//------------------------------------------------------------------------------
// <copyright file="XslAst.cs" company="Microsoft">
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// </copyright>
// <owner current="true" primary="true">Microsoft</owner>
//------------------------------------------------------------------------------

using System.Text;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Diagnostics;
using System.Globalization;
using System.Xml.Xsl.Qil;

namespace System.Xml.Xsl.Xslt {
    using ContextInfo     = XsltInput.ContextInfo;
    using XPathQilFactory = System.Xml.Xsl.XPath.XPathQilFactory;

    // Set of classes that represent XSLT AST

    // XSLT AST is a tree of nodes that represent content of xsl template.
    // All nodes are subclasses of QilNode. This was done to keep NodeCtor and Text ctors
    // the sames nodes thay will be in resulting QilExpression tree.
    // So we have: ElementCtor, AttributeCtor, QilTextCtor, CommentCtor, PICtor, NamespaceDecl, List.
    // Plus couple subclasses of XslNode that represent different xslt instructions
    // including artifitial: Sort, ExNamespaceDecl, UseAttributeSets

    internal enum XslNodeType {
        Unknown = 0,
        ApplyImports,
        ApplyTemplates,
        Attribute,
        AttributeSet,
        CallTemplate,
        Choose,
        Comment,
        Copy,
        CopyOf,
        Element,
        Error,
        ForEach,
        If,
        Key,
        List,
        LiteralAttribute,
        LiteralElement,
        Message,
        Nop,
        Number,
        Otherwise,
        Param,
        PI,
        Sort,
        Template,
        Text,
        UseAttributeSet,
        ValueOf,
        ValueOfDoe,
        Variable,
        WithParam,
    }

    internal class NsDecl {
        public readonly NsDecl Prev;
        public readonly string Prefix;  // Empty string denotes the default namespace, null - extension or excluded namespace
        public readonly string NsUri;   // null means "#all" -- all namespace defined above this one are excluded.

        public NsDecl(NsDecl prev, string prefix, string nsUri) {
            Debug.Assert(nsUri != null || Prefix == null);
            this.Prev   = prev;
            this.Prefix = prefix;
            this.NsUri  = nsUri;
        }
    }

    internal class XslNode {
        public readonly XslNodeType NodeType;
        public ISourceLineInfo      SourceLine;
        public NsDecl               Namespaces;
        public readonly QilName     Name;   // name or mode
        public readonly object      Arg;    // select or test or terminate or stylesheet;-)
        public readonly XslVersion  XslVersion;
        public XslFlags             Flags;
        private List<XslNode>       content;

        public XslNode(XslNodeType nodeType, QilName name, object arg, XslVersion xslVer) {
            this.NodeType   = nodeType;
            this.Name       = name;
            this.Arg        = arg;
            this.XslVersion = xslVer;
        }

        public XslNode(XslNodeType nodeType) {
            this.NodeType   = nodeType;
            this.XslVersion = XslVersion.Current;
        }

        public string   Select              { get { return (string)Arg; } }
        public bool     ForwardsCompatible  { get { return XslVersion == XslVersion.ForwardsCompatible; } }

        // -------------------------------- Content Management --------------------------------

        private static readonly IList<XslNode> EmptyList = new List<XslNode>().AsReadOnly();

        public IList<XslNode> Content {
            get { return content ?? EmptyList; }
        }

        public void SetContent(List<XslNode> content) {
            this.content = content;
        }

        public void AddContent(XslNode node) {
            Debug.Assert(node != null);
            if (content == null) {
                content = new List<XslNode>();
            }
            content.Add(node);
        }

        public void InsertContent(IEnumerable<XslNode> collection) {
            if (content == null) {
                content = new List<XslNode>(collection);
            } else {
                content.InsertRange(0, collection);
            }
        }

        internal string TraceName {
            get {
            #if DEBUG
                System.Text.StringBuilder sb = new System.Text.StringBuilder();
                string nodeTypeName;
                switch (NodeType) {
                case XslNodeType.AttributeSet : nodeTypeName = "attribute-set"; break;
                case XslNodeType.Template     : nodeTypeName = "template";      break;
                case XslNodeType.Param        : nodeTypeName = "param";         break;
                case XslNodeType.Variable     : nodeTypeName = "variable";      break;
                case XslNodeType.WithParam    : nodeTypeName = "with-param";    break;
                default                       : nodeTypeName = NodeType.ToString(); break;
                }
                sb.Append(nodeTypeName);
                if (Name != null) {
                    sb.Append(' ');
                    sb.Append(Name.QualifiedName);
                }
                ISourceLineInfo lineInfo = SourceLine;
                if (lineInfo == null && NodeType == XslNodeType.AttributeSet) {
                    lineInfo = Content[0].SourceLine;
                    Debug.Assert(lineInfo != null);
                }
                if (lineInfo != null) {
                    string fileName = SourceLineInfo.GetFileName(lineInfo.Uri);
                    int idx = fileName.LastIndexOf(System.IO.Path.DirectorySeparatorChar) + 1;
                    sb.Append(" (");
                    sb.Append(fileName, idx, fileName.Length - idx);
                    sb.Append(':');
                    sb.Append(lineInfo.Start.Line);
                    sb.Append(')');
                }
                return sb.ToString();
            #else
                return null;
            #endif
            }
        }
    }

    internal abstract class ProtoTemplate : XslNode {
        public QilFunction  Function;                   // Compiled body

        public ProtoTemplate(XslNodeType nt, QilName name, XslVersion xslVer) : base(nt, name, null, xslVer) {}
        public abstract string GetDebugName();
    }

    internal enum CycleCheck {
        NotStarted  = 0,
        Processing  = 1,
        Completed   = 2,
    }

    internal class AttributeSet : ProtoTemplate {
        public CycleCheck               CycleCheck;     // Used to detect circular references

        public AttributeSet(QilName name, XslVersion xslVer) : base(XslNodeType.AttributeSet, name, xslVer) {}

        public override string GetDebugName() {
            StringBuilder dbgName = new StringBuilder();
            dbgName.Append("<xsl:attribute-set name=\"");
            dbgName.Append(Name.QualifiedName);
            dbgName.Append("\">");
            return dbgName.ToString();
        }

        public new void AddContent(XslNode node) {
            Debug.Assert(node != null && node.NodeType == XslNodeType.List);
            base.AddContent(node);
        }

        public void MergeContent(AttributeSet other) {
            InsertContent(other.Content);
        }
    }

    internal class Template : ProtoTemplate {
        public readonly string  Match;
        public readonly QilName Mode;
        public readonly double  Priority;
        public int              ImportPrecedence;
        public int              OrderNumber;

        public Template(QilName name, string match, QilName mode, double priority, XslVersion xslVer)
            : base(XslNodeType.Template, name, xslVer)
        {
            this.Match      = match;
            this.Mode       = mode;
            this.Priority   = priority;
        }

        public override string GetDebugName() {
            StringBuilder dbgName = new StringBuilder();
            dbgName.Append("<xsl:template");
            if (Match != null) {
                dbgName.Append(" match=\"");
                dbgName.Append(Match);
                dbgName.Append('"');
            }
            if (Name != null) {
                dbgName.Append(" name=\"");
                dbgName.Append(Name.QualifiedName);
                dbgName.Append('"');
            }
            if (!double.IsNaN(Priority)) {
                dbgName.Append(" priority=\"");
                dbgName.Append(Priority.ToString(CultureInfo.InvariantCulture));
                dbgName.Append('"');
            }
            if (Mode.LocalName.Length != 0) {
                dbgName.Append(" mode=\"");
                dbgName.Append(Mode.QualifiedName);
                dbgName.Append('"');
            }
            dbgName.Append('>');
            return dbgName.ToString();
        }
    }

    internal class VarPar : XslNode {
        public XslFlags DefValueFlags;
        public QilNode  Value;          // Contains value for WithParams and global VarPars

        public VarPar(XslNodeType nt, QilName name, string select, XslVersion xslVer) : base(nt, name, select, xslVer) {}
    }

    internal class Sort : XslNode {
        public readonly string  Lang;
        public readonly string  DataType;
        public readonly string  Order;
        public readonly string  CaseOrder;

        public Sort(string select, string lang, string dataType, string order, string caseOrder, XslVersion xslVer)
            : base(XslNodeType.Sort, null, select, xslVer)
        {
            this.Lang       = lang;
            this.DataType   = dataType;
            this.Order      = order;
            this.CaseOrder  = caseOrder;
        }
    }

    internal class Keys : KeyedCollection<QilName, List<Key>> {
        protected override QilName GetKeyForItem(List<Key> list) {
            Debug.Assert(list != null && list.Count > 0);
            return list[0].Name;
        }
    }

    internal class Key : XslNode {
        public readonly string  Match;
        public readonly string  Use;
        public QilFunction      Function;

        public Key(QilName name, string match, string use, XslVersion xslVer)
            : base(XslNodeType.Key, name, null, xslVer)
        {
            // match and use can be null in case of incorrect stylesheet
            Debug.Assert(name != null);
            this.Match  = match;
            this.Use    = use;
        }

        public string GetDebugName() {
            StringBuilder dbgName = new StringBuilder();
            dbgName.Append("<xsl:key name=\"");
            dbgName.Append(Name.QualifiedName);
            dbgName.Append('"');

            if (Match != null) {
                dbgName.Append(" match=\"");
                dbgName.Append(Match);
                dbgName.Append('"');
            }
            if (Use != null) {
                dbgName.Append(" use=\"");
                dbgName.Append(Use);
                dbgName.Append('"');
            }
            dbgName.Append('>');
            return dbgName.ToString();
        }
    }

    internal enum NumberLevel {
        Single,
        Multiple,
        Any,
    }

    internal class Number : XslNode {
        public readonly NumberLevel Level;
        public readonly string      Count;
        public readonly string      From;
        public readonly string      Value;
        public readonly string      Format;
        public readonly string      Lang;
        public readonly string      LetterValue;
        public readonly string      GroupingSeparator;
        public readonly string      GroupingSize;

        public Number(NumberLevel level, string count, string from, string value,
            string format, string lang, string letterValue, string groupingSeparator, string groupingSize,
            XslVersion xslVer) : base(XslNodeType.Number, null, null, xslVer)
        {
            this.Level  = level;
            this.Count  = count;
            this.From   = from;
            this.Value  = value;
            this.Format = format;
            this.Lang   = lang;
            this.LetterValue       = letterValue;
            this.GroupingSeparator = groupingSeparator;
            this.GroupingSize      = groupingSize;
        }
    }

    internal class NodeCtor : XslNode {
        public readonly string  NameAvt;
        public readonly string  NsAvt;

        public NodeCtor(XslNodeType nt, string nameAvt, string nsAvt, XslVersion xslVer)
            : base(nt, null, null, xslVer)
        {
            this.NameAvt = nameAvt;
            this.NsAvt   = nsAvt;
        }
    }

    internal class Text : XslNode {
        public readonly SerializationHints  Hints;

        public Text(string data, SerializationHints hints, XslVersion xslVer)
            : base(XslNodeType.Text, null, data, xslVer)
        {
            this.Hints = hints;
        }
    }

    internal class XslNodeEx : XslNode {
        public readonly ISourceLineInfo ElemNameLi;
        public readonly ISourceLineInfo EndTagLi;

        public XslNodeEx(XslNodeType t, QilName name, object arg, ContextInfo ctxInfo, XslVersion xslVer)
            : base(t, name, arg, xslVer)
        {
            ElemNameLi = ctxInfo.elemNameLi;
            EndTagLi = ctxInfo.endTagLi;
        }

        public XslNodeEx(XslNodeType t, QilName name, object arg, XslVersion xslVer) : base(t, name, arg, xslVer) {
        }
    }

    internal static class AstFactory {
        public static XslNode XslNode(XslNodeType nodeType, QilName name, string arg, XslVersion xslVer) {
            return new XslNode(nodeType, name, arg, xslVer);
        }

        public static XslNode ApplyImports(QilName mode, Stylesheet sheet, XslVersion xslVer) {
            return new XslNode(XslNodeType.ApplyImports, mode, sheet, xslVer);
        }

        public static XslNodeEx ApplyTemplates(QilName mode, string select, ContextInfo ctxInfo, XslVersion xslVer) {
            return new XslNodeEx(XslNodeType.ApplyTemplates, mode, select, ctxInfo, xslVer);
        }

        // Special node for start apply-templates
        public static XslNodeEx ApplyTemplates(QilName mode) {
            return new XslNodeEx(XslNodeType.ApplyTemplates, mode, /*select:*/null, XslVersion.Current);
        }

        public static NodeCtor Attribute(string nameAvt, string nsAvt, XslVersion xslVer) {
            return new NodeCtor(XslNodeType.Attribute, nameAvt, nsAvt, xslVer);
        }

        public static AttributeSet AttributeSet(QilName name) {
            return new AttributeSet(name, XslVersion.Current);
        }

        public static XslNodeEx CallTemplate(QilName name, ContextInfo ctxInfo) {
            return new XslNodeEx(XslNodeType.CallTemplate, name, null, ctxInfo, XslVersion.Current);
        }

        public static XslNode Choose() {
            return new XslNode(XslNodeType.Choose);
        }

        public static XslNode Comment() {
            return new XslNode(XslNodeType.Comment);
        }

        public static XslNode Copy() {
            return new XslNode(XslNodeType.Copy);
        }

        public static XslNode CopyOf(string select, XslVersion xslVer) {
            return new XslNode(XslNodeType.CopyOf, null, select, xslVer);
        }

        public static NodeCtor Element(string nameAvt, string nsAvt, XslVersion xslVer) {
            return new NodeCtor(XslNodeType.Element, nameAvt, nsAvt, xslVer);
        }

        public static XslNode Error(string message) {
            return new XslNode(XslNodeType.Error, null, message, XslVersion.Current);
        }

        public static XslNodeEx ForEach(string select, ContextInfo ctxInfo, XslVersion xslVer) {
            return new XslNodeEx(XslNodeType.ForEach, null, select, ctxInfo, xslVer);
        }

        public static XslNode If(string test, XslVersion xslVer) {
            return new XslNode(XslNodeType.If, null, test, xslVer);
        }

        public static Key Key(QilName name, string match, string use, XslVersion xslVer) {
            return new Key(name, match, use, xslVer);
        }

        public static XslNode List() {
            return new XslNode(XslNodeType.List);
        }

        public static XslNode LiteralAttribute(QilName name, string value, XslVersion xslVer) {
            return new XslNode(XslNodeType.LiteralAttribute, name, value, xslVer);
        }

        public static XslNode LiteralElement(QilName name) {
            return new XslNode(XslNodeType.LiteralElement, name, null, XslVersion.Current);
        }

        public static XslNode Message(bool term) {
            return new XslNode(XslNodeType.Message, null, term, XslVersion.Current);
        }

        public static XslNode Nop() {
            return new XslNode(XslNodeType.Nop);
        }

        public static Number Number(NumberLevel level, string count, string from, string value,
            string format, string lang, string letterValue, string groupingSeparator, string groupingSize,
            XslVersion xslVer)
        {
            return new Number(level, count, from, value, format, lang, letterValue, groupingSeparator, groupingSize, xslVer);
        }

        public static XslNode Otherwise() {
            return new XslNode(XslNodeType.Otherwise);
        }

        public static XslNode PI(string name, XslVersion xslVer) {
            return new XslNode(XslNodeType.PI, null, name, xslVer);
        }

        public static Sort Sort(string select, string lang, string dataType, string order, string caseOrder, XslVersion xslVer) {
            return new Sort(select, lang, dataType, order, caseOrder, xslVer);
        }

        public static Template Template(QilName name, string match, QilName mode, double priority, XslVersion xslVer) {
            return new Template(name, match, mode, priority, xslVer);
        }

        public static XslNode Text(string data) {
            return new Text(data, SerializationHints.None, XslVersion.Current);
        }

        public static XslNode Text(string data, SerializationHints hints) {
            return new Text(data, hints, XslVersion.Current);
        }

        public static XslNode UseAttributeSet(QilName name) {
            return new XslNode(XslNodeType.UseAttributeSet, name, null, XslVersion.Current);
        }

        public static VarPar VarPar(XslNodeType nt, QilName name, string select, XslVersion xslVer) {
            return new VarPar(nt, name, select, xslVer);
        }

        public static VarPar WithParam(QilName name) {
            return VarPar(XslNodeType.WithParam, name, /*select*/null, XslVersion.Current);
        }

        private static QilFactory f = new QilFactory();

        public static QilName QName(string local, string uri, string prefix) {
            return f.LiteralQName(local, uri, prefix);
        }

        public static QilName QName(string local) {
            return f.LiteralQName(local);
        }
    }
}