// 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.Immutable;
using Microsoft.CodeAnalysis.Operations;

namespace Microsoft.CodeAnalysis.ConvertIfToSwitch;

internal abstract partial class AbstractConvertIfToSwitchCodeRefactoringProvider<
    TIfStatementSyntax,
    TExpressionSyntax,
    TIsExpressionSyntax,
    TPatternSyntax>
    where TIfStatementSyntax : SyntaxNode
    where TExpressionSyntax : SyntaxNode
    where TIsExpressionSyntax : SyntaxNode
    where TPatternSyntax : SyntaxNode
{
    /// <summary>
    /// Represents a switch-section constructed from a series of
    /// if-conditions, possibly combined with logical-or operator
    /// </summary>
    internal sealed class AnalyzedSwitchSection(ImmutableArray<AnalyzedSwitchLabel> labels, IOperation body, SyntaxNode syntaxToRemove)
    {
        public readonly ImmutableArray<AnalyzedSwitchLabel> Labels = labels;
        public readonly IOperation Body = body;
        public readonly SyntaxNode SyntaxToRemove = syntaxToRemove;
    }

    /// <summary>
    /// Represents a switch-label constructed from a series of
    /// if-conditions, possibly combined by logical-and operator
    /// </summary>
    internal sealed class AnalyzedSwitchLabel(AnalyzedPattern pattern, ImmutableArray<TExpressionSyntax> guards)
    {
        public readonly AnalyzedPattern Pattern = pattern;
        public readonly ImmutableArray<TExpressionSyntax> Guards = guards;
    }

    /// <summary>
    /// Base class to represents a case clause (pattern) constructed from various checks
    /// </summary>
    internal abstract class AnalyzedPattern
    {
        private AnalyzedPattern()
        {
        }

        /// <summary>
        /// Represents a type-pattern, constructed from is-expression
        /// </summary>
        internal sealed class Type(TIsExpressionSyntax expression) : AnalyzedPattern
        {
            public readonly TIsExpressionSyntax IsExpressionSyntax = expression;
        }

        /// <summary>
        /// Represents a source-pattern constructed from C# patterns
        /// </summary>
        internal sealed class Source(TPatternSyntax patternSyntax) : AnalyzedPattern
        {
            public readonly TPatternSyntax PatternSyntax = patternSyntax;
        }

        /// <summary>
        /// Represents a constant-pattern constructed from an equality check
        /// </summary>
        internal sealed class Constant(TExpressionSyntax expression) : AnalyzedPattern
        {
            public readonly TExpressionSyntax ExpressionSyntax = expression;
        }

        /// <summary>
        /// Represents a relational-pattern constructed from comparison operators
        /// </summary>
        internal sealed class Relational(BinaryOperatorKind operatorKind, TExpressionSyntax value) : AnalyzedPattern
        {
            public readonly BinaryOperatorKind OperatorKind = operatorKind;
            public readonly TExpressionSyntax Value = value;
        }

        /// <summary>
        /// Represents a range-pattern constructed from a couple of comparison operators
        /// </summary>
        internal sealed class Range(TExpressionSyntax lowerBound, TExpressionSyntax higherBound) : AnalyzedPattern
        {
            public readonly TExpressionSyntax LowerBound = lowerBound;
            public readonly TExpressionSyntax HigherBound = higherBound;
        }

        /// <summary>
        /// Represents an and-pattern, constructed from two other patterns.
        /// </summary>
        internal sealed class And(AnalyzedPattern leftPattern, AnalyzedPattern rightPattern) : AnalyzedPattern
        {
            public readonly AnalyzedPattern LeftPattern = leftPattern;
            public readonly AnalyzedPattern RightPattern = rightPattern;
        }
    }
}