// Copyright © Microsoft Corporation.
// This source file is subject to the Microsoft Permissive License.
// See http://www.microsoft.com/resources/sharedsource/licensingbasics/sharedsourcelicenses.mspx.
// All other rights reserved.

using System;
using System.IO;
using System.Xml;
using System.Xml.Xsl;
using Microsoft.Ddue.Tools.CommandLine;


namespace Microsoft.Ddue.Tools
{
    public class XslTransformer
    {
        public static int Main(string[] args)
        {
            // specify options
            OptionCollection options = new OptionCollection();
            options.Add(new SwitchOption("?", "Show this help page."));
            options.Add(new ListOption("xsl", "Sepcify transform files.", "xsltPath"));
            options.Add(new ListOption("arg", "Sepcify arguments.", "name=value"));
            options.Add(new StringOption("out", "Specify an output file. If unspecified, output goes to the console.", "outputFilePath"));
            options.Add(new SwitchOption("w", "Do not ignore insignificant whitespace. By default insignificant whitespace is ignored."));

            ConsoleApplication.WriteBanner();

            // process options
            ParseArgumentsResult results = options.ParseArguments(args);
            if (results.Options["?"].IsPresent)
            {
                Console.WriteLine("XslTransformer xsl_file [xml_file] [options]");
                options.WriteOptionSummary(Console.Out);
                return (0);
            }

            // check for invalid options
            if (!results.Success)
            {
                results.WriteParseErrors(Console.Out);
                return (1);
            }

            // check for missing or extra assembly directories
            if (results.UnusedArguments.Count != 1)
            {
                Console.WriteLine("Specify one input XML input file.");
                return (1);
            }

            if (!results.Options["xsl"].IsPresent)
            {
                Console.WriteLine("Specify at least one XSL transform file.");
                return (1);
            }

            // set whitespace setting
            bool ignoreWhitespace = !results.Options["w"].IsPresent;

            // Load transforms
            string[] transformFiles = (string[])results.Options["xsl"].Value;
            XslCompiledTransform[] transforms = new XslCompiledTransform[transformFiles.Length];
            for (int i = 0; i < transformFiles.Length; i++)
            {
                string transformFile = Environment.ExpandEnvironmentVariables(transformFiles[i]);
                transforms[i] = new XslCompiledTransform();
                XsltSettings transformSettings = new XsltSettings(true, true);
                try
                {
                    transforms[i].Load(transformFile, transformSettings, new XmlUrlResolver());
                }
                catch (IOException e)
                {
                    ConsoleApplication.WriteMessage(LogLevel.Error, String.Format("The transform file '{0}' could not be loaded. The error is: {1}", transformFile, e.Message));
                    return (1);
                }
                catch (UnauthorizedAccessException e)
                {
                    ConsoleApplication.WriteMessage(LogLevel.Error, String.Format("The transform file '{0}' could not be loaded. The error is: {1}", transformFile, e.Message));
                    return (1);
                }
                catch (XsltException e)
                {
                    if (e.InnerException != null)
                    {
                        ConsoleApplication.WriteMessage(LogLevel.Error, String.Format("The transformation file '{0}' is not valid. The error is: {1}", transformFile, e.InnerException.Message));
                    }
                    else
                    {
                        ConsoleApplication.WriteMessage(LogLevel.Error, String.Format("The transformation file '{0}' is not valid. The error is: {1}", transformFile, e.Message));
                    }
                    return (1);
                }
                catch (XmlException e)
                {
                    ConsoleApplication.WriteMessage(LogLevel.Error, String.Format("The transform file '{0}' is not well-formed. The error is: {1}", transformFile, e.Message));
                    return (1);
                }
            }

            // Compose the arguments
            XsltArgumentList arguments = new XsltArgumentList();
            if (results.Options["arg"].IsPresent)
            {
                string[] nameValueStrings = (string[])results.Options["arg"].Value;
                foreach (string nameValueString in nameValueStrings)
                {
                    string[] nameValuePair = nameValueString.Split('=');
                    if (nameValuePair.Length != 2) continue;
                    arguments.AddParam(nameValuePair[0], String.Empty, nameValuePair[1]);
                }
            }

            string input = Environment.ExpandEnvironmentVariables(results.UnusedArguments[0]);

            // prepare the reader
            XmlReaderSettings readerSettings = new XmlReaderSettings();
            readerSettings.IgnoreWhitespace = ignoreWhitespace;

            // Do each transform
            for (int i = 0; i < transforms.Length; i++)
            {
                ConsoleApplication.WriteMessage(LogLevel.Info, String.Format("Applying XSL transformation '{0}'.", transformFiles[i]));

                // get the transform
                XslCompiledTransform transform = transforms[i];

                // figure out where to put the output
                string output;
                if (i < (transforms.Length - 1))
                {
                    try
                    {
                        output = Path.GetTempFileName();
                        File.SetAttributes(output, FileAttributes.Temporary);
                    }
                    catch (IOException e)
                    {
                        ConsoleApplication.WriteMessage(LogLevel.Error, String.Format("An error occured while attempting to create a temporary file. The error message is: {0}", e.Message));
                        return (1);
                    }
                }
                else
                {
                    if (results.Options["out"].IsPresent)
                    {
                        output = Environment.ExpandEnvironmentVariables((string)results.Options["out"].Value);
                    }
                    else
                    {
                        output = null;
                    }
                }

                // create a reader
                Stream readStream;
                try
                {
                    readStream = File.Open(input, FileMode.Open, FileAccess.Read, FileShare.ReadWrite | FileShare.Delete);
                }
                catch (IOException e)
                {
                    ConsoleApplication.WriteMessage(LogLevel.Error, String.Format("The input file '{0}' could not be loaded. The error is: {1}", input, e.Message));
                    return (1);
                }
                catch (UnauthorizedAccessException e)
                {
                    ConsoleApplication.WriteMessage(LogLevel.Error, String.Format("The input file '{0}' could not be loaded. The error is: {1}", input, e.Message));
                    return (1);
                }

                using (XmlReader reader = XmlReader.Create(readStream, readerSettings))
                {
                    // create a writer
                    Stream outputStream;
                    if (output == null)
                    {
                        outputStream = Console.OpenStandardOutput();
                    }
                    else
                    {
                        try
                        {
                            outputStream = File.Open(output, FileMode.Create, FileAccess.Write, FileShare.Read | FileShare.Delete);
                        }
                        catch (IOException e)
                        {
                            ConsoleApplication.WriteMessage(LogLevel.Error, String.Format("The output file '{0}' could not be loaded. The error is: {1}", output, e.Message));
                            return (1);
                        }
                        catch (UnauthorizedAccessException e)
                        {
                            ConsoleApplication.WriteMessage(LogLevel.Error, String.Format("The output file '{0}' could not be loaded. The error is: {1}", output, e.Message));
                            return (1);
                        }
                    }

                    using (XmlWriter writer = XmlWriter.Create(outputStream, transform.OutputSettings))
                    {
                        try
                        {
                            // do the deed
                            transform.Transform(reader, arguments, writer);
                        }
                        catch (XsltException e)
                        {
                            ConsoleApplication.WriteMessage(LogLevel.Error, String.Format("An error occured during the transformation. The error message is: {0}",
                                (e.InnerException == null) ? e.Message : e.InnerException.Message));
                            return (1);
                        }
                        catch (XmlException e)
                        {
                            ConsoleApplication.WriteMessage(LogLevel.Error, String.Format("The input file '{0}' is not well-formed. The error is: {1}", input, e.Message));
                            return (1);
                        }
                    }
                }

                // if the last input was a temp file, delete it
                if (i > 0)
                {
                    // Console.WriteLine("deleting {0}", input);
                    try
                    {
                        File.Delete(input);
                    }
                    catch (IOException e)
                    {
                        ConsoleApplication.WriteMessage(LogLevel.Warn, String.Format("The temporary file '{0}' could not be deleted. The error message is: {1}", input, e.Message));
                    }
                }

                // the last output file is the next input file
                input = output;

            }

            return (0);
        }
    }

    internal class TransformInfo
    {
        public TransformInfo(string file)
        {
            this.file = file;
            transform.Load(file, settings, resolver);
        }

        private string file;

        private XslCompiledTransform transform = new XslCompiledTransform();

        public string File
        {
            get
            {
                return (file);
            }
        }

        public XslCompiledTransform Transform
        {
            get
            {
                return (transform);
            }
        }

        private static XsltSettings settings = new XsltSettings(true, true);

        private static XmlUrlResolver resolver = new XmlUrlResolver();
    }
}