using System;

using System.Text;

namespace Microsoft.PowerShell

{

internal class Range

{

internal Range(int offset, int count)

{

Offset = offset;

Count = count;

}

internal int Offset { get; }

internal int Count { get; }

}

internal static class StringBuilderLinewiseExtensions

{

/// <summary>

/// Determines the offset and the length of the fragment

/// in the specified buffer that corresponds to a

/// given number of lines starting from the specified line index

/// </summary>

/// <param name="buffer" />

/// <param name="lineIndex" />

/// <param name="lineCount" />

internal static Range GetRange(this StringBuilder buffer, int lineIndex, int lineCount)

{

// this method considers lines by the first '\n' character from the previous line

// up until the last non new-line character of the current line.

//

// buffer: line 0\nline 1\nline 2[...]\nline n

// lines: 0....._1......_2......[...]_3......

var length = buffer.Length;

var startPosition = 0;

var startPositionIdentified = false;

var endPosition = length - 1;

var currentLine = 0;

if (lineIndex == 0)

{

startPosition = 0;

startPositionIdentified = true;

}

for (var position = 0; position < length; position++)

{

if (buffer[position] == '\n')

{

currentLine++;

if (!startPositionIdentified && currentLine == lineIndex)

{

startPosition = position;

startPositionIdentified = true;

}

if (currentLine == lineIndex + lineCount)

{

endPosition = position - 1;

break;

}

}

}

return new Range(

startPosition,

endPosition - startPosition + 1

);

}

}

internal static class StringBuilderPredictionExtensions

{

internal static StringBuilder EndColorSection(this StringBuilder buffer, string selectionHighlighting)

{

return buffer.Append(VTColorUtils.AnsiReset).Append(selectionHighlighting);

}

}

}