//! Rendering helpers with no knowledge of routes: Markdown, syntax

//! highlighting, diffs, the history graph, and human times. Each is pure

//! and unit tested.

pub mod diff;

pub mod graph;

pub mod highlight;

pub mod markdown;

pub mod refs;

pub mod time;

/// HTML-escape text for insertion into element content or attributes.

pub fn escape(s: &str) -> String {

    let mut out = String::with_capacity(s.len());

    for c in s.chars() {

        match c {

            '&' => out.push_str("&"),

            '<' => out.push_str("&lt;"),

            '>' => out.push_str(">"),

            '"' => out.push_str("""),

            '\'' => out.push_str("'"),

            _ => out.push(c),

        }

    }

    out

}

/// `1.2 KiB`, `3.4 MiB`, `512 B`.

pub fn bytes(n: u64) -> String {

    const UNITS: [&str; 5] = ["B", "KiB", "MiB", "GiB", "TiB"];

    let mut v = n as f64;

    let mut i = 0;

    while v >= 1024.0 && i < UNITS.len() - 1 {

        v /= 1024.0;

        i += 1;

    }

    if i == 0 {

        format!("{n} B")

    } else {

        format!("{v:.1} {}", UNITS[i])

    }

}

#[cfg(test)]

mod tests {

    use super::*;

    #[test]

    fn escaping_and_sizes() {

        assert_eq!(escape("<a href=\"x\">&'"), "&lt;a href=&quot;x&quot;&gt;&amp;&#39;");

        assert_eq!(bytes(512), "512 B");

        assert_eq!(bytes(1536), "1.5 KiB");

        assert_eq!(bytes(5 << 20), "5.0 MiB");

    }

}