group config files refactored to groups.d and subfolders, WIP common config file

README.md

@@ -36,7 +36,7 @@ You can also run the program using Cargo, that is handy for development: `cargo
 3. **Make sure you auth as the correct user!** 
 4. Paste the Oauth2 token you got into the terminal, hit enter.
 
-The program now ends. The credentials are saved in a file `groups.json`.
+The program now ends. The credentials are saved in the directory `groups.d/account@server/`, which is created if missing.
 
 You can repeat this for any number of groups.
 
@@ -44,53 +44,82 @@ In case you need to re-authenticate an existing group, do the same but use `-A`
 
 ### Editing config
 
-**Do not edit the config while the group service is running, it will overwrite your changes!**
+**Do not edit the config while the group service is running, it may overwrite your changes!**
+
+Each group is stored as a sub-directory in `groups.d`. The sub-directories are normally named after their accounts, 
+but this is not required.
+
+The group's config and state is split into three files:
+
+- `config.json` - immutable config, never changed beside when you run the -A command to reauth the group.
+  This is where the auth token and the `enabled` flag are stored.
+- `control.json` - settings and state that changes at runtime or can be set using slash commands.
+  This file is overwritten by the group service when needed.
+- `state.json` - frequently changing state data. The last-seen status/notification timestamps are kept here.
+  State is split from Control to reduce the risk of damaging the control file. Timestamps can be updated multiple times
+  per minute.
+
+The JSON files are easily editable, you can e.g. add yourself as an admin (use the e-mail format, e.g. `piggo@piggo.space`). 
+
+When adding hashtags, note that *they must be entered as lowercase*!
 
-The JSON file is easily editable, you can e.g. add yourself as an admin (use the e-mail format, e.g. `piggo@piggo.space`). 
 The file format is quite self-explanatory.
 
+#### config.json
+
 ```json
 {
-  "groups": {
-    "group@myserver.xyz": {
-      "enabled": true,
-      "acct": "group@myserver.xyz",
-      "appdata": {
-        "base": "https://myserver.xyz",
-        "client_id": "...",
-        "client_secret": "...",
-        "redirect": "urn:ietf:wg:oauth:2.0:oob",
-        "token": "..."
-      },
-      "group_tags": [
-        "grouptest"
-      ],
-      "admin_users": [
-        "admin@myserver.xyz"
-      ],
-      "member_only": false,
-      "member_users": [],
-      "banned_users": [],
-      "banned_servers": [
-        "bad-stuff-here.cc"
-      ],
-      "last_notif_ts": 1630011219000,
-      "last_status_ts": 1630011362000
-    }
+  "enabled": true,
+  "acct": "group@myserver.xyz",
+  "appdata": {
+    "base": "https://myserver.xyz",
+    "client_id": "...",
+    "client_secret": "...",
+    "redirect": "urn:ietf:wg:oauth:2.0:oob",
+    "token": "..."
   }
 }
 ```
 
-- `group_tags` - group hashtags (without the `#`). The group reblogs anything with these hashtags if the author is a member.
+#### control.json
+
+```json
+{
+  "group_tags": [
+    "grouptest"
+  ],
+  "admin_users": [
+    "admin@myserver.xyz"
+  ],
+  "member_only": false,
+  "member_users": [],
+  "banned_users": [],
+  "banned_servers": [
+    "bad-stuff-here.cc"
+  ]
+}
+```
+
+- `group_tags` - group hashtags (without the `#`), lowercase! The group reblogs anything with these hashtags if the author is a member.
 - `member_users` - group members, used to track whose hashtags should be reblogged; in member-only groups, this is also a user whitelist.
 - `banned_users` - can't post or interact with the group service
 - `banned_servers` - work like an instance block
 
+#### state.json
+
+```json
+{
+  "last_notif_ts": 1630011219000,
+  "last_status_ts": 1630011362000
+}
+```
+
 ### Running
 
-To run the group service, simply run it with no arguments. It will read what to do from `groups.json`.
+To run the group service, simply run it with no arguments. It will find groups in `groups.d` and start the service threads for you.
 
-Note that the file must be writable, it is updated at run-time.
+Note that the control and status files must be writable, they are updated at run-time. Config files can have restricted permissions
+to avoid accidental overwrite.
 
 An example systemd service file is included in the repository as well. Make sure to set up the system user/group and file permissions according to your needs. You can use targets in the included `Makefile` to manage the systemd service and look at logs.
 
@@ -116,7 +145,7 @@ These won't be shared:
 - `ducks suck`
 - `@group #ducks /i` (anything with the "ignore" command is ignored)
 - `@group /remove #ducks` (admin command, even if it includes a group hashtag)
-- `@otheruser tell me about ducks` (in a thread)
+- `@otheruser tell me about #ducks` (in a thread)
 - `@otheruser @group tell me about ducks` (in a thread)
 
 ### Commands