// 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.Text;
using System.Xml;
using System.Xml.XPath;
using System.Collections.Generic;

namespace Microsoft.Ddue.Tools {

    public class FileCreatedEventArgs : EventArgs {

        private string filePath;
        private string hxfPath;
        
        public FileCreatedEventArgs(string filePath, string hxfPath) {
            this.filePath = filePath;
            this.hxfPath = hxfPath;
        }

        public string FilePath {
            get {
                return(filePath);
            }
        }

        public string HxfPath {
            get {
                return (hxfPath);
            }
        }

    }

    public class HxfGeneratorComponent : BuildComponent {

        public HxfGeneratorComponent (BuildAssembler assembler, XPathNavigator configuration) : base(assembler, configuration) {

            // get configuration data
            inputValue = configuration.GetAttribute("input", String.Empty);
            if (!String.IsNullOrEmpty(inputValue)) inputValue = Environment.ExpandEnvironmentVariables(inputValue);
            outputValue = configuration.GetAttribute("output", String.Empty);
            if (!String.IsNullOrEmpty(outputValue)) outputValue = Environment.ExpandEnvironmentVariables(outputValue);
           
            // subscribe to component events
            assembler.ComponentEvent += new EventHandler(FileCreatedHandler);
        }

        private string inputValue;

        private string outputValue;

        private XmlWriter writer;

        private Dictionary<string, XmlWriter> writers = new Dictionary<string, XmlWriter>();

        private void FileCreatedHandler (Object o, EventArgs e) {
            FileCreatedEventArgs fe = e as FileCreatedEventArgs;
            if (fe == null) return;
            
            string path = Path.Combine(fe.HxfPath, outputValue).ToLower();
           
            XmlWriter tempWriter;
            if (!writers.TryGetValue(path, out tempWriter)) {
                if (writer != null) {
                    writer.WriteEndDocument();
                    writer.Close();
                }
                WriteFile(path);
            }
            
            WriteFileElement(fe.FilePath);
                       
        }

        private void WriteFileElement (string url) {
            writer.WriteStartElement("File");
            writer.WriteAttributeString("Url", url);
            writer.WriteEndElement();
        }

        protected override void Dispose(bool disposing) {
            if (disposing) {
                writer.WriteEndDocument();
                writer.Close();
            }
            base.Dispose(disposing);
        }

        public void WriteFile(string path) {
            XmlWriterSettings writerSettings = new XmlWriterSettings();
            writerSettings.Indent = true;
            writer = XmlWriter.Create(path);
            writer.WriteStartDocument();
            writer.WriteStartElement("HelpFileList");
            writer.WriteAttributeString("DTDVersion", "1.0");

            // use the input to seed the output
            if (!String.IsNullOrEmpty(inputValue)) {

                try {
                    TextReader reader = File.OpenText(inputValue);

                    try {
                        while (true) {
                            string line = reader.ReadLine();
                            if (line == null) break;
                            WriteFileElement(line);
                        }
                    }
                    finally {
                        reader.Close();
                    }
                }
                catch (IOException ex) {
                    WriteMessage(MessageLevel.Error, String.Format("An access error occured while attempting to copy the input HxF data. The error message is:", ex.Message));
                }
            }

            writers.Add(path, writer);
        }

        // don't do anything for individual files
        public override void Apply (XmlDocument document, string key) {}

    }

}