// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
//---------------------------------------------------------------------------
//
// Description: The task that merges all the localization directives files
//
//---------------------------------------------------------------------------
 
using System;
using System.IO;
using System.Text;
using System.Runtime.InteropServices;
 
using Microsoft.Build.Framework;
using Microsoft.Build.Utilities;
 
using MS.Internal.Globalization;
using MS.Internal.Tasks;
using MS.Utility;                   // For SR
 
namespace Microsoft.Build.Tasks.Windows
{
    /// <summary>
    /// This task merges the localization directives files of single bamls
    /// into one file corresponding to for the compiled assembly.
    /// </summary>
    public sealed class MergeLocalizationDirectives : Task
    {
        //--------------------------------
        // Constructor
        //--------------------------------
        /// <summary>
        /// Default constructor of the task
        /// </summary>
        public MergeLocalizationDirectives() : base(SR.SharedResourceManager)
        {
        }
 
        //--------------------------------
        // Public methods
        //--------------------------------
 
        /// <summary>
        /// Method invoked by MSBuild to merge localization files of single bamls to
        /// one file for the whole Assembly.
        /// </summary>
        public override bool Execute()
        {
            TaskHelper.DisplayLogo(Log, nameof(MergeLocalizationDirectives));
            if (GeneratedLocalizationFiles.Length > 0)
            {
                try {
 
                    string absoluteFilePath = Path.Combine(
                        Directory.GetCurrentDirectory(),
                        _outputFile
                        );
 
                    using (StreamWriter streamWriter = new StreamWriter(
                              new FileStream(absoluteFilePath, FileMode.Create),
                              new UTF8Encoding(true)
                              )
                          )
                    {
 
                        Log.LogMessageFromResources(nameof(SR.CommentFileGenerating), _outputFile);
 
                        streamWriter.WriteLine($"<{LocComments.LocDocumentRoot}>");
 
                        // keep things simple and fast. Just keep appending the
                        // xml fragments that are already outputed.
                        foreach (ITaskItem item in GeneratedLocalizationFiles)
                        {
                            using (StreamReader locStreamReader = new StreamReader(item.ItemSpec))
                            {
                                // directly concat Xml fragments
                                streamWriter.WriteLine(locStreamReader.ReadToEnd());
                            }
                        }
 
                        streamWriter.WriteLine($"</{LocComments.LocDocumentRoot}>");
                        Log.LogMessageFromResources(nameof(SR.CommentFileGenerated), _outputFile);
                    }
                }
                catch (Exception e)
                {
                    if (e is NullReferenceException || e is SEHException)
                    {
                        throw;
                    }
                    else
                    {
                        Log.LogErrorFromException(e);
                        return false;
                    }
                }
                catch // Non-CLS compliant errors
                {
                    Log.LogErrorWithCodeFromResources(nameof(SR.NonClsError));
                    return false;
                }
            }
 
            return true;
        }
 
        //--------------------------------
        // Public properties
        //--------------------------------
 
        /// <summary>
        /// The list of localization directives files for individual Bamls.
        /// </summary>
        [Required]
        public ITaskItem[] GeneratedLocalizationFiles
        {
            get { return _generatedLocalizationFiles; }
            set { _generatedLocalizationFiles = value; }
        }
 
        /// <summary>
        /// The output path of the compiled assembly
        /// </summary>
        [Required]
        [Output]
        public string OutputFile
        {
            get { return _outputFile; }
            set { _outputFile = value; }
        }
 
        //---------------------------------
        // Private members
        //---------------------------------
        private ITaskItem[] _generatedLocalizationFiles;
        private string      _outputFile;
    }
}