// 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.Collections.Immutable;
using System.Threading;
using System.Threading.Tasks;
 
namespace Microsoft.CodeAnalysis.FindSymbols;
 
// This file contains the legacy FindReferences APIs.  The APIs are legacy because they
// do not contain enough information for us to effectively remote them over to the OOP
// process to do the work.  Specifically, they lack the "current project context" necessary
// to be able to effectively serialize symbols to/from the remote process.
 
public static partial class SymbolFinder
{
    /// <summary>
    /// Finds all references to a symbol throughout a solution
    /// </summary>
    /// <param name="symbol">The symbol to find references to.</param>
    /// <param name="solution">The solution to find references within.</param>
    /// <param name="cancellationToken">A cancellation token.</param>
    public static Task<IEnumerable<ReferencedSymbol>> FindReferencesAsync(
        ISymbol symbol,
        Solution solution,
        CancellationToken cancellationToken = default)
    {
        if (symbol is null)
            throw new System.ArgumentNullException(nameof(symbol));
        if (solution is null)
            throw new System.ArgumentNullException(nameof(solution));
 
        return FindReferencesAsync(symbol, solution, FindReferencesSearchOptions.Default, cancellationToken);
    }
 
    internal static async Task<IEnumerable<ReferencedSymbol>> FindReferencesAsync(
        ISymbol symbol,
        Solution solution,
        FindReferencesSearchOptions options,
        CancellationToken cancellationToken)
    {
        var progressCollector = new StreamingProgressCollector();
        await FindReferencesAsync(
            symbol, solution, progressCollector,
            documents: null, options, cancellationToken).ConfigureAwait(false);
        return progressCollector.GetReferencedSymbols();
    }
 
    /// <summary>
    /// Finds all references to a symbol throughout a solution
    /// </summary>
    /// <param name="symbol">The symbol to find references to.</param>
    /// <param name="solution">The solution to find references within.</param>
    /// <param name="documents">A set of documents to be searched. If documents is null, then that means "all documents".</param>
    /// <param name="cancellationToken">A cancellation token.</param>
    public static Task<IEnumerable<ReferencedSymbol>> FindReferencesAsync(
        ISymbol symbol,
        Solution solution,
        IImmutableSet<Document>? documents,
        CancellationToken cancellationToken = default)
    {
        if (symbol is null)
            throw new System.ArgumentNullException(nameof(symbol));
        if (solution is null)
            throw new System.ArgumentNullException(nameof(solution));
        return FindReferencesAsync(symbol, solution, progress: null, documents: documents, cancellationToken: cancellationToken);
    }
 
    /// <summary>
    /// Finds all references to a symbol throughout a solution
    /// </summary>
    /// <param name="symbol">The symbol to find references to.</param>
    /// <param name="solution">The solution to find references within.</param>
    /// <param name="progress">An optional progress object that will receive progress
    /// information as the search is undertaken.</param>
    /// <param name="documents">An optional set of documents to be searched. If documents is null, then that means "all documents".</param>
    /// <param name="cancellationToken">An optional cancellation token.</param>
    public static async Task<IEnumerable<ReferencedSymbol>> FindReferencesAsync(
        ISymbol symbol,
        Solution solution,
        IFindReferencesProgress? progress,
        IImmutableSet<Document>? documents,
        CancellationToken cancellationToken = default)
    {
        if (symbol is null)
            throw new System.ArgumentNullException(nameof(symbol));
        if (solution is null)
            throw new System.ArgumentNullException(nameof(solution));
        return await FindReferencesAsync(
            symbol, solution, progress, documents,
            FindReferencesSearchOptions.Default, cancellationToken).ConfigureAwait(false);
    }
 
    internal static async Task<ImmutableArray<ReferencedSymbol>> FindReferencesAsync(
        ISymbol symbol,
        Solution solution,
        IFindReferencesProgress? progress,
        IImmutableSet<Document>? documents,
        FindReferencesSearchOptions options,
        CancellationToken cancellationToken)
    {
        progress ??= NoOpFindReferencesProgress.Instance;
        var streamingProgress = new StreamingProgressCollector(
            new StreamingFindReferencesProgressAdapter(progress));
        await FindReferencesAsync(
            symbol, solution, streamingProgress, documents,
            options, cancellationToken).ConfigureAwait(false);
        return streamingProgress.GetReferencedSymbols();
    }
 
    internal static class TestAccessor
    {
        internal static Task<ImmutableArray<ReferencedSymbol>> FindReferencesAsync(
            ISymbol symbol,
            Solution solution,
            IFindReferencesProgress progress,
            IImmutableSet<Document> documents,
            FindReferencesSearchOptions options,
            CancellationToken cancellationToken)
        {
            return SymbolFinder.FindReferencesAsync(symbol, solution, progress, documents, options, cancellationToken);
        }
    }
}