| 1 | #nullable enable |
| 2 | |
| 3 | namespace CascadeIDE.Services.Intercom; |
| 4 | |
| 5 | /// <summary>Разбиение markdown на prose и fenced code (ADR 0129 §5).</summary> |
| 6 | internal static class MarkdownProseSegments |
| 7 | { |
| 8 | public static IEnumerable<string> EnumerateProse(string markdown) |
| 9 | { |
| 10 | if (string.IsNullOrEmpty(markdown)) |
| 11 | yield break; |
| 12 | |
| 13 | var i = 0; |
| 14 | var inFence = false; |
| 15 | while (i < markdown.Length) |
| 16 | { |
| 17 | if (IsFenceOpenAt(markdown, i)) |
| 18 | { |
| 19 | var close = FindFenceClose(markdown, i + 3); |
| 20 | if (close < 0) |
| 21 | yield break; |
| 22 | |
| 23 | i = close + 3; |
| 24 | inFence = !inFence; |
| 25 | continue; |
| 26 | } |
| 27 | |
| 28 | if (inFence) |
| 29 | { |
| 30 | i++; |
| 31 | continue; |
| 32 | } |
| 33 | |
| 34 | var nextFence = FindNextFenceOpen(markdown, i); |
| 35 | var end = nextFence < 0 ? markdown.Length : nextFence; |
| 36 | if (end > i) |
| 37 | yield return markdown[i..end]; |
| 38 | |
| 39 | i = end; |
| 40 | } |
| 41 | } |
| 42 | |
| 43 | private static bool IsFenceOpenAt(string text, int index) |
| 44 | { |
| 45 | if (index + 2 >= text.Length) |
| 46 | return false; |
| 47 | if (text[index] != '`' || text[index + 1] != '`' || text[index + 2] != '`') |
| 48 | return false; |
| 49 | |
| 50 | if (index > 0 && text[index - 1] == '`') |
| 51 | return false; |
| 52 | |
| 53 | return true; |
| 54 | } |
| 55 | |
| 56 | private static int FindNextFenceOpen(string text, int start) |
| 57 | { |
| 58 | for (var i = start; i + 2 < text.Length; i++) |
| 59 | { |
| 60 | if (IsFenceOpenAt(text, i)) |
| 61 | return i; |
| 62 | } |
| 63 | |
| 64 | return -1; |
| 65 | } |
| 66 | |
| 67 | private static int FindFenceClose(string text, int afterOpen) |
| 68 | { |
| 69 | for (var i = afterOpen; i + 2 < text.Length; i++) |
| 70 | { |
| 71 | if (text[i] != '`' || text[i + 1] != '`' || text[i + 2] != '`') |
| 72 | continue; |
| 73 | |
| 74 | if (i > afterOpen && text[i - 1] == '`') |
| 75 | continue; |
| 76 | |
| 77 | return i; |
| 78 | } |
| 79 | |
| 80 | return -1; |
| 81 | } |
| 82 | } |
| 83 | |