Merge pull request #2156 from github/autocompletebox

Migrating and Updating AutoCompleteBox from *original* GitHub Desktop for Windows

Author: StanleyGoldman

src/GitHub.App/Models/SuggestionItem.cs

@@ -0,0 +1,51 @@
+using System;
+using GitHub.Extensions;
+using GitHub.Helpers;
+
+namespace GitHub.Models
+{
+    /// <summary>
+    /// Represents a single auto completion suggestion (mentions, emojis, issues) in a generic format that can be
+    /// easily cached.
+    /// </summary>
+    public class SuggestionItem
+    {
+        public SuggestionItem(string name, string description)
+        {
+            Guard.ArgumentNotEmptyString(name, "name");
+            Guard.ArgumentNotEmptyString(description, "description");
+
+            Name = name;
+            Description = description;
+        }
+
+        public SuggestionItem(string name, string description, string imageUrl)
+        {
+            Guard.ArgumentNotEmptyString(name, "name");
+
+            Name = name;
+            Description = description;
+            ImageUrl = imageUrl;
+        }
+
+        /// <summary>
+        /// The name to display for this entry
+        /// </summary>
+        public string Name { get; set; }
+
+        /// <summary>
+        /// Additional details about the entry
+        /// </summary>
+        public string Description { get; set; }
+
+        /// <summary>
+        /// An image url for this entry
+        /// </summary>
+        public string ImageUrl { get; set; }
+
+        /// <summary>
+        /// The date this suggestion was last modified according to the API.
+        /// </summary>
+        public DateTimeOffset? LastModifiedDate { get; set; }
+    }
+}

src/GitHub.App/SampleData/CommentViewModelDesigner.cs

@@ -3,6 +3,7 @@
 using System.Reactive;
 using System.Threading.Tasks;
 using GitHub.Models;
+using GitHub.Services;
 using GitHub.ViewModels;
 using ReactiveUI;
 
@@ -37,6 +38,7 @@ public CommentViewModelDesigner()
         public ReactiveCommand<Unit, Unit> CommitEdit { get; }
         public ReactiveCommand<Unit, Unit> OpenOnGitHub { get; } = ReactiveCommand.Create(() => { });
         public ReactiveCommand<Unit, Unit> Delete { get; }
+        public IAutoCompleteAdvisor AutoCompleteAdvisor { get; }
 
         public Task InitializeAsync(ICommentThreadViewModel thread, ActorModel currentUser, CommentModel comment, CommentEditState state)
         {

src/GitHub.App/SampleData/PullRequestCreationViewModelDesigner.cs

@@ -4,6 +4,7 @@
 using System.Reactive;
 using System.Threading.Tasks;
 using GitHub.Models;
+using GitHub.Services;
 using GitHub.Validation;
 using GitHub.ViewModels.GitHubPane;
 using ReactiveUI;
@@ -53,6 +54,7 @@ public PullRequestCreationViewModelDesigner()
         public string PRTitle { get; set; }
 
         public ReactivePropertyValidator TitleValidator { get; }
+        public IAutoCompleteAdvisor AutoCompleteAdvisor { get; }
 
         public ReactivePropertyValidator BranchValidator { get; }
 

src/GitHub.App/SampleData/PullRequestReviewAuthoringViewModelDesigner.cs

@@ -3,6 +3,7 @@
 using System.Reactive;
 using System.Threading.Tasks;
 using GitHub.Models;
+using GitHub.Services;
 using GitHub.ViewModels.GitHubPane;
 using ReactiveUI;
 
@@ -53,6 +54,7 @@ public PullRequestReviewAuthoringViewModelDesigner()
         public ReactiveCommand<Unit, Unit> Comment { get; }
         public ReactiveCommand<Unit, Unit> RequestChanges { get; }
         public ReactiveCommand<Unit, Unit> Cancel { get; }
+        public IAutoCompleteAdvisor AutoCompleteAdvisor { get; }
 
         public Task InitializeAsync(
             LocalRepositoryModel localRepository,

src/GitHub.App/Services/AutoCompleteAdvisor.cs

@@ -0,0 +1,121 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.ComponentModel.Composition;
+using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
+using System.Globalization;
+using System.Linq;
+using System.Reactive.Linq;
+using GitHub.Extensions;
+using GitHub.Logging;
+using GitHub.Models;
+using Serilog;
+
+namespace GitHub.Services
+{
+    [Export(typeof(IAutoCompleteAdvisor))]
+    [PartCreationPolicy(CreationPolicy.Shared)]
+    public class AutoCompleteAdvisor : IAutoCompleteAdvisor
+    {
+        const int SuggestionCount = 5; // The number of suggestions we'll provide. github.com does 5.
+
+        static readonly ILogger log = LogManager.ForContext<AutoCompleteAdvisor>();
+        readonly Lazy<Dictionary<string, IAutoCompleteSource>> prefixSourceMap;
+
+        [ImportingConstructor]
+        public AutoCompleteAdvisor([ImportMany(typeof(IAutoCompleteSource))]IEnumerable<IAutoCompleteSource> autocompleteSources)
+        {
+            prefixSourceMap = new Lazy<Dictionary<string, IAutoCompleteSource>>(
+                () => autocompleteSources.ToDictionary(s => s.Prefix, s => s));
+        }
+
+        public IObservable<AutoCompleteResult> GetAutoCompletionSuggestions(string text, int caretPosition)
+        {
+            Guard.ArgumentNotNull("text", text);
+
+            if (caretPosition < 0 || caretPosition > text.Length)
+            {
+                string error = String.Format(CultureInfo.InvariantCulture,
+                    "The CaretPosition '{0}', is not in the range of '0' and the text length '{1}' for the text '{2}'",
+                    caretPosition,
+                    text.Length,
+                    text);
+
+                // We need to be alerted when this happens because it should never happen.
+                // But it apparently did happen in production.
+                Debug.Fail(error);
+                log.Error(error);
+                return Observable.Empty<AutoCompleteResult>();
+            }
+            var tokenAndSource = PrefixSourceMap
+                .Select(kvp => new {Source = kvp.Value, Token = ParseAutoCompletionToken(text, caretPosition, kvp.Key)})
+                .FirstOrDefault(s => s.Token != null);
+
+            if (tokenAndSource == null)
+            {
+                return Observable.Return(AutoCompleteResult.Empty);
+            }
+
+            return tokenAndSource.Source.GetSuggestions()
+                .Select(suggestion => new
+                {
+                    suggestion,
+                    rank = suggestion.GetSortRank(tokenAndSource.Token.SearchSearchPrefix)
+                })
+                .Where(suggestion => suggestion.rank > -1)
+                .ToList()
+                .Select(suggestions => suggestions
+                    .OrderByDescending(s => s.rank)
+                    .ThenBy(s => s.suggestion.Name)
+                    .Take(SuggestionCount)
+                    .Select(s => s.suggestion)
+                    .ToList())
+                .Select(suggestions => new AutoCompleteResult(tokenAndSource.Token.Offset,
+                    new ReadOnlyCollection<AutoCompleteSuggestion>(suggestions)))
+                .Catch<AutoCompleteResult, Exception>(e =>
+                {
+                    log.Error(e, "Error Getting AutoCompleteResult");
+                    return Observable.Return(AutoCompleteResult.Empty);
+                });
+        }
+
+        [SuppressMessage("Microsoft.Usage", "CA2233:OperationsShouldNotOverflow", MessageId = "caretPosition-1"
+            , Justification = "We ensure the argument is greater than -1 so it can't overflow")]
+        public static AutoCompletionToken ParseAutoCompletionToken(string text, int caretPosition, string triggerPrefix)
+        {
+            Guard.ArgumentNotNull("text", text);
+            Guard.ArgumentInRange(caretPosition, 0, text.Length, "caretPosition");
+            if (caretPosition == 0 || text.Length == 0) return null;
+
+            // :th     : 1
+            //:th      : 0
+            //Hi :th   : 3
+            int beginningOfWord = text.LastIndexOfAny(new[] { ' ', '\n' }, caretPosition - 1) + 1;
+            string word = text.Substring(beginningOfWord, caretPosition - beginningOfWord);
+            if (!word.StartsWith(triggerPrefix, StringComparison.Ordinal)) return null;
+
+            return new AutoCompletionToken(word.Substring(1), beginningOfWord);
+        }
+
+        Dictionary<string, IAutoCompleteSource> PrefixSourceMap { get { return prefixSourceMap.Value; } }
+    }
+
+    public class AutoCompletionToken
+    {
+        public AutoCompletionToken(string searchPrefix, int offset)
+        {
+            Guard.ArgumentNotNull(searchPrefix, "searchPrefix");
+            Guard.ArgumentNonNegative(offset, "offset");
+
+            SearchSearchPrefix = searchPrefix;
+            Offset = offset;
+        }
+
+        /// <summary>
+        /// Used to filter the list of auto complete suggestions to what the user has typed in.
+        /// </summary>
+        public string SearchSearchPrefix { get; private set; }
+        public int Offset { get; private set; }
+    }
+}

src/GitHub.App/Services/IAutoCompleteSource.cs

@@ -0,0 +1,13 @@
+using System;
+using GitHub.Models;
+
+namespace GitHub.Services
+{
+    public interface IAutoCompleteSource
+    {
+        IObservable<AutoCompleteSuggestion> GetSuggestions();
+
+        // The prefix used to trigger auto completion.
+        string Prefix { get; }
+    }
+}

src/GitHub.App/Services/IssuesAutoCompleteSource.cs

@@ -0,0 +1,136 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.Composition;
+using System.Linq;
+using System.Reactive.Linq;
+using GitHub.Api;
+using GitHub.Extensions;
+using GitHub.Models;
+using GitHub.Primitives;
+using Octokit.GraphQL;
+using Octokit.GraphQL.Model;
+using static Octokit.GraphQL.Variable;
+
+namespace GitHub.Services
+{
+    [Export(typeof(IAutoCompleteSource))]
+    [PartCreationPolicy(CreationPolicy.Shared)]
+    public class IssuesAutoCompleteSource : IAutoCompleteSource
+    {
+        readonly ITeamExplorerContext teamExplorerContext;
+        readonly IGraphQLClientFactory graphqlFactory;
+        ICompiledQuery<Page<SuggestionItem>> query;
+
+        [ImportingConstructor]
+        public IssuesAutoCompleteSource(ITeamExplorerContext teamExplorerContext, IGraphQLClientFactory graphqlFactory)
+        {
+            Guard.ArgumentNotNull(teamExplorerContext, nameof(teamExplorerContext));
+            Guard.ArgumentNotNull(graphqlFactory, nameof(graphqlFactory));
+
+            this.teamExplorerContext = teamExplorerContext;
+            this.graphqlFactory = graphqlFactory;
+        }
+
+        public IObservable<AutoCompleteSuggestion> GetSuggestions()
+        {
+            var localRepositoryModel = teamExplorerContext.ActiveRepository;
+
+            var hostAddress = HostAddress.Create(localRepositoryModel.CloneUrl.Host);
+            var owner = localRepositoryModel.Owner;
+            var name = localRepositoryModel.Name;
+
+            string filter;
+            string after;
+
+            if (query == null)
+            {
+               query = new Query().Search(query: Var(nameof(filter)), SearchType.Issue, 100, after: Var(nameof(after)))
+                       .Select(item => new Page<SuggestionItem>
+                       {
+                           Items = item.Nodes.Select(searchResultItem => 
+                               searchResultItem.Switch<SuggestionItem>(selector => selector
+                                       .Issue(i => new SuggestionItem("#" + i.Number, i.Title) { LastModifiedDate = i.LastEditedAt })
+                                       .PullRequest(p => new SuggestionItem("#" + p.Number, p.Title) { LastModifiedDate = p.LastEditedAt }))
+                               ).ToList(),
+                           EndCursor = item.PageInfo.EndCursor,
+                           HasNextPage = item.PageInfo.HasNextPage,
+                           TotalCount = item.IssueCount
+                       })
+                       .Compile();
+            }
+
+            filter = $"repo:{owner}/{name}";
+
+            return Observable.FromAsync(async () =>
+            {
+                var results = new List<SuggestionItem>();
+
+                var variables = new Dictionary<string, object>
+                {
+                    {nameof(filter), filter },
+                };
+
+                var connection = await graphqlFactory.CreateConnection(hostAddress);
+                var searchResults = await connection.Run(query, variables);
+
+                results.AddRange(searchResults.Items);
+
+                while (searchResults.HasNextPage)
+                {
+                    variables[nameof(after)] = searchResults.EndCursor;
+                    searchResults = await connection.Run(query, variables);
+
+                    results.AddRange(searchResults.Items);
+                }
+
+                return results.Select(item => new IssueAutoCompleteSuggestion(item, Prefix));
+
+            }).SelectMany(observable => observable);
+        }
+
+        class SearchResult
+        {
+            public SuggestionItem SuggestionItem { get; set; }
+        }
+
+        public string Prefix
+        {
+            get { return "#"; }
+        }
+
+        class IssueAutoCompleteSuggestion : AutoCompleteSuggestion
+        {
+            // Just needs to be some value before GitHub stored its first issue.
+            static readonly DateTimeOffset lowerBound = new DateTimeOffset(2000, 1, 1, 12, 0, 0, TimeSpan.FromSeconds(0));
+
+            readonly SuggestionItem suggestion;
+            public IssueAutoCompleteSuggestion(SuggestionItem suggestion, string prefix)
+                : base(suggestion.Name, suggestion.Description, prefix)
+            {
+                this.suggestion = suggestion;
+            }
+
+            public override int GetSortRank(string text)
+            {
+                // We need to override the sort rank behavior because when we display issues, we include the prefix
+                // unlike mentions. So we need to account for that in how we do filtering.
+                if (text.Length == 0)
+                {
+                    return (int) ((suggestion.LastModifiedDate ?? lowerBound) - lowerBound).TotalSeconds;
+                }
+                // Name is always "#" followed by issue number.
+                return Name.StartsWith("#" + text, StringComparison.OrdinalIgnoreCase)
+                        ? 1
+                        : DescriptionWords.Any(word => word.StartsWith(text, StringComparison.OrdinalIgnoreCase))
+                            ? 0
+                            : -1;
+            }
+
+            // This is what gets "completed" when you tab.
+            public override string ToString()
+            {
+                return Name;
+            }
+        }
+    }
+}