add option to override locale messages per-group, update readme

README.md

@@ -55,43 +55,74 @@ A typical setup could look like this:
 │   │   ├── control.json
 │   │   └── state.json
 │   └── chatterbox@botsin.space
-│       ├── config.json
-│       ├── control.json
-│       └── state.json
+│       ├── config.json   ... fixed config edited manually 
+│       ├── messages.json ... custom locale overrides (optional)
+│       ├── control.json  ... mutable config updated by the group service
+│       └── state.json    ... group state data
+├── locales
+│   ├── ... custom locale files, same format like en.json
+│   └── ru.json
 └── groups.json
 ```
 
+#### Locales
+
+English locale ("en") is bundled in the binary. Additional locales can be placed in the `locales` folder.
+If an entry is missing, the English version will be used.
+
+The locale file looks like this (excerpt):
+
+```json
+{
+  "group_announcement": "**📢Group announcement**\n{message}",
+  "ping_response": "pong, this is fedigroups service v{version}"
+}
+```
+
+- Words in curly braces (`{}`) are substitution tokens. These must be preserved in all translations.
+- Pay attention to line endings and blank lines (`\n`). Some messages from the locale file are combined to form the
+  final post, leaving out newlines can result in a mangled output.
+
+The locale to use is chosen in each group's `config.json`, "en" by default (if not specified).
+
+Group-specific overrides are also possible: create a file `messages.json` in the group folder
+and define messages you wish to change, e.g. the greeting or announcement templates.
+
 #### Common config
 
 There is one shared config file: `groups.json`
 
-- If the file does not exist, default settings are used. This is usually good enough.
-- This file applies to all groups
-- Prior to 0.3, the groups were also configured here. 
-- Running 0.3+ with the old file will produce an error, you need to update the config before continuing - move groups to subfolders
+- If the file does not exist, default settings are used. This is usually sufficient.
+- This file applies to all groups and serves as the default config.
 
 ```
 {
+    // name of the directory with groups
+    "groups_dir": "groups",
+    // name of the directory with locales
+    "locales_dir": "locales",
+    // Show warning if locales are missing keys
+    "validate_locales": true,
     // Max number of missed notifs to process after connect
-    max_catchup_notifs: 30,
+    "max_catchup_notifs": 30,
     // Max number of missed statuses to process after connect
-    max_catchup_statuses: 50,
+    "max_catchup_statuses": 50,
     // Delay between fetched pages when catching up
-    delay_fetch_page_s: 0.25,
+    "delay_fetch_page_s": 0.25,
     // Delay after sending a status, making a follow or some other action.
     // Set if there are Throttled errors and you need to slow the service down.
-    delay_after_post_s: 0.0,
+    "delay_after_post_s": 0.0,
     // Delay before trying to re-connect after the server closed the socket
-    delay_reopen_closed_s: 0.5,
+    "delay_reopen_closed_s": 0.5,
     // Delay before trying to re-connect after an error
-    delay_reopen_error_s: 5.0,
+    "delay_reopen_error_s": 5.0,
     // Timeout for a notification/timeline socket to be considered alive.
     // If nothing arrives in this interval, reopen it. Some servers have a buggy socket
     // implementation where it stays open but no longer works.
-    socket_alive_timeout_s: 30.0,
+    "socket_alive_timeout_s": 30.0,
     // Time after which a socket is always closed, even if seemingly alive.
     // This is a work-around for servers that stop sending notifs after a while.
-    socket_retire_time_s: 120.0,
+    "socket_retire_time_s": 120.0
 }
 ```
 
@@ -111,6 +142,7 @@ Only the `config.json` file with credentials is required; the others will be cre
 - `state.json` - frequently changing state data. The last-seen status/notification timestamps are kept here.
   State is split from Control to limit the write frequency of the control file. Timestamps can be updated multiple times
   per minute.
+- `messages.json` - optional per-group locale overrides
 
 **Do not edit the control and state files while the group service is running, it may overwrite your changes!**
 
@@ -127,9 +159,11 @@ The file formats are quite self-explanatory (again, remove comments before copyi
 {
   // Enable or disable the group service
   "enabled": true,
+  // Group locale (optional, defaults to "en")
+  "locale": "en",
   // Group account name
   "acct": "group@myserver.xyz",
-  // Saved mastodon API credentials
+  // Saved mastodon API credentials, this is created when authenticating the group.
   "appdata": {
     "base": "https://myserver.xyz",
     "client_id": "...",

locales/cs.json

@@ -1,4 +1,3 @@
 {
-  "welcome_public": "Ahoj",
   "ping_response": "pong, toto je fedigroups verze {version}"
 }

src/group_handler/handle_mention.rs

@@ -35,7 +35,7 @@ pub struct ProcessMention<'a> {
 
 impl<'a> ProcessMention<'a> {
     fn tr(&self) -> &TranslationTable {
-        self.cc.tr(self.config.get_locale())
+        self.config.tr()
     }
 
     async fn lookup_acct_id(&self, acct: &str, followed: bool) -> Result<Option<String>, GroupError> {

src/group_handler/mod.rs

@@ -529,7 +529,7 @@ impl GroupHandle {
     }
 
     fn tr(&self) -> &TranslationTable {
-        self.cc.tr(self.config.get_locale())
+        self.config.tr()
     }
 
     async fn handle_new_follow(&mut self, notif_acct: &str, notif_user_id: &str) {

src/store/common_config.rs

@@ -7,6 +7,7 @@ use crate::tr::TranslationTable;
 pub struct CommonConfig {
     pub groups_dir: String,
     pub locales_dir: String,
+    pub validate_locales: bool,
     /// Max number of missed notifs to process after connect
     pub max_catchup_notifs: usize,
     /// Max number of missed statuses to process after connect
@@ -36,6 +37,7 @@ impl Default for CommonConfig {
         Self {
             groups_dir: "groups".to_string(),
             locales_dir: "locales".to_string(),
+            validate_locales: true,
             max_catchup_notifs: 30,
             max_catchup_statuses: 50,
             delay_fetch_page_s: 0.25,

src/store/group_config.rs

@@ -4,7 +4,8 @@ use std::path::{Path, PathBuf};
 use elefren::AppData;
 
 use crate::error::GroupError;
-use crate::store::DEFAULT_LOCALE_NAME;
+use crate::store::{DEFAULT_LOCALE_NAME, CommonConfig};
+use crate::tr::TranslationTable;
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(default, deny_unknown_fields)]
@@ -69,6 +70,8 @@ pub struct GroupConfig {
     control: MutableConfig,
     /// State config with timestamps and transient data that is changed frequently
     state: StateConfig,
+    /// Group-specific translation table; this is a clone of the global table with group-specific overrides applied.
+    _group_tr: TranslationTable,
 }
 
 impl Default for FixedConfig {
@@ -155,16 +158,6 @@ impl_change_tracking!(FixedConfig);
 impl_change_tracking!(MutableConfig);
 impl_change_tracking!(StateConfig);
 
-impl Default for GroupConfig {
-    fn default() -> Self {
-        Self {
-            config: Default::default(),
-            control: Default::default(),
-            state: Default::default(),
-        }
-    }
-}
-
 async fn load_or_create_control_file(control_path: impl AsRef<Path>) -> Result<MutableConfig, GroupError> {
     let control_path = control_path.as_ref();
     let mut dirty = false;
@@ -209,7 +202,22 @@ async fn load_or_create_state_file(state_path: impl AsRef<Path>) -> Result<State
     Ok(state)
 }
 
+async fn load_locale_override_file(locale_path: impl AsRef<Path>) -> Result<Option<TranslationTable>, GroupError> {
+    let locale_path = locale_path.as_ref();
+    if locale_path.is_file() {
+        let f = tokio::fs::read(&locale_path).await?;
+        let opt : TranslationTable = serde_json::from_slice(&f)?;
+        Ok(Some(opt))
+    } else {
+        Ok(None)
+    }
+}
+
 impl GroupConfig {
+    pub fn tr(&self) -> &TranslationTable {
+        &self._group_tr
+    }
+
     pub(crate) fn is_dirty(&self) -> bool {
         self.config.is_dirty() || self.control.is_dirty() || self.state.is_dirty()
     }
@@ -251,7 +259,7 @@ impl GroupConfig {
     }
 
     /// (re)init using new authorization
-    pub(crate) async fn from_appdata(acct: String, appdata: AppData, group_dir: PathBuf) -> Result<Self, GroupError> {
+    pub(crate) async fn initialize_by_appdata(acct: String, appdata: AppData, group_dir: PathBuf) -> Result<(), GroupError> {
         if !group_dir.is_dir() {
             debug!("Creating group directory");
             tokio::fs::create_dir_all(&group_dir).await?;
@@ -298,15 +306,16 @@ impl GroupConfig {
         /* state */
         let state = load_or_create_state_file(state_path).await?;
 
-        let g = GroupConfig { config, control, state };
+        let g = GroupConfig { config, control, state, _group_tr: TranslationTable::new() };
         g.warn_of_bad_config();
-        Ok(g)
+        Ok(())
     }
 
-    pub(crate) async fn from_dir(group_dir: PathBuf) -> Result<Self, GroupError> {
+    pub(crate) async fn from_dir(group_dir: PathBuf, cc : &CommonConfig) -> Result<Self, GroupError> {
         let config_path = group_dir.join("config.json");
         let control_path = group_dir.join("control.json");
         let state_path = group_dir.join("state.json");
+        let locale_path = group_dir.join("messages.json");
 
         // try to reuse content of the files, if present
 
@@ -321,7 +330,15 @@ impl GroupConfig {
         /* state */
         let state = load_or_create_state_file(state_path).await?;
 
-        let g = GroupConfig { config, control, state };
+        /* translation table */
+        let mut tr = cc.tr(&config.locale).clone();
+        if let Some(locale_overrides) = load_locale_override_file(locale_path).await? {
+            for (k, v) in locale_overrides.entries() {
+                tr.add_translation(k, v);
+            }
+        }
+
+        let g = GroupConfig { config, control, state, _group_tr: tr };
         g.warn_of_bad_config();
         Ok(g)
     }
@@ -369,10 +386,6 @@ impl GroupConfig {
         &self.config.appdata
     }
 
-    pub(crate) fn get_locale(&self) -> &str {
-        &self.config.locale
-    }
-
     pub(crate) fn set_appdata(&mut self, appdata: AppData) {
         if self.config.appdata != appdata {
             self.config.mark_dirty();

src/store/mod.rs

@@ -127,7 +127,7 @@ impl ConfigStore {
 
         let group_dir = self.groups_path.join(&opts.acct);
 
-        let _data = GroupConfig::from_appdata(opts.acct.clone(), appdata, group_dir).await?;
+        GroupConfig::initialize_by_appdata(opts.acct.clone(), appdata, group_dir).await?;
 
         // save & persist
 
@@ -151,7 +151,7 @@ impl ConfigStore {
     pub async fn reauth_group(&self, acct: &str) -> Result<(), GroupError> {
         let group_dir = self.groups_path.join(&acct);
 
-        let mut config = GroupConfig::from_dir(group_dir).await?;
+        let mut config = GroupConfig::from_dir(group_dir, &self.config).await?;
 
         println!("--- Re-authenticating bot user @{} ---", acct);
         let registration = Registration::new(config.get_appdata().base.to_string())
@@ -233,11 +233,12 @@ impl ConfigStore {
 
                 for (k, v) in def_tr.entries() {
                     if !tr.translation_exists(k) {
-                        warn!("locale \"{}\" is missing \"{}\", default: {:?}",
-                            locale_name,
-                            k,
-                            def_tr.get_translation_raw(k).unwrap());
-
+                        if self.config.validate_locales {
+                            warn!("locale \"{}\" is missing \"{}\", default: {:?}",
+                                locale_name,
+                                k,
+                                def_tr.get_translation_raw(k).unwrap());
+                        }
                         tr.add_translation(k, v);
                     }
                 }
@@ -261,7 +262,7 @@ impl ConfigStore {
             .map(|entry_maybe: Result<std::fs::DirEntry, std::io::Error>| async {
                 match entry_maybe {
                     Ok(entry) => {
-                        let gc = GroupConfig::from_dir(entry.path()).await.ok()?;
+                        let gc = GroupConfig::from_dir(entry.path(), &config).await.ok()?;
 
                         if !gc.is_enabled() {
                             debug!("Group @{} is DISABLED", gc.get_acct());

src/tr.rs

@@ -23,6 +23,7 @@ impl TranslationTable {
         self.entries.get(key).map(|s| s.as_str())
     }
 
+    /// Add or update a translation
     pub fn add_translation(&mut self, key : impl ToString, subs : impl ToString) {
         self.entries.insert(key.to_string(), subs.to_string());
     }