//
// Mono.Xml.XPath.DTMXPathDocumentBuilder
//
// Author:
//	Atsushi Enomoto (ginga@kit.hi-ho.ne.jp)
//
// (C) 2003 Atsushi Enomoto
//
//#define DTM_CLASS

//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;
using System.Collections;
using System.IO;
using System.Xml;
using System.Xml.Schema;
using System.Xml.XPath;

namespace Mono.Xml.XPath
{

#if OUTSIDE_SYSTEM_XML
	public
#else
	internal
#endif
	class DTMXPathDocumentBuilder
	{
		public DTMXPathDocumentBuilder (string url)
			: this (url, XmlSpace.None, 200)
		{
		}

		public DTMXPathDocumentBuilder (string url, XmlSpace space)
			: this (url, space, 200)
		{
		}

		public DTMXPathDocumentBuilder (string url, XmlSpace space, int defaultCapacity)
		{
			XmlReader r = null;
			try {
				r = new XmlTextReader (url);
				Init (r, space, defaultCapacity);
			} finally {
				if (r != null)
					r.Close ();
			}
		}

		public DTMXPathDocumentBuilder (XmlReader reader)
			: this (reader, XmlSpace.None, 200)
		{
		}

		public DTMXPathDocumentBuilder (XmlReader reader, XmlSpace space)
			: this (reader, space, 200)
		{
		}

		public DTMXPathDocumentBuilder (XmlReader reader, XmlSpace space, int defaultCapacity)
		{
			Init (reader, space, defaultCapacity);
		}

		private void Init (XmlReader reader, XmlSpace space, int defaultCapacity)
		{
			this.xmlReader = reader;
			this.validatingReader = reader as XmlValidatingReader;
			lineInfo = reader as IXmlLineInfo;
			this.xmlSpace = space;
			this.nameTable = reader.NameTable;
			nodeCapacity = defaultCapacity;
			attributeCapacity = nodeCapacity;
			nsCapacity = 10;
			idTable = new Hashtable ();

			nodes = new DTMXPathLinkedNode [nodeCapacity];
			attributes = new DTMXPathAttributeNode [attributeCapacity];
			namespaces = new DTMXPathNamespaceNode [nsCapacity];

			Compile ();
		}
		
		XmlReader xmlReader;
		XmlValidatingReader validatingReader;
		XmlSpace xmlSpace;
		XmlNameTable nameTable;
		IXmlLineInfo lineInfo;
		int nodeCapacity;
		int attributeCapacity;
		int nsCapacity;

		// Linked Node
		DTMXPathLinkedNode [] nodes;

		// Attribute
		DTMXPathAttributeNode [] attributes;

		// NamespaceNode
		DTMXPathNamespaceNode [] namespaces;

		// idTable [string value] -> int nodeId
		Hashtable idTable;

		int nodeIndex;
		int attributeIndex;
		int nsIndex;

		// for attribute processing; should be reset per each element.
		bool hasAttributes;
		bool hasLocalNs;
		int attrIndexAtStart;
		int nsIndexAtStart;

		int lastNsInScope;
		bool skipRead = false;

		int [] parentStack = new int [10];
		int parentStackIndex = 0;

		public DTMXPathDocument CreateDocument ()
		{
			return new DTMXPathDocument (nameTable,
				nodes,
				attributes,
				namespaces,
				idTable
			);
		}

		public void Compile ()
		{
			// index 0 is dummy. No node (including Root) is assigned to this index
			// So that we can easily compare index != 0 instead of index < 0.
			// (Difference between jnz or jbe in 80x86.)
			AddNode (0, 0, 0, XPathNodeType.All, "", false, "", "", "", "", "", 0, 0, 0);
			nodeIndex++;
			AddAttribute (0, null, null, null, null, 0, 0);
			AddNsNode (0, null, null, 0);
			nsIndex++;
			AddNsNode (1, "xml", XmlNamespaces.XML, 0);

			// add root.
			AddNode (0, 0, 0, XPathNodeType.Root, xmlReader.BaseURI, false, "", "", "", "", "", 1, 0, 0);

			this.nodeIndex = 1;
			this.lastNsInScope = 1;
			parentStack [0] = nodeIndex;

			while (!xmlReader.EOF)
				Read ();
			SetNodeArrayLength (nodeIndex + 1);
			SetAttributeArrayLength (attributeIndex + 1);
			SetNsArrayLength (nsIndex + 1);

			xmlReader = null;	// It is no more required.
		}

		public void Read ()
		{
			if (!skipRead)
				if (!xmlReader.Read ())
					return;
			skipRead = false;
			int parent = parentStack [parentStackIndex];
			int prevSibling = nodeIndex;

			switch (xmlReader.NodeType) {
			case XmlNodeType.Element:
			case XmlNodeType.CDATA:
			case XmlNodeType.SignificantWhitespace:
			case XmlNodeType.Comment:
			case XmlNodeType.Text:
			case XmlNodeType.ProcessingInstruction:
				if (parent == nodeIndex)
					prevSibling = 0;
				else
					while (nodes [prevSibling].Parent != parent)
						prevSibling = nodes [prevSibling].Parent;

				nodeIndex++;

				if (prevSibling != 0)
					nodes [prevSibling].NextSibling = nodeIndex;
				if (parentStack [parentStackIndex] == nodeIndex - 1)
					nodes [parent].FirstChild = nodeIndex;
				break;
			case XmlNodeType.Whitespace:
				if (xmlSpace == XmlSpace.Preserve)
					goto case XmlNodeType.Text;
				else
					goto default;
			case XmlNodeType.EndElement:
				parentStackIndex--;
				return;
			default:
				// No operations. Doctype, EntityReference, 
				return;
			}

			string value = null;
			XPathNodeType nodeType = XPathNodeType.Text;

			switch (xmlReader.NodeType) {
			case XmlNodeType.Element:
				ProcessElement (parent, prevSibling);
				break;
			case XmlNodeType.SignificantWhitespace:
				nodeType = XPathNodeType.SignificantWhitespace;
				goto case XmlNodeType.Text;
			case XmlNodeType.Whitespace:
				nodeType = XPathNodeType.Whitespace;
				goto case XmlNodeType.Text;
			case XmlNodeType.CDATA:
			case XmlNodeType.Text:
				AddNode (parent,
					0,
					prevSibling,
					nodeType,
					xmlReader.BaseURI,
					xmlReader.IsEmptyElement,
					xmlReader.LocalName,	// for PI
					xmlReader.NamespaceURI,	// for PI
					xmlReader.Prefix,
					value,
					xmlReader.XmlLang,
					nsIndex,
					lineInfo != null ? lineInfo.LineNumber : 0,
					lineInfo != null ? lineInfo.LinePosition : 0);
				// this code is tricky, but after sequential
				// Read() invokation, xmlReader is moved to
				// next node.
				if (value == null) {
					bool loop = true;
					value = String.Empty;
					XPathNodeType type = XPathNodeType.Whitespace;
					do {
						switch (xmlReader.NodeType) {
						case XmlNodeType.Text:
						case XmlNodeType.CDATA:
							type = XPathNodeType.Text;
							goto case XmlNodeType.Whitespace;
						case XmlNodeType.SignificantWhitespace:
							if (type == XPathNodeType.Whitespace)
								type = XPathNodeType.SignificantWhitespace;
							goto case XmlNodeType.Whitespace;
						case XmlNodeType.Whitespace:
							if (xmlReader.NodeType != XmlNodeType.Whitespace || xmlSpace == XmlSpace.Preserve)
								value += xmlReader.Value;
							loop = xmlReader.Read ();
							skipRead = true;
							continue;
						default:
							loop = false;
							break;
						}
					} while (loop);
					nodes [nodeIndex].Value = value;
					nodes [nodeIndex].NodeType = type;
				}
				break;
			case XmlNodeType.Comment:
				value = xmlReader.Value;
				nodeType = XPathNodeType.Comment;
				goto case XmlNodeType.Text;
			case XmlNodeType.ProcessingInstruction:
				value = xmlReader.Value;
				nodeType = XPathNodeType.ProcessingInstruction;
				goto case XmlNodeType.Text;
			}
		}

		private void ProcessElement (int parent, int previousSibling)
		{
			WriteStartElement (parent, previousSibling);

			// process namespaces and attributes.
			if (xmlReader.MoveToFirstAttribute ()) {
				do {
					string prefix = xmlReader.Prefix;
					string ns = xmlReader.NamespaceURI;
					if (ns == XmlNamespaces.XMLNS)
						ProcessNamespace ((prefix == null || prefix == String.Empty) ? "" : xmlReader.LocalName, xmlReader.Value);
					else
						ProcessAttribute (prefix, xmlReader.LocalName, ns, xmlReader.Value);

				} while (xmlReader.MoveToNextAttribute ());
				xmlReader.MoveToElement ();
			}

			CloseStartElement ();
		}

		private void PrepareStartElement (int previousSibling)
		{
			hasAttributes = false;
			hasLocalNs = false;
			attrIndexAtStart = attributeIndex;
			nsIndexAtStart = nsIndex;

			while (namespaces [lastNsInScope].DeclaredElement == previousSibling) {
				lastNsInScope = namespaces [lastNsInScope].NextNamespace;
			}
		}

		private void WriteStartElement (int parent, int previousSibling)
		{
			PrepareStartElement (previousSibling);

			AddNode (parent,
				0, // dummy:firstAttribute
				previousSibling,
				XPathNodeType.Element,
				xmlReader.BaseURI,
				xmlReader.IsEmptyElement,
				xmlReader.LocalName,
				xmlReader.NamespaceURI,
				xmlReader.Prefix,
				"",	// Element has no internal value.
				xmlReader.XmlLang,
				lastNsInScope,
				lineInfo != null ? lineInfo.LineNumber : 0,
				lineInfo != null ? lineInfo.LinePosition : 0);

		}

		private void CloseStartElement ()
		{
			if (attrIndexAtStart != attributeIndex)
				nodes [nodeIndex].FirstAttribute = attrIndexAtStart + 1;
			if (nsIndexAtStart != nsIndex) {
				nodes [nodeIndex].FirstNamespace = nsIndex;
				if (!xmlReader.IsEmptyElement)
					lastNsInScope = nsIndex;
			}

			if (!nodes [nodeIndex].IsEmptyElement) {
				parentStackIndex++;
				if (parentStack.Length == parentStackIndex) {
					int [] tmp = new int [parentStackIndex * 2];
					Array.Copy (parentStack, tmp, parentStackIndex);
					parentStack = tmp;
				}
				parentStack [parentStackIndex] = nodeIndex;
			}
		}

		private void ProcessNamespace (string prefix, string ns)
		{
			int nextTmp = hasLocalNs ?
				nsIndex : nodes [nodeIndex].FirstNamespace;

			nsIndex++;

			this.AddNsNode (nodeIndex,
				prefix,
				ns,
				nextTmp);
			hasLocalNs = true;
		}

		private void ProcessAttribute (string prefix, string localName, string ns, string value)
		{
			attributeIndex ++;

			this.AddAttribute (nodeIndex,
				localName,
				ns, 
				prefix != null ? prefix : String.Empty, 
				value,
				lineInfo != null ? lineInfo.LineNumber : 0,
				lineInfo != null ? lineInfo.LinePosition : 0);
			if (hasAttributes)
				attributes [attributeIndex - 1].NextAttribute = attributeIndex;
			else
				hasAttributes = true;

			// Identity infoset
			if (validatingReader != null) {
				XmlSchemaDatatype dt = validatingReader.SchemaType as XmlSchemaDatatype;
				if (dt == null) {
					XmlSchemaType xsType = validatingReader.SchemaType as XmlSchemaType;
					if (xsType != null)
						dt = xsType.Datatype;
				}
				if (dt != null && dt.TokenizedType == XmlTokenizedType.ID)
					idTable.Add (value, nodeIndex);
			}
		}

		private void SetNodeArrayLength (int size)
		{
			DTMXPathLinkedNode [] newArr = new DTMXPathLinkedNode [size];
			Array.Copy (nodes, newArr, System.Math.Min (size, nodes.Length));
			nodes = newArr;
		}

		private void SetAttributeArrayLength (int size)
		{
			DTMXPathAttributeNode [] newArr = 
				new DTMXPathAttributeNode [size];
			Array.Copy (attributes, newArr, System.Math.Min (size, attributes.Length));
			attributes = newArr;
		}

		private void SetNsArrayLength (int size)
		{
			DTMXPathNamespaceNode [] newArr =
				new DTMXPathNamespaceNode [size];
			Array.Copy (namespaces, newArr, System.Math.Min (size, namespaces.Length));
			namespaces = newArr;
		}

		// Here followings are skipped: firstChild, nextSibling, 
		public void AddNode (int parent, int firstAttribute, int previousSibling, XPathNodeType nodeType, string baseUri, bool isEmptyElement, string localName, string ns, string prefix, string value, string xmlLang, int namespaceNode, int lineNumber, int linePosition)
		{
			if (nodes.Length < nodeIndex + 1) {
				nodeCapacity *= 4;
				SetNodeArrayLength (nodeCapacity);
			}

#if DTM_CLASS
			nodes [nodeIndex] = new DTMXPathLinkedNode ();
#endif
			nodes [nodeIndex].FirstChild = 0;		// dummy
			nodes [nodeIndex].Parent = parent;
			nodes [nodeIndex].FirstAttribute = firstAttribute;
			nodes [nodeIndex].PreviousSibling = previousSibling;
			nodes [nodeIndex].NextSibling = 0;	// dummy
			nodes [nodeIndex].NodeType = nodeType;
			nodes [nodeIndex].BaseURI = baseUri;
			nodes [nodeIndex].IsEmptyElement = isEmptyElement;
			nodes [nodeIndex].LocalName = localName;
			nodes [nodeIndex].NamespaceURI = ns;
			nodes [nodeIndex].Prefix = prefix;
			nodes [nodeIndex].Value = value;
			nodes [nodeIndex].XmlLang = xmlLang;
			nodes [nodeIndex].FirstNamespace = namespaceNode;
			nodes [nodeIndex].LineNumber = lineNumber;
			nodes [nodeIndex].LinePosition = linePosition;
		}

		// Followings are skipped: nextAttribute,
		public void AddAttribute (int ownerElement, string localName, string ns, string prefix, string value, int lineNumber, int linePosition)
		{
			if (attributes.Length < attributeIndex + 1) {
				attributeCapacity *= 4;
				SetAttributeArrayLength (attributeCapacity);
			}

#if DTM_CLASS
			attributes [attributeIndex] = new DTMXPathAttributeNode ();
#endif
			attributes [attributeIndex].OwnerElement = ownerElement;
			attributes [attributeIndex].LocalName = localName;
			attributes [attributeIndex].NamespaceURI = ns;
			attributes [attributeIndex].Prefix = prefix;
			attributes [attributeIndex].Value = value;
			attributes [attributeIndex].LineNumber = lineNumber;
			attributes [attributeIndex].LinePosition = linePosition;
		}

		// Followings are skipped: nextNsNode (may be next attribute in the same element, or ancestors' nsNode)
		public void AddNsNode (int declaredElement, string name, string ns, int nextNs)
		{
			if (namespaces.Length < nsIndex + 1) {
				nsCapacity *= 4;
				SetNsArrayLength (nsCapacity);
			}

#if DTM_CLASS
			namespaces [nsIndex] = new DTMXPathNamespaceNode ();
#endif
			namespaces [nsIndex].DeclaredElement = declaredElement;
			namespaces [nsIndex].Name = name;
			namespaces [nsIndex].Namespace = ns;
			namespaces [nsIndex].NextNamespace = nextNs;
		}
	}
}