1 files changed, 175 insertions, 0 deletions
diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..87fd1a4
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,175 @@
+use anyhow::anyhow;
+use rand::seq::IndexedRandom;
+use regex::{Regex, RegexBuilder, RegexSet};
+use std::collections::HashMap;
+use std::io;
+use std::ops::Range;
+use std::path::PathBuf;
+
+mod config;
+
+struct Config {
+    patterns: Vec<Regex>,
+    set: RegexSet,
+}
+
+impl Config {
+    fn new(patterns: Vec<Regex>) -> Self {
+        let set = RegexSet::new(patterns.iter().map(|x| x.to_string())).unwrap();
+        Self { patterns, set }
+    }
+}
+
+struct Match {
+    line: String,
+    group: Range<usize>,
+}
+
+impl Match {
+    fn new(line: String, group: Range<usize>) -> Self {
+        Self { line, group }
+    }
+
+    fn prefix(&self) -> &str {
+        &self.line[0..self.group.start]
+    }
+
+    fn infix(&self) -> &str {
+        &self.line[self.group.clone()]
+    }
+
+    fn suffix(&self) -> &str {
+        &self.line[self.group.end..self.line.len()]
+    }
+}
+
+struct PatternGroup {
+    matches: Vec<Match>,
+}
+
+impl PatternGroup {
+    fn new(matches: Vec<Match>) -> Self {
+        Self { matches }
+    }
+
+    fn calculate_groups(&self) -> Vec<usize> {
+        let mut groups = Vec::with_capacity(self.matches.len());
+        groups.push(0);
+        for i in 1..self.matches.len() {
+            if self.matches[i - 1].prefix() != self.matches[i].prefix()
+                || self.matches[i - 1].suffix() != self.matches[i].suffix()
+            {
+                groups.push(i);
+            }
+        }
+        groups
+    }
+}
+
+fn load_config(path: &PathBuf) -> anyhow::Result<Config> {
+    if !path.try_exists()? {
+        return Ok(default_config());
+    }
+    let groups = config::load_groups(path)?;
+    if let Some(patterns_str) = groups.get("groups") {
+        let mut patterns_regex = Vec::with_capacity(patterns_str.len());
+        for pattern in patterns_str {
+            let regex = RegexBuilder::new(pattern).size_limit(42_000).build()?;
+            if regex.captures_len() != 1 {
+                return Err(anyhow!(
+                    "Invalid pattern {}, capture groups are not one",
+                    pattern
+                ));
+            }
+            patterns_regex.push(regex);
+        }
+        return Ok(Config::new(patterns_regex));
+    }
+    Ok(Config::new(vec![]))
+}
+
+fn default_config() -> Config {
+    Config::new(vec![Regex::new(r"part([0-9]+)").unwrap()])
+}
+
+fn get_group(config: &Config, input: &str) -> (i64, Range<usize>) {
+    if let Some(index) = config.set.matches(input).iter().next() {
+        return (
+            index as i64,
+            config.patterns[index]
+                .captures(input)
+                .unwrap()
+                .get(1)
+                .unwrap()
+                .range(),
+        );
+    }
+    (-1, 0..input.len())
+}
+
+fn print_group(matches: &[Match]) {
+    for m in matches {
+        println!("{}", m.line);
+    }
+}
+
+fn main() -> anyhow::Result<()> {
+    let xdg_dirs = xdg::BaseDirectories::new();
+    let config;
+    if let Some(config_path) = xdg_dirs.get_config_file("shuf-grp.conf") {
+        config = load_config(&config_path)
+            .unwrap_or_else(|err| panic!("Error parsing {}: {}", config_path.display(), err));
+    } else {
+        eprintln!("Using default config, create ~/.config/shuf-grp.conf");
+        config = default_config();
+    }
+
+    let stdin = io::stdin();
+    let mut groups = HashMap::new();
+    loop {
+        let mut buffer = String::new();
+        let bytes = stdin.read_line(&mut buffer)?;
+        if bytes == 0 {
+            break;
+        }
+        buffer.truncate(buffer.trim_end().len());
+        let (group, part) = get_group(&config, &buffer);
+        let m = Match::new(buffer, part);
+        if let std::collections::hash_map::Entry::Vacant(e) = groups.entry(group) {
+            e.insert(PatternGroup::new(vec![m]));
+        } else {
+            let pattern_group: &mut PatternGroup = groups.get_mut(&group).unwrap();
+            match pattern_group.matches.binary_search_by(|x| {
+                x.prefix().cmp(m.prefix()).then(
+                    x.suffix()
+                        .cmp(m.suffix())
+                        .then(natord::compare(x.infix(), m.infix())),
+                )
+            }) {
+                Ok(pos) => pattern_group.matches.insert(pos, m),
+                Err(pos) => pattern_group.matches.insert(pos, m),
+            }
+        }
+    }
+
+    let mut indexes = Vec::<(i64, Range<usize>)>::with_capacity(groups.len());
+
+    for pattern_group in groups.iter_mut() {
+        let groups = pattern_group.1.calculate_groups();
+        for i in 1..groups.len() {
+            indexes.push((*pattern_group.0, groups[i - 1]..groups[i]));
+        }
+        indexes.push((
+            *pattern_group.0,
+            groups[groups.len() - 1]..pattern_group.1.matches.len(),
+        ));
+    }
+
+    let mut rng = rand::rng();
+
+    for (group, range) in indexes.choose_multiple(&mut rng, indexes.len()) {
+        print_group(&groups.get(group).unwrap().matches[range.clone()]);
+    }
+
+    Ok(())
+}