| 1 | package tinyclient |
| 2 | |
| 3 | import ( |
| 4 | "html" |
| 5 | "html/template" |
| 6 | "path/filepath" |
| 7 | "strings" |
| 8 | "unicode" |
| 9 | "unicode/utf8" |
| 10 | ) |
| 11 | |
| 12 | const sourcePreviewLimit = 256 * 1024 |
| 13 | const sourcePreviewLines = 10000 |
| 14 | |
| 15 | // A byte bound alone permits hundreds of thousands of empty table rows. |
| 16 | // Bound the preview markup separately; raw downloads remain complete. |
| 17 | func previewLines(content string) ([]string, bool) { |
| 18 | if content == "" { |
| 19 | return nil, false |
| 20 | } |
| 21 | content = strings.TrimSuffix(content, "\n" ) |
| 22 | lines := strings.SplitN(content, "\n" , sourcePreviewLines+1) |
| 23 | if len(lines) > sourcePreviewLines { |
| 24 | return lines[:sourcePreviewLines], true |
| 25 | } |
| 26 | return lines, false |
| 27 | } |
| 28 | |
| 29 | // sourceHTML renders a bounded source preview. It returns template.HTML only |
| 30 | // after escaping every source byte and constructing the surrounding markup. |
| 31 | // The markup is wrapped in a <source-view lang="..."> element and uses only |
| 32 | // semantic elements so styling needs no class hooks. |
| 33 | func sourceHTML(value any) template.HTML { |
| 34 | m := valueMap(value) |
| 35 | content, _ := m["content" ].(string) |
| 36 | name, _ := m["path" ].(string) |
| 37 | if name == "" { |
| 38 | name, _ = m["name" ].(string) |
| 39 | } |
| 40 | language := sourceLanguage(name) |
| 41 | providedTruncated, _ := m["truncated" ].(bool) |
| 42 | truncated := providedTruncated || len(content) > sourcePreviewLimit |
| 43 | if truncated { |
| 44 | content = boundedContent(content) |
| 45 | } |
| 46 | lines, linesTruncated := previewLines(content) |
| 47 | var out strings.Builder |
| 48 | out.Grow(len(content) + len(lines)*120) |
| 49 | out.WriteString(`<source-view lang="` ) |
| 50 | out.WriteString(language) |
| 51 | out.WriteString(`"><table><tbody>` ) |
| 52 | state := highlightState{} |
| 53 | for number, line := range lines { |
| 54 | out.WriteString(`<tr id="L` ) |
| 55 | writeUint(&out, number+1) |
| 56 | out.WriteString(`"><td><a href="#L` ) |
| 57 | writeUint(&out, number+1) |
| 58 | out.WriteString(`">` ) |
| 59 | writeUint(&out, number+1) |
| 60 | out.WriteString(`</a></td><td><code>` ) |
| 61 | highlightLine(&out, line, language, &state) |
| 62 | out.WriteString(`</code></td></tr>` ) |
| 63 | } |
| 64 | out.WriteString(`</tbody>` ) |
| 65 | if truncated || linesTruncated { |
| 66 | out.WriteString(`<tfoot><tr><td colspan="2">Preview truncated (256 KiB or 10,000 lines). Use the raw/download control to view the complete file.</td></tr></tfoot>` ) |
| 67 | } |
| 68 | out.WriteString(`</table></source-view>` ) |
| 69 | return template.HTML(out.String()) |
| 70 | } |
| 71 | |
| 72 | // diffHTML renders a line-oriented diff without interpreting its content. |
| 73 | // Added lines are wrapped in <ins>, removed lines in <del>, and hunk headers |
| 74 | // in <b>; context lines carry no wrapper. |
| 75 | func diffHTML(value any) template.HTML { |
| 76 | m := valueMap(value) |
| 77 | diff, _ := m["diff" ].(string) |
| 78 | if diff == "" { |
| 79 | if text, ok := value.(string); ok { |
| 80 | diff = text |
| 81 | } |
| 82 | } |
| 83 | providedTruncated, _ := m["truncated" ].(bool) |
| 84 | truncated := providedTruncated || len(diff) > sourcePreviewLimit |
| 85 | if truncated { |
| 86 | diff = boundedContent(diff) |
| 87 | } |
| 88 | lines, linesTruncated := previewLines(diff) |
| 89 | var out strings.Builder |
| 90 | out.Grow(len(diff) + len(lines)*140) |
| 91 | out.WriteString(`<diff-view><table><tbody>` ) |
| 92 | for number, line := range lines { |
| 93 | wrapper := "" |
| 94 | switch { |
| 95 | case strings.HasPrefix(line, "@@" ): |
| 96 | wrapper = "b" |
| 97 | case strings.HasPrefix(line, "+" ): |
| 98 | wrapper = "ins" |
| 99 | case strings.HasPrefix(line, "-" ): |
| 100 | wrapper = "del" |
| 101 | } |
| 102 | out.WriteString(`<tr id="D` ) |
| 103 | writeUint(&out, number+1) |
| 104 | out.WriteString(`"><td><a href="#D` ) |
| 105 | writeUint(&out, number+1) |
| 106 | out.WriteString(`">` ) |
| 107 | writeUint(&out, number+1) |
| 108 | out.WriteString(`</a></td><td><code>` ) |
| 109 | writeWrapped(&out, wrapper, line) |
| 110 | out.WriteString(`</code></td></tr>` ) |
| 111 | } |
| 112 | out.WriteString(`</tbody>` ) |
| 113 | if truncated || linesTruncated { |
| 114 | out.WriteString(`<tfoot><tr><td colspan="2">Diff preview truncated (256 KiB or 10,000 lines).</td></tr></tfoot>` ) |
| 115 | } |
| 116 | out.WriteString(`</table></diff-view>` ) |
| 117 | return template.HTML(out.String()) |
| 118 | } |
| 119 | |
| 120 | func boundedContent(content string) string { |
| 121 | if len(content) <= sourcePreviewLimit { |
| 122 | return content |
| 123 | } |
| 124 | content = content[:sourcePreviewLimit] |
| 125 | for len(content) > 0 && !utf8.ValidString(content) { |
| 126 | content = content[:len(content)-1] |
| 127 | } |
| 128 | return content |
| 129 | } |
| 130 | |
| 131 | func sourceLanguage(name string) string { |
| 132 | switch strings.ToLower(filepath.Ext(name)) { |
| 133 | case ".go" : |
| 134 | return "go" |
| 135 | case ".js" , ".jsx" : |
| 136 | return "javascript" |
| 137 | case ".ts" , ".tsx" : |
| 138 | return "typescript" |
| 139 | case ".css" : |
| 140 | return "css" |
| 141 | case ".html" , ".htm" : |
| 142 | return "html" |
| 143 | case ".json" : |
| 144 | return "json" |
| 145 | case ".md" , ".markdown" : |
| 146 | return "markdown" |
| 147 | case ".sh" , ".bash" : |
| 148 | return "shell" |
| 149 | case ".py" : |
| 150 | return "python" |
| 151 | case ".sql" : |
| 152 | return "sql" |
| 153 | default: |
| 154 | return "text" |
| 155 | } |
| 156 | } |
| 157 | |
| 158 | type highlightState struct{ blockComment bool } |
| 159 | |
| 160 | func highlightLine(out *strings.Builder, line, language string, state *highlightState) { |
| 161 | for len(line) > 0 { |
| 162 | if state.blockComment { |
| 163 | end := strings.Index(line, "*/" ) |
| 164 | if end < 0 { |
| 165 | writeToken(out, "comment" , line) |
| 166 | return |
| 167 | } |
| 168 | writeToken(out, "comment" , line[:end+2]) |
| 169 | line = line[end+2:] |
| 170 | state.blockComment = false |
| 171 | continue |
| 172 | } |
| 173 | if strings.HasPrefix(line, "/*" ) { |
| 174 | end := strings.Index(line[2:], "*/" ) |
| 175 | if end < 0 { |
| 176 | state.blockComment = true |
| 177 | writeToken(out, "comment" , line) |
| 178 | return |
| 179 | } |
| 180 | end += 4 |
| 181 | writeToken(out, "comment" , line[:end]) |
| 182 | line = line[end:] |
| 183 | continue |
| 184 | } |
| 185 | if prefix := commentPrefix(line, language); prefix != "" { |
| 186 | writeToken(out, "comment" , line) |
| 187 | return |
| 188 | } |
| 189 | if line[0] == '\'' || line[0] == '"' || line[0] == '`' { |
| 190 | quote := line[0] |
| 191 | end := quotedEnd(line, quote) |
| 192 | writeToken(out, "string" , line[:end]) |
| 193 | line = line[end:] |
| 194 | continue |
| 195 | } |
| 196 | value, size := utf8.DecodeRuneInString(line) |
| 197 | if isWordStart(value) { |
| 198 | end := size |
| 199 | for end < len(line) { |
| 200 | next, width := utf8.DecodeRuneInString(line[end:]) |
| 201 | if !isWordPart(next) { |
| 202 | break |
| 203 | } |
| 204 | end += width |
| 205 | } |
| 206 | word := line[:end] |
| 207 | if keyword(language, word) { |
| 208 | writeToken(out, "keyword" , word) |
| 209 | } else { |
| 210 | writeToken(out, "" , word) |
| 211 | } |
| 212 | line = line[end:] |
| 213 | continue |
| 214 | } |
| 215 | if unicode.IsDigit(value) { |
| 216 | end := size |
| 217 | for end < len(line) { |
| 218 | next, width := utf8.DecodeRuneInString(line[end:]) |
| 219 | if !unicode.IsDigit(next) && !strings.ContainsRune("._" , next) { |
| 220 | break |
| 221 | } |
| 222 | end += width |
| 223 | } |
| 224 | writeToken(out, "number" , line[:end]) |
| 225 | line = line[end:] |
| 226 | continue |
| 227 | } |
| 228 | writeToken(out, "" , line[:size]) |
| 229 | line = line[size:] |
| 230 | } |
| 231 | } |
| 232 | |
| 233 | // tokenElements maps token kinds to the semantic element that carries them. |
| 234 | var tokenElements = map[string]string{"keyword" : "b" , "comment" : "i" , "string" : "q" , "number" : "var" } |
| 235 | |
| 236 | func writeToken(out *strings.Builder, kind, value string) { |
| 237 | writeWrapped(out, tokenElements[kind], value) |
| 238 | } |
| 239 | |
| 240 | // writeWrapped escapes value and, when element is not empty, wraps it in that |
| 241 | // attribute-free element. |
| 242 | func writeWrapped(out *strings.Builder, element, value string) { |
| 243 | if element != "" { |
| 244 | out.WriteByte('<' ) |
| 245 | out.WriteString(element) |
| 246 | out.WriteByte('>' ) |
| 247 | } |
| 248 | out.WriteString(html.EscapeString(value)) |
| 249 | if element != "" { |
| 250 | out.WriteString("</" ) |
| 251 | out.WriteString(element) |
| 252 | out.WriteByte('>' ) |
| 253 | } |
| 254 | } |
| 255 | |
| 256 | func quotedEnd(line string, quote byte) int { |
| 257 | for index := 1; index < len(line); index++ { |
| 258 | if line[index] == '\\' { |
| 259 | index++ |
| 260 | continue |
| 261 | } |
| 262 | if line[index] == quote { |
| 263 | return index + 1 |
| 264 | } |
| 265 | } |
| 266 | return len(line) |
| 267 | } |
| 268 | |
| 269 | func commentPrefix(line, language string) string { |
| 270 | if strings.HasPrefix(line, "//" ) || strings.HasPrefix(line, "#" ) { |
| 271 | return line[:1] |
| 272 | } |
| 273 | if language == "sql" && strings.HasPrefix(line, "--" ) { |
| 274 | return "--" |
| 275 | } |
| 276 | return "" |
| 277 | } |
| 278 | |
| 279 | func isWordStart(value rune) bool { return unicode.IsLetter(value) || value == '_' } |
| 280 | func isWordPart(value rune) bool { |
| 281 | return unicode.IsLetter(value) || unicode.IsDigit(value) || value == '_' |
| 282 | } |
| 283 | |
| 284 | func keyword(language, word string) bool { |
| 285 | switch language { |
| 286 | case "go" : |
| 287 | return containsWord(word, "package import func type struct interface var const if else for range return go defer switch case select chan map" ) |
| 288 | case "javascript" , "typescript" : |
| 289 | return containsWord(word, "const let var function return if else for class interface type import export async await" ) |
| 290 | case "python" : |
| 291 | return containsWord(word, "def class return if else for import from in with" ) |
| 292 | default: |
| 293 | return false |
| 294 | } |
| 295 | } |
| 296 | |
| 297 | func containsWord(word, list string) bool { |
| 298 | for _, candidate := range strings.Fields(list) { |
| 299 | if candidate == word { |
| 300 | return true |
| 301 | } |
| 302 | } |
| 303 | return false |
| 304 | } |
| 305 | |
| 306 | func writeUint(out *strings.Builder, value int) { |
| 307 | if value == 0 { |
| 308 | out.WriteByte('0' ) |
| 309 | return |
| 310 | } |
| 311 | var digits [20]byte |
| 312 | index := len(digits) |
| 313 | for value > 0 { |
| 314 | index-- |
| 315 | digits[index] = byte('0' + value%10) |
| 316 | value /= 10 |
| 317 | } |
| 318 | out.Write(digits[index:]) |
| 319 | } |
