fix: stabilize plugin config directories

1 files changed, 128 insertions, 0 deletions

diff --git a/src/plugin_paths.rs b/src/plugin_paths.rs
new file mode 100644
index 00000000..18a16a77
--- /dev/null
+++ b/src/plugin_paths.rs
@@ -0,0 +1,128 @@
+use std::path::{Path, PathBuf};
+
+const PLUGIN_CONFIG_PATH_COMPONENT_MAX_CHARS: usize = 120;
+
+pub(crate) fn plugin_config_dir(plugin_id: &str) -> PathBuf {
+    crate::config::config_dir()
+        .join("plugins")
+        .join("config")
+        .join(plugin_config_path_component(plugin_id))
+}
+
+pub(crate) fn plugin_state_dir(plugin_id: &str) -> PathBuf {
+    crate::config::state_dir()
+        .join("plugins")
+        .join(plugin_config_path_component(plugin_id))
+}
+
+pub(crate) fn ensure_plugin_user_dirs(plugin_id: &str) -> std::io::Result<()> {
+    ensure_plugin_config_dir(plugin_id)?;
+    std::fs::create_dir_all(plugin_state_dir(plugin_id))?;
+    Ok(())
+}
+
+fn ensure_plugin_config_dir(plugin_id: &str) -> std::io::Result<()> {
+    let config_dir = plugin_config_dir(plugin_id);
+    if config_dir.exists() {
+        return std::fs::create_dir_all(config_dir);
+    }
+    if let Some(legacy_dir) = legacy_plugin_config_dirs(plugin_id)
+        .into_iter()
+        .find(|path| path.is_dir())
+    {
+        copy_dir_all(&legacy_dir, &config_dir)?;
+        return Ok(());
+    }
+    std::fs::create_dir_all(config_dir)
+}
+
+fn legacy_plugin_config_dirs(plugin_id: &str) -> Vec<PathBuf> {
+    let plugins_dir = crate::config::config_dir().join("plugins");
+    let old_unhashed =
+        (!matches!(plugin_id, "config" | "github")).then(|| plugins_dir.join(plugin_id));
+    let current_hashed =
+        plugins_dir.join(crate::api::schema::plugin_managed_path_component(plugin_id));
+    let mut candidates = Vec::new();
+    if let Some(old_unhashed) = old_unhashed {
+        if old_unhashed != current_hashed {
+            candidates.push(old_unhashed);
+        }
+    }
+    candidates.push(current_hashed);
+    candidates
+}
+
+fn plugin_config_path_component(value: &str) -> String {
+    let mut component = String::new();
+    for byte in value.bytes() {
+        if byte.is_ascii_lowercase() || byte.is_ascii_digit() || matches!(byte, b'.' | b'_' | b'-')
+        {
+            component.push(byte as char);
+        } else {
+            use std::fmt::Write as _;
+            let _ = write!(component, "%{byte:02X}");
+        }
+    }
+    if component.ends_with('.') {
+        component.pop();
+        component.push_str("%2E");
+    }
+    if component.is_empty() {
+        return "%plugin".to_string();
+    }
+    if crate::api::schema::has_windows_reserved_stem_for_path_component(&component) {
+        component = format!("%{component}");
+    }
+    if component.chars().count() > PLUGIN_CONFIG_PATH_COMPONENT_MAX_CHARS {
+        let hash = crate::api::schema::short_plugin_id_hash_for_path_component(value);
+        let prefix_len = PLUGIN_CONFIG_PATH_COMPONENT_MAX_CHARS - hash.len() - 1;
+        let prefix = component.chars().take(prefix_len).collect::<String>();
+        return format!("{prefix}-{hash}");
+    }
+    component
+}
+
+fn copy_dir_all(source: &Path, destination: &Path) -> std::io::Result<()> {
+    std::fs::create_dir_all(destination)?;
+    for entry in std::fs::read_dir(source)? {
+        let entry = entry?;
+        let file_type = entry.file_type()?;
+        let destination_path = destination.join(entry.file_name());
+        if file_type.is_dir() {
+            copy_dir_all(&entry.path(), &destination_path)?;
+        } else {
+            std::fs::copy(entry.path(), destination_path)?;
+        }
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn plugin_config_path_component_is_readable_and_collision_free() {
+        assert_eq!(
+            plugin_config_path_component("examples.agent-telegram-notify"),
+            "examples.agent-telegram-notify"
+        );
+        assert_eq!(plugin_config_path_component("example:a"), "example%3Aa");
+        assert_eq!(plugin_config_path_component("Example"), "%45xample");
+        assert_ne!(
+            plugin_config_path_component("example:a"),
+            plugin_config_path_component("example-a")
+        );
+        assert_ne!(
+            plugin_config_path_component("Example"),
+            plugin_config_path_component("example")
+        );
+        assert_ne!(
+            plugin_config_path_component(&"A".repeat(120)),
+            plugin_config_path_component(&"B".repeat(120))
+        );
+        assert!(plugin_config_path_component(&"A".repeat(120)).len() <= 120);
+        assert_eq!(plugin_config_path_component("con"), "%con");
+        assert_eq!(plugin_config_path_component("example."), "example%2E");
+    }
+}