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