// 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.
 
namespace Roslyn.LanguageServer.Protocol
{
    using System.Text.Json.Serialization;
 
    /// <summary>
    /// Report of spell checkable ranges.
    /// </summary>
    internal class VSInternalSpellCheckableRangeReport
    {
        /// <summary>
        /// Gets or sets the server-generated version number for the spell checkable ranges.
        /// This is treated as a black box by the client: it is stored on the client
        /// for each textDocument and sent back to the server when requesting
        /// spell checkable ranges. The server can use this result ID to avoid resending
        /// spell checkable ranges that had previously been sent.
        /// </summary>
        [JsonPropertyName("_vs_resultId")]
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public string? ResultId { get; set; }
 
        /// <summary>
        /// Gets or sets an array containing encoded ranges to spell check.
        /// </summary>
        /// <remarks>
        /// The data structure is as the following:
        /// 1. <see cref="Ranges"/> property can contain multiple spans to spell check.
        /// 2. Each span is defined by a set of 3 ordered integers in the <see cref="Ranges"/> property.
        /// 3. The span's ordered information are the following:
        ///     1. A kind, corresponding to the numeric value of <see cref="VSInternalSpellCheckableRangeKind"/>.
        ///     2. A start position, which is the character index where the span starts in the document buffer.
        ///        The start position should be the relative offset from the end of the previous span, regardless of whether that span is the same range
        ///        or a prior range.
        ///     3. The length of the span.
        /// 4. Spans should be ordered by their absolute start position in the document buffer.
        /// </remarks>
        /// <example>
        /// [
        ///     /* ---- First span in the document, admitting this is the first report returned. ---- */
        ///     1,   // The kind of the span. Equivalent to <see cref="VSInternalSpellCheckableRangeKind.Comment"/>.
        ///     123, // This is the very first span's start position. The position is relative to the beginning of the document buffer.
        ///     5,   // Span length
        ///     /* ---- Second span in the document ---- */
        ///     0,   // Equivalent to <see cref="VSInternalSpellCheckableRangeKind.String"/>.
        ///     6,   // Start position relative to the first span in the document. Absolute span position is therefore (123 + 5) + 6 = 134.
        ///     4,   // Span length
        ///     /* ---- Third span in the document ---- */
        ///     0,   // Equivalent to <see cref="VSInternalSpellCheckableRangeKind.String"/>.
        ///     12,  // Start position relative to the second span. Absolute span position is therefore (134 + 4) + 12 = 150
        ///     5    // Span length
        /// ]
        /// </example>
        [JsonPropertyName("_vs_ranges")]
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public int[]? Ranges
        {
            get;
            set;
        }
    }
}