Use XDG config directory as default config path

- Look for config at $XDG_CONFIG_HOME/converge/config.yaml by default
- --config still overrides to an explicit path
- Falls back to single-repo --repo mode if no config file found
- New defaultConfigPath and configFileExists helpers in Converge module

README.md

@@ -6,41 +6,47 @@ Converge notifies the user via libnotify / `notify-send` whenever a merge confli
 
 ## Usage
 
-### Single repository
+### Configuration
+
+Converge looks for its config file at `$XDG_CONFIG_HOME/converge/config.yaml` (typically `~/.config/converge/config.yaml`). If found, it uses that file automatically.
 
 ```bash
-# Watch the current directory (defaults)
+# Run with the default XDG config file
 ./scripts/run
-
-# Watch a specific repo
-./scripts/run -- --repo /path/to/repo --branch master --debounce 10000
 ```
 
-### Multiple repositories (config file)
+You can also specify a config file explicitly:
 
 ```bash
-# Create a config file
-cp converge.example.yaml converge.yaml
-# Edit to list your repos
-vim converge.yaml
+./scripts/run -- --config /path/to/converge.yaml
+```
 
-# Run with config
-./scripts/run -- --config converge.yaml
+### Single repository (no config file)
+
+If no config file exists, converge falls back to watching a single repository:
+
+```bash
+# Watch the current directory
+./scripts/run
+
+# Watch a specific repo with options
+./scripts/run -- --repo /path/to/repo --branch master --debounce 10000
 ```
 
 ### Options
 
 | Option | Default | Description |
 |--------|---------|-------------|
-| `-c`, `--config FILE` | — | Path to YAML config file listing repositories |
-| `-r`, `--repo PATH` | `.` (cwd) | Path to a single git repository |
-| `-d`, `--debounce MS` | `5000` | Debounce window in milliseconds (overrides config) |
-| `--remote NAME` | `origin` | Remote name (single-repo mode) |
-| `-b`, `--branch NAME` | `main` | Branch to pull (single-repo mode) |
+| `-c`, `--config FILE` | `$XDG_CONFIG_HOME/converge/config.yaml` | Path to YAML config file listing repositories |
+| `-r`, `--repo PATH` | `.` (cwd) | Path to a single git repository (single-repo fallback mode) |
+| `-d`, `--debounce MS` | `5000` | Debounce window in milliseconds (overrides config file) |
+| `--remote NAME` | `origin` | Remote name (single-repo fallback mode) |
+| `-b`, `--branch NAME` | `main` | Branch to pull (single-repo fallback mode) |
 
 ### Config file format
 
 ```yaml
+# ~/.config/converge/config.yaml  (XDG default)
 repos:
   - path: /absolute/or/relative/path
     remote: origin    # optional, defaults to "origin"
@@ -74,5 +80,5 @@ All development tools run inside Docker via the `hs` wrapper script.
 - **File watching**: [fsnotify](https://hackage.haskell.org/package/fsnotify)
 - **Concurrency**: one watcher thread per repository via `async`
 - **Notifications**: shell out to `notify-send` (libnotify)
-- **Configuration**: YAML config file for multi-repo, CLI flags for single-repo
+- **Configuration**: YAML config file at XDG config path for multi-repo, CLI flags for single-repo fallback
 - **Daemonization**: TBD (likely systemd service)

app/Main.hs

@@ -76,16 +76,22 @@ main :: IO ()
 main = do
     cli <- execParser parserInfo
     let mDebounceOverride = cliDebounce cli
-    options <- case cliConfig cli of
+    (options, configSource) <- case cliConfig cli of
         Just cfgPath -> do
             cfg <- loadConfig cfgPath
-            let opts = configToOptions cfg
-            pure $ case mDebounceOverride of
-                Just ms -> opts{optDebounceMs = ms}
-                Nothing -> opts
-        Nothing ->
-            pure $
-                defaultOptions
+            let opts = applyDebounce mDebounceOverride (configToOptions cfg)
+            pure (opts, Just cfgPath)
+        Nothing -> do
+            exists <- configFileExists
+            if exists
+                then do
+                    cfgPath <- defaultConfigPath
+                    cfg <- loadConfig cfgPath
+                    let opts = applyDebounce mDebounceOverride (configToOptions cfg)
+                    pure (opts, Just cfgPath)
+                else
+                    pure
+                        ( defaultOptions
                             { optRepos =
                                 [ defaultRepoConfig
                                     { rcPath = fromMaybe "." (cliRepo cli)
@@ -95,8 +101,15 @@ main = do
                                 ]
                             , optDebounceMs = fromMaybe 5000 mDebounceOverride
                             }
+                        , Nothing
+                        )
+    case configSource of
+        Just path ->
+            hPutStrLn stderr ("Using config: " <> path)
+        Nothing ->
+            hPutStrLn stderr "No config file found, using single-repo mode"
     hPutStrLn stderr $
-        "Converge watching "
+        "Watching "
             <> show (length (optRepos options))
             <> " repo(s)"
             <> " (debounce: "
@@ -104,3 +117,7 @@ main = do
             <> "ms)"
     mapM_ (\r -> hPutStrLn stderr ("  - " <> rcPath r)) (optRepos options)
     runConverge options
+
+applyDebounce :: Maybe Int -> Options -> Options
+applyDebounce (Just ms) opts = opts{optDebounceMs = ms}
+applyDebounce Nothing opts = opts

converge.example.yaml

@@ -1,5 +1,6 @@
 # Example converge configuration file.
-# Usage: converge --config converge.yaml
+# Place at ~/.config/converge/config.yaml to use by default,
+# or pass explicitly with: converge --config converge.yaml
 
 repos:
   - path: /home/jbrechtel/org

src/Converge.hs

@@ -9,6 +9,8 @@ module Converge (
     Config (..),
     loadConfig,
     configToOptions,
+    defaultConfigPath,
+    configFileExists,
 
     -- * Running
     runConverge,
@@ -31,7 +33,7 @@ import Data.Maybe (fromMaybe)
 import Data.Text (Text)
 import qualified Data.Text as T
 import Data.Yaml (FromJSON (..), decodeFileThrow, withObject, (.:), (.:?))
-import System.Directory (getCurrentDirectory)
+import System.Directory (XdgDirectory (XdgConfig), doesFileExist, getCurrentDirectory, getXdgDirectory)
 import System.Exit (ExitCode (..))
 import System.FSNotify
 import System.FilePath (isAbsolute, (</>))
@@ -114,6 +116,14 @@ configToOptions cfg =
         , optDebounceMs = fromMaybe 5000 (cfgDebounceMs cfg)
         }
 
+-- | The default XDG config file path: @$XDG_CONFIG_HOME/converge/config.yaml@.
+defaultConfigPath :: IO FilePath
+defaultConfigPath = (</> "converge/config.yaml") <$> getXdgDirectory XdgConfig ""
+
+-- | Check whether the default config file exists.
+configFileExists :: IO Bool
+configFileExists = defaultConfigPath >>= doesFileExist
+
 ----------------------------------------------------------------------
 -- Running
 ----------------------------------------------------------------------