From 5b5eb10c5985d21f5ae3a1d84ff3e3ecfce10ea5 Mon Sep 17 00:00:00 2001
From: Tim Keller <tjk@tjkeller.xyz>
Date: Sat, 30 Aug 2025 16:38:19 -0500
Subject: allow setting default application for generic categories of
 mime-types instead of the mimewiz like method

---
 home-manager/xdg-mime.nix | 37 ++++++++++++++++++++++++++++---------
 1 file changed, 28 insertions(+), 9 deletions(-)

(limited to 'home-manager/xdg-mime.nix')

diff --git a/home-manager/xdg-mime.nix b/home-manager/xdg-mime.nix
index 043b214..420510f 100644
--- a/home-manager/xdg-mime.nix
+++ b/home-manager/xdg-mime.nix
@@ -1,22 +1,41 @@
 { config, lib, pkgs, ... }: let
-	cfg = config.xdg.mimeApps._setDefaultApplications;
-	mimeDir = ./resources/xdg-mime;
+	cfg = config.xdg.mimeApps._defaultCategoryApplications;
 
-	getApplicationMimeTypes = applicationName: lib.filter (s: s != "") (lib.splitString "\n" (builtins.readFile "${mimeDir}/${applicationName}"));
+	# Mime-type category files are stored here
+	mimeResources = ./resources/xdg-mime;
 
-	getMimeTypeApplicationList = applicationName: lib.mkMerge (lib.map (mimetype:
-		{ "${mimetype}" = [ "${applicationName}.desktop" ]; }
-	) (getApplicationMimeTypes applicationName));
+	# Files present in mimeResources with newline separated mime-types
+	# Would be more fun to load these dynamically with builtins.readDir, but I will be disciplined
+	categories = [ "audio" "email" "image" "pdf" "text" "video" ];
 
-	defaultApplications = lib.mkMerge (lib.mapAttrsToList (appPath: pathType: lib.mkIf (pathType == "regular") (getMimeTypeApplicationList appPath)) (builtins.readDir mimeDir));
+	# Dynamically generate categories
+	categoryApplications = (lib.genAttrs categories (category: lib.mkOption {
+		type = lib.types.listOf lib.types.str;
+		default = [ ];
+		description = "set the default application used for ${category} files. omit '.desktop'";
+	}));
+
+	# Create list of mime-types from the category file
+	getCategoryMimeTypes = category: lib.filter (s: s != "") (lib.splitString "\n" (builtins.readFile "${mimeResources}/${category}"));
+
+	# Structure default applications for a specified category how home-manager expects
+	assignMimeTypes = applications: category: lib.map (mimetype:
+		{ "${mimetype}" = lib.mkIf (applications != []) (lib.map (app: "${app}.desktop") applications); }
+	) (getCategoryMimeTypes category);
+
+	# Combine all category applications
+	defaultApplications = lib.mkMerge (lib.flatten (
+		lib.map (category: assignMimeTypes cfg.categoryApplications.${category} category) categories
+	));
 in {
-	options.xdg.mimeApps._setDefaultApplications = {
+	options.xdg.mimeApps._defaultCategoryApplications = {
 		enable = lib.mkEnableOption "set default applications as defined in the resources dir";
+		inherit categoryApplications;
 	};
 
 	config = lib.mkIf cfg.enable {
 		xdg.mimeApps = {
-			enable = true;
+			enable = lib.mkDefault true;
 			inherit defaultApplications;
 		};
 	};
-- 
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