// 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.
 
using System;
using System.Collections.Immutable;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.Host;
using Microsoft.CodeAnalysis.Options;
using Microsoft.CodeAnalysis.Shared.Extensions;
using Microsoft.CodeAnalysis.Text;
 
namespace Microsoft.CodeAnalysis.CaseCorrection
{
    internal static class CaseCorrector
    {
        /// <summary>
        /// The annotation normally used on nodes to request case correction.
        /// </summary>
        public static readonly SyntaxAnnotation Annotation = new();
 
        /// <summary>
        /// Case corrects all names found in the provided document.
        /// </summary>
        public static async Task<Document> CaseCorrectAsync(Document document, CancellationToken cancellationToken = default)
        {
            var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
            if (root is null)
            {
                throw new NotSupportedException(WorkspacesResources.Document_does_not_support_syntax_trees);
            }
 
            return await CaseCorrectAsync(document, root.FullSpan, cancellationToken).ConfigureAwait(false);
        }
 
        /// <summary>
        /// Case corrects all names found in the spans of any nodes annotated with the provided
        /// annotation.
        /// </summary>
        public static async Task<Document> CaseCorrectAsync(Document document, SyntaxAnnotation annotation, CancellationToken cancellationToken = default)
        {
            var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
            if (root is null)
            {
                throw new NotSupportedException(WorkspacesResources.Document_does_not_support_syntax_trees);
            }
 
            return await CaseCorrectAsync(document, root.GetAnnotatedNodesAndTokens(annotation).Select(n => n.Span).ToImmutableArray(), cancellationToken).ConfigureAwait(false);
        }
 
        /// <summary>
        /// Case corrects all names found in the span.
        /// </summary>
        public static async Task<Document> CaseCorrectAsync(Document document, TextSpan span, CancellationToken cancellationToken = default)
        {
            return await CaseCorrectAsync(document, ImmutableArray.Create(span), cancellationToken).ConfigureAwait(false);
        }
 
        /// <summary>
        /// Case corrects all names found in the provided spans.
        /// </summary>
        public static Task<Document> CaseCorrectAsync(Document document, ImmutableArray<TextSpan> spans, CancellationToken cancellationToken = default)
            => document.GetRequiredLanguageService<ICaseCorrectionService>().CaseCorrectAsync(document, spans, cancellationToken);
 
        /// <summary>
        /// Case correct only things that don't require semantic information
        /// </summary>
        internal static SyntaxNode CaseCorrect(SyntaxNode root, ImmutableArray<TextSpan> spans, SolutionServices services, CancellationToken cancellationToken = default)
            => services.GetRequiredLanguageService<ICaseCorrectionService>(root.Language).CaseCorrect(root, spans, cancellationToken);
    }
}