[rbdr/gema_texto] / src / html_renderer.rs

use crate::gemini_parser::GeminiLine;

/// Renders HTML from a vector of `GeminiLine` elements.
///
/// # Arguments
/// * `lines` - Vector of `GeminiLine` elements to render
///
/// # Returns
/// A String containing the rendered HTML.
///
/// # Examples
/// ```
/// use std::fs::read_to_string;
/// use gema_texto::gemini_parser::parse;
/// use gema_texto::html_renderer::render_html;
///
/// let gemini_source = "\
/// # Hello
/// This is some gemini text!
/// => https://test Go to the test page.
/// ";
///
/// let gemini_lines = parse(&gemini_source);
/// let html_source = render_html(&gemini_lines);
/// println!("{html_source}");
/// ```
#[must_use]
pub fn render_html(lines: &[GeminiLine]) -> String {
    let mut heading_stack = Vec::new();
    let mut last_line: Option<&GeminiLine> = None;
    let mut result = String::new();

    for line in lines {
        result.push_str(&line_preamble(line, last_line, &mut heading_stack));
        result.push_str(&line_content(line));
        result.push('\n');
        last_line = Some(line);
    }

    result.push_str(&finalize_html(&heading_stack, last_line));
    result
}

fn line_preamble(
    line: &GeminiLine,
    last_line: Option<&GeminiLine>,
    heading_stack: &mut Vec<u8>,
) -> String {
    let mut html = String::new();

    if let Some(last_line) = last_line {
        match last_line {
            GeminiLine::ListItem(_) => match line {
                GeminiLine::ListItem(_) => {}
                _ => html.push_str("</ul>\n"),
            },
            GeminiLine::Quote(_) => match line {
                GeminiLine::Quote(_) => {}
                _ => html.push_str("</blockquote>\n"),
            },
            _ => {}
        }
    }

    match line {
        GeminiLine::Heading(level, _) => {
            while let Some(open_heading) = heading_stack.pop() {
                // You just encountered a more important heading.
                // Put it back. Desist.
                if open_heading < *level {
                    heading_stack.push(open_heading);
                    break;
                }

                html.push_str("</section>\n");

                if open_heading == *level {
                    break;
                }
            }
            heading_stack.push(*level);
            html.push_str(&format!("<section class=\"h{level}\">\n"));
        }
        GeminiLine::ListItem(_) => match last_line {
            Some(GeminiLine::ListItem(_)) => {}
            _ => html.push_str("<ul>\n"),
        },
        GeminiLine::Quote(_) => match last_line {
            Some(GeminiLine::Quote(_)) => {}
            _ => html.push_str("<blockquote>\n"),
        },
        _ => {}
    }

    html
}

fn line_content(line: &GeminiLine) -> String {
    match line {
        GeminiLine::Text(content, false) => format!("<p>{content}</p>"),
        GeminiLine::Link(url, text) => {
            let display = if text.is_empty() { url } else { text };
            format!("<p class=\"a\"><a href=\"{url}\">{display}</a></p>")
        }
        GeminiLine::Heading(level, content) => format!("<h{level}>{content}</h{level}>"),
        GeminiLine::ListItem(content) => format!("<li>{content}</li>"),
        GeminiLine::PreformattedToggle(true, alt_text) => {
            format!("<pre aria-label=\"{alt_text}\">")
        }
        GeminiLine::PreformattedToggle(false, _) => "</pre>".to_string(),
        GeminiLine::Text(content, true) | GeminiLine::Quote(content) => content.to_string(),
    }
}

fn finalize_html(heading_stack: &[u8], last_line: Option<&GeminiLine>) -> String {
    let mut html = String::new();

    match last_line {
        Some(GeminiLine::ListItem(_)) => html.push_str("</ul>\n"),
        Some(GeminiLine::Quote(_)) => html.push_str("</blockquote>\n"),
        _ => {}
    }

    for _ in heading_stack {
        html.push_str("</section>\n");
    }

    html
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_simple_text() {
        let input = vec![GeminiLine::Text("Hello world".to_string(), false)];
        assert_eq!(render_html(&input), "<p>Hello world</p>\n");
    }

    #[test]
    fn test_heading_nesting() {
        let input = vec![
            GeminiLine::Heading(1, "Top".to_string()),
            GeminiLine::Heading(2, "Sub".to_string()),
            GeminiLine::Heading(3, "SubSub".to_string()),
            GeminiLine::Heading(2, "Another Sub".to_string()),
        ];
        assert_eq!(
            render_html(&input),
            "<section class=\"h1\">\n\
             <h1>Top</h1>\n\
             <section class=\"h2\">\n\
             <h2>Sub</h2>\n\
             <section class=\"h3\">\n\
             <h3>SubSub</h3>\n\
             </section>\n\
             </section>\n\
             <section class=\"h2\">\n\
             <h2>Another Sub</h2>\n\
             </section>\n\
             </section>\n"
        );
    }

    #[test]
    fn test_list_transitions() {
        let input = vec![
            GeminiLine::ListItem("First".to_string()),
            GeminiLine::ListItem("Second".to_string()),
            GeminiLine::Text("Break".to_string(), false),
            GeminiLine::ListItem("New list".to_string()),
        ];
        assert_eq!(
            render_html(&input),
            "<ul>\n\
             <li>First</li>\n\
             <li>Second</li>\n\
             </ul>\n\
             <p>Break</p>\n\
             <ul>\n\
             <li>New list</li>\n\
             </ul>\n"
        );
    }

    #[test]
    fn test_quote_transitions() {
        let input = vec![
            GeminiLine::Quote("First quote".to_string()),
            GeminiLine::Quote("Still quoting".to_string()),
            GeminiLine::Text("Normal text".to_string(), false),
            GeminiLine::Quote("New quote".to_string()),
        ];
        assert_eq!(
            render_html(&input),
            "<blockquote>\n\
             First quote\n\
             Still quoting\n\
             </blockquote>\n\
             <p>Normal text</p>\n\
             <blockquote>\n\
             New quote\n\
             </blockquote>\n"
        );
    }

    #[test]
    fn test_preformatted() {
        let input = vec![
            GeminiLine::PreformattedToggle(true, "code".to_string()),
            GeminiLine::Text("let x = 42;".to_string(), true),
            GeminiLine::PreformattedToggle(false, String::new()),
        ];
        assert_eq!(
            render_html(&input),
            "<pre aria-label=\"code\">\n\
             let x = 42;\n\
             </pre>\n"
        );
    }

    #[test]
    fn test_links() {
        let input = vec![
            GeminiLine::Link("https://example.com".to_string(), "Example".to_string()),
            GeminiLine::Link("https://rust-lang.org".to_string(), String::new()),
        ];
        assert_eq!(
            render_html(&input),
            "<p class=\"a\"><a href=\"https://example.com\">Example</a></p>\n\
             <p class=\"a\"><a href=\"https://rust-lang.org\">https://rust-lang.org</a></p>\n"
        );
    }

    #[test]
    fn test_complex_nesting() {
        let input = vec![
            GeminiLine::Heading(1, "Title".to_string()),
            GeminiLine::Text("Intro".to_string(), false),
            GeminiLine::Heading(2, "Section".to_string()),
            GeminiLine::ListItem("Point 1".to_string()),
            GeminiLine::ListItem("Point 2".to_string()),
            GeminiLine::Quote("Important quote".to_string()),
            GeminiLine::Heading(2, "Another Section".to_string()),
        ];
        assert_eq!(
            render_html(&input),
            "<section class=\"h1\">\n\
             <h1>Title</h1>\n\
             <p>Intro</p>\n\
             <section class=\"h2\">\n\
             <h2>Section</h2>\n\
             <ul>\n\
             <li>Point 1</li>\n\
             <li>Point 2</li>\n\
             </ul>\n\
             <blockquote>\n\
             Important quote\n\
             </blockquote>\n\
             </section>\n\
             <section class=\"h2\">\n\
             <h2>Another Section</h2>\n\
             </section>\n\
             </section>\n"
        );
    }

    #[test]
    fn test_empty_input() {
        let input = Vec::new();
        assert_eq!(render_html(&input), "");
    }
}
Commit	Line	Data
8beb2bfa RBR	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 display = if text.is_empty() { url } else { text };
103	format!("<p class=\"a\"><a href=\"{url}\">{display}</a></p>")
104	}
105	GeminiLine::Heading(level, content) => format!("<h{level}>{content}</h{level}>"),
106	GeminiLine::ListItem(content) => format!("<li>{content}</li>"),
107	GeminiLine::PreformattedToggle(true, alt_text) => {
108	format!("<pre aria-label=\"{alt_text}\">")
109	}
110	GeminiLine::PreformattedToggle(false, _) => "</pre>".to_string(),
111	GeminiLine::Text(content, true) \| GeminiLine::Quote(content) => content.to_string(),
112	}
113	}
114
115	fn finalize_html(heading_stack: &[u8], last_line: Option<&GeminiLine>) -> String {
116	let mut html = String::new();
117
118	match last_line {
119	Some(GeminiLine::ListItem(_)) => html.push_str("</ul>\n"),
120	Some(GeminiLine::Quote(_)) => html.push_str("</blockquote>\n"),
121	_ => {}
122	}
123
124	for _ in heading_stack {
125	html.push_str("</section>\n");
126	}
127
128	html
129	}
130
131	#[cfg(test)]
132	mod tests {
133	use super::*;
134
135	#[test]
136	fn test_simple_text() {
137	let input = vec![GeminiLine::Text("Hello world".to_string(), false)];
138	assert_eq!(render_html(&input), "<p>Hello world</p>\n");
139	}
140
141	#[test]
142	fn test_heading_nesting() {
143	let input = vec![
144	GeminiLine::Heading(1, "Top".to_string()),
145	GeminiLine::Heading(2, "Sub".to_string()),
146	GeminiLine::Heading(3, "SubSub".to_string()),
147	GeminiLine::Heading(2, "Another Sub".to_string()),
148	];
149	assert_eq!(
150	render_html(&input),
151	"<section class=\"h1\">\n\
152	<h1>Top</h1>\n\
153	<section class=\"h2\">\n\
154	<h2>Sub</h2>\n\
155	<section class=\"h3\">\n\
156	<h3>SubSub</h3>\n\
157	</section>\n\
158	</section>\n\
159	<section class=\"h2\">\n\
160	<h2>Another Sub</h2>\n\
161	</section>\n\
162	</section>\n"
163	);
164	}
165
166	#[test]
167	fn test_list_transitions() {
168	let input = vec![
169	GeminiLine::ListItem("First".to_string()),
170	GeminiLine::ListItem("Second".to_string()),
171	GeminiLine::Text("Break".to_string(), false),
172	GeminiLine::ListItem("New list".to_string()),
173	];
174	assert_eq!(
175	render_html(&input),
176	"<ul>\n\
177	<li>First</li>\n\
178	<li>Second</li>\n\
179	</ul>\n\
180	<p>Break</p>\n\
181	<ul>\n\
182	<li>New list</li>\n\
183	</ul>\n"
184	);
185	}
186
187	#[test]
188	fn test_quote_transitions() {
189	let input = vec![
190	GeminiLine::Quote("First quote".to_string()),
191	GeminiLine::Quote("Still quoting".to_string()),
192	GeminiLine::Text("Normal text".to_string(), false),
193	GeminiLine::Quote("New quote".to_string()),
194	];
195	assert_eq!(
196	render_html(&input),
197	"<blockquote>\n\
198	First quote\n\
199	Still quoting\n\
200	</blockquote>\n\
201	<p>Normal text</p>\n\
202	<blockquote>\n\
203	New quote\n\
204	</blockquote>\n"
205	);
206	}
207
208	#[test]
209	fn test_preformatted() {
210	let input = vec![
211	GeminiLine::PreformattedToggle(true, "code".to_string()),
212	GeminiLine::Text("let x = 42;".to_string(), true),
213	GeminiLine::PreformattedToggle(false, String::new()),
214	];
215	assert_eq!(
216	render_html(&input),
217	"<pre aria-label=\"code\">\n\
218	let x = 42;\n\
219	</pre>\n"
220	);
221	}
222
223	#[test]
224	fn test_links() {
225	let input = vec![
226	GeminiLine::Link("https://example.com".to_string(), "Example".to_string()),
227	GeminiLine::Link("https://rust-lang.org".to_string(), String::new()),
228	];
229	assert_eq!(
230	render_html(&input),
231	"<p class=\"a\"><a href=\"https://example.com\">Example</a></p>\n\
232	<p class=\"a\"><a href=\"https://rust-lang.org\">https://rust-lang.org</a></p>\n"
233	);
234	}
235
236	#[test]
237	fn test_complex_nesting() {
238	let input = vec![
239	GeminiLine::Heading(1, "Title".to_string()),
240	GeminiLine::Text("Intro".to_string(), false),
241	GeminiLine::Heading(2, "Section".to_string()),
242	GeminiLine::ListItem("Point 1".to_string()),
243	GeminiLine::ListItem("Point 2".to_string()),
244	GeminiLine::Quote("Important quote".to_string()),
245	GeminiLine::Heading(2, "Another Section".to_string()),
246	];
247	assert_eq!(
248	render_html(&input),
249	"<section class=\"h1\">\n\
250	<h1>Title</h1>\n\
251	<p>Intro</p>\n\
252	<section class=\"h2\">\n\
253	<h2>Section</h2>\n\
254	<ul>\n\
255	<li>Point 1</li>\n\
256	<li>Point 2</li>\n\
257	</ul>\n\
258	<blockquote>\n\
259	Important quote\n\
260	</blockquote>\n\
261	</section>\n\
262	<section class=\"h2\">\n\
263	<h2>Another Section</h2>\n\
264	</section>\n\
265	</section>\n"
266	);
267	}
268
269	#[test]
270	fn test_empty_input() {
271	let input = Vec::new();
272	assert_eq!(render_html(&input), "");
273	}
274	}