// 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.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using Microsoft.VisualStudio.Text.Editor;
using Roslyn.Utilities;
 
namespace Microsoft.CodeAnalysis.Diagnostics;
 
internal sealed class EditorAnalyzerConfigOptions : AnalyzerConfigOptions
{
    private readonly IDictionary<string, object> _configOptions;
 
    internal EditorAnalyzerConfigOptions(IEditorOptions editorOptions)
    {
        _configOptions = (editorOptions.GetOptionValue(DefaultOptions.RawCodingConventionsSnapshotOptionName) as IDictionary<string, object>) ??
            SpecializedCollections.EmptyDictionary<string, object>();
    }
 
    public override bool TryGetValue(string key, [NotNullWhen(true)] out string? value)
    {
        // TODO: the editor currently seems to store both lower-cased keys and original casing, the comparer is case-sensitive 
        // https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1556206
 
        if (_configOptions.TryGetValue(key.ToLowerInvariant(), out var objectValue))
        {
            // TODO: Although the editor exposes values typed to object they are actually strings.
            value = objectValue switch
            {
                null => null,
                string s => s,
                object o => o.ToString()
            };
 
            return value != null;
        }
 
        value = null;
        return false;
    }
 
    public override IEnumerable<string> Keys
        => _configOptions.Keys.Where(IsLowercase);
 
    private static bool IsLowercase(string str)
    {
        foreach (var c in str)
        {
            if (!char.IsLower(c))
            {
                return false;
            }
        }
 
        return true;
    }
}
 
internal static partial class EditorOptionsExtensions
{
    public static StructuredAnalyzerConfigOptions ToAnalyzerConfigOptions(this IEditorOptions editorOptions, StructuredAnalyzerConfigOptions fallbackOptions)
        => StructuredAnalyzerConfigOptions.Create(new EditorAnalyzerConfigOptions(editorOptions), fallbackOptions);
}