Add obsidian theme

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

hosts/common/user/configs/gui/obsidian/options.nix

@@ -89,6 +89,12 @@ in
           type = raw;
           default = [ ];
         };
+
+        theme = mkOption {
+          description = "Obsidian theme package.";
+          type = raw;
+          default = null;
+        };
       };
 
       vaults = mkOption {
@@ -134,6 +140,12 @@ in
                     type = listOf path;
                     default = cfg.sharedSettings.cssSnippets;
                   };
+
+                  theme = mkOption {
+                    description = "Obsidian theme package.";
+                    type = nullOr package;
+                    default = cfg.sharedSettings.theme;
+                  };
                 };
               };
 
@@ -148,6 +160,7 @@ in
   config =
     let
       vaults = builtins.filter (vault: vault.enable == true) (builtins.attrValues cfg.vaults);
+      getThemeName = theme: (builtins.fromJSON (builtins.readFile "${theme}/manifest.json")).name;
     in
     lib.mkIf cfg.enable {
       home = {
@@ -171,6 +184,9 @@ in
                       snippet: lib.strings.removeSuffix ".css" (builtins.baseNameOf snippet)
                     ) vault.settings.cssSnippets;
                   }
+                  // lib.attrsets.optionalAttrs (vault.settings.theme != null) {
+                    cssTheme = getThemeName vault.settings.theme;
+                  }
                 );
               };
             };
@@ -203,6 +219,14 @@ in
                   source = snippet;
                 };
               }) vault.settings.cssSnippets;
+            mkTheme =
+              vault:
+              lib.attrsets.optionalAttrs (vault.settings.theme != null) {
+                name = "${vault.target}/.obsidian/themes/${getThemeName vault.settings.theme}";
+                value = {
+                  source = vault.settings.theme;
+                };
+              };
           in
           builtins.listToAttrs (
             lib.lists.flatten (
@@ -211,6 +235,7 @@ in
                 (mkAppearance vault)
                 (mkCorePlugins vault)
                 (mkCssSnippets vault)
+                (mkTheme vault)
               ]) vaults
             )
           );