// 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.Generic;
using System.Collections.Immutable;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.CodeActions;
using Microsoft.CodeAnalysis.CodeFixesAndRefactorings;
using Microsoft.CodeAnalysis.Text;
 
namespace Microsoft.CodeAnalysis.CodeFixes
{
    /// <summary>
    /// Implement this abstract type to provide fix all/multiple occurrences code fixes for source code problems.
    /// Alternatively, you can use any of the well known fix all providers from <see cref="WellKnownFixAllProviders"/>.
    /// </summary>
    public abstract class FixAllProvider : IFixAllProvider
    {
        private protected static ImmutableArray<FixAllScope> DefaultSupportedFixAllScopes
            = ImmutableArray.Create(FixAllScope.Document, FixAllScope.Project, FixAllScope.Solution);
 
        /// <summary>
        /// Gets the supported scopes for fixing all occurrences of a diagnostic.
        /// By default, it returns the following scopes:
        /// (a) <see cref="FixAllScope.Document"/>
        /// (b) <see cref="FixAllScope.Project"/> and
        /// (c) <see cref="FixAllScope.Solution"/>
        /// </summary>
        public virtual IEnumerable<FixAllScope> GetSupportedFixAllScopes()
            => DefaultSupportedFixAllScopes;
 
        /// <summary>
        /// Gets the diagnostic IDs for which fix all occurrences is supported.
        /// By default, it returns <see cref="CodeFixProvider.FixableDiagnosticIds"/> for the given <paramref name="originalCodeFixProvider"/>.
        /// </summary>
        /// <param name="originalCodeFixProvider">Original code fix provider that returned this fix all provider from <see cref="CodeFixProvider.GetFixAllProvider"/> method.</param>
        public virtual IEnumerable<string> GetSupportedFixAllDiagnosticIds(CodeFixProvider originalCodeFixProvider)
            => originalCodeFixProvider.FixableDiagnosticIds;
 
        /// <summary>
        /// Gets fix all occurrences fix for the given fixAllContext.
        /// </summary>
        public abstract Task<CodeAction?> GetFixAsync(FixAllContext fixAllContext);
 
        /// <summary>
        /// Create a <see cref="FixAllProvider"/> that fixes documents independently.  This should be used instead of
        /// <see cref="WellKnownFixAllProviders.BatchFixer"/> in the case where fixes for a <see cref="Diagnostic"/>
        /// only affect the <see cref="Document"/> the diagnostic was produced in.
        /// </summary>
        /// <param name="fixAllAsync">
        /// Callback that will the fix diagnostics present in the provided document.  The document returned will only be
        /// examined for its content (e.g. it's <see cref="SyntaxTree"/> or <see cref="SourceText"/>.  No other aspects
        /// of it (like attributes), or changes to the <see cref="Project"/> or <see cref="Solution"/> it points at
        /// will be considered.
        /// </param>
        public static FixAllProvider Create(Func<FixAllContext, Document, ImmutableArray<Diagnostic>, Task<Document?>> fixAllAsync)
            => Create(fixAllAsync, DefaultSupportedFixAllScopes);
 
        /// <summary>
        /// Create a <see cref="FixAllProvider"/> that fixes documents independently for the given <paramref name="supportedFixAllScopes"/>.
        /// This should be used instead of <see cref="WellKnownFixAllProviders.BatchFixer"/> in the case where
        /// fixes for a <see cref="Diagnostic"/> only affect the <see cref="Document"/> the diagnostic was produced in.
        /// </summary>
        /// <param name="fixAllAsync">
        /// Callback that will the fix diagnostics present in the provided document.  The document returned will only be
        /// examined for its content (e.g. it's <see cref="SyntaxTree"/> or <see cref="SourceText"/>.  No other aspects
        /// of it (like attributes), or changes to the <see cref="Project"/> or <see cref="Solution"/> it points at
        /// will be considered.
        /// </param>
        /// <param name="supportedFixAllScopes">
        /// Supported <see cref="FixAllScope"/>s for the fix all provider.
        /// Note that <see cref="FixAllScope.Custom"/> is not supported by the <see cref="DocumentBasedFixAllProvider"/>
        /// and should not be part of the supported scopes.
        /// </param>
        public static FixAllProvider Create(
            Func<FixAllContext, Document, ImmutableArray<Diagnostic>, Task<Document?>> fixAllAsync,
            ImmutableArray<FixAllScope> supportedFixAllScopes)
        {
            if (fixAllAsync is null)
                throw new ArgumentNullException(nameof(fixAllAsync));
 
            if (supportedFixAllScopes.IsDefault)
                throw new ArgumentNullException(nameof(supportedFixAllScopes));
 
            if (supportedFixAllScopes.Contains(FixAllScope.Custom))
                throw new ArgumentException(WorkspacesResources.FixAllScope_Custom_is_not_supported_with_this_API, nameof(supportedFixAllScopes));
 
            return new CallbackDocumentBasedFixAllProvider(fixAllAsync, supportedFixAllScopes);
        }
 
        #region IFixAllProvider implementation
        Task<CodeAction?> IFixAllProvider.GetFixAsync(IFixAllContext fixAllContext)
            => this.GetFixAsync((FixAllContext)fixAllContext);
        #endregion
 
        private class CallbackDocumentBasedFixAllProvider : DocumentBasedFixAllProvider
        {
            private readonly Func<FixAllContext, Document, ImmutableArray<Diagnostic>, Task<Document?>> _fixAllAsync;
 
            public CallbackDocumentBasedFixAllProvider(
                Func<FixAllContext, Document, ImmutableArray<Diagnostic>, Task<Document?>> fixAllAsync,
                ImmutableArray<FixAllScope> supportedFixAllScopes)
                : base(supportedFixAllScopes)
            {
                _fixAllAsync = fixAllAsync;
            }
 
            protected override Task<Document?> FixAllAsync(FixAllContext context, Document document, ImmutableArray<Diagnostic> diagnostics)
                => _fixAllAsync(context, document, diagnostics);
        }
    }
}