Finished project

src/theme.rs

@@ -0,0 +1,141 @@
+use anyhow::{Context, Result};
+use dirs::home_dir;
+use std::fs;
+use std::path::{Path, PathBuf};
+
+pub fn themes_root() -> Result<PathBuf> {
+    if let Ok(root) = std::env::var("DM_THEMES_ROOT") {
+        return Ok(PathBuf::from(root));
+    }
+    let home = home_dir().context("failed to find home directory")?;
+    Ok(home.join("dotfiles").join("themes"))
+}
+
+pub fn discover_themes() -> Result<Vec<String>> {
+    let root = themes_root()?;
+    let entries = fs::read_dir(&root)
+        .with_context(|| format!("failed to read themes directory: {}", root.display()))?;
+
+    let mut themes = Vec::new();
+
+    for entry in entries {
+        let entry = entry.with_context(|| {
+            format!(
+                "failed to read an entry from themes directory: {}",
+                root.display()
+            )
+        })?;
+        let path = entry.path();
+
+        if path.is_dir() {
+            let Some(name) = path.file_name().and_then(|name| name.to_str()) else {
+                continue;
+            };
+            themes.push(name.to_string());
+        }
+    }
+
+    themes.sort();
+    Ok(themes)
+}
+
+/// Recursively enumerate all files under `theme_dir`.
+/// Returns `(theme_relative_path, absolute_source_path)` pairs sorted by path.
+pub fn enumerate_theme_files(theme_dir: &Path) -> Result<Vec<(PathBuf, PathBuf)>> {
+    let mut files = Vec::new();
+    enumerate_recursive(theme_dir, theme_dir, &mut files)?;
+    files.sort_by(|a, b| a.0.cmp(&b.0));
+    Ok(files)
+}
+
+fn enumerate_recursive(
+    root: &Path,
+    current: &Path,
+    files: &mut Vec<(PathBuf, PathBuf)>,
+) -> Result<()> {
+    let entries = fs::read_dir(current)
+        .with_context(|| format!("failed to read directory: {}", current.display()))?;
+
+    for entry in entries {
+        let entry =
+            entry.with_context(|| format!("failed to read entry from: {}", current.display()))?;
+        let path = entry.path();
+
+        // Skip symlinks inside a theme source tree
+        if path
+            .symlink_metadata()
+            .map(|m| m.file_type().is_symlink())
+            .unwrap_or(false)
+        {
+            continue;
+        }
+
+        if path.is_dir() {
+            enumerate_recursive(root, &path, files)?;
+        } else if path.is_file() {
+            let relative = path
+                .strip_prefix(root)
+                .with_context(|| format!("failed to strip prefix from: {}", path.display()))?;
+            files.push((relative.to_path_buf(), path));
+        }
+    }
+
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::test_utils::ENV_MUTEX;
+    use std::fs;
+    use tempfile::TempDir;
+
+    fn make_theme(root: &Path, theme: &str, files: &[&str]) {
+        for rel in files {
+            let p = root.join(theme).join(rel);
+            fs::create_dir_all(p.parent().unwrap()).unwrap();
+            fs::write(&p, "").unwrap();
+        }
+    }
+
+    #[test]
+    fn discover_themes_returns_directory_names() {
+        let _guard = ENV_MUTEX.lock().unwrap();
+        let tmp = TempDir::new().unwrap();
+        fs::create_dir(tmp.path().join("dracula")).unwrap();
+        fs::create_dir(tmp.path().join("catppuccin")).unwrap();
+        fs::write(tmp.path().join("not-a-dir.txt"), "").unwrap();
+
+        unsafe { std::env::set_var("DM_THEMES_ROOT", tmp.path()) };
+        let themes = discover_themes().unwrap();
+        unsafe { std::env::remove_var("DM_THEMES_ROOT") };
+
+        assert_eq!(themes, vec!["catppuccin", "dracula"]);
+    }
+
+    #[test]
+    fn enumerate_theme_files_returns_relative_paths() {
+        let tmp = TempDir::new().unwrap();
+        make_theme(tmp.path(), "dracula", &[".config/nvim/init.lua", ".zshrc"]);
+
+        let theme_dir = tmp.path().join("dracula");
+        let files = enumerate_theme_files(&theme_dir).unwrap();
+        let relatives: Vec<PathBuf> = files.into_iter().map(|(r, _)| r).collect();
+
+        assert!(relatives.contains(&PathBuf::from(".config/nvim/init.lua")));
+        assert!(relatives.contains(&PathBuf::from(".zshrc")));
+    }
+
+    #[test]
+    fn enumerate_theme_files_is_sorted() {
+        let tmp = TempDir::new().unwrap();
+        make_theme(tmp.path(), "t", &["b.txt", "a.txt", ".config/z.txt"]);
+
+        let theme_dir = tmp.path().join("t");
+        let files = enumerate_theme_files(&theme_dir).unwrap();
+        let relatives: Vec<PathBuf> = files.into_iter().map(|(r, _)| r).collect();
+        let mut sorted = relatives.clone();
+        sorted.sort();
+        assert_eq!(relatives, sorted);
+    }
+}