// 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 Microsoft.CodeAnalysis.Text;
using Roslyn.Utilities;
 
namespace Microsoft.CodeAnalysis.Formatting.Rules
{
    /// <summary>
    /// set indentation level for the given text span. it can be relative, absolute or dependent to other tokens
    /// </summary>
    internal sealed class IndentBlockOperation
    {
        internal IndentBlockOperation(SyntaxToken startToken, SyntaxToken endToken, TextSpan textSpan, int indentationDelta, IndentBlockOption option)
        {
            Contract.ThrowIfFalse(option.IsMaskOn(IndentBlockOption.PositionMask));
 
            Contract.ThrowIfTrue(textSpan.Start < 0 || textSpan.Length < 0);
            Contract.ThrowIfTrue(startToken.RawKind == 0);
            Contract.ThrowIfTrue(endToken.RawKind == 0);
 
            this.BaseToken = default;
            this.TextSpan = textSpan;
 
            this.Option = option;
            this.StartToken = startToken;
            this.EndToken = endToken;
 
            this.IsRelativeIndentation = false;
            this.IndentationDeltaOrPosition = indentationDelta;
        }
 
        internal IndentBlockOperation(SyntaxToken baseToken, SyntaxToken startToken, SyntaxToken endToken, TextSpan textSpan, int indentationDelta, IndentBlockOption option)
        {
            Contract.ThrowIfFalse(option.IsMaskOn(IndentBlockOption.PositionMask));
 
            Contract.ThrowIfFalse(option.IsMaskOn(IndentBlockOption.RelativePositionMask));
            Contract.ThrowIfFalse(baseToken.Span.End <= textSpan.Start);
 
            Contract.ThrowIfTrue(textSpan.Start < 0 || textSpan.Length < 0);
            Contract.ThrowIfTrue(startToken.RawKind == 0);
            Contract.ThrowIfTrue(endToken.RawKind == 0);
 
            this.BaseToken = baseToken;
            this.TextSpan = textSpan;
 
            this.Option = option;
            this.StartToken = startToken;
            this.EndToken = endToken;
 
            this.IsRelativeIndentation = true;
            this.IndentationDeltaOrPosition = indentationDelta;
        }
 
        public SyntaxToken BaseToken { get; }
        public TextSpan TextSpan { get; }
 
        public IndentBlockOption Option { get; }
 
        public SyntaxToken StartToken { get; }
        public SyntaxToken EndToken { get; }
 
        public bool IsRelativeIndentation { get; }
        public int IndentationDeltaOrPosition { get; }
 
#if DEBUG
        public override string ToString()
            => $"Indent {TextSpan} from '{StartToken}' to '{EndToken}', by {IndentationDeltaOrPosition}, with base token '{BaseToken}'";
#endif
    }
}