// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
#nullable disable
 
using Microsoft.CodeAnalysis.CSharp;
using Roslyn.Test.Utilities;
 
namespace Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.IntelliSense.CompletionSetSources;
 
public abstract class AbstractContextTests
{
    protected abstract void CheckResult(bool validLocation, int position, SyntaxTree syntaxTree);
 
    private void VerifyWorker(string markup, bool validLocation, CSharpParseOptions options = null)
    {
        MarkupTestFile.GetPosition(markup, out var code, out int position);
 
        VerifyAtPosition(code, position, validLocation, options: options);
        VerifyInFrontOfComment(code, position, validLocation, options: options);
        VerifyAtEndOfFile(code, position, validLocation, options: options);
        VerifyAtPosition_TypePartiallyWritten(code, position, validLocation, options: options);
        VerifyInFrontOfComment_TypePartiallyWritten(code, position, validLocation, options: options);
        VerifyAtEndOfFile_TypePartiallyWritten(code, position, validLocation, options: options);
    }
 
    private void VerifyInFrontOfComment(
        string text,
        int position,
        bool validLocation,
        string insertText,
        CSharpParseOptions options)
    {
        text = text[..position] + insertText + "/**/" + text[position..];
 
        position += insertText.Length;
 
        var tree = SyntaxFactory.ParseSyntaxTree(text, options: options);
 
        CheckResult(validLocation, position, tree);
    }
 
    private void VerifyInFrontOfComment(string text, int position, bool validLocation, CSharpParseOptions options)
        => VerifyInFrontOfComment(text, position, validLocation, string.Empty, options: options);
 
    private void VerifyInFrontOfComment_TypePartiallyWritten(string text, int position, bool validLocation, CSharpParseOptions options)
        => VerifyInFrontOfComment(text, position, validLocation, "Str", options: options);
 
    private void VerifyAtPosition(
        string text,
        int position,
        bool validLocation,
        string insertText,
        CSharpParseOptions options)
    {
        text = text[..position] + insertText + text[position..];
 
        position += insertText.Length;
 
        var tree = SyntaxFactory.ParseSyntaxTree(text, options: options);
        CheckResult(validLocation, position, tree);
    }
 
    private void VerifyAtPosition(string text, int position, bool validLocation, CSharpParseOptions options)
        => VerifyAtPosition(text, position, validLocation, string.Empty, options: options);
 
    private void VerifyAtPosition_TypePartiallyWritten(string text, int position, bool validLocation, CSharpParseOptions options)
        => VerifyAtPosition(text, position, validLocation, "Str", options: options);
 
    private void VerifyAtEndOfFile(
        string text,
        int position,
        bool validLocation,
        string insertText,
        CSharpParseOptions options)
    {
        // only do this if the placeholder was at the end of the text.
        if (text.Length != position)
        {
            return;
        }
 
        text = text[..position] + insertText;
 
        position += insertText.Length;
 
        var tree = SyntaxFactory.ParseSyntaxTree(text, options: options);
        CheckResult(validLocation, position, tree);
    }
 
    private void VerifyAtEndOfFile(string text, int position, bool validLocation, CSharpParseOptions options)
        => VerifyAtEndOfFile(text, position, validLocation, string.Empty, options: options);
 
    private void VerifyAtEndOfFile_TypePartiallyWritten(string text, int position, bool validLocation, CSharpParseOptions options)
        => VerifyAtEndOfFile(text, position, validLocation, "Str", options: options);
 
    protected void VerifyTrue(string text)
    {
        // run the verification in both context(normal and script)
        VerifyWorker(text, validLocation: true);
        VerifyWorker(text, validLocation: true, options: Options.Script);
    }
 
    protected void VerifyOnlyInScript(string text)
    {
        // run the verification in both context(normal and script)
        VerifyWorker(text, validLocation: false);
        VerifyWorker(text, validLocation: true, options: Options.Script);
    }
 
    protected void VerifyFalse(string text)
    {
        // run the verification in both context(normal and script)
        VerifyWorker(text, validLocation: false);
        VerifyWorker(text, validLocation: false, options: Options.Script);
    }
 
    protected static string AddInsideMethod(string text)
    {
        return
            """
            class C
            {
              void F()
              {
            """ + text +
            """
              }
            }
            """;
    }
 
    protected static string AddInsideClass(string text)
    {
        return
            """
            class C
            {
            """ + text +
@"}";
    }
}