/src/Updates/CheckingState.cs

/////////////////////////////////////////////////////////////////////////////////

// Paint.NET                                                                   //

// Copyright (C) dotPDN LLC, Rick Brewster, Tom Jackson, and contributors.     //

// Portions Copyright (C) Microsoft Corporation. All Rights Reserved.          //

// See src/Resources/Files/License.txt for full licensing and attribution      //

// details.                                                                    //

// .                                                                           //

/////////////////////////////////////////////////////////////////////////////////



using PaintDotNet.SystemLayer;

using System;

using System.Collections.Generic;

using System.Collections.Specialized;

using System.Globalization;

using System.IO;

using System.Net;

using System.Text;

using System.Threading;

using System.Windows.Forms;



namespace PaintDotNet.Updates

{

    internal class CheckingState

        : UpdatesState

    {

        // versions.txt schema:

        //     ; This is a comment

        //     DownloadPageUrl=downloadPageUrl                  // This should link to the main download page

        //     StableVersions=version1,version2,...,versionN    // A comma-separated list of all available stable versions available for download

        //     BetaVersions=version1,version2,...,versionN      // A comma-separated list of all available beta/pre-release versions available for download

        //

        //     version1_Name=name1                              // Friendly name for a given version

        //     version1_NetFxVersion=netFxVersion1              // What version of .NET does this version require?

        //                                                         For .NET 2.0, this should be specificed as 2.0.x, where x used to be the build number (50727) but is now ignored

        //                                                         For .NET 3.5, this should be specificed as 3.5.x, where x is the required service pack level

        //     version1_InfoUrl=infoUrl1                        // A URL that contains information about the given version

        //     version1_ZipUrlList="zipUrl1","zipUrl2",...,"zipUrlN"

        //                                                      // A comma-delimited list of URL's for mirrors to download the updater. One will be chosen at random.

        //     version1_FullZipUrlList="zipFullUrl1","zipFullUrl2",...,"zipFullUrlN"

        //                                                      // A comma-delimited list of URL's for mirrors to download the 'full' installer ('full' means it bundles the appropriate .NET installer

        //     ...

        //     versionN_Name=name1                              // Friendly name for a given version

        //     versionN_NetFxVersion=netFxVersionN              // What version of .NET does this version require?

        //     versionN_InfoUrl=infoUrlN                        // A URL that contains information about the given version

        //     versionN_ZipUrlList=zipUrlN                      // A comma-delimited list of URL's for mirrors to download the updater. One will be chosen at random.

        //     versionN_FullZipUrl=zipFullUrlN                  // A comma-delimited list of URL's for mirrors to download the 'full' installer ('full' means it bundles the appropriate .NET installer

        //     

        // Example:

        //     ; Paint.NET versions download manifest

        //     DownloadPageUrl=http://www.getpaint.net/download.htm

        //     StableVersions=2.1.1958.27164

        //     BetaVersions=2.5.2013.31044

        //     

        //     2.1.1958.27164_Name=Paint.NET v2.1b     

        //     2.1.1958.27164_InfoUrl=http://www.getpaint.net/roadmap.htm#v2_1

        //     2.1.1958.27164_NetFxVersion=1.1.4322

        //     2.1.1958.27164_ZipUrlList=http://www.getpaint.net/zip/PaintDotNet_2_1b.zip

        //     2.1.1958.27164_FullZipUrlList=http://www.getpaint.net/zip/PaintDotNet_2_1b_Full.zip

        //     

        //     2.5.2013.31044_Name=Paint.NET v2.5        

        //     2.5.2013.31044_InfoUrl=http://www.getpaint.net/roadmap.htm#v2_5

        //     2.5.2013.31044_NetFxVersion=1.1.4322

        //     2.5.2013.31044_ZipUrlList=http://www.getpaint.net/zip/PaintDotNet_2_5.zip

        //     2.5.2013.31044_FullZipUrlList=http://www.getpaint.net/zip/PaintDotNet_2_5_Full.zip

        //     

        //     2.6.2113.23752_Name=Paint.NET v2.6 Beta 1

        //     2.6.2113.23752_InfoUrl=http://www.getpaint.net/roadmap.htm#v2_6

        //     2.6.2113.23752_NetFxVersion=2.0.50727

        //     2.6.2113.23752_ZipUrlList="http://www.getpaint.net/zip/PaintDotNet_2_6_Beta1.zip","http://www.someotherhost.com/files/PaintDotNet_2_6_Beta1.zip"

        //     2.6.2113.23752_FullZipUrlList="http://www.getpaint.net/zip/PaintDotNet_2_6_Beta1_Full.zip","http://www.someotherhost.com/files/PaintDotNet_2_6_Beta1_Full.zip"

        //     

        // Notes:

        //     A line may have a comment on it. Just start the line with an asterisk, '*'

        //     Versions must be formatted in a manner parseable by the System.Version class.

        //     BetaVersions may be an empty list: "BetaVersions="

        //     versionN_InfoUrl may not be blank

        //     versionN_ZipUrl may not be blank

        //     versionN_ZipUrlSize must be greater than 0.

        //     If any error is detected while parsing, the entire schema will be declared as invalid and ignored.

        //     Everything is case-sensitive.



        private const string downloadPageUrlName = "DownloadPageUrl";

        private const string stableVersionsName = "StableVersions";

        private const string betaVersionsName = "BetaVersions";

        private const string nameNameFormat = "{0}_Name";

        private const string netFxVersionNameFormat = "{0}_NetFxVersion";

        private const string infoUrlNameFormat = "{0}_InfoUrl";

        private const string zipUrlListNameFormat = "{0}_ZipUrlList";

        private const string fullZipUrlListNameFormat = "{0}_FullZipUrlList";

        private const char commentChar = ';';



        // {0} is schema version

        // {1} is Windows revision (501 for XP, 502 for Server 2k3, 600 for Vista, 601 for Win7)

        // {2} is platform (x86, x64)

        // {3} is the locale (en, etc)

        private const string versionManifestRelativeUrlFormat = "/updates/versions.{0}.{1}.{2}.{3}.txt";

        private const string versionManifestTestRelativeUrl = "/updates/versions.txt.test.txt";

        private const int schemaVersion = 5;



        private PdnVersionManifest manifest;

        private int latestVersionIndex;

        private Exception exception;



        private ManualResetEvent checkingEvent = new ManualResetEvent(false);

        private ManualResetEvent abortEvent = new ManualResetEvent(false);



        private static string GetNeutralLocaleName(CultureInfo ci)

        {

            if (ci.IsNeutralCulture)

            {

                return ci.Name;

            }



            if (ci.Parent == null)

            {

                return ci.Name;

            }



            if (ci.Parent == ci)

            {

                return ci.Name;

            }



            return GetNeutralLocaleName(ci.Parent);

        }



        private static string VersionManifestUrl

        {

            get

            {

                Uri websiteUri = new Uri(InvariantStrings.WebsiteUrl);

                string versionManifestUrl;



                if (PdnInfo.IsTestMode)

                {

                    Uri versionManifestTestUri = new Uri(websiteUri, versionManifestTestRelativeUrl);

                    versionManifestUrl = versionManifestTestUri.ToString();

                }

                else

                {

                    string schemaVersionStr = schemaVersion.ToString(CultureInfo.InvariantCulture);

                    Version osVersion = Environment.OSVersion.Version;

                    ProcessorArchitecture platform = SystemLayer.Processor.Architecture;

                    OSType osType = SystemLayer.OS.Type;



                    // If this is XP x64, we want to fudge the NT version to be 5.1 instead of 5.2

                    // This helps us discern between XP x64 and Server 2003 x64 stats.

                    if (osVersion.Major == 5 && osVersion.Minor == 2 && platform == ProcessorArchitecture.X64 && osType == OSType.Workstation)

                    {

                        osVersion = new Version(5, 1, osVersion.Build, osVersion.Revision);

                    }



                    int osVersionInt = (osVersion.Major * 100) + osVersion.Minor;

                    string osVersionStr = osVersionInt.ToString(CultureInfo.InvariantCulture);

                    string platformStr = platform.ToString().ToLower();

                    string localeStr = GetNeutralLocaleName(PdnResources.Culture);

                    Uri versionManifestUrlFormatUri = new Uri(websiteUri, versionManifestRelativeUrlFormat);

                    string versionManifestUrlFormat = versionManifestUrlFormatUri.ToString();



                    versionManifestUrl = string.Format(versionManifestUrlFormat, schemaVersionStr, osVersionStr, platformStr, localeStr);

                }



                return versionManifestUrl;

            }

        }



        private static string[] BreakIntoLines(string text)

        {

            StringReader sr = new StringReader(text);

            List<string> strings = new List<string>();

            string line;



            while ((line = sr.ReadLine()) != null)

            {

                if (line.Length > 0 && line[0] != commentChar)

                {

                    strings.Add(line);

                }

            }



            return strings.ToArray();

        }



        private static void LineToNameValue(string line, out string name, out string value)

        {

            int equalIndex = line.IndexOf('=');



            if (equalIndex == -1)

            {

                throw new FormatException("Line had no equal sign (=) present");

            }



            name = line.Substring(0, equalIndex);



            int valueLength = line.Length - equalIndex - 1;



            if (valueLength == 0)

            {

                value = string.Empty;

            }

            else

            {

                value = line.Substring(equalIndex + 1, line.Length - equalIndex - 1);

            }

        }



        private static NameValueCollection LinesToNameValues(string[] lines)

        {

            NameValueCollection nvc = new NameValueCollection();



            foreach (string line in lines)

            {

                string name;

                string value;



                LineToNameValue(line, out name, out value);

                nvc.Add(name, value);

            }



            return nvc;

        }



        private static Version[] VersionStringToArray(string versions)

        {

            string[] versionStrings = versions.Split(',');



            // For the 'null' case...

            if (versionStrings.Length == 0 ||

                (versionStrings.Length == 1 && versionStrings[0].Length == 0))

            {

                return new Version[0];

            }



            Version[] versionList = new Version[versionStrings.Length];



            for (int i = 0; i < versionStrings.Length; ++i)

            {

                versionList[i] = new Version(versionStrings[i]);

            }



            return versionList;

        }



        private static string[] BuildVersionValueMapping(NameValueCollection nameValues, Version[] versions, string secondaryKeyFormat)

        {

            string[] newValues = new string[versions.Length];



            for (int i = 0; i < versions.Length; ++i)

            {

                string versionString = versions[i].ToString();

                string secondaryKey = string.Format(secondaryKeyFormat, versionString);

                string secondaryValue = nameValues[secondaryKey];

                newValues[i] = secondaryValue;

            }



            return newValues;

        }



        private static void SplitUrlList(string urlList, List<string> urlsOutput)

        {

            if (string.IsNullOrEmpty(urlList))

            {

                return;

            }



            string trimUrlList = urlList.Trim();

            string url;

            int commaIndex;

            

            if (trimUrlList[0] == '"')

            {

                int endQuoteIndex = trimUrlList.IndexOf('"', 1);

                commaIndex = trimUrlList.IndexOf(',', endQuoteIndex);

                url = trimUrlList.Substring(1, endQuoteIndex - 1);

            }

            else

            {

                commaIndex = trimUrlList.IndexOf(',');



                if (commaIndex == -1)

                {

                    url = trimUrlList;

                }

                else

                {

                    url = trimUrlList.Substring(0, commaIndex);

                }

            }



            string urlTail;

            if (commaIndex == -1)

            {

                urlTail = null;

            }

            else

            {

                urlTail = trimUrlList.Substring(commaIndex + 1);

            }



            urlsOutput.Add(url);

            SplitUrlList(urlTail, urlsOutput);

        }



        /// <summary>

        /// Downloads the latest updates manifest from the Paint.NET web server.

        /// </summary>

        /// <returns>The latest updates manifest, or null if there was an error in which case the exception argument will be non-null.</returns>

        private static PdnVersionManifest GetUpdatesManifest(out Exception exception)

        {

            try

            {

                string versionsUrl = VersionManifestUrl;



                Uri versionsUri = new Uri(versionsUrl);

                byte[] manifestBuffer = Utility.DownloadSmallFile(versionsUri);

                string manifestText = System.Text.Encoding.UTF8.GetString(manifestBuffer);

                string[] manifestLines = BreakIntoLines(manifestText);

                NameValueCollection nameValues = LinesToNameValues(manifestLines);



                string downloadPageUrl = nameValues[downloadPageUrlName];



                string stableVersionsStrings = nameValues[stableVersionsName];

                Version[] stableVersions = VersionStringToArray(stableVersionsStrings);

                string[] stableNames = BuildVersionValueMapping(nameValues, stableVersions, nameNameFormat);

                string[] stableNetFxVersions = BuildVersionValueMapping(nameValues, stableVersions, netFxVersionNameFormat);

                string[] stableInfoUrls = BuildVersionValueMapping(nameValues, stableVersions, infoUrlNameFormat);

                string[] stableZipUrls = BuildVersionValueMapping(nameValues, stableVersions, zipUrlListNameFormat);

                string[] stableFullZipUrls = BuildVersionValueMapping(nameValues, stableVersions, fullZipUrlListNameFormat);



                string betaVersionsStrings = nameValues[betaVersionsName];

                Version[] betaVersions = VersionStringToArray(betaVersionsStrings);

                string[] betaNames = BuildVersionValueMapping(nameValues, betaVersions, nameNameFormat);

                string[] betaNetFxVersions = BuildVersionValueMapping(nameValues, betaVersions, netFxVersionNameFormat);

                string[] betaInfoUrls = BuildVersionValueMapping(nameValues, betaVersions, infoUrlNameFormat);

                string[] betaZipUrls = BuildVersionValueMapping(nameValues, betaVersions, zipUrlListNameFormat);

                string[] betaFullZipUrls = BuildVersionValueMapping(nameValues, betaVersions, fullZipUrlListNameFormat);



                PdnVersionInfo[] versionInfos = new PdnVersionInfo[betaVersions.Length + stableVersions.Length];



                int cursor = 0;

                for (int i = 0; i < stableVersions.Length; ++i)

                {

                    List<string> zipUrlList = new List<string>();

                    SplitUrlList(stableZipUrls[i], zipUrlList);



                    List<string> fullZipUrlList = new List<string>();

                    SplitUrlList(stableFullZipUrls[i], fullZipUrlList);



                    Version netFxVersion = new Version(stableNetFxVersions[i]);



                    if (netFxVersion.Major == 2 && netFxVersion.Minor == 0)

                    {

                        netFxVersion = new Version(2, 0, 0); // discard the build # that is specified, since we use that for Service Pack level now

                    }



                    PdnVersionInfo info = new PdnVersionInfo(

                        stableVersions[i], 

                        stableNames[i], 

                        netFxVersion.Major,

                        netFxVersion.Minor,

                        netFxVersion.Build, // service pack

                        stableInfoUrls[i], 

                        zipUrlList.ToArray(), 

                        fullZipUrlList.ToArray(), 

                        true);



                    versionInfos[cursor] = info;

                    ++cursor;

                }



                for (int i = 0; i < betaVersions.Length; ++i)

                {

                    List<string> zipUrlList = new List<string>();

                    SplitUrlList(betaZipUrls[i], zipUrlList);



                    List<string> fullZipUrlList = new List<string>();

                    SplitUrlList(betaFullZipUrls[i], fullZipUrlList);



                    Version netFxVersion = new Version(betaNetFxVersions[i]);



                    if (netFxVersion.Major == 2 && netFxVersion.Minor == 0)

                    {

                        netFxVersion = new Version(2, 0, 0); // discard the build # that is specified, since we use that for Service Pack level now

                    }



                    PdnVersionInfo info = new PdnVersionInfo(

                        betaVersions[i], 

                        betaNames[i],

                        netFxVersion.Major,

                        netFxVersion.Minor,

                        netFxVersion.Build, // service pack

                        betaInfoUrls[i], 

                        zipUrlList.ToArray(), 

                        fullZipUrlList.ToArray(), 

                        false);



                    versionInfos[cursor] = info;

                    ++cursor;

                }



                PdnVersionManifest manifest = new PdnVersionManifest(downloadPageUrl, versionInfos);

                exception = null;

                return manifest;

            }



            catch (Exception ex)

            {

                exception = ex;

                return null;

            }

        }



        private static void CheckForUpdates(

            out PdnVersionManifest manifestResult,

            out int latestVersionIndexResult,

            out Exception exception)

        {

            exception = null;

            PdnVersionManifest manifest = null;

            manifestResult = null;

            latestVersionIndexResult = -1;



            int retries = 2;



            while (retries > 0)

            {

                try

                {

                    manifest = GetUpdatesManifest(out exception);

                    retries = 0;

                }



                catch (Exception ex)

                {

                    exception = ex;

                    --retries;



                    if (retries == 0)

                    {

                        manifest = null;

                    }

                }

            }



            if (manifest != null)

            {

                int stableIndex = manifest.GetLatestStableVersionIndex();

                int betaIndex = manifest.GetLatestBetaVersionIndex();



                // Check for betas as well?

                bool checkForBetas = ("1" == Settings.SystemWide.GetString(SettingNames.AlsoCheckForBetas, "0"));



                // Figure out which version we want to compare against the current version

                int latestIndex = stableIndex;



                if (checkForBetas)

                {

                    // If they like betas, and if the beta is newer than the latest stable release,

                    // then offer it to them.

                    if (betaIndex != -1 &&

                        (stableIndex == -1 || manifest.VersionInfos[betaIndex].Version >= manifest.VersionInfos[stableIndex].Version))

                    {

                        latestIndex = betaIndex;

                    }

                }



                // Now compare that version against the current version

                if (latestIndex != -1)

                {

                    if (PdnInfo.IsTestMode ||

                        manifest.VersionInfos[latestIndex].Version > PdnInfo.GetVersion())

                    {

                        manifestResult = manifest;

                        latestVersionIndexResult = latestIndex;

                    }

                }

            }

        }



        public override bool CanAbort

        {

            get

            {

                return true;

            }

        }



        protected override void OnAbort()

        {

            this.abortEvent.Set();

            base.OnAbort();

        }



        private void DoCheckThreadProc(object ignored)

        {

            try

            {

                System.Threading.Thread.Sleep(1500);

                CheckForUpdates(out this.manifest, out this.latestVersionIndex, out this.exception);

            }



            finally

            {

                this.checkingEvent.Set();

            }

        }



        public override void OnEnteredState()

        {

            this.checkingEvent.Reset();

            this.abortEvent.Reset();



            ThreadPool.QueueUserWorkItem(new WaitCallback(DoCheckThreadProc));



            WaitHandleArray events = new WaitHandleArray(2);

            events[0] = this.checkingEvent;

            events[1] = this.abortEvent;

            int waitResult = events.WaitAny();



            if (waitResult == 0 && manifest != null && latestVersionIndex != -1)

            {

                StateMachine.QueueInput(PrivateInput.GoToUpdateAvailable);

            }

            else if (waitResult == 1)

            {

                StateMachine.QueueInput(PrivateInput.GoToAborted);

            }

            else if (this.exception != null)

            {

                StateMachine.QueueInput(PrivateInput.GoToError);

            }

            else

            {

                StateMachine.QueueInput(PrivateInput.GoToDone);

            }

        }



        public override void ProcessInput(object input, out State newState)

        {

            if (input.Equals(PrivateInput.GoToUpdateAvailable))

            {

                newState = new UpdateAvailableState(this.manifest.VersionInfos[this.latestVersionIndex]);

            }

            else if (input.Equals(PrivateInput.GoToError))

            {

                string errorMessage;



                if (this.exception is WebException)

                {

                    errorMessage = Utility.WebExceptionToErrorMessage((WebException)this.exception);

                }

                else

                {

                    errorMessage = PdnResources.GetString("Updates.CheckingState.GenericError");

                }



                newState = new ErrorState(this.exception, errorMessage);

            }

            else if (input.Equals(PrivateInput.GoToDone))

            {

                newState = new DoneState();

            }

            else if (input.Equals(PrivateInput.GoToAborted))

            {

                newState = new AbortedState();

            }

            else

            {

                throw new ArgumentException();

            }

        }



        public CheckingState()

            : base(false, false, MarqueeStyle.Marquee)

        {

        }

    }

}