////////////////////////////////////////////////////////////////////////////////
//
//  Microsoft Research Singularity
//
//  Copyright (c) Microsoft Corporation.  All rights reserved.
//
//  Note:   Native image building tool.
//

using System;
using FileSystem.Utils;

using System.Collections;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.IO;
using System.Text;
using System.Threading;
using Microsoft.Singularity.Xml;

using Microsoft.SingSharp;
using Microsoft.Singularity;
using Microsoft.Singularity.Channels;
using Microsoft.Singularity.Directory;
using Microsoft.Singularity.Extending;
using Microsoft.Singularity.Io;
using Microsoft.Singularity.Memory;
using Microsoft.Singularity.Xml;

public class NibHelper
{
    internal const long readSize = 4096;
    private static TRef<DirectoryServiceContract.Imp:Ready>       m_epNS = null;
    
    public static XmlNode OpenXmlDocument(string fileName)
    {
        return CreateXmlDocument(fileName);
    }

    public static XmlNode CreateXmlDocument(string fileName)
    {
        // read file into memory region
     
        int size; 
        
        DirectoryServiceContract.Imp! ds = GetDirectoryServiceContract();
        try {
            if (fileName == null) return null;
            byte[] xmlRegion = FileUtils.ReadEntireFile(fileName, ds);
            if (xmlRegion == null) return null;
            
            XmlReader xmlReader = new XmlReader();
            if (xmlReader == null) return null; 
            
            return xmlReader.Parse(xmlRegion);
        }
        finally {
            ReleaseDirectoryServiceContract(ds);
        }
        return null;
    }
    
    public static void SaveXmlDocument(XmlWriter writer, XmlNode doc)
    {
        if (writer == null || doc == null) {
            throw new Exception("Args_null");
        }
        writer.WriteStartDocument(false);
        doc.WriteTo(writer);
        writer.Flush();
    }

    public static DirectoryServiceContract.Imp:Ready! GetDirectoryServiceContract()
    {
        if (m_epNS == null) {
            m_epNS = new TRef<DirectoryServiceContract.Imp:Ready>(DirectoryService.NewClientEndpoint());
        }

        return m_epNS.Acquire();
    }

    public static void ReleaseDirectoryServiceContract([Claims] DirectoryServiceContract.Imp:Ready! imp)
    {
        assert m_epNS != null;
        m_epNS.Release(imp);
    }

        //////////////////////////////////////////////////////////////////////////
        // kinda dumb...
        private static bool CommandLineSyntaxCheck(string! commandLine)
        {
            int quoteCount = 0;
            for (int i = 0; i < commandLine.Length; i++) {
                if (commandLine[i] == '\'') {
                    quoteCount++;
                }
            }

            return (quoteCount % 2 == 0);
        }

        private static bool InSeparators(char c, char []! separators)
        {
            for (int i = 0; i < separators.Length; i++) {
                if (separators[i] == c)
                    return true;
            }
            return false;
        }

        private static ArrayList! Tokenize(string! input, int last,
                                           char []! separators)
        {
            ArrayList tokens = new ArrayList();

            for (int i = 0; i <= last;) {
                // Skip separators
                while (i <= last && InSeparators(input[i], separators)) {
                    i++;
                }

                if (i > last)
                    break;

                // Try to slurp word
                int start = i;
                while (i <= last &&
                       !InSeparators(input[i], separators) &&
                       input[i] != '\'')
                {
                    i++;
                }
                if (i != start) {
                    tokens.Add(input.Substring(start, i - start));
                }

                // Skip separators
                while (i <= last && InSeparators(input[i], separators)) {
                    i++;
                }

                if (i > last)
                    break;

                // Try to quoted slurp word
                if (input[i] == '\'') {
                    start = i;
                    i++;
                    while (i <= last && input[i] != '\'') {
                        i++;
                    }

                    if (i <= last && input[i] == '\'') {
                        tokens.Add(input.Substring(start + 1, i - start - 1));
                        i++;
                    }
                    else {
                        tokens.Add(input.Substring(start, i - start));
                        i++;
                    }
                }
            } // end for

            return tokens;
        }

        public static void BreakCommandLine(string!       input,
                                             char []!      separators,
                                             out string    command,
                                             out string[]! commandArguments)
        {

            if (!CommandLineSyntaxCheck(input)) {
                command = "";
                commandArguments = new string[0];
                return;
            }

            // Scan for trailing ampersand first
            int last = input.Length - 1;
            while (last > 0 && InSeparators(input[last], separators)) {
                last--;
            }


            ArrayList tokens = Tokenize(input, last, separators);

            if (tokens.Count == 0) {
                command = "";
                commandArguments = new string[0];
                return;
            }

            command = (string) tokens[0];
            commandArguments = new string [tokens.Count];
            for (int i = 0; i < tokens.Count; i++) {
                commandArguments[i] = (string) tokens[i];
            }
        }
}