// 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.Diagnostics;
using Analyzer.Utilities;
using Analyzer.Utilities.Extensions;
using System.Diagnostics;

namespace Microsoft.CodeQuality.Analyzers.ApiDesignGuidelines
{
    using static MicrosoftCodeQualityAnalyzersResources;

    /// <summary>
    /// CA1044: <inheritdoc cref="PropertiesShouldNotBeWriteOnlyTitle"/>
    /// </summary>
    [DiagnosticAnalyzer(LanguageNames.CSharp, LanguageNames.VisualBasic)]
    public sealed class PropertiesShouldNotBeWriteOnlyAnalyzer : DiagnosticAnalyzer
    {
        internal const string RuleId = "CA1044";

        private static readonly LocalizableString s_localizableTitle = CreateLocalizableResourceString(nameof(PropertiesShouldNotBeWriteOnlyTitle));
        private static readonly LocalizableString s_localizableDescription = CreateLocalizableResourceString(nameof(PropertiesShouldNotBeWriteOnlyDescription));

        internal static readonly DiagnosticDescriptor AddGetterRule = DiagnosticDescriptorHelper.Create(
            RuleId,
            s_localizableTitle,
            CreateLocalizableResourceString(nameof(PropertiesShouldNotBeWriteOnlyMessageAddGetter)),
            DiagnosticCategory.Design,
            RuleLevel.Disabled,
            description: s_localizableDescription,
            isPortedFxCopRule: true,
            isDataflowRule: false);

        internal static readonly DiagnosticDescriptor MakeMoreAccessibleRule = DiagnosticDescriptorHelper.Create(
            RuleId,
            s_localizableTitle,
            CreateLocalizableResourceString(nameof(PropertiesShouldNotBeWriteOnlyMessageMakeMoreAccessible)),
            DiagnosticCategory.Design,
            RuleLevel.Disabled,
            description: s_localizableDescription,
            isPortedFxCopRule: true,
            isDataflowRule: false);

        public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics { get; } = ImmutableArray.Create(AddGetterRule, MakeMoreAccessibleRule);

        public override void Initialize(AnalysisContext context)
        {
            context.EnableConcurrentExecution();
            context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.None);

            context.RegisterSymbolAction(AnalyzeSymbol, SymbolKind.Property);
        }

        /// <summary>
        /// Implementation for CA1044: Properties should not be write only
        /// </summary>
        private static void AnalyzeSymbol(SymbolAnalysisContext context)
        {
            var property = (IPropertySymbol)context.Symbol;

            // not raising a violation for when:
            //     property is overridden because the issue can only be fixed in the base type
            //     property is the implementation of any interface member
            if (property.IsOverride || GetRule(property) is not DiagnosticDescriptor descriptor || property.IsImplementationOfAnyInterfaceMember())
            {
                return;
            }

            Debug.Assert(context.Options.MatchesConfiguredVisibility(MakeMoreAccessibleRule, property, context.Compilation) == context.Options.MatchesConfiguredVisibility(AddGetterRule, property, context.Compilation));
            Debug.Assert(descriptor == MakeMoreAccessibleRule || descriptor == AddGetterRule);

            // Only analyze externally visible properties by default
            if (context.Options.MatchesConfiguredVisibility(descriptor, property, context.Compilation))
            {
                context.ReportDiagnostic(property.CreateDiagnostic(descriptor, property.Name));
            }
        }

        private static DiagnosticDescriptor? GetRule(IPropertySymbol property)
        {
            // We handled the non-CA1044 cases earlier.  Now, we handle CA1044 cases
            // If there is no getter then it is not accessible
            if (property.IsWriteOnly)
            {
                return AddGetterRule;
            }
            // Otherwise if there is a setter, check for its relative accessibility
            else if (!property.IsReadOnly && (property.GetMethod!.DeclaredAccessibility < property.SetMethod!.DeclaredAccessibility))
            {
                return MakeMoreAccessibleRule;
            }

            return null;
        }
    }
}