using Sarand.Net.Standard.Base.App;
using Sarand.Net.Standard.Base.Core;
using Sarand.Net.Standard.Base.Dbas;
using Sarand.Net.Standard.Base.IO;
using Sarand.Net.Standard.Base.Procs;
using Sarand.Net.Standard.Base.Utils;
using Sarand.Net.Standard.Dbas.Base;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml.Linq;

namespace Sarand.Net.Standard.Dbas.Proc
{
	//=======================================================================
	public class SaDbProcess_ConvertDbSchema : SacsProcess
	{
		//-------------------------------------------------------------------
		// Configuration.
		public new class Config : SacsProcess.Config
		{
			public Config()
			{
			}
		}

		//-------------------------------------------------------------------
		// Data members.
		private Config config;

		//-------------------------------------------------------------------
		// Construction.
		public SaDbProcess_ConvertDbSchema(Config config) : base(config)
		{
			this.config = config;
		}
		protected override void Dispose(bool disposing)
		{
			if (disposing)
			{
			}
			base.Dispose(disposing);
		}

		//-------------------------------------------------------------------
		// Properties.
		public override string ProcessDescription { get; } = "Database Definition Convertor";
		public String XmlSchemaRootElementName { get; } = "DbDfnDatabase";

		// Processing.
		protected override bool Run()
		{
			throw new NotSupportedException(ProcessDescription + " - 'Run' not supported. Use a specific conversion method.");
		}

		//-------------------------------------------------------------------
		//                        X M L   T o   T a b l e s
		//-------------------------------------------------------------------
		public List<DbDfnTable> ConvertXmlToTables(String xmlSchemaData)
		{
			ClearProcessError();
			String fn = GetType().Name + ".ConvertXmlToTables";
			Dictionary<String, DbDfnTable> tables = new Dictionary<String, DbDfnTable>(StringComparer.OrdinalIgnoreCase);

			try
			{
				// Load XML data.
				XDocument xmlSchema = XDocument.Parse(xmlSchemaData);

				// Root element.
				XElement rootElement = xmlSchema.Root;
				if (rootElement == null)
					throw new NotSupportedException("XML schema missing root node");
				String rootElementName = rootElement.GetLocalName();
				if (!rootElementName.EqualsCI(XmlSchemaRootElementName))
					throw new NotSupportedException("XML schema has invalid root node. Expected: " + XmlSchemaRootElementName + ". Found: " + rootElementName);

				// 'Tables' element.
				XElement tablesElement = rootElement.GetFirstChildElement("Tables");
				if (tablesElement == null)
					throw new NotSupportedException("XML schema missing tables node");

				// Iterate tables.
				foreach (XElement tableElement in tablesElement.GetChildElements("DbDfnTable"))
				{
					DbDfnTable tableDfn = new DbDfnTable()
					{
						Schema = tableElement.GetChildText("Schema"),
						Name = tableElement.GetChildText("Name"),
						Remarks = tableElement.GetChildText("Remarks")
					};
					if (tableDfn.Name.IsEmpty())
						throw new NotSupportedException("XML schema contains blank table name.");
					if (tables.ContainsKey(tableDfn.QualifiedName))
						throw new NotSupportedException("XML schema contains duplicate table: " + tableDfn.QualifiedName);
					tables[tableDfn.QualifiedName] = tableDfn;

					// Columns.
					XElement columnsElement = tableElement.GetFirstChildElement("Columns");
					if (tablesElement == null)
						throw new NotSupportedException("XML schema table missing columns node: " + tableDfn.QualifiedName);

					// Iterate columns.
					foreach (XElement columnElement in columnsElement.GetChildElements("DbDfnColumn"))
					{
						DbDfnColumn columnDfn = new DbDfnColumn()
						{
							Schema = tableDfn.Schema,
							Table = tableDfn.Name,
							Pos = StringUtil.ToShort(columnElement.GetChildText("Pos")),
							Name = columnElement.GetChildText("Name"),
							DataType = EnumUtil.ParseEnum(columnElement.GetChildText("DataType"), DbColumnDataType.Unknown),
							DataTypeName = columnElement.GetChildText("DataTypeName"),
							DataTypeNative = StringUtil.ToShort(columnElement.GetChildText("DataTypeNative")),
							DataTypeNameNative = columnElement.GetChildText("DataTypeNameNative"),
							IsIdentity = StringUtil.ToBool(columnElement.GetChildText("IsIdentity")),
							Size = StringUtil.ToLong(columnElement.GetChildText("Size")),
							BufferLen = StringUtil.ToLong(columnElement.GetChildText("BufferLen")),
							DecimalDigits = StringUtil.ToShort(columnElement.GetChildText("DecimalDigits")),
							Nullable = EnumUtil.ParseEnum(columnElement.GetChildText("Nullable"), DbColumnNullable.Unknown),
							IsNullable = StringUtil.ToBool(columnElement.GetChildText("IsNullable")),
							Remarks = columnElement.GetChildText("Remarks")
						};
						tableDfn.AddColumn(columnDfn);
					}

					// Indices.
					XElement IndicesElement = tableElement.GetFirstChildElement("Indices");
					if (IndicesElement == null)
						throw new NotSupportedException("XML schema table missing indices node: " + tableDfn.QualifiedName);

					// Iterate indices.
					foreach (XElement indexElement in IndicesElement.GetChildElements("DbDfnIndex"))
					{
						DbDfnIndex indexDfn = new DbDfnIndex()
						{
							Schema = tableDfn.Schema,
							Table = tableDfn.Name,
							Name = indexElement.GetChildText("Name"),
							IndexType = StringUtil.ToInt(indexElement.GetChildText("IndexType")),
							Unique = StringUtil.ToBool(indexElement.GetChildText("Unique")),
							Primary = StringUtil.ToBool(indexElement.GetChildText("Primary")),
							Clustered = StringUtil.ToBool(indexElement.GetChildText("Clustered")),
							Nullable = StringUtil.ToBool(indexElement.GetChildText("Nullable")),
							Pages = StringUtil.ToInt(indexElement.GetChildText("Pages")),
							UniqueValues = StringUtil.ToInt(indexElement.GetChildText("UniqueValues")),
							HasColumns = StringUtil.ToBool(indexElement.GetChildText("HasColumns")),
						};

						// Index columns.
						XElement IndexColumnsElement = indexElement.GetFirstChildElement("Columns");
						foreach (XElement indexColumnElement in IndexColumnsElement?.GetChildElements("DbDfnIndexColumn") ?? Enumerable.Empty<XElement>())
						{
							DbDfnIndexColumn indexColumn = new DbDfnIndexColumn()
							{
								Seq = StringUtil.ToShort(indexColumnElement.GetChildText("Seq")),
								Name = indexColumnElement.GetChildText("Name"),
								Ascend = StringUtil.ToBool(indexColumnElement.GetChildText("Ascend")),
							};
							indexDfn.AddColumn(indexColumn);
						}
						tableDfn.AddIndex(indexDfn);
					}
				}
			}
			catch (Exception exc)
			{
				SetProcessError(exc.GetErrorStateMessage());
				SaLogger.Warn(fn + " " + ExceptionUtil.GetLogMessage(exc));
			}

			return tables.Values.ToList();
		}

		//-------------------------------------------------------------------
	}

	//=======================================================================
}