specfold-core 0.4.0

//! Directory patterns: `services/*`-style kinds and path matchers for public and retired lists.

use globset::{GlobBuilder, GlobMatcher};
use std::path::Path;

/// A path or glob; a plain path also matches everything under it.
#[derive(Debug, Clone)]
pub enum PathMatch {
    Prefix(String),
    Glob(GlobMatcher),
}

impl PathMatch {
    pub fn is_match(&self, rel: &str) -> bool {
        match self {
            PathMatch::Prefix(p) => rel == p || rel.starts_with(&format!("{p}/")),
            PathMatch::Glob(g) => g.is_match(rel),
        }
    }
}

/// Globs follow gitignore conventions: `*` stays within one path segment, `**` crosses them, and a
/// pattern without a slash matches a file name at any depth.
pub fn matcher(pattern: &str) -> Option<PathMatch> {
    let p = pattern.trim_end_matches('/');
    if p.contains(['*', '?', '[', '{']) {
        let full = if p.contains('/') { p.to_string() } else { format!("**/{p}") };
        GlobBuilder::new(&full).literal_separator(true).build().ok().map(|g| PathMatch::Glob(g.compile_matcher()))
    } else {
        Some(PathMatch::Prefix(p.to_string()))
    }
}

/// C185: a literal path as a glob that matches only it: each of `[ * ? {` becomes a one-character
/// class (`[[]`, `[*]`, …), which every glob reader takes literally. Other paths come back as is.
pub fn escape_glob(path: &str) -> String {
    let mut out = String::with_capacity(path.len());
    for ch in path.chars() {
        if matches!(ch, '[' | '*' | '?' | '{') {
            out.push('[');
            out.push(ch);
            out.push(']');
        } else {
            out.push(ch);
        }
    }
    out
}

/// The literal text before the first wildcard, reading `[c]` escapes of `[ * ? {` as `c`; the
/// bool says whether a wildcard was found.
pub fn literal_prefix(glob: &str) -> (String, bool) {
    let b: Vec<char> = glob.chars().collect();
    let mut out = String::new();
    let mut i = 0;
    while i < b.len() {
        match b[i] {
            '[' if b.len() > i + 2 && matches!(b[i + 1], '[' | '*' | '?' | '{') && b[i + 2] == ']' => {
                out.push(b[i + 1]);
                i += 3;
            }
            '[' | '*' | '?' | '{' => return (out, true),
            c => {
                out.push(c);
                i += 1;
            }
        }
    }
    (out, false)
}

/// Expands a pattern of literal segments and `*` into existing directories, returning each with
/// the values its `*` segments took.
/// C210: owner patterns take literal folder names and whole `*` segments only. The problem
/// with `pattern`, if it has one.
pub fn kind_pattern_problem(pattern: &str) -> Option<String> {
    let bad = pattern.trim_matches('/').split('/').find(|seg| *seg != "*" && seg.contains(['*', '?', '[', '{']))?;
    Some(format!(
        "owner pattern '{pattern}' has the segment '{bad}'; owner patterns take literal folder names and whole '*' segments, e.g. services/*"
    ))
}

/// The number of `*` segments in an owner pattern: the captures `{1}`..`{N}` can name.
pub fn kind_stars(pattern: &str) -> usize {
    pattern.trim_matches('/').split('/').filter(|s| *s == "*").count()
}

pub fn expand(root: &Path, pattern: &str) -> Vec<(String, Vec<String>)> {
    let mut acc: Vec<(String, Vec<String>)> = vec![(String::new(), vec![])];
    for seg in pattern.trim_matches('/').split('/') {
        let mut next = vec![];
        for (base, caps) in &acc {
            let dir = if base.is_empty() { root.to_path_buf() } else { root.join(base) };
            if seg == "*" {
                for name in subdirs(&dir) {
                    let mut c = caps.clone();
                    c.push(name.clone());
                    next.push((join(base, &name), c));
                }
            } else if dir.join(seg).is_dir() {
                next.push((join(base, seg), caps.clone()));
            }
        }
        acc = next;
    }
    acc
}

fn subdirs(dir: &Path) -> Vec<String> {
    let Ok(rd) = std::fs::read_dir(dir) else { return vec![] };
    let mut names: Vec<String> = rd
        .flatten()
        .filter(|e| e.file_type().map(|t| t.is_dir()).unwrap_or(false))
        .map(|e| e.file_name().to_string_lossy().into_owned())
        .filter(|n| !n.starts_with('.') && n != "node_modules" && n != "target")
        .collect();
    names.sort();
    names
}

fn join(base: &str, seg: &str) -> String {
    if base.is_empty() { seg.to_string() } else { format!("{base}/{seg}") }
}

/// Fills `{1}`, `{2}` … in an owner id template.
pub fn render_id(template: &str, caps: &[String]) -> String {
    caps.iter().enumerate().fold(template.to_string(), |s, (i, c)| s.replace(&format!("{{{}}}", i + 1), c))
}

pub fn has_manifest(dir: &Path, manifests: &[String]) -> bool {
    manifests.iter().any(|m| match m.strip_prefix("*.") {
        Some(ext) => std::fs::read_dir(dir)
            .map(|rd| rd.flatten().any(|e| e.path().extension().is_some_and(|x| x == ext)))
            .unwrap_or(false),
        None => dir.join(m).is_file(),
    })
}

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

    #[test]
    fn globs_follow_gitignore_conventions() {
        let m = |p: &str, rel: &str| matcher(p).unwrap().is_match(rel);
        assert!(m("docs/plans/*.md", "docs/plans/a.md"));
        assert!(!m("docs/plans/*.md", "docs/plans/a/10-steps.md"));
        assert!(m("docs/**/*.md", "docs/plans/a/10-steps.md"));
        assert!(m("*.md", "docs/plans/a.md"));
        assert!(m("services/shop", "services/shop/src/main.rs"));
    }
}