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

using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Text;
using System.Security.Permissions;
using System.Runtime.Versioning;

#if !SILVERLIGHT
#if !HIDE_XSL
using System.Xml.Xsl.Runtime;
#endif
#endif

namespace System.Xml {

#if !SILVERLIGHT
    public enum XmlOutputMethod {
        Xml = 0,    // Use Xml 1.0 rules to serialize
        Html = 1,    // Use Html rules specified by Xslt specification to serialize
        Text = 2,    // Only serialize text blocks
        AutoDetect = 3,    // Choose between Xml and Html output methods at runtime (using Xslt rules to do so)
    }
#endif

    /// <summary>
    /// Three-state logic enumeration.
    /// </summary>
    internal enum TriState {
        Unknown = -1,
        False = 0,
        True = 1,
    };

    internal enum XmlStandalone {
        // Do not change the constants - XmlBinaryWriter depends in it
        Omit = 0,
        Yes = 1,
        No = 2,
    }

    // XmlWriterSettings class specifies basic features of an XmlWriter.
#if !SILVERLIGHT
    [PermissionSetAttribute(SecurityAction.InheritanceDemand, Name = "FullTrust")]
#endif
    public sealed class XmlWriterSettings {
        //
        // Fields
        //

#if ASYNC || FEATURE_NETCORE
        bool useAsync;
#endif

        // Text settings
        Encoding encoding;

#if FEATURE_LEGACYNETCF
        private bool dontWriteEncodingTag;
#endif

        bool omitXmlDecl;
        NewLineHandling newLineHandling;
        string newLineChars;
        TriState indent;
        string indentChars;
        bool newLineOnAttributes;
        bool closeOutput;
        NamespaceHandling namespaceHandling;

        // Conformance settings
        ConformanceLevel conformanceLevel;
        bool checkCharacters;
        bool writeEndDocumentOnClose;

#if !SILVERLIGHT
        // Xslt settings
        XmlOutputMethod outputMethod;
        List<XmlQualifiedName> cdataSections = new List<XmlQualifiedName>();
        bool doNotEscapeUriAttributes;
        bool mergeCDataSections;
        string mediaType;
        string docTypeSystem;
        string docTypePublic;
        XmlStandalone standalone;
        bool autoXmlDecl;
#endif

        // read-only flag
        bool isReadOnly;

        //
        // Constructor
        //
        public XmlWriterSettings() {
            Initialize();
        }

        //
        // Properties
        //

#if ASYNC || FEATURE_NETCORE
        public bool Async {
            get {
                return useAsync;
            }
            set {
                CheckReadOnly("Async");
                useAsync = value;
            }
        }
#endif

        // Text
        public Encoding Encoding {
            get {
                return encoding;
            }
            set {
                CheckReadOnly("Encoding");
                encoding = value;
            }
        }

#if FEATURE_LEGACYNETCF
        internal bool DontWriteEncodingTag
        {
            get
            {
                return dontWriteEncodingTag;
            }
            set
            {
                CheckReadOnly("DontWriteEncodingTag");
                dontWriteEncodingTag = value;
            }
        }
#endif

        // True if an xml declaration should *not* be written.
        public bool OmitXmlDeclaration {
            get {
                return omitXmlDecl;
            }
            set {
                CheckReadOnly("OmitXmlDeclaration");
                omitXmlDecl = value;
            }
        }

        // See NewLineHandling enum for details.
        public NewLineHandling NewLineHandling {
            get {
                return newLineHandling;
            }
            set {
                CheckReadOnly("NewLineHandling");

                if ((uint)value > (uint)NewLineHandling.None) {
                    throw new ArgumentOutOfRangeException("value");
                }
                newLineHandling = value;
            }
        }

        // Line terminator string. By default, this is a carriage return followed by a line feed ("\r\n").
        public string NewLineChars {
            get {
                return newLineChars;
            }
            set {
                CheckReadOnly("NewLineChars");

                if (value == null) {
                    throw new ArgumentNullException("value");
                }
                newLineChars = value;
            }
        }

        // True if output should be indented using rules that are appropriate to the output rules (i.e. Xml, Html, etc).
        public bool Indent {
            get {
                return indent == TriState.True;
            }
            set {
                CheckReadOnly("Indent");
                indent = value ? TriState.True : TriState.False;
            }
        }

        // Characters to use when indenting. This is usually tab or some spaces, but can be anything.
        public string IndentChars {
            get {
                return indentChars;
            }
            set {
                CheckReadOnly("IndentChars");

                if (value == null) {
                    throw new ArgumentNullException("value");
                }
                indentChars = value;
            }
        }

        // Whether or not indent attributes on new lines.
        public bool NewLineOnAttributes {
            get {
                return newLineOnAttributes;
            }
            set {
                CheckReadOnly("NewLineOnAttributes");
                newLineOnAttributes = value;
            }
        }

        // Whether or not the XmlWriter should close the underlying stream or TextWriter when Close is called on the XmlWriter.
        public bool CloseOutput {
            get {
                return closeOutput;
            }
            set {
                CheckReadOnly("CloseOutput");
                closeOutput = value;
            }
        }


        // Conformance
        // See ConformanceLevel enum for details.
        public ConformanceLevel ConformanceLevel {
            get {
                return conformanceLevel;
            }
            set {
                CheckReadOnly("ConformanceLevel");

                if ((uint)value > (uint)ConformanceLevel.Document) {
                    throw new ArgumentOutOfRangeException("value");
                }
                conformanceLevel = value;
            }
        }

        // Whether or not to check content characters that they are valid XML characters.
        public bool CheckCharacters {
            get {
                return checkCharacters;
            }
            set {
                CheckReadOnly("CheckCharacters");
                checkCharacters = value;
            }
        }

        // Whether or not to remove duplicate namespace declarations
        public NamespaceHandling NamespaceHandling {
            get {
                return namespaceHandling;
            }
            set {
                CheckReadOnly("NamespaceHandling");
                if ((uint)value > (uint)(NamespaceHandling.OmitDuplicates)) {
                    throw new ArgumentOutOfRangeException("value");
                }
                namespaceHandling = value;
            }
        }

        //Whether or not to auto complete end-element when close/dispose
        public bool WriteEndDocumentOnClose {
            get {
                return writeEndDocumentOnClose;
            }
            set {
                CheckReadOnly("WriteEndDocumentOnClose");
                writeEndDocumentOnClose = value;
            }
        }

#if !SILVERLIGHT
        // Specifies the method (Html, Xml, etc.) that will be used to serialize the result tree.
        public XmlOutputMethod OutputMethod {
            get {
                return outputMethod;
            }
            internal set {
                outputMethod = value;
            }
        }
#endif

        //
        // Public methods
        //
        public void Reset() {
            CheckReadOnly("Reset");
            Initialize();
        }

        // Deep clone all settings (except read-only, which is always set to false).  The original and new objects
        // can now be set independently of each other.
        public XmlWriterSettings Clone() {
            XmlWriterSettings clonedSettings = MemberwiseClone() as XmlWriterSettings;

#if !SILVERLIGHT
            // Deep clone shared settings that are not immutable
            clonedSettings.cdataSections = new List<XmlQualifiedName>(cdataSections);
#endif

            clonedSettings.isReadOnly = false;
            return clonedSettings;
        }

//
// Internal properties
//
#if !SILVERLIGHT
        // Set of XmlQualifiedNames that identify any elements that need to have text children wrapped in CData sections.
        internal List<XmlQualifiedName> CDataSectionElements {
            get {
                Debug.Assert(cdataSections != null);
                return cdataSections;
            }
        }

        // Used in Html writer to disable encoding of uri attributes
        public bool DoNotEscapeUriAttributes
        {
            get
            {
                return doNotEscapeUriAttributes;
            }
            set
            {
                CheckReadOnly("DoNotEscapeUriAttributes");
                doNotEscapeUriAttributes = value;
            }
        }

        internal bool MergeCDataSections {
            get {
                return mergeCDataSections;
            }
            set {
                CheckReadOnly("MergeCDataSections");
                mergeCDataSections = value;
            }
        }

        // Used in Html writer when writing Meta element.  Null denotes the default media type.
        internal string MediaType {
            get {
                return mediaType;
            }
            set {
                CheckReadOnly("MediaType");
                mediaType = value;
            }
        }

        // System Id in doc-type declaration.  Null denotes the absence of the system Id.
        internal string DocTypeSystem {
            get {
                return docTypeSystem;
            }
            set {
                CheckReadOnly("DocTypeSystem");
                docTypeSystem = value;
            }
        }

        // Public Id in doc-type declaration.  Null denotes the absence of the public Id.
        internal string DocTypePublic {
            get {
                return docTypePublic;
            }
            set {
                CheckReadOnly("DocTypePublic");
                docTypePublic = value;
            }
        }

        // Yes for standalone="yes", No for standalone="no", and Omit for no standalone.
        internal XmlStandalone Standalone {
            get {
                return standalone;
            }
            set {
                CheckReadOnly("Standalone");
                standalone = value;
            }
        }

        // True if an xml declaration should automatically be output (no need to call WriteStartDocument)
        internal bool AutoXmlDeclaration {
            get {
                return autoXmlDecl;
            }
            set {
                CheckReadOnly("AutoXmlDeclaration");
                autoXmlDecl = value;
            }
        }

        // If TriState.Unknown, then Indent property was not explicitly set.  In this case, the AutoDetect output
        // method will default to Indent=true for Html and Indent=false for Xml.
        internal TriState IndentInternal {
            get {
                return indent;
            }
            set {
                indent = value;
            }
        }

        internal bool IsQuerySpecific {
            get {
                return cdataSections.Count != 0 || docTypePublic != null ||
                       docTypeSystem != null || standalone == XmlStandalone.Yes;
            }
        }
#endif

#if !SILVERLIGHT
        [ResourceConsumption(ResourceScope.Machine)]
        [ResourceExposure(ResourceScope.Machine)]
        internal XmlWriter CreateWriter(string outputFileName) {
            if (outputFileName == null) {
                throw new ArgumentNullException("outputFileName");
            }

            // need to clone the settigns so that we can set CloseOutput to true to make sure the stream gets closed in the end
            XmlWriterSettings newSettings = this;
            if (!newSettings.CloseOutput) {
                newSettings = newSettings.Clone();
                newSettings.CloseOutput = true;
            }

            FileStream fs = null;
            try {
                // open file stream
#if !ASYNC
                fs = new FileStream(outputFileName, FileMode.Create, FileAccess.Write, FileShare.Read);
#else
                fs = new FileStream(outputFileName, FileMode.Create, FileAccess.Write, FileShare.Read, 0x1000, useAsync);
#endif

                // create writer
                return newSettings.CreateWriter(fs);
            }
            catch {
                if (fs != null) {
                    fs.Close();
                }
                throw;
            }
        }
#endif

        internal XmlWriter CreateWriter(Stream output) {
            if (output == null) {
                throw new ArgumentNullException("output");
            }

            XmlWriter writer;
            
            // create raw writer
#if SILVERLIGHT
            Debug.Assert(Encoding.UTF8.WebName == "utf-8");
            if (this.Encoding.WebName == "utf-8") { // Encoding.CodePage is not supported in Silverlight
                // create raw UTF-8 writer
                if (this.Indent) {
                    writer = new XmlUtf8RawTextWriterIndent(output, this);
                }
                else {
                    writer = new XmlUtf8RawTextWriter(output, this);
                }
            }
            else {
                // create raw writer for other encodings
                if (this.Indent) {
                    writer = new XmlEncodedRawTextWriterIndent(output, this);
                }
                else {
                    writer = new XmlEncodedRawTextWriter(output, this);
                }
            }
#else
            Debug.Assert(Encoding.UTF8.WebName == "utf-8");
            if (this.Encoding.WebName == "utf-8") { // Encoding.CodePage is not supported in Silverlight
                // create raw UTF-8 writer
                switch (this.OutputMethod) {
                    case XmlOutputMethod.Xml:
                        if (this.Indent) {
                            writer = new XmlUtf8RawTextWriterIndent(output, this);
                        }
                        else {
                            writer = new XmlUtf8RawTextWriter(output, this);
                        }
                        break;
                    case XmlOutputMethod.Html:
                        if (this.Indent) {
                            writer = new HtmlUtf8RawTextWriterIndent(output, this);
                        }
                        else {
                            writer = new HtmlUtf8RawTextWriter(output, this);
                        }
                        break;
                    case XmlOutputMethod.Text:
                        writer = new TextUtf8RawTextWriter(output, this);
                        break;
                    case XmlOutputMethod.AutoDetect:
                        writer = new XmlAutoDetectWriter(output, this);
                        break;
                    default:
                        Debug.Assert(false, "Invalid XmlOutputMethod setting.");
                        return null;
                }
            }
            else {
                // Otherwise, create a general-purpose writer than can do any encoding
                switch (this.OutputMethod) {
                    case XmlOutputMethod.Xml:
                        if (this.Indent) {
                            writer = new XmlEncodedRawTextWriterIndent(output, this);
                        }
                        else {
                            writer = new XmlEncodedRawTextWriter(output, this);
                        }
                        break;
                    case XmlOutputMethod.Html:
                        if (this.Indent) {
                            writer = new HtmlEncodedRawTextWriterIndent(output, this);
                        }
                        else {
                            writer = new HtmlEncodedRawTextWriter(output, this);
                        }
                        break;
                    case XmlOutputMethod.Text:
                        writer = new TextEncodedRawTextWriter(output, this);
                        break;
                    case XmlOutputMethod.AutoDetect:
                        writer = new XmlAutoDetectWriter(output, this);
                        break;
                    default:
                        Debug.Assert(false, "Invalid XmlOutputMethod setting.");
                        return null;
                }
            }

            // Wrap with Xslt/XQuery specific writer if needed; 
            // XmlOutputMethod.AutoDetect writer does this lazily when it creates the underlying Xml or Html writer.
            if (this.OutputMethod != XmlOutputMethod.AutoDetect) {
                if (this.IsQuerySpecific) {
                    // Create QueryOutputWriter if CData sections or DocType need to be tracked
                    writer = new QueryOutputWriter((XmlRawWriter)writer, this);
                }
            }
#endif // !SILVERLIGHT

            // wrap with well-formed writer
            writer = new XmlWellFormedWriter(writer, this);

#if ASYNC
            if (useAsync) {
                writer = new XmlAsyncCheckWriter(writer);
            }
#endif

            return writer;
        }

        internal XmlWriter CreateWriter(TextWriter output) {
            if (output == null) {
                throw new ArgumentNullException("output");
            }

            XmlWriter writer;

            // create raw writer
#if SILVERLIGHT
            if (this.Indent) {
                writer = new XmlEncodedRawTextWriterIndent(output, this);
            }
            else {
                writer = new XmlEncodedRawTextWriter(output, this);
            }
#else 
            switch (this.OutputMethod) {
                case XmlOutputMethod.Xml:
                    if (this.Indent) {
                        writer = new XmlEncodedRawTextWriterIndent(output, this);
                    }
                    else {
                        writer = new XmlEncodedRawTextWriter(output, this);
                    }
                    break;
                case XmlOutputMethod.Html:
                    if (this.Indent) {
                        writer = new HtmlEncodedRawTextWriterIndent(output, this);
                    }
                    else {
                        writer = new HtmlEncodedRawTextWriter(output, this);
                    }
                    break;
                case XmlOutputMethod.Text:
                    writer = new TextEncodedRawTextWriter(output, this);
                    break;
                case XmlOutputMethod.AutoDetect:
                    writer = new XmlAutoDetectWriter(output, this);
                    break;
                default:
                    Debug.Assert(false, "Invalid XmlOutputMethod setting.");
                    return null;
            }

            // XmlOutputMethod.AutoDetect writer does this lazily when it creates the underlying Xml or Html writer.
            if (this.OutputMethod != XmlOutputMethod.AutoDetect) {
                if (this.IsQuerySpecific) {
                    // Create QueryOutputWriter if CData sections or DocType need to be tracked
                    writer = new QueryOutputWriter((XmlRawWriter)writer, this);
                }
            }
#endif //SILVERLIGHT

            // wrap with well-formed writer
            writer = new XmlWellFormedWriter(writer, this);

#if ASYNC
            if (useAsync) {
                writer = new XmlAsyncCheckWriter(writer);
            }
#endif
            return writer;
        }

        internal XmlWriter CreateWriter(XmlWriter output) {
            if (output == null) {
                throw new ArgumentNullException("output");
            }

            return AddConformanceWrapper(output);
        }


        internal bool ReadOnly {
            get {
                return isReadOnly;
            }
            set {
                isReadOnly = value;
            }
        }

        void CheckReadOnly(string propertyName) {
            if (isReadOnly) {
                throw new XmlException(Res.Xml_ReadOnlyProperty, this.GetType().Name + '.' + propertyName);
            }
        }

//
// Private methods
//
        void Initialize() {
            encoding = Encoding.UTF8;
            omitXmlDecl = false;
            newLineHandling = NewLineHandling.Replace;
            newLineChars = Environment.NewLine; // "\r\n" on Windows, "\n" on Unix
            indent = TriState.Unknown;
            indentChars = "  ";
            newLineOnAttributes = false;
            closeOutput = false;
            namespaceHandling = NamespaceHandling.Default;
            conformanceLevel = ConformanceLevel.Document;
            checkCharacters = true;
            writeEndDocumentOnClose = true;

#if !SILVERLIGHT
            outputMethod = XmlOutputMethod.Xml;
            cdataSections.Clear();
            mergeCDataSections = false;
            mediaType = null;
            docTypeSystem = null;
            docTypePublic = null;
            standalone = XmlStandalone.Omit;
            doNotEscapeUriAttributes = false;
#endif

#if ASYNC || FEATURE_NETCORE
            useAsync = false;
#endif
            isReadOnly = false;
        }

        private XmlWriter AddConformanceWrapper(XmlWriter baseWriter) {
            ConformanceLevel confLevel = ConformanceLevel.Auto;
            XmlWriterSettings baseWriterSettings = baseWriter.Settings;
            bool checkValues = false;
            bool checkNames = false;
            bool replaceNewLines = false;
            bool needWrap = false;

            if (baseWriterSettings == null) {
                // assume the V1 writer already do all conformance checking; 
                // wrap only if NewLineHandling == Replace or CheckCharacters is true
                if (this.newLineHandling == NewLineHandling.Replace) {
                    replaceNewLines = true;
                    needWrap = true;
                }
                if (this.checkCharacters) {
                    checkValues = true;
                    needWrap = true;
                }
            }
            else {
                if (this.conformanceLevel != baseWriterSettings.ConformanceLevel) {
                    confLevel = this.ConformanceLevel;
                    needWrap = true;
                }
                if (this.checkCharacters && !baseWriterSettings.CheckCharacters) {
                    checkValues = true;
                    checkNames = confLevel == ConformanceLevel.Auto;
                    needWrap = true;
                }
                if (this.newLineHandling == NewLineHandling.Replace &&
                     baseWriterSettings.NewLineHandling == NewLineHandling.None) {
                    replaceNewLines = true;
                    needWrap = true;
                }
            }

            XmlWriter writer = baseWriter;

            if (needWrap) {
                if (confLevel != ConformanceLevel.Auto) {
                    writer = new XmlWellFormedWriter(writer, this);
                }
                if (checkValues || replaceNewLines) {
                    writer = new XmlCharCheckingWriter(writer, checkValues, checkNames, replaceNewLines, this.NewLineChars);
                }
            }

#if !SILVERLIGHT
            if (this.IsQuerySpecific && (baseWriterSettings == null || !baseWriterSettings.IsQuerySpecific)) {
                // Create QueryOutputWriterV1 if CData sections or DocType need to be tracked
                writer = new QueryOutputWriterV1(writer, this);
            }
#endif

            return writer;
        }

//
// Internal methods
//

#if !SILVERLIGHT

#if !HIDE_XSL
#if !DISABLE_XSLT_COMPILER
        /// <summary>
        /// Serialize the object to BinaryWriter.
        /// </summary>
        internal void GetObjectData(XmlQueryDataWriter writer) {
            // Encoding encoding;
            // NOTE: For Encoding we serialize only CodePage, and ignore EncoderFallback/DecoderFallback.
            // It suffices for XSLT purposes, but not in the general case.
            Debug.Assert(Encoding.Equals(Encoding.GetEncoding(Encoding.CodePage)), "Cannot serialize encoding correctly");
            writer.Write(Encoding.CodePage);
            // bool omitXmlDecl;
            writer.Write(OmitXmlDeclaration);
            // NewLineHandling newLineHandling;
            writer.Write((sbyte)NewLineHandling);
            // string newLineChars;
            writer.WriteStringQ(NewLineChars);
            // TriState indent;
            writer.Write((sbyte)IndentInternal);
            // string indentChars;
            writer.WriteStringQ(IndentChars);
            // bool newLineOnAttributes;
            writer.Write(NewLineOnAttributes);
            // bool closeOutput;
            writer.Write(CloseOutput);
            // ConformanceLevel conformanceLevel;
            writer.Write((sbyte)ConformanceLevel);
            // bool checkCharacters;
            writer.Write(CheckCharacters);
            // XmlOutputMethod outputMethod;
            writer.Write((sbyte)outputMethod);
            // List<XmlQualifiedName> cdataSections;
            writer.Write(cdataSections.Count);
            foreach (XmlQualifiedName qname in cdataSections) {
                writer.Write(qname.Name);
                writer.Write(qname.Namespace);
            }
            // bool mergeCDataSections;
            writer.Write(mergeCDataSections);
            // string mediaType;
            writer.WriteStringQ(mediaType);
            // string docTypeSystem;
            writer.WriteStringQ(docTypeSystem);
            // string docTypePublic;
            writer.WriteStringQ(docTypePublic);
            // XmlStandalone standalone;
            writer.Write((sbyte)standalone);
            // bool autoXmlDecl;
            writer.Write(autoXmlDecl);
            // bool isReadOnly;
            writer.Write(ReadOnly);
        }

        /// <summary>
        /// Deserialize the object from BinaryReader.
        /// </summary>
        internal XmlWriterSettings(XmlQueryDataReader reader) {
            // Encoding encoding;
            Encoding = Encoding.GetEncoding(reader.ReadInt32());
            // bool omitXmlDecl;
            OmitXmlDeclaration = reader.ReadBoolean();
            // NewLineHandling newLineHandling;
            NewLineHandling = (NewLineHandling)reader.ReadSByte(0, (sbyte)NewLineHandling.None);
            // string newLineChars;
            NewLineChars = reader.ReadStringQ();
            // TriState indent;
            IndentInternal = (TriState)reader.ReadSByte((sbyte)TriState.Unknown, (sbyte)TriState.True);
            // string indentChars;
            IndentChars = reader.ReadStringQ();
            // bool newLineOnAttributes;
            NewLineOnAttributes = reader.ReadBoolean();
            // bool closeOutput;
            CloseOutput = reader.ReadBoolean();
            // ConformanceLevel conformanceLevel;
            ConformanceLevel = (ConformanceLevel)reader.ReadSByte(0, (sbyte)ConformanceLevel.Document);
            // bool checkCharacters;
            CheckCharacters = reader.ReadBoolean();
            // XmlOutputMethod outputMethod;
            outputMethod = (XmlOutputMethod)reader.ReadSByte(0, (sbyte)XmlOutputMethod.AutoDetect);
            // List<XmlQualifiedName> cdataSections;
            int length = reader.ReadInt32();
            cdataSections = new List<XmlQualifiedName>(length);
            for (int idx = 0; idx < length; idx++) {
                cdataSections.Add(new XmlQualifiedName(reader.ReadString(), reader.ReadString()));
            }
            // bool mergeCDataSections;
            mergeCDataSections = reader.ReadBoolean();
            // string mediaType;
            mediaType = reader.ReadStringQ();
            // string docTypeSystem;
            docTypeSystem = reader.ReadStringQ();
            // string docTypePublic;
            docTypePublic = reader.ReadStringQ();
            // XmlStandalone standalone;
            Standalone = (XmlStandalone)reader.ReadSByte(0, (sbyte)XmlStandalone.No);
            // bool autoXmlDecl;
            autoXmlDecl = reader.ReadBoolean();
            // bool isReadOnly;
            ReadOnly = reader.ReadBoolean();
        }
#endif
#else
        internal void GetObjectData(object writer) { }
        internal XmlWriterSettings(object reader) { }
#endif

#endif
    }
}