// 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.Threading;
using Roslyn.Utilities;

namespace Microsoft.CodeAnalysis.CSharp.Symbols
{
    internal partial class SourceNamespaceSymbol
    {
        internal override void ForceComplete(SourceLocation? locationOpt, Predicate<Symbol>? filter, CancellationToken cancellationToken)
        {
            if (filter?.Invoke(this) == false)
            {
                return;
            }

            while (true)
            {
                cancellationToken.ThrowIfCancellationRequested();
                var incompletePart = _state.NextIncompletePart;
                switch (incompletePart)
                {
                    case CompletionPart.NameToMembersMap:
                        {
                            var tmp = GetNameToMembersMap();
                        }
                        break;

                    case CompletionPart.MembersCompleted:
                        {
                            SingleNamespaceDeclaration? targetDeclarationWithImports = null;

                            // ensure relevant imports are complete.
                            foreach (var declaration in _mergedDeclaration.Declarations)
                            {
                                // We don't have to check `filter`: it was already checked above, so if it's not null and we're here, it must have returned true.
                                if (locationOpt == null || locationOpt.SourceTree == declaration.SyntaxReference.SyntaxTree)
                                {
                                    if (declaration.HasGlobalUsings || declaration.HasUsings || declaration.HasExternAliases)
                                    {
                                        targetDeclarationWithImports = declaration;
                                        GetAliasesAndUsings(declaration).Complete(this, declaration.SyntaxReference, cancellationToken);
                                    }
                                }
                            }

                            if (IsGlobalNamespace && (locationOpt is null || targetDeclarationWithImports is object))
                            {
                                GetMergedGlobalAliasesAndUsings(basesBeingResolved: null, cancellationToken).Complete(this, cancellationToken);
                            }

                            var members = this.GetMembers();

                            bool allCompleted = true;

                            if (this.DeclaringCompilation.Options.ConcurrentBuild)
                            {
                                RoslynParallel.For(
                                    0,
                                    members.Length,
                                    UICultureUtilities.WithCurrentUICulture<int>(i => ForceCompleteMemberConditionally(locationOpt, filter, members[i], cancellationToken)),
                                    cancellationToken);

                                foreach (var member in members)
                                {
                                    if (!member.HasComplete(CompletionPart.All))
                                    {
                                        allCompleted = false;
                                        break;
                                    }
                                }
                            }
                            else
                            {
                                foreach (var member in members)
                                {
                                    ForceCompleteMemberConditionally(locationOpt, filter, member, cancellationToken);
                                    allCompleted = allCompleted && member.HasComplete(CompletionPart.All);
                                }
                            }

                            if (allCompleted)
                            {
                                _state.NotePartComplete(CompletionPart.MembersCompleted);
                                break;
                            }
                            else
                            {
                                // NOTE: we're going to kick out of the completion part loop after this,
                                // so not making progress isn't a problem.
                                goto done;
                            }
                        }

                    case CompletionPart.None:
                        return;

                    default:
                        // any other values are completion parts intended for other kinds of symbols
                        _state.NotePartComplete(CompletionPart.All & ~CompletionPart.NamespaceSymbolAll);
                        break;
                }

                _state.SpinWaitComplete(incompletePart, cancellationToken);
            }

done:
// Don't return until we've seen all of the CompletionParts. This ensures all
// diagnostics have been reported (not necessarily on this thread).
            CompletionPart allParts = (locationOpt == null && filter == null) ? CompletionPart.NamespaceSymbolAll : CompletionPart.NamespaceSymbolAll & ~CompletionPart.MembersCompleted;
            _state.SpinWaitComplete(allParts, cancellationToken);
        }

        internal override bool HasComplete(CompletionPart part)
        {
            return _state.HasComplete(part);
        }
    }
}