Terminal.Gui/UnitTests/Views/AppendAutocompleteTests.cs

using System;
using System.Collections.Generic;
using System.Linq;
using Xunit;
using Xunit.Abstractions;

namespace Terminal.Gui.TextTests;

public class AppendAutocompleteTests {
	readonly ITestOutputHelper output;

	public AppendAutocompleteTests (ITestOutputHelper output) => this.output = output;

	[Fact]
	[AutoInitShutdown]
	public void TestAutoAppend_ShowThenAccept_MatchCase ()
	{
		var tf = GetTextFieldsInView ();

		tf.Autocomplete = new AppendAutocomplete (tf);
		var generator = (SingleWordSuggestionGenerator)tf.Autocomplete.SuggestionGenerator;
		generator.AllSuggestions = new List<string> { "fish" };

		tf.Draw ();
		tf.PositionCursor ();
		TestHelpers.AssertDriverContentsAre ("", output);

		tf.NewKeyDownEvent (new Key ('f'));

		tf.Draw ();
		tf.PositionCursor ();
		TestHelpers.AssertDriverContentsAre ("fish", output);
		Assert.Equal ("f", tf.Text);

		Application.Driver.SendKeys ('\t', ConsoleKey.Tab, false, false, false);

		tf.Draw ();
		TestHelpers.AssertDriverContentsAre ("fish", output);
		Assert.Equal ("fish", tf.Text);

		// Tab should autcomplete but not move focus
		Assert.Same (tf, Application.Top.Focused);

		// Second tab should move focus (nothing to autocomplete)
		Application.Driver.SendKeys ('\t', ConsoleKey.Tab, false, false, false);
		Assert.NotSame (tf, Application.Top.Focused);
	}

	[Fact]
	[AutoInitShutdown]
	public void TestAutoAppend_ShowThenAccept_CasesDiffer ()
	{
		var tf = GetTextFieldsInView ();

		tf.Autocomplete = new AppendAutocomplete (tf);
		var generator = (SingleWordSuggestionGenerator)tf.Autocomplete.SuggestionGenerator;
		generator.AllSuggestions = new List<string> { "FISH" };

		tf.Draw ();
		tf.PositionCursor ();
		TestHelpers.AssertDriverContentsAre ("", output);
		tf.NewKeyDownEvent (new Key ((KeyCode)'m'));
		tf.NewKeyDownEvent (new Key ((KeyCode)'y'));
		tf.NewKeyDownEvent (new Key (KeyCode.Space));
		tf.NewKeyDownEvent (new Key ((KeyCode)'f'));
		Assert.Equal ("my f", tf.Text);

		// Even though there is no match on case we should still get the suggestion
		tf.Draw ();
		tf.PositionCursor ();
		TestHelpers.AssertDriverContentsAre ("my fISH", output);
		Assert.Equal ("my f", tf.Text);

		// When tab completing the case of the whole suggestion should be applied
		Application.Driver.SendKeys ('\t', ConsoleKey.Tab, false, false, false);
		tf.Draw ();
		TestHelpers.AssertDriverContentsAre ("my FISH", output);
		Assert.Equal ("my FISH", tf.Text);
	}

	[Fact]
	[AutoInitShutdown]
	public void TestAutoAppend_AfterCloseKey_NoAutocomplete ()
	{
		var tf = GetTextFieldsInViewSuggesting ("fish");

		// f is typed and suggestion is "fish"
		Application.Driver.SendKeys ('f', ConsoleKey.F, false, false, false);
		tf.Draw ();
		tf.PositionCursor ();
		TestHelpers.AssertDriverContentsAre ("fish", output);
		Assert.Equal ("f", tf.Text);

		// When cancelling autocomplete
		Application.Driver.SendKeys ('e', ConsoleKey.Escape, false, false, false);

		// Suggestion should disappear
		tf.Draw ();
		TestHelpers.AssertDriverContentsAre ("f", output);
		Assert.Equal ("f", tf.Text);

		// Still has focus though
		Assert.Same (tf, Application.Top.Focused);

		// But can tab away
		Application.Driver.SendKeys ('\t', ConsoleKey.Tab, false, false, false);
		Assert.NotSame (tf, Application.Top.Focused);
	}

	[Fact]
	[AutoInitShutdown]
	public void TestAutoAppend_AfterCloseKey_ReappearsOnLetter ()
	{
		var tf = GetTextFieldsInViewSuggesting ("fish");

		// f is typed and suggestion is "fish"
		Application.Driver.SendKeys ('f', ConsoleKey.F, false, false, false);
		tf.Draw ();
		tf.PositionCursor ();
		TestHelpers.AssertDriverContentsAre ("fish", output);
		Assert.Equal ("f", tf.Text);

		// When cancelling autocomplete
		Application.Driver.SendKeys ('\0', ConsoleKey.Escape, false, false, false);

		// Suggestion should disappear
		tf.Draw ();
		TestHelpers.AssertDriverContentsAre ("f", output);
		Assert.Equal ("f", tf.Text);

		// Should reappear when you press next letter
		Application.Driver.SendKeys ('i', ConsoleKey.I, false, false, false);
		tf.Draw ();
		tf.PositionCursor ();
		TestHelpers.AssertDriverContentsAre ("fish", output);
		Assert.Equal ("fi", tf.Text);
	}

	[Theory]
	[AutoInitShutdown]
	[InlineData ("ffffffffffffffffffffffffff", "ffffffffff")]
	[InlineData ("f234567890", "f234567890")]
	[InlineData ("fisérables", "fisérables")]
	public void TestAutoAppendRendering_ShouldNotOverspill (string overspillUsing, string expectRender)
	{
		var tf = GetTextFieldsInViewSuggesting (overspillUsing);

		// f is typed we should only see 'f' up to size of View (10)
		Application.Driver.SendKeys ('f', ConsoleKey.F, false, false, false);
		tf.Draw ();
		tf.PositionCursor ();
		TestHelpers.AssertDriverContentsAre (expectRender, output);
		Assert.Equal ("f", tf.Text);
	}

	[Theory]
	[AutoInitShutdown]
	[InlineData (ConsoleKey.UpArrow)]
	[InlineData (ConsoleKey.DownArrow)]
	public void TestAutoAppend_CycleSelections (ConsoleKey cycleKey)
	{
		var tf = GetTextFieldsInViewSuggesting ("fish", "friend");

		// f is typed and suggestion is "fish"
		Application.Driver.SendKeys ('f', ConsoleKey.F, false, false, false);
		tf.Draw ();
		tf.PositionCursor ();
		TestHelpers.AssertDriverContentsAre ("fish", output);
		Assert.Equal ("f", tf.Text);

		// When cycling autocomplete
		Application.Driver.SendKeys (' ', cycleKey, false, false, false);

		tf.Draw ();
		tf.PositionCursor ();
		TestHelpers.AssertDriverContentsAre ("friend", output);
		Assert.Equal ("f", tf.Text);

		// Should be able to cycle in circles endlessly
		Application.Driver.SendKeys (' ', cycleKey, false, false, false);
		tf.Draw ();
		tf.PositionCursor ();
		TestHelpers.AssertDriverContentsAre ("fish", output);
		Assert.Equal ("f", tf.Text);
	}

	[Fact]
	[AutoInitShutdown]
	public void TestAutoAppend_NoRender_WhenNoMatch ()
	{
		var tf = GetTextFieldsInViewSuggesting ("fish");

		// f is typed and suggestion is "fish"
		Application.Driver.SendKeys ('f', ConsoleKey.F, false, false, false);
		tf.Draw ();
		tf.PositionCursor ();
		TestHelpers.AssertDriverContentsAre ("fish", output);
		Assert.Equal ("f", tf.Text);

		// x is typed and suggestion should disappear
		Application.Driver.SendKeys ('x', ConsoleKey.X, false, false, false);
		tf.Draw ();
		TestHelpers.AssertDriverContentsAre ("fx", output);
		Assert.Equal ("fx", tf.Text);
	}

	[Fact]
	[AutoInitShutdown]
	public void TestAutoAppend_NoRender_WhenCursorNotAtEnd ()
	{
		var tf = GetTextFieldsInViewSuggesting ("fish");

		// f is typed and suggestion is "fish"
		Application.Driver.SendKeys ('f', ConsoleKey.F, false, false, false);
		tf.Draw ();
		tf.PositionCursor ();
		TestHelpers.AssertDriverContentsAre ("fish", output);
		Assert.Equal ("f", tf.Text);

		// add a space then go back 1
		Application.Driver.SendKeys (' ', ConsoleKey.Spacebar, false, false, false);
		Application.Driver.SendKeys ('<', ConsoleKey.LeftArrow, false, false, false);

		tf.Draw ();
		TestHelpers.AssertDriverContentsAre ("f", output);
		Assert.Equal ("f ", tf.Text);
	}


	TextField GetTextFieldsInViewSuggesting (params string [] suggestions)
	{
		var tf = GetTextFieldsInView ();

		tf.Autocomplete = new AppendAutocomplete (tf);
		var generator = (SingleWordSuggestionGenerator)tf.Autocomplete.SuggestionGenerator;
		generator.AllSuggestions = suggestions.ToList ();

		tf.Draw ();
		tf.PositionCursor ();
		TestHelpers.AssertDriverContentsAre ("", output);

		return tf;
	}

	TextField GetTextFieldsInView ()
	{
		var tf = new TextField {
			Width = 10
		};
		var tf2 = new TextField {
			Y = 1,
			Width = 10
		};

		var top = Application.Top;
		top.Add (tf);
		top.Add (tf2);

		Application.Begin (top);

		Assert.Same (tf, top.Focused);

		return tf;
	}
}