git.r.bdr.sh - rbdr/gema_texto/blob - src/html_renderer.rs

   1 use crate::gemini_parser::GeminiLine;
   2
   3 /// Renders HTML from a vector of `GeminiLine` elements.
   4 ///
   5 /// # Arguments
   6 /// * `lines` - Vector of `GeminiLine` elements to render
   7 ///
   8 /// # Returns
   9 /// A String containing the rendered HTML.
  10 ///
  11 /// # Examples
  12 /// ```
  13 /// use std::fs::read_to_string;
  14 /// use gema_texto::gemini_parser::parse;
  15 /// use gema_texto::html_renderer::render_html;
  16 ///
  17 /// let gemini_source = "\
  18 /// # Hello
  19 /// This is some gemini text!
  20 /// => https://test Go to the test page.
  21 /// ";
  22 ///
  23 /// let gemini_lines = parse(&gemini_source);
  24 /// let html_source = render_html(&gemini_lines);
  25 /// println!("{html_source}");
  26 /// ```
  27 #[must_use]
  28 pub fn render_html(lines: &[GeminiLine]) -> String {
  29     let mut heading_stack = Vec::new();
  30     let mut last_line: Option<&GeminiLine> = None;
  31     let mut result = String::new();
  32
  33     for line in lines {
  34         result.push_str(&line_preamble(line, last_line, &mut heading_stack));
  35         result.push_str(&line_content(line));
  36         result.push('\n');
  37         last_line = Some(line);
  38     }
  39
  40     result.push_str(&finalize_html(&heading_stack, last_line));
  41     result
  42 }
  43
  44 fn line_preamble(
  45     line: &GeminiLine,
  46     last_line: Option<&GeminiLine>,
  47     heading_stack: &mut Vec<u8>,
  48 ) -> String {
  49     let mut html = String::new();
  50
  51     if let Some(last_line) = last_line {
  52         match last_line {
  53             GeminiLine::ListItem(_) => match line {
  54                 GeminiLine::ListItem(_) => {}
  55                 _ => html.push_str("</ul>\n"),
  56             },
  57             GeminiLine::Quote(_) => match line {
  58                 GeminiLine::Quote(_) => {}
  59                 _ => html.push_str("</blockquote>\n"),
  60             },
  61             _ => {}
  62         }
  63     }
  64
  65     match line {
  66         GeminiLine::Heading(level, _) => {
  67             while let Some(open_heading) = heading_stack.pop() {
  68                 // You just encountered a more important heading.
  69                 // Put it back. Desist.
  70                 if open_heading < *level {
  71                     heading_stack.push(open_heading);
  72                     break;
  73                 }
  74
  75                 html.push_str("</section>\n");
  76
  77                 if open_heading == *level {
  78                     break;
  79                 }
  80             }
  81             heading_stack.push(*level);
  82             html.push_str(&format!("<section class=\"h{level}\">\n"));
  83         }
  84         GeminiLine::ListItem(_) => match last_line {
  85             Some(GeminiLine::ListItem(_)) => {}
  86             _ => html.push_str("<ul>\n"),
  87         },
  88         GeminiLine::Quote(_) => match last_line {
  89             Some(GeminiLine::Quote(_)) => {}
  90             _ => html.push_str("<blockquote>\n"),
  91         },
  92         _ => {}
  93     }
  94
  95     html
  96 }
  97
  98 fn line_content(line: &GeminiLine) -> String {
  99     match line {
 100         GeminiLine::Text(content, false) => format!("<p>{content}</p>"),
 101         GeminiLine::Link(url, text) => {
 102             let processed_url;
 103             if !url.starts_with("gemini:") && url.ends_with(".gmi") {
 104                 processed_url = url.replace(".gmi", ".html");
 105             } else {
 106                 processed_url = url.to_string();
 107             }
 108             let display = if text.is_empty() { &processed_url } else { text };
 109             format!("<p class=\"a\"><a href=\"{processed_url}\">{display}</a></p>")
 110         }
 111         GeminiLine::Heading(level, content) => format!("<h{level}>{content}</h{level}>"),
 112         GeminiLine::ListItem(content) => format!("<li>{content}</li>"),
 113         GeminiLine::PreformattedToggle(true, alt_text) => {
 114             format!("<pre aria-label=\"{alt_text}\">")
 115         }
 116         GeminiLine::PreformattedToggle(false, _) => "</pre>".to_string(),
 117         GeminiLine::Text(content, true) | GeminiLine::Quote(content) => content.to_string(),
 118     }
 119 }
 120
 121 fn finalize_html(heading_stack: &[u8], last_line: Option<&GeminiLine>) -> String {
 122     let mut html = String::new();
 123
 124     match last_line {
 125         Some(GeminiLine::ListItem(_)) => html.push_str("</ul>\n"),
 126         Some(GeminiLine::Quote(_)) => html.push_str("</blockquote>\n"),
 127         _ => {}
 128     }
 129
 130     for _ in heading_stack {
 131         html.push_str("</section>\n");
 132     }
 133
 134     html
 135 }
 136
 137 #[cfg(test)]
 138 mod tests {
 139     use super::*;
 140
 141     #[test]
 142     fn test_simple_text() {
 143         let input = vec![GeminiLine::Text("Hello world".to_string(), false)];
 144         assert_eq!(render_html(&input), "<p>Hello world</p>\n");
 145     }
 146
 147     #[test]
 148     fn test_heading_nesting() {
 149         let input = vec![
 150             GeminiLine::Heading(1, "Top".to_string()),
 151             GeminiLine::Heading(2, "Sub".to_string()),
 152             GeminiLine::Heading(3, "SubSub".to_string()),
 153             GeminiLine::Heading(2, "Another Sub".to_string()),
 154         ];
 155         assert_eq!(
 156             render_html(&input),
 157             "<section class=\"h1\">\n\
 158              <h1>Top</h1>\n\
 159              <section class=\"h2\">\n\
 160              <h2>Sub</h2>\n\
 161              <section class=\"h3\">\n\
 162              <h3>SubSub</h3>\n\
 163              </section>\n\
 164              </section>\n\
 165              <section class=\"h2\">\n\
 166              <h2>Another Sub</h2>\n\
 167              </section>\n\
 168              </section>\n"
 169         );
 170     }
 171
 172     #[test]
 173     fn test_list_transitions() {
 174         let input = vec![
 175             GeminiLine::ListItem("First".to_string()),
 176             GeminiLine::ListItem("Second".to_string()),
 177             GeminiLine::Text("Break".to_string(), false),
 178             GeminiLine::ListItem("New list".to_string()),
 179         ];
 180         assert_eq!(
 181             render_html(&input),
 182             "<ul>\n\
 183              <li>First</li>\n\
 184              <li>Second</li>\n\
 185              </ul>\n\
 186              <p>Break</p>\n\
 187              <ul>\n\
 188              <li>New list</li>\n\
 189              </ul>\n"
 190         );
 191     }
 192
 193     #[test]
 194     fn test_quote_transitions() {
 195         let input = vec![
 196             GeminiLine::Quote("First quote".to_string()),
 197             GeminiLine::Quote("Still quoting".to_string()),
 198             GeminiLine::Text("Normal text".to_string(), false),
 199             GeminiLine::Quote("New quote".to_string()),
 200         ];
 201         assert_eq!(
 202             render_html(&input),
 203             "<blockquote>\n\
 204              First quote\n\
 205              Still quoting\n\
 206              </blockquote>\n\
 207              <p>Normal text</p>\n\
 208              <blockquote>\n\
 209              New quote\n\
 210              </blockquote>\n"
 211         );
 212     }
 213
 214     #[test]
 215     fn test_preformatted() {
 216         let input = vec![
 217             GeminiLine::PreformattedToggle(true, "code".to_string()),
 218             GeminiLine::Text("let x = 42;".to_string(), true),
 219             GeminiLine::PreformattedToggle(false, String::new()),
 220         ];
 221         assert_eq!(
 222             render_html(&input),
 223             "<pre aria-label=\"code\">\n\
 224              let x = 42;\n\
 225              </pre>\n"
 226         );
 227     }
 228
 229     #[test]
 230     fn test_links() {
 231         let input = vec![
 232             GeminiLine::Link("gemini://hi.gmi".to_string(), "Example".to_string()),
 233             GeminiLine::Link("/hi.gmi/kidding".to_string(), "Example".to_string()),
 234             GeminiLine::Link("/hi.gmi".to_string(), "Example".to_string()),
 235             GeminiLine::Link("https://example.com".to_string(), "Example".to_string()),
 236             GeminiLine::Link("https://rust-lang.org".to_string(), String::new()),
 237         ];
 238         assert_eq!(
 239             render_html(&input),
 240             "<p class=\"a\"><a href=\"gemini://hi.gmi\">Example</a></p>\n\
 241              <p class=\"a\"><a href=\"/hi.gmi/kidding\">Example</a></p>\n\
 242              <p class=\"a\"><a href=\"/hi.html\">Example</a></p>\n\
 243              <p class=\"a\"><a href=\"https://example.com\">Example</a></p>\n\
 244              <p class=\"a\"><a href=\"https://rust-lang.org\">https://rust-lang.org</a></p>\n"
 245         );
 246     }
 247
 248     #[test]
 249     fn test_complex_nesting() {
 250         let input = vec![
 251             GeminiLine::Heading(1, "Title".to_string()),
 252             GeminiLine::Text("Intro".to_string(), false),
 253             GeminiLine::Heading(2, "Section".to_string()),
 254             GeminiLine::ListItem("Point 1".to_string()),
 255             GeminiLine::ListItem("Point 2".to_string()),
 256             GeminiLine::Quote("Important quote".to_string()),
 257             GeminiLine::Heading(2, "Another Section".to_string()),
 258         ];
 259         assert_eq!(
 260             render_html(&input),
 261             "<section class=\"h1\">\n\
 262              <h1>Title</h1>\n\
 263              <p>Intro</p>\n\
 264              <section class=\"h2\">\n\
 265              <h2>Section</h2>\n\
 266              <ul>\n\
 267              <li>Point 1</li>\n\
 268              <li>Point 2</li>\n\
 269              </ul>\n\
 270              <blockquote>\n\
 271              Important quote\n\
 272              </blockquote>\n\
 273              </section>\n\
 274              <section class=\"h2\">\n\
 275              <h2>Another Section</h2>\n\
 276              </section>\n\
 277              </section>\n"
 278         );
 279     }
 280
 281     #[test]
 282     fn test_empty_input() {
 283         let input = Vec::new();
 284         assert_eq!(render_html(&input), "");
 285     }
 286 }