using Sarand.Net.Standard.Base.Core;
using Sarand.Net.Standard.Base.Utils;
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Xml;
using System.Xml.Linq;

namespace Sarand.Net.Standard.Base.Utils
{
	//=======================================================================
	public static class SacsXmlUtil
	{
		//-------------------------------------------------------------------
		// Data members.
		public static Encoding DefaultEncoding { get; } = Encoding.UTF8;

		//-------------------------------------------------------------------
		/// <summary>Retrieve the Xml Declaration from the XML document.</summary>
		public static XDeclaration GetXmlDeclaration (this XDocument xmlDoc)
		{
			return xmlDoc.Declaration;
		}

		//-------------------------------------------------------------------
		// Namespace.
		public static String GetNamespacePrefix (this XElement element)
		{
			if (element.Name.Namespace != null)
				return element.GetPrefixOfNamespace(element.Name.Namespace);
			return "";
		}

		//-------------------------------------------------------------------
		// Convert XML document to string.
		public static String GetXml (this XContainer container, Encoding encoding = null)
		{
			//return container.ToString(SaveOptions.DisableFormatting);

			var builder = new StringBuilder();
			var settings = new XmlWriterSettings()
			{
				Indent = false
			};
			using (var writer = XmlWriter.Create(builder, settings))
			{
				container.WriteTo(writer);
			}
			return builder.ToString();
		}
		public static String FormatXml (this XContainer container, Encoding encoding = null)
		{
			//return container.ToString();

			var builder = new StringBuilder();
			var settings = new XmlWriterSettings()
			{
				Indent = true
			};
			using (var writer = XmlWriter.Create(builder, settings))
			{
				container.WriteTo(writer);
			}
			return builder.ToString();
		}

		//-------------------------------------------------------------------
		//                        N o d e   N a m e
		//-------------------------------------------------------------------
		public static String GetLocalName (this XElement element)
		{
			return element?.Name?.LocalName ?? "";
		}

		//-------------------------------------------------------------------
		//                        A t t r i b u t e s
		//-------------------------------------------------------------------
		public static XAttribute GetAttribute (this XElement element, String name)
		{
			foreach (XAttribute attribute in element.Attributes())
				if (attribute.Name.LocalName.EqualsCI(name))
					return attribute;
			return null;
		}
		public static bool HasAttribute (this XElement element, String name)
		{
			return element.GetAttribute(name) != null;
		}
		public static String GetAttributeValue (this XElement element, String name)
		{
			XAttribute attribute = element.GetAttribute(name);
			if (attribute != null) return attribute.Value;
			return "";
		}
		public static void SetAttribute (this XElement element, String name, String value)
		{
			element.SetAttributeValue(name, value);
		}

		//-------------------------------------------------------------------
		//                       C h i l d   N o d e s
		//-------------------------------------------------------------------
		public static List<XElement> GetChildElements (this XContainer container, String name = "")
		{
			List<XElement> childElements = new List<XElement>();
			if (container == null) return childElements;
			foreach (XElement element in container.Elements())
			{
				if (StringUtil.IsEmpty(name) || element.Name.LocalName.EqualsCI(name))
					childElements.Add(new XElement(element));
			}
			return childElements;
		}
		public static bool HasChildNode (this XContainer container, String name)
		{
			if (container == null) return false;
			foreach (XElement element in container.Elements())
			{
				if (StringUtil.IsEmpty(name) || element.Name.LocalName.EqualsCI(name))
					return true;
			}
			return false;
		}
		public static XElement GetFirstChildElement (this XContainer container, String name = "")
		{
			if (container == null) return null;
			foreach (XElement element in container.Elements())
			{
				if (StringUtil.IsEmpty(name) || element.Name.LocalName.EqualsCI(name))
					return element;
			}
			return null;
		}
		public static XElement GetNextSiblingElement (this XElement child, String name = "")
		{
			if (child == null) return null;
			XNode sibling = null;
			while ((sibling = child.NextNode) != null)
			{
				if (sibling is XElement && (StringUtil.IsEmpty(name) || (sibling as XElement).Name.LocalName.EqualsCI(name)))
					return sibling as XElement;
			}
			return null;
		}

		//-------------------------------------------------------------------
		// System.Xml.Linq variation.
		/// <summary>Get text from first child that matches the node name.</summary>
		public static String GetChildText (this XElement element, String name)
		{
			foreach (XElement child in element.Elements())
				if (child.Name.LocalName.EqualsCI(name))
					return child.Value;
			return String.Empty;
		}
		// System.Xml varations.
		public static String GetChildText(this XmlNode node, String name)
		{
			foreach (XmlNode child in node.ChildNodes)
				if (child.Name.EqualsCI(name))
					return child.InnerText;
			return String.Empty;
		}

		//-------------------------------------------------------------------
		// Append element to node.
		// System.Xml.Linq variation.
		public static XElement AppendElement (this XContainer container, XElement element)
		{
			container.Add(element);
			return element;
		}
		public static XElement AppendElement (this XContainer container, String name, String text = "")
		{
			XElement child = new XElement(name, text);
			container.Add(child);
			return child;
		}
		public static XElement AppendElement (this XContainer container, XNamespace xmlNamespace, String name, String text = "")
		{
			XElement child = new XElement(xmlNamespace + name, text);
			container.Add(child);
			return child;
		}
		// System.Xml varations.
		public static XmlElement AppendElement(this XmlNode node, String name, String text = "")
		{
			XmlDocument doc = (node is XmlDocument ? node as XmlDocument : node.OwnerDocument);
			XmlElement child = (XmlElement)node.AppendChild(doc.CreateElement(name));
			if (!StringUtil.IsEmpty(text))
				child.AppendChild(doc.CreateTextNode(text));
			return child;
		}

		//-------------------------------------------------------------------
	}
	//=======================================================================
}