// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.Collections.Immutable;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.Diagnostics;

namespace Microsoft.DotNet.CodeAnalysis.Analyzers;

[DiagnosticAnalyzer(LanguageNames.CSharp)]
public class ResourceUsageAnalyzer : BaseAnalyzer
{
    private const string Title = "Invalid SR.Format call";
    private const string Description = "The SR.Format call should be removed.";
    private const string AnalyzerName = "ResourceUsageAnalyzer";

    private static DiagnosticDescriptor InvalidSRFormatCall = new DiagnosticDescriptor(DiagnosticIds.BCL0020.ToString(), Title, "", AnalyzerName, DiagnosticSeverity.Error, isEnabledByDefault: true, description: Description);

    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics { get { return ImmutableArray.Create(InvalidSRFormatCall); } }

    INamedTypeSymbol SRSymbol { get; set; }

    public override void OnCompilationStart(CompilationStartAnalysisContext context)
    {
        SRSymbol = context.Compilation.GetTypeByMetadataName("System.SR");
        if (SRSymbol != null)
        {
            context.RegisterSyntaxNodeAction(AnalyzeNode, SyntaxKind.InvocationExpression);
        }
    }

    private void AnalyzeNode(SyntaxNodeAnalysisContext context)
    {
        InvocationExpressionSyntax invokeExpr = context.Node as InvocationExpressionSyntax;

        if (invokeExpr == null) return;

        MemberAccessExpressionSyntax memberAccessExpr = invokeExpr.Expression as MemberAccessExpressionSyntax;
        if (memberAccessExpr == null) return;

        IMethodSymbol memberSymbol = context.SemanticModel.GetSymbolInfo(memberAccessExpr).Symbol as IMethodSymbol;
        if (memberSymbol == null) return;

        if (memberSymbol.Name.Equals("Format") &&
            SymbolEqualityComparer.Default.Equals(memberSymbol.ContainingType, SRSymbol) &&
            memberSymbol.Parameters.Length == 1)
        {
            // There's no valid reason to call SR.Format(singleArg).  This generally happens accidentally
            // if someone is porting code and ends up with `SR.Format(SR.Something)`, in which case it should
            // just be simplified to `SR.Something`.
            context.ReportDiagnostic(Diagnostic.Create(InvalidSRFormatCall, invokeExpr.GetLocation(), invokeExpr.GetText()));
        }
    }
}