| | | 1 | | using System.Text; |
| | | 2 | | |
| | | 3 | | namespace TeleFlow.Telegram.Formatting; |
| | | 4 | | |
| | | 5 | | /// <summary> |
| | | 6 | | /// Composes safe formatted text for one explicit Telegram Bot API parse mode. |
| | | 7 | | /// The builder escapes plain values and keeps rendered fragments separate from |
| | | 8 | | /// application strings, preventing accidental double escaping during composition. |
| | | 9 | | /// </summary> |
| | | 10 | | public sealed class TelegramTextBuilder |
| | | 11 | | { |
| | | 12 | | private readonly TelegramTextRenderer _renderer; |
| | 23 | 13 | | private readonly StringBuilder _content = new(); |
| | | 14 | | |
| | | 15 | | internal TelegramTextBuilder(TelegramTextRenderer renderer) |
| | | 16 | | { |
| | 23 | 17 | | ArgumentNullException.ThrowIfNull(renderer); |
| | 23 | 18 | | _renderer = renderer; |
| | 23 | 19 | | } |
| | | 20 | | |
| | | 21 | | /// <summary> |
| | | 22 | | /// Appends plain text after escaping it for the selected parse mode. |
| | | 23 | | /// </summary> |
| | | 24 | | public TelegramTextBuilder Text(string text) |
| | | 25 | | { |
| | 5 | 26 | | ArgumentNullException.ThrowIfNull(text); |
| | 5 | 27 | | _content.Append(_renderer.EscapeText(text)); |
| | 5 | 28 | | return this; |
| | | 29 | | } |
| | | 30 | | |
| | | 31 | | /// <summary> |
| | | 32 | | /// Appends a line break. |
| | | 33 | | /// </summary> |
| | | 34 | | public TelegramTextBuilder LineBreak() |
| | | 35 | | { |
| | 1 | 36 | | _content.Append('\n'); |
| | 1 | 37 | | return this; |
| | | 38 | | } |
| | | 39 | | |
| | | 40 | | /// <summary> |
| | | 41 | | /// Appends a formatted value that uses the same parse mode as this builder. |
| | | 42 | | /// </summary> |
| | | 43 | | public TelegramTextBuilder Append(TelegramFormattedText text) |
| | | 44 | | { |
| | 1 | 45 | | ArgumentNullException.ThrowIfNull(text); |
| | | 46 | | |
| | 1 | 47 | | if (text.ParseMode != _renderer.ParseMode) |
| | | 48 | | { |
| | 1 | 49 | | throw new InvalidOperationException( |
| | 1 | 50 | | $"Formatted text with parse mode '{text.ParseMode}' cannot be appended to a builder using '{_renderer.Pa |
| | | 51 | | } |
| | | 52 | | |
| | 0 | 53 | | _content.Append(text.Text); |
| | 0 | 54 | | return this; |
| | | 55 | | } |
| | | 56 | | |
| | | 57 | | /// <summary> |
| | | 58 | | /// Appends bold text. |
| | | 59 | | /// </summary> |
| | | 60 | | public TelegramTextBuilder Bold(string text) |
| | | 61 | | { |
| | 8 | 62 | | return AppendWrapped(text, _renderer.Bold); |
| | | 63 | | } |
| | | 64 | | |
| | | 65 | | /// <summary> |
| | | 66 | | /// Appends bold nested content. |
| | | 67 | | /// </summary> |
| | | 68 | | public TelegramTextBuilder Bold(Action<TelegramTextBuilder> content) |
| | | 69 | | { |
| | 1 | 70 | | return AppendNested(content, _renderer.Bold); |
| | | 71 | | } |
| | | 72 | | |
| | | 73 | | /// <summary> |
| | | 74 | | /// Appends italic text. |
| | | 75 | | /// </summary> |
| | | 76 | | public TelegramTextBuilder Italic(string text) |
| | | 77 | | { |
| | 0 | 78 | | return AppendWrapped(text, _renderer.Italic); |
| | | 79 | | } |
| | | 80 | | |
| | | 81 | | /// <summary> |
| | | 82 | | /// Appends italic nested content. |
| | | 83 | | /// </summary> |
| | | 84 | | public TelegramTextBuilder Italic(Action<TelegramTextBuilder> content) |
| | | 85 | | { |
| | 0 | 86 | | return AppendNested(content, _renderer.Italic); |
| | | 87 | | } |
| | | 88 | | |
| | | 89 | | /// <summary> |
| | | 90 | | /// Appends underlined text. |
| | | 91 | | /// </summary> |
| | | 92 | | public TelegramTextBuilder Underline(string text) |
| | | 93 | | { |
| | 0 | 94 | | return AppendWrapped(text, _renderer.Underline); |
| | | 95 | | } |
| | | 96 | | |
| | | 97 | | /// <summary> |
| | | 98 | | /// Appends underlined nested content. |
| | | 99 | | /// </summary> |
| | | 100 | | public TelegramTextBuilder Underline(Action<TelegramTextBuilder> content) |
| | | 101 | | { |
| | 0 | 102 | | return AppendNested(content, _renderer.Underline); |
| | | 103 | | } |
| | | 104 | | |
| | | 105 | | /// <summary> |
| | | 106 | | /// Appends strike-through text. |
| | | 107 | | /// </summary> |
| | | 108 | | public TelegramTextBuilder Strikethrough(string text) |
| | | 109 | | { |
| | 0 | 110 | | return AppendWrapped(text, _renderer.Strikethrough); |
| | | 111 | | } |
| | | 112 | | |
| | | 113 | | /// <summary> |
| | | 114 | | /// Appends strike-through nested content. |
| | | 115 | | /// </summary> |
| | | 116 | | public TelegramTextBuilder Strikethrough(Action<TelegramTextBuilder> content) |
| | | 117 | | { |
| | 0 | 118 | | return AppendNested(content, _renderer.Strikethrough); |
| | | 119 | | } |
| | | 120 | | |
| | | 121 | | /// <summary> |
| | | 122 | | /// Appends spoiler text. |
| | | 123 | | /// </summary> |
| | | 124 | | public TelegramTextBuilder Spoiler(string text) |
| | | 125 | | { |
| | 1 | 126 | | return AppendWrapped(text, _renderer.Spoiler); |
| | | 127 | | } |
| | | 128 | | |
| | | 129 | | /// <summary> |
| | | 130 | | /// Appends spoiler nested content. |
| | | 131 | | /// </summary> |
| | | 132 | | public TelegramTextBuilder Spoiler(Action<TelegramTextBuilder> content) |
| | | 133 | | { |
| | 0 | 134 | | return AppendNested(content, _renderer.Spoiler); |
| | | 135 | | } |
| | | 136 | | |
| | | 137 | | /// <summary> |
| | | 138 | | /// Appends inline code. Nested Telegram entities are intentionally not supported inside code. |
| | | 139 | | /// </summary> |
| | | 140 | | public TelegramTextBuilder Code(string text) |
| | | 141 | | { |
| | 1 | 142 | | ArgumentException.ThrowIfNullOrEmpty(text); |
| | 1 | 143 | | _content.Append(_renderer.Code(text)); |
| | 1 | 144 | | return this; |
| | | 145 | | } |
| | | 146 | | |
| | | 147 | | /// <summary> |
| | | 148 | | /// Appends a preformatted block. Nested Telegram entities are intentionally not supported inside the block. |
| | | 149 | | /// </summary> |
| | | 150 | | public TelegramTextBuilder Pre(string text, string? language = null) |
| | | 151 | | { |
| | 4 | 152 | | ArgumentException.ThrowIfNullOrEmpty(text); |
| | | 153 | | |
| | 4 | 154 | | if (language is { Length: 0 }) |
| | | 155 | | { |
| | 0 | 156 | | throw new ArgumentException("Preformatted language must be null or non-empty.", nameof(language)); |
| | | 157 | | } |
| | | 158 | | |
| | 4 | 159 | | _content.Append(_renderer.Pre(text, language)); |
| | 1 | 160 | | return this; |
| | | 161 | | } |
| | | 162 | | |
| | | 163 | | /// <summary> |
| | | 164 | | /// Appends a link with an escaped label and target. |
| | | 165 | | /// </summary> |
| | | 166 | | public TelegramTextBuilder Link(Uri uri, string label) |
| | | 167 | | { |
| | 2 | 168 | | ArgumentNullException.ThrowIfNull(uri); |
| | 2 | 169 | | ArgumentException.ThrowIfNullOrEmpty(label); |
| | | 170 | | |
| | 2 | 171 | | if (!uri.IsAbsoluteUri) |
| | | 172 | | { |
| | 0 | 173 | | throw new ArgumentException("Telegram links must use an absolute URI.", nameof(uri)); |
| | | 174 | | } |
| | | 175 | | |
| | 2 | 176 | | _content.Append(_renderer.Link(uri.OriginalString, label)); |
| | 2 | 177 | | return this; |
| | | 178 | | } |
| | | 179 | | |
| | | 180 | | /// <summary> |
| | | 181 | | /// Appends a Telegram user mention with an escaped label. |
| | | 182 | | /// </summary> |
| | | 183 | | public TelegramTextBuilder Mention(long userId, string label) |
| | | 184 | | { |
| | 2 | 185 | | if (userId <= 0) |
| | | 186 | | { |
| | 0 | 187 | | throw new ArgumentOutOfRangeException(nameof(userId), userId, "Telegram user id must be positive."); |
| | | 188 | | } |
| | | 189 | | |
| | 2 | 190 | | ArgumentException.ThrowIfNullOrEmpty(label); |
| | 2 | 191 | | _content.Append(_renderer.Mention(userId, label)); |
| | 2 | 192 | | return this; |
| | | 193 | | } |
| | | 194 | | |
| | | 195 | | /// <summary> |
| | | 196 | | /// Appends a block quote. Nested entities are intentionally not supported inside the quote. |
| | | 197 | | /// </summary> |
| | | 198 | | public TelegramTextBuilder BlockQuote(string text, bool expandable = false) |
| | | 199 | | { |
| | 2 | 200 | | ArgumentException.ThrowIfNullOrEmpty(text); |
| | 2 | 201 | | _content.Append(_renderer.BlockQuote(text, expandable)); |
| | 2 | 202 | | return this; |
| | | 203 | | } |
| | | 204 | | |
| | | 205 | | /// <summary> |
| | | 206 | | /// Appends a custom emoji with a required fallback emoji. |
| | | 207 | | /// Telegram may show the fallback in notifications, forwards, and unsupported clients. |
| | | 208 | | /// </summary> |
| | | 209 | | public TelegramTextBuilder CustomEmoji(string customEmojiId, string fallbackEmoji) |
| | | 210 | | { |
| | 7 | 211 | | ArgumentException.ThrowIfNullOrWhiteSpace(customEmojiId); |
| | 5 | 212 | | ArgumentException.ThrowIfNullOrWhiteSpace(fallbackEmoji); |
| | 3 | 213 | | _content.Append(_renderer.CustomEmoji(customEmojiId, fallbackEmoji)); |
| | 3 | 214 | | return this; |
| | | 215 | | } |
| | | 216 | | |
| | | 217 | | /// <summary> |
| | | 218 | | /// Builds an immutable value for framework helpers or explicit generated-client arguments. |
| | | 219 | | /// </summary> |
| | | 220 | | public TelegramFormattedText Build() |
| | | 221 | | { |
| | 14 | 222 | | var text = _content.ToString(); |
| | | 223 | | |
| | 14 | 224 | | if (text.Length == 0) |
| | | 225 | | { |
| | 1 | 226 | | throw new InvalidOperationException("Formatted text must not be empty."); |
| | | 227 | | } |
| | | 228 | | |
| | 13 | 229 | | return new TelegramFormattedText(text, _renderer.ParseMode); |
| | | 230 | | } |
| | | 231 | | |
| | | 232 | | private TelegramTextBuilder AppendWrapped(string text, Func<string, string> format) |
| | | 233 | | { |
| | 9 | 234 | | ArgumentException.ThrowIfNullOrEmpty(text); |
| | 9 | 235 | | _content.Append(format(_renderer.EscapeText(text))); |
| | 9 | 236 | | return this; |
| | | 237 | | } |
| | | 238 | | |
| | | 239 | | private TelegramTextBuilder AppendNested( |
| | | 240 | | Action<TelegramTextBuilder> content, |
| | | 241 | | Func<string, string> format) |
| | | 242 | | { |
| | 1 | 243 | | ArgumentNullException.ThrowIfNull(content); |
| | | 244 | | |
| | 1 | 245 | | var nested = new TelegramTextBuilder(_renderer); |
| | 1 | 246 | | content(nested); |
| | 1 | 247 | | var nestedText = nested._content.ToString(); |
| | | 248 | | |
| | 1 | 249 | | if (nestedText.Length == 0) |
| | | 250 | | { |
| | 0 | 251 | | throw new InvalidOperationException("Formatted nested content must not be empty."); |
| | | 252 | | } |
| | | 253 | | |
| | 1 | 254 | | _content.Append(format(nestedText)); |
| | 1 | 255 | | return this; |
| | | 256 | | } |
| | | 257 | | } |
| | | 258 | | |
| | | 259 | | /// <summary> |
| | | 260 | | /// Renders the shared safe formatting vocabulary for one Telegram parse mode. |
| | | 261 | | /// It is intentionally local to the client package and has no framework or transport dependency. |
| | | 262 | | /// </summary> |
| | | 263 | | internal abstract class TelegramTextRenderer |
| | | 264 | | { |
| | | 265 | | public abstract TelegramParseMode ParseMode { get; } |
| | | 266 | | |
| | | 267 | | public abstract string EscapeText(string text); |
| | | 268 | | |
| | | 269 | | public abstract string Bold(string text); |
| | | 270 | | |
| | | 271 | | public abstract string Italic(string text); |
| | | 272 | | |
| | | 273 | | public abstract string Underline(string text); |
| | | 274 | | |
| | | 275 | | public abstract string Strikethrough(string text); |
| | | 276 | | |
| | | 277 | | public abstract string Spoiler(string text); |
| | | 278 | | |
| | | 279 | | public abstract string Code(string text); |
| | | 280 | | |
| | | 281 | | public abstract string Pre(string text, string? language); |
| | | 282 | | |
| | | 283 | | public abstract string Link(string uri, string label); |
| | | 284 | | |
| | | 285 | | public abstract string Mention(long userId, string label); |
| | | 286 | | |
| | | 287 | | public abstract string BlockQuote(string text, bool expandable); |
| | | 288 | | |
| | | 289 | | public abstract string CustomEmoji(string customEmojiId, string fallbackEmoji); |
| | | 290 | | } |
| | | 291 | | |
| | | 292 | | /// <summary> |
| | | 293 | | /// Renders safe Telegram HTML fragments for normal Bot API text messages. |
| | | 294 | | /// </summary> |
| | | 295 | | internal sealed class TelegramHtmlTextRenderer : TelegramTextRenderer |
| | | 296 | | { |
| | | 297 | | public static TelegramHtmlTextRenderer Instance { get; } = new(); |
| | | 298 | | |
| | | 299 | | public override TelegramParseMode ParseMode => TelegramParseMode.Html; |
| | | 300 | | |
| | | 301 | | public override string EscapeText(string text) |
| | | 302 | | { |
| | | 303 | | return TelegramHtmlEscaper.EscapeText(text); |
| | | 304 | | } |
| | | 305 | | |
| | | 306 | | public override string Bold(string text) => $"<b>{text}</b>"; |
| | | 307 | | |
| | | 308 | | public override string Italic(string text) => $"<i>{text}</i>"; |
| | | 309 | | |
| | | 310 | | public override string Underline(string text) => $"<u>{text}</u>"; |
| | | 311 | | |
| | | 312 | | public override string Strikethrough(string text) => $"<s>{text}</s>"; |
| | | 313 | | |
| | | 314 | | public override string Spoiler(string text) => $"<tg-spoiler>{text}</tg-spoiler>"; |
| | | 315 | | |
| | | 316 | | public override string Code(string text) => $"<code>{EscapeText(text)}</code>"; |
| | | 317 | | |
| | | 318 | | public override string Pre(string text, string? language) |
| | | 319 | | { |
| | | 320 | | var escapedText = EscapeText(text); |
| | | 321 | | |
| | | 322 | | if (language is null) |
| | | 323 | | { |
| | | 324 | | return $"<pre>{escapedText}</pre>"; |
| | | 325 | | } |
| | | 326 | | |
| | | 327 | | ValidateLanguage(language); |
| | | 328 | | return $"<pre><code class=\"language-{EscapeAttribute(language)}\">{escapedText}</code></pre>"; |
| | | 329 | | } |
| | | 330 | | |
| | | 331 | | public override string Link(string uri, string label) |
| | | 332 | | { |
| | | 333 | | return $"<a href=\"{EscapeAttribute(uri)}\">{EscapeText(label)}</a>"; |
| | | 334 | | } |
| | | 335 | | |
| | | 336 | | public override string Mention(long userId, string label) |
| | | 337 | | { |
| | | 338 | | return Link($"tg://user?id={userId}", label); |
| | | 339 | | } |
| | | 340 | | |
| | | 341 | | public override string BlockQuote(string text, bool expandable) |
| | | 342 | | { |
| | | 343 | | return expandable |
| | | 344 | | ? $"<blockquote expandable>{EscapeText(text)}</blockquote>" |
| | | 345 | | : $"<blockquote>{EscapeText(text)}</blockquote>"; |
| | | 346 | | } |
| | | 347 | | |
| | | 348 | | public override string CustomEmoji(string customEmojiId, string fallbackEmoji) |
| | | 349 | | { |
| | | 350 | | return $"<tg-emoji emoji-id=\"{EscapeAttribute(customEmojiId)}\">{EscapeText(fallbackEmoji)}</tg-emoji>"; |
| | | 351 | | } |
| | | 352 | | |
| | | 353 | | private static string EscapeAttribute(string value) |
| | | 354 | | { |
| | | 355 | | return TelegramHtmlEscaper.EscapeInterpolation(value); |
| | | 356 | | } |
| | | 357 | | |
| | | 358 | | private static void ValidateLanguage(string language) |
| | | 359 | | { |
| | | 360 | | if (language.Any(static character => |
| | | 361 | | !char.IsAsciiLetterOrDigit(character) && |
| | | 362 | | character is not '-' and not '_')) |
| | | 363 | | { |
| | | 364 | | throw new ArgumentException( |
| | | 365 | | "Preformatted language may contain only ASCII letters, digits, '-' and '_'.", |
| | | 366 | | nameof(language)); |
| | | 367 | | } |
| | | 368 | | } |
| | | 369 | | } |
| | | 370 | | |
| | | 371 | | /// <summary> |
| | | 372 | | /// Renders safe Telegram MarkdownV2 fragments for normal Bot API text messages. |
| | | 373 | | /// </summary> |
| | | 374 | | internal sealed class TelegramMarkdownV2TextRenderer : TelegramTextRenderer |
| | | 375 | | { |
| | | 376 | | private const string ReservedCharacters = "_*[]()~`>#+-=|{}.!\\"; |
| | | 377 | | |
| | | 378 | | public static TelegramMarkdownV2TextRenderer Instance { get; } = new(); |
| | | 379 | | |
| | | 380 | | public override TelegramParseMode ParseMode => TelegramParseMode.MarkdownV2; |
| | | 381 | | |
| | | 382 | | public override string EscapeText(string text) |
| | | 383 | | { |
| | | 384 | | var builder = new StringBuilder(text.Length); |
| | | 385 | | |
| | | 386 | | foreach (var character in text) |
| | | 387 | | { |
| | | 388 | | if (ReservedCharacters.Contains(character)) |
| | | 389 | | { |
| | | 390 | | builder.Append('\\'); |
| | | 391 | | } |
| | | 392 | | |
| | | 393 | | builder.Append(character); |
| | | 394 | | } |
| | | 395 | | |
| | | 396 | | return builder.ToString(); |
| | | 397 | | } |
| | | 398 | | |
| | | 399 | | public override string Bold(string text) => $"*{text}*"; |
| | | 400 | | |
| | | 401 | | public override string Italic(string text) => $"_{text}_"; |
| | | 402 | | |
| | | 403 | | public override string Underline(string text) => $"__{text}__"; |
| | | 404 | | |
| | | 405 | | public override string Strikethrough(string text) => $"~{text}~"; |
| | | 406 | | |
| | | 407 | | public override string Spoiler(string text) => $"||{text}||"; |
| | | 408 | | |
| | | 409 | | public override string Code(string text) => $"`{EscapeCode(text)}`"; |
| | | 410 | | |
| | | 411 | | public override string Pre(string text, string? language) |
| | | 412 | | { |
| | | 413 | | if (language is not null) |
| | | 414 | | { |
| | | 415 | | ValidateLanguage(language); |
| | | 416 | | } |
| | | 417 | | |
| | | 418 | | return language is null |
| | | 419 | | ? $"```\n{EscapeCode(text)}\n```" |
| | | 420 | | : $"```{language}\n{EscapeCode(text)}\n```"; |
| | | 421 | | } |
| | | 422 | | |
| | | 423 | | public override string Link(string uri, string label) |
| | | 424 | | { |
| | | 425 | | return $"[{EscapeText(label)}]({EscapeLinkTarget(uri)})"; |
| | | 426 | | } |
| | | 427 | | |
| | | 428 | | public override string Mention(long userId, string label) |
| | | 429 | | { |
| | | 430 | | return Link($"tg://user?id={userId}", label); |
| | | 431 | | } |
| | | 432 | | |
| | | 433 | | public override string BlockQuote(string text, bool expandable) |
| | | 434 | | { |
| | | 435 | | var lines = text |
| | | 436 | | .Replace("\r\n", "\n", StringComparison.Ordinal) |
| | | 437 | | .Replace('\r', '\n') |
| | | 438 | | .Split('\n'); |
| | | 439 | | var builder = new StringBuilder(text.Length + lines.Length * 2); |
| | | 440 | | |
| | | 441 | | for (var index = 0; index < lines.Length; index++) |
| | | 442 | | { |
| | | 443 | | builder.Append("> "); |
| | | 444 | | builder.Append(EscapeText(lines[index])); |
| | | 445 | | |
| | | 446 | | if (index == lines.Length - 1 && expandable) |
| | | 447 | | { |
| | | 448 | | builder.Append("||"); |
| | | 449 | | } |
| | | 450 | | |
| | | 451 | | if (index < lines.Length - 1) |
| | | 452 | | { |
| | | 453 | | builder.Append('\n'); |
| | | 454 | | } |
| | | 455 | | } |
| | | 456 | | |
| | | 457 | | return builder.ToString(); |
| | | 458 | | } |
| | | 459 | | |
| | | 460 | | public override string CustomEmoji(string customEmojiId, string fallbackEmoji) |
| | | 461 | | { |
| | | 462 | | return $"})"; |
| | | 463 | | } |
| | | 464 | | |
| | | 465 | | private static string EscapeCode(string value) |
| | | 466 | | { |
| | | 467 | | return value |
| | | 468 | | .Replace("\\", "\\\\", StringComparison.Ordinal) |
| | | 469 | | .Replace("`", "\\`", StringComparison.Ordinal); |
| | | 470 | | } |
| | | 471 | | |
| | | 472 | | private static string EscapeLinkTarget(string value) |
| | | 473 | | { |
| | | 474 | | return value |
| | | 475 | | .Replace("\\", "\\\\", StringComparison.Ordinal) |
| | | 476 | | .Replace(")", "\\)", StringComparison.Ordinal); |
| | | 477 | | } |
| | | 478 | | |
| | | 479 | | private static void ValidateLanguage(string language) |
| | | 480 | | { |
| | | 481 | | if (language.Any(static character => |
| | | 482 | | !char.IsAsciiLetterOrDigit(character) && |
| | | 483 | | character is not '-' and not '_')) |
| | | 484 | | { |
| | | 485 | | throw new ArgumentException( |
| | | 486 | | "Preformatted language may contain only ASCII letters, digits, '-' and '_'.", |
| | | 487 | | nameof(language)); |
| | | 488 | | } |
| | | 489 | | } |
| | | 490 | | } |