaName = "pi_timeseries";

        private const string XmlSchemaNameSharedTypes = "pi_sharedtypes";

        /// <summary>
        /// Holds the xml namespace
        /// </summary>
        private const string XmlElementNamespace = "http://www.wldelft.nl/fews/PI";

        /// <summary>
        /// Holds the common part of the path to the embedded resource
        /// </summary>
        private const string EmbeddedResourcePath = "Deltares.Dam.Data.Xsd";

        /// <summary>
        /// Holds the xsd resource path 
        /// </summary>
        private const string XsdEmbeddedResourcePath = EmbeddedResourcePath + "." + XmlSchemaName + ".xsd";

        private const string XsdEmbeddedResourcePathSharedTypes = EmbeddedResourcePath + "." + XmlSchemaNameSharedTypes + ".xsd";

        public const string XmlVersionAttributeName = "version";
        public const string XmlTimeZoneElementName = "timeZone";
        public const string XmlSeriesElementName = "series";
        public const string XmlHeaderElementName = "header";
        public const string XmlTypeElementName = "type";
        public const string XmlLocationIdElementName = "locationId";
        public const string XmlParameterIdElementName = "parameterId";
        public const string XmlTimeStepElementName = "timeStep";
        public const string XmlStartDateElementName = "startDate";
        public const string XmlEndDateElementName = "endDate";
        public const string XmlForecastDateElementName = "forecastDate";
        public const string XmlMissValElementName = "missVal";
        public const string XmlLongNameElementName = "longName";
        public const string XmlStationNameElementName = "stationName";
        public const string XmlUnitsElementName = "units";
        public const string XmlSourceOrganisationElementName = "sourceOrganisation";
        public const string XmlSourceSystemElementName = "sourceSystem";
        public const string XmlFileDescriptionElementName = "fileDescription";
        public const string XmlCreationDateElementName = "creationDate";
        public const string XmlCreationTimeElementName = "creationTime";
        public const string XmlRegionElementName = "region";
        public const string XmlUnitAttributeName = "unit";
        public const string XmlDividerAttributeName = "divider";
        public const string XmlMultiplierAttributeName = "multiplier";
        public const string XmlDateAttributeName = "date";
        public const string XmlTimeAttributeName = "time";
        public const string XmlEntryElementName = "event";
        public const string XmlValueAttributeName = "value";
        public const string XmlFlagAttributeName = "flag";
        public const string XMLCommentElementName = "comment";


        #endregion

        public TimeSeriesAssembler()
            : base(XmlElementName, XmlElementNamespace, Assembly.GetExecutingAssembly().GetEmbeddedFile(XsdEmbeddedResourcePath))
        {
            AddOrUpdateMapping("Version", XmlVersionAttributeName);
        }

        public override TimeSerieCollection CreateDomainObject(XElement dtoObj)
        {
            TimeSerieCollection timeSerieCollection = base.CreateDomainObject(dtoObj);

            XNamespace tns = this.ElementNamespace;

            // Time zone
            XElement timeZoneElement = dtoObj.Element(tns + TimeSeriesAssembler.XmlTimeZoneElementName);
            if (timeZoneElement != null)
            {
                timeSerieCollection.TimeZone = Double.Parse(timeZoneElement.Value, CultureInfo.InvariantCulture);
            }

            // Series
            IEnumerable<XElement> serieElementCollection = dtoObj.Elements(tns + TimeSeriesAssembler.XmlSeriesElementName);

            foreach (XElement serieElement in serieElementCollection)
            {
                var timeSerie = new TimeSerie();

                // Header
                XElement headerElement = serieElement.Element(tns + TimeSeriesAssembler.XmlHeaderElementName);

                timeSerie.Type = GetElementValue<string>(headerElement, tns + XmlTypeElementName);
                timeSerie.LocationId = GetElementValue<string>(headerElement, tns + XmlLocationIdElementName);
                timeSerie.ParameterId = GetElementValue<string>(headerElement, tns + XmlParameterIdElementName);

                XElement timeStepElement = headerElement.Element(tns + TimeSeriesAssembler.XmlTimeStepElementName);
                timeSerie.TimeStep.Unit = (TimeStepUnit)Enum.Parse(typeof(TimeStepUnit), timeStepElement.AttributeAs<string>(TimeSeriesAssembler.XmlUnitAttributeName), true);

                timeSerie.TimeStep.Divider = timeStepElement.AttributeAs<uint>(TimeSeriesAssembler.XmlDividerAttributeName);

                timeSerie.TimeStep.Multiplier = timeStepElement.AttributeAs<uint>(TimeSeriesAssembler.XmlMultiplierAttributeName);
                XElement startDateElement = headerElement.Element(tns + TimeSeriesAssembler.XmlStartDateElementName);
                timeSerie.StartDateTime = startDateElement.AttributeAs<DateTime>(TimeSeriesAssembler.XmlDateAttributeName).Date +
                                          startDateElement.AttributeAs<DateTime>(TimeSeriesAssembler.XmlTimeAttributeName).TimeOfDay;
                XElement endDateElement = headerElement.Element(tns + TimeSeriesAssembler.XmlEndDateElementName);
                timeSerie.EndDateTime = endDateElement.AttributeAs<DateTime>(TimeSeriesAssembler.XmlDateAttributeName).Date +
                                        endDateElement.AttributeAs<DateTime>(TimeSeriesAssembler.XmlTimeAttributeName).TimeOfDay;
                XElement forecastDateElement = headerElement.Element(tns + TimeSeriesAssembler.XmlForecastDateElementName);

                if (forecastDateElement != null)
                {
                    timeSerie.ForecastDateTime = forecastDateElement.AttributeAs<DateTime>(TimeSeriesAssembler.XmlDateAttributeName).Date +
                                            forecastDateElement.AttributeAs<DateTime>(TimeSeriesAssembler.XmlTimeAttributeName).TimeOfDay;
                }

                timeSerie.MissVal = GetElementValue<double>(headerElement, tns + XmlMissValElementName);
                timeSerie.LongName = GetElementValue<string>(headerElement, tns + XmlLongNameElementName);
                timeSerie.StationName = GetElementValue<string>(headerElement, tns + XmlStationNameElementName);
                timeSerie.Units = GetElementValue<string>(headerElement, tns + XmlUnitsElementName);
                timeSerie.SourceOrganisation = GetElementValue<string>(headerElement, tns + XmlSourceOrganisationElementName);
                timeSerie.SourceSystem = GetElementValue<string>(headerElement, tns + XmlSourceSystemElementName);
                timeSerie.FileDescription = GetElementValue<string>(headerElement, tns + XmlFileDescriptionElementName);

                XElement creationDateElement = headerElement.Element(tns + XmlCreationDateElementName);
                XElement creationTimeElement = headerElement.Element(tns + XmlCreationTimeElementName);
                if (creationDateElement != null)
                {
                    timeSerie.CreationDateTime = creationDateElement.Value.ToType<DateTime>().Date;
                    if (creationTimeElement != null)
                    {
                        timeSerie.CreationDateTime += creationTimeElement.Value.ToType<DateTime>().TimeOfDay;
                    }
                }

                timeSerie.Region = GetElementValue<string>(headerElement, tns + XmlRegionElementName);

                // Entries
                IEnumerable<XElement> entryElementCollection = serieElement.Elements(tns + TimeSeriesAssembler.XmlEntryElementName);

                foreach (XElement entryElement in entryElementCollection)
                {
                    TimeSerieEntry entry = new TimeSerieEntry();
                    entry.DateTime = entryElement.AttributeAs<DateTime>(XmlDateAttributeName).Date +
                                              entryElement.AttributeAs<DateTime>(XmlTimeAttributeName).TimeOfDay;
                    entry.Value = entryElement.AttributeAs<double>(XmlValueAttributeName);
                    entry.Flag = entryElement.AttributeAs<int>(XmlFlagAttributeName);

                    timeSerie.Entries.Add(entry);
                }

                // Comment
                XElement commentElement = serieElement.Element(tns + XMLCommentElementName);
                if (commentElement != null)
                    timeSerie.Comment = commentElement.Value;

                timeSerieCollection.Series.Add(timeSerie);
            }

            return timeSerieCollection;
        }

        private static T GetElementValue<T>(XContainer parent, XName name)
        {
            var element = parent.Element(name);
            if (element != null)
                return element.Value.ToType<T>();

            return default(T);
        }

        public override XElement CreateDataTransferObject(TimeSerieCollection timeSerieCollection)
        {
            XElement rootElement = base.CreateDataTransferObject(timeSerieCollection);

            XNamespace tns = ElementNamespace;

            // Time zone
            rootElement.Add(new XElement(tns + XmlTimeZoneElementName, timeSerieCollection.TimeZone));

            // Series
            foreach (TimeSerie timeSerie in timeSerieCollection.Series)
            {
                XElement serieElement = new XElement(tns + XmlSeriesElementName);

                XElement headerElement = new XElement(tns + XmlHeaderElementName);
                headerElement.Add(new XElement(tns + XmlTypeElementName, timeSerie.Type));
                headerElement.Add(new XElement(tns + XmlLocationIdElementName, timeSerie.LocationId));
                headerElement.Add(new XElement(tns + XmlParameterIdElementName, timeSerie.ParameterId));

                headerElement.Add(new XElement(tns + XmlTimeStepElementName,
                                               new XAttribute(XmlUnitAttributeName, timeSerie.TimeStep.Unit.ToString().ToLower()),
                                               (timeSerie.TimeStep.MultiplierSpecified ? new XAttribute(XmlMultiplierAttributeName, timeSerie.TimeStep.Multiplier) : null),
                                               (timeSerie.TimeStep.DividerSpecified ? new XAttribute(XmlDividerAttributeName, timeSerie.TimeStep.Divider) : null)
                                               ));

                headerElement.Add(new XElement(tns + XmlStartDateElementName,
                                               new XAttribute(XmlDateAttributeName, timeSerie.StartDateTime.ToString("yyyy-MM-dd")),
                                               new XAttribute(XmlTimeAttributeName, timeSerie.StartDateTime.ToString("HH:mm:ss"))));
                headerElement.Add(new XElement(tns + XmlEndDateElementName,
                                               new XAttribute(XmlDateAttributeName, timeSerie.EndDateTime.ToString("yyyy-MM-dd")),
                                               new XAttribute(XmlTimeAttributeName, timeSerie.EndDateTime.ToString("HH:mm:ss"))));

                if (!timeSerie.ForecastDateTime.Equals(DateTime.MinValue))
                headerElement.Add(new XElement(tns + XmlForecastDateElementName,
                                               new XAttribute(XmlDateAttributeName, timeSerie.ForecastDateTime.ToString("yyyy-MM-dd")),
                                               new XAttribute(XmlTimeAttributeName, timeSerie.ForecastDateTime.ToString("HH:mm:ss"))));

                headerElement.Add(new XElement(tns + XmlMissValElementName, timeSerie.MissVal));
                if (timeSerie.LongName != null)
                    headerElement.Add(new XElement(tns + XmlLongNameElementName, timeSerie.LongName));
                if (timeSerie.StationName != null)
                    headerElement.Add(new XElement(tns + XmlStationNameElementName, timeSerie.StationName));
                if (timeSerie.Units != null)
                    headerElement.Add(new XElement(tns + XmlUnitsElementName, timeSerie.Units));
                if (timeSerie.SourceOrganisation != null)
                    headerElement.Add(new XElement(tns + XmlSourceOrganisationElementName, timeSerie.SourceOrganisation));
                if (timeSerie.SourceSystem != null)
                    headerElement.Add(new XElement(tns + XmlSourceSystemElementName, timeSerie.SourceSystem));
                if (timeSerie.FileDescription != null)
                    headerElement.Add(new XElement(tns + XmlFileDescriptionElementName, timeSerie.FileDescription));
                if (timeSerie.CreationDateTime != null)
                {
                    headerElement.Add(new XElement(tns + XmlCreationDateElementName, timeSerie.CreationDateTime.Value.ToString("yyyy-MM-dd")));
                    headerElement.Add(new XElement(tns + XmlCreationTimeElementName, timeSerie.CreationDateTime.Value.ToString("HH:mm:ss")));
                }
                if (timeSerie.Region != null)
                    headerElement.Add(new XElement(tns + XmlRegionElementName, timeSerie.Region));

                serieElement.Add(headerElement);

                // Entries
                foreach (var entry in timeSerie.Entries)
                {
                    XElement entryElement = new XElement(tns + XmlEntryElementName,
                                                         new XAttribute(XmlDateAttributeName, entry.DateTime.ToString("yyyy-MM-dd")),
                                                         new XAttribute(XmlTimeAttributeName, entry.DateTime.ToString("HH:mm:ss")),
                                                         new XAttribute(XmlValueAttributeName, entry.Value),
                                                         new XAttribute(XmlFlagAttributeName, entry.Flag));
                    serieElement.Add(entryElement);
                }

                // Comment
                if (timeSerie.Comment != null)
                {
                    XElement commentElement = new XElement(tns + XMLCommentElementName, timeSerie.Comment);
                    serieElement.Add(commentElement);
                }

                rootElement.Add(serieElement);
            }

            return rootElement;
        }

        public XDocument CreateDataTransferDocument(TimeSerieCollection timeSerieCollection)
        {
            XDocument doc = new XDocument(new XDeclaration("1.0", "utf-8", "yes"));

            XNamespace xsi = "http://www.w3.org/2001/XMLSchema-instance";


            XElement root = CreateDataTransferObject(timeSerieCollection);

            doc.Add(root);

            root.Add(new XAttribute(XNamespace.Xmlns + "xsi", xsi.NamespaceName));

            return doc;
        }

        public bool ValidateSchema(XDocument doc, out string message)
        {
            bool result = true;
            string errorMessage = String.Empty;

            XmlSchemaSet schemas = new XmlSchemaSet();

            Stream xsdStream = Assembly.GetExecutingAssembly().GetEmbeddedFile(XsdEmbeddedResourcePath);
            schemas.Add(XmlElementNamespace, XmlReader.Create(xsdStream));
            xsdStream = Assembly.GetExecutingAssembly().GetEmbeddedFile(XsdEmbeddedResourcePathSharedTypes);
            schemas.Add(XmlElementNamespace, XmlReader.Create(xsdStream));

            doc.Validate(schemas, (o, e) => { result = false; errorMessage = e.Message; }, true);

            message = errorMessage;

            return result;
        }
    }
}