// 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.

#nullable disable

using System.Collections.Generic;
using System.Collections.Immutable;
using System.Diagnostics;
using Microsoft.CodeAnalysis.CSharp.Symbols;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.PooledObjects;
using Microsoft.CodeAnalysis.Text;
using Roslyn.Utilities;

namespace Microsoft.CodeAnalysis.CSharp
{
    internal sealed class FixedStatementBinder : LocalScopeBinder
    {
        private readonly FixedStatementSyntax _syntax;

        public FixedStatementBinder(Binder enclosing, FixedStatementSyntax syntax)
            : base(enclosing)
        {
            Debug.Assert(syntax != null);
            _syntax = syntax;
        }

        protected override ImmutableArray<LocalSymbol> BuildLocals()
        {
            if (_syntax.Declaration != null)
            {
                var locals = new ArrayBuilder<LocalSymbol>(_syntax.Declaration.Variables.Count);

                _syntax.Declaration.Type.VisitRankSpecifiers((rankSpecifier, args) =>
                {
                    foreach (var size in rankSpecifier.Sizes)
                    {
                        if (size.Kind() != SyntaxKind.OmittedArraySizeExpression)
                        {
                            ExpressionVariableFinder.FindExpressionVariables(args.binder, args.locals, size);
                        }
                    }
                }, (binder: this, locals: locals));

                foreach (VariableDeclaratorSyntax declarator in _syntax.Declaration.Variables)
                {
                    locals.Add(MakeLocal(_syntax.Declaration, declarator, LocalDeclarationKind.FixedVariable, allowScoped: false));

                    // also gather expression-declared variables from the bracketed argument lists and the initializers
                    ExpressionVariableFinder.FindExpressionVariables(this, locals, declarator);
                }

                return locals.ToImmutable();
            }

            return ImmutableArray<LocalSymbol>.Empty;
        }

        internal override ImmutableArray<LocalSymbol> GetDeclaredLocalsForScope(SyntaxNode scopeDesignator)
        {
            if (_syntax == scopeDesignator)
            {
                return this.Locals;
            }

            throw ExceptionUtilities.Unreachable();
        }

        internal override ImmutableArray<LocalFunctionSymbol> GetDeclaredLocalFunctionsForScope(CSharpSyntaxNode scopeDesignator)
        {
            throw ExceptionUtilities.Unreachable();
        }

        internal override SyntaxNode ScopeDesignator
        {
            get
            {
                return _syntax;
            }
        }
    }
}