Add syntax highlighting (currently only for matrix codeblocks)

1 files changed, 43 insertions, 6 deletions

diff --git a/src/plugins/Matrix.cpp b/src/plugins/Matrix.cpp
index a9284f5..d1a060d 100644
--- a/src/plugins/Matrix.cpp
+++ b/src/plugins/Matrix.cpp
@@ -2289,10 +2289,21 @@ namespace QuickMedia {
         bool inside_font_tag = false;
         bool font_tag_has_custom_color = false;
         bool inside_code_tag = false;
+        std::string_view code_tag_language;
         bool allow_formatted_text = false;
+        bool inside_source_highlight = false;
+        bool supports_syntax_highlight = false;
         mgl::Color font_color = mgl::Color(255, 255, 255, 255);
     };
 
+    static int accumulate_string(char *data, int size, void *userdata) {
+        std::string *str = (std::string*)userdata;
+        if(str->size() + size > 1024 * 1024 * 100) // 100mb sane limit, TODO: make configurable
+            return 1;
+        str->append(data, size);
+        return 0;
+    }
+
     // TODO: Full proper parsing with tag depth
     static int formattext_text_parser_callback(HtmlParser *html_parser, HtmlParseType parse_type, void *userdata) {
         FormattedTextParseUserdata &parse_userdata = *(FormattedTextParseUserdata*)userdata;
@@ -2304,8 +2315,10 @@ namespace QuickMedia {
                     parse_userdata.inside_font_tag = true;
                 else if(html_parser->tag_name.size == 8 && memcmp(html_parser->tag_name.data, "mx-reply", 8) == 0)
                     ++parse_userdata.mx_reply_depth;
-                else if(html_parser->tag_name.size == 4 && memcmp(html_parser->tag_name.data, "code", 4) == 0)
+                else if(html_parser->tag_name.size == 4 && memcmp(html_parser->tag_name.data, "code", 4) == 0) {
                     parse_userdata.inside_code_tag = true;
+                    parse_userdata.code_tag_language = std::string_view();
+                }
                 break;
             }
             case HTML_PARSE_TAG_END: {
@@ -2325,6 +2338,9 @@ namespace QuickMedia {
                 if(parse_userdata.inside_font_tag && html_parser->attribute_key.size == 5 && memcmp(html_parser->attribute_key.data, "color", 5) == 0) {
                     if(parse_hex_set_color(html_parser->attribute_value.data, html_parser->attribute_value.size, parse_userdata.font_color))
                         parse_userdata.font_tag_has_custom_color = true;
+                } else if(parse_userdata.inside_code_tag && html_parser->attribute_key.size == 5 && memcmp(html_parser->attribute_key.data, "class", 5) == 0) {
+                    if(html_parser->attribute_value.size > 9 && memcmp(html_parser->attribute_value.data, "language-", 9) == 0)
+                        parse_userdata.code_tag_language = std::string_view(html_parser->attribute_value.data + 9, html_parser->attribute_value.size - 9);
                 }
                 break;
             }
@@ -2335,12 +2351,32 @@ namespace QuickMedia {
                     html_unescape_sequences(text_to_add);
 
                     uint8_t formatted_text_flags = FORMATTED_TEXT_FLAG_NONE;
-                    if(parse_userdata.font_tag_has_custom_color)
-                        formatted_text_flags |= FORMATTED_TEXT_FLAG_COLOR;
-                    if(parse_userdata.inside_code_tag)
-                        formatted_text_flags |= FORMATTED_TEXT_FLAG_MONOSPACE;
+                    if(parse_userdata.allow_formatted_text) {
+                        if(parse_userdata.font_tag_has_custom_color)
+                            formatted_text_flags |= FORMATTED_TEXT_FLAG_COLOR;
+                        
+                        if(parse_userdata.inside_source_highlight || !parse_userdata.supports_syntax_highlight || (parse_userdata.inside_code_tag && parse_userdata.code_tag_language.size() == 0)) {
+                            formatted_text_flags |= FORMATTED_TEXT_FLAG_MONOSPACE;
+                        } else if(parse_userdata.inside_code_tag) {
+                            formatted_text_flags |= FORMATTED_TEXT_FLAG_MONOSPACE;
+                            // TODO: guess language from code if no language is set.
+                            // TODO: Allow the user to choose style in config file.
+
+                            const std::string code_language(parse_userdata.code_tag_language);
+                            const char *args[] = { "source-highlight", "-f", "html", "-s", code_language.c_str(), "--style-file=esc256.style", "-o", "STDOUT", nullptr };
+                            std::string output;
+                            if(exec_program_write_stdin(args, text_to_add.c_str(), text_to_add.size(), accumulate_string, &output) == 0) {
+                                FormattedTextParseUserdata code_parse_userdata;
+                                code_parse_userdata.allow_formatted_text = true;
+                                code_parse_userdata.inside_source_highlight = true;
+                                html_parser_parse(output.c_str(), output.size(), formattext_text_parser_callback, &code_parse_userdata);
+                                text_to_add = std::move(code_parse_userdata.result);
+                                formatted_text_flags = FORMATTED_TEXT_FLAG_NONE;
+                            }
+                        }
+                    }
 
-                    if(formatted_text_flags != FORMATTED_TEXT_FLAG_NONE && parse_userdata.allow_formatted_text)
+                    if(formatted_text_flags != FORMATTED_TEXT_FLAG_NONE)
                         parse_userdata.result += Text::formatted_text(text_to_add, parse_userdata.font_color, formatted_text_flags);
                     else
                         parse_userdata.result += std::move(text_to_add);
@@ -2354,6 +2390,7 @@ namespace QuickMedia {
     std::string formatted_text_to_qm_text(const char *str, size_t size, bool allow_formatted_text) {
         FormattedTextParseUserdata parse_userdata;
         parse_userdata.allow_formatted_text = allow_formatted_text;
+        parse_userdata.supports_syntax_highlight = is_program_executable_by_name("source-highlight");
         html_parser_parse(str, size, formattext_text_parser_callback, &parse_userdata);
         return std::move(parse_userdata.result);
     }