home/modules/downloads-sorter: extend

home/modules/services/downloads-sorter.nix

@@ -10,7 +10,7 @@ in
   options.services.downloads-sorter = {
     enable = lib.mkEnableOption "downloads sorter units, path activated units to keep the download dir clean";
 
-    downloadsDir = lib.mkOption {
+    downloadsDirectory = lib.mkOption {
       type = lib.types.path;
       description = "Which directory to keep clean";
       default = if config.xdg.userDirs.enable then config.xdg.userDirs.download else "${config.home.homeDirectory}/Downloads";
@@ -22,9 +22,57 @@ in
       '';
     };
 
-    # TODO: allow specifying a dynamic filter together with a system path trigger in an attrset.
     mappings = lib.mkOption {
-      type = with lib.types; attrsOf (listOf str);
+      type = let
+        mappingType = lib.types.submodule ({ name, ... }: {
+          options = {
+            unitName = lib.mkOption {
+              type = lib.types.str;
+              description = ''
+                The basename of the path/service unit responsible for this mapping
+              '';
+              default = "downloads-sorter@${name}";
+              example = "downloads-sorter@asdf";
+            };
+
+            dir = lib.mkOption {
+              type = lib.types.path;
+              description = ''
+                Absolute path to the directory where matching files should be moved.
+              '';
+              default = if builtins.substring 0 1 name == "/" then name else "${cfg.downloadsDirectory}/${name}";
+              defaultText = ''
+                if builtins.substring 0 1 name == "/" then name else "''${config.services.downloads-sorter.downloadsDirectory}/''${name}"
+              '';
+            };
+
+            globs = lib.mkOption {
+              type = with lib.types; listOf str;
+              description = ''
+                A list of globs that match the files that should be moved.
+              '';
+              example = [
+                "*.jpg"
+                "IMG_*_2020_*.png"
+              ];
+              apply = map (g: "${cfg.downloadsDirectory}/${g}");
+            };
+
+            createDirIfNotExists = lib.mkOption {
+              type = lib.types.bool;
+              description = ''
+                Whether to create the target directory if it does not exist yet.
+
+                Turn this off if you'd like the target directory to be a symlink or similar.
+              '';
+              default = true;
+              example = false;
+            };
+
+            # TODO: allow specifying a dynamic filter together with a system path trigger in an attrset.
+          };
+        });
+      in with lib.types; attrsOf (coercedTo (listOf str) (globs: { inherit globs; }) mappingType);
       description = ''
         A mapping from a file pattern to the location where it should be moved.
 
@@ -37,22 +85,23 @@ in
           "*.png"
           "*.jpg"
         ];
-        "documents" = [ "*.pdf" ];
+        "documents" = {
+          createDirIfNotExists = false;
+          globs = [ "*.pdf" ];
+        };
         "/home/<user>/archives" = [ "*.rar" ];
       };
     };
   };
 
   config = lib.mkIf cfg.enable {
-    systemd.user.paths = lib.mapAttrs' (dir: globs: let
-      unitName = "downloads-sorter@${dir}";
-    in {
-      name = unitName;
+    systemd.user.paths = lib.mapAttrs' (dir: mapping: {
+      name = mapping.unitName;
       value = {
         Install.WantedBy = [ "paths.target" ];
         Path = {
-          PathExistsGlob = map (g: "${cfg.downloadsDir}/${g}") globs;
-          Unit = "${unitName}.service";
+          PathExistsGlob = mapping.globs;
+          Unit = "${mapping.unitName}.service";
           TriggerLimitIntervalSec = "1s";
           TriggerLimitBurst = "1";
         };
@@ -60,29 +109,25 @@ in
     }) cfg.mappings;
 
     # TODO: deduplicate
-    systemd.user.services = lib.mapAttrs' (dir: globs: let
-      unitName = "downloads-sorter@${dir}";
-    in {
-      name = unitName;
+    systemd.user.services = lib.mapAttrs' (dir: mapping: {
+      name = mapping.unitName;
       value = {
         Unit.Description = "Downloads directory watchdog, sorts the downloads directory";
         Service = {
           Type = "oneshot";
-          SyslogIdentifier = unitName;
+          SyslogIdentifier = mapping.unitName;
           ExecStart = let
-            absolutePath = if (builtins.substring 0 1 dir) == "/" then dir else "${cfg.downloadsDir}/${dir}";
-
             script = pkgs.writeShellApplication {
               name = "downloads-sorter-${dir}.sh";
               runtimeInputs = [ pkgs.coreutils ];
               text = ''
                 shopt -s nullglob
 
-                FILES=(${lib.concatMapStringsSep " " (g: "'${cfg.downloadsDir}'/${g}") globs})
+                FILES=(${builtins.concatStringsSep " " mapping.globs})
 
                 for file in "''${FILES[@]}"; do
-                  echo "$file -> ${absolutePath}"
-                  mv "$file" '${absolutePath}'
+                  echo "$file -> ${mapping.dir}"
+                  mv "$file" '${mapping.dir}'
                 done
               '';
             };
@@ -100,7 +145,11 @@ in
     })  cfg.mappings;
 
     systemd.user.tmpfiles.settings."10-downloads-sorter-service" = let
-      absolutePaths = map (p: if (builtins.substring 0 1 p) == "/" then p else "${cfg.downloadsDir}/${p}") (builtins.attrNames cfg.mappings);
+      absolutePaths = lib.pipe cfg.mappings [
+        builtins.attrValues
+        (builtins.filter (m: m.createDirIfNotExists))
+        (map (m: m.dir))
+      ];
     in lib.genAttrs absolutePaths (_: {
       d = {
         user = config.home.username;