flake: move packages to a by-name overlay

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I6a6a69642d9409f7d32e01a140cb62c2173b5226

flake/packages.nix

@@ -9,29 +9,59 @@
     lib,
     ...
   }: let
+    inherit (lib.customisation) makeScope;
+    inherit (lib.attrsets) isDerivation isAttrs concatMapAttrs;
+    inherit (lib.strings) concatStringsSep;
+    inherit (lib.filesystem) packagesFromDirectoryRecursive;
+
+    # Entrypoint for nvf documentation and relevant packages.
     docs = import ../docs {inherit pkgs inputs lib;};
+
+    # Helper function for creating demo configurations for nvf
+    # TODO: make this more generic.
     buildPkg = maximal:
       (args.config.flake.lib.nvim.neovimConfiguration {
         inherit pkgs;
         modules = [(import ../configuration.nix maximal)];
       }).neovim;
-  in {
-    packages = {
-      blink-cmp = pkgs.callPackage ./blink {};
-      avante-nvim = let
-        pin = self.pins.avante-nvim;
-      in
-        pkgs.callPackage ./avante-nvim {
-          version = pin.branch;
-          src = pkgs.fetchFromGitHub {
-            inherit (pin.repository) owner repo;
-            rev = pin.revision;
-            sha256 = pin.hash;
-          };
-          pins = self.pins;
+
+    # This constructs a by-name overlay similar to the one found in Nixpkgs.
+    # The goal is to automatically discover and packages found in pkgs/by-name
+    # as long as they have a 'package.nix' in the package directory. We also
+    # pass 'inputs' and 'pins' to all packages in the 'callPackage' scope, therefore
+    # they are always available in the relevant 'package.nix' files.
+    # ---
+    # The logic is borrowed from drupol/pkgs-by-name-for-flake-parts, available
+    # under the MIT license.
+    flattenPkgs = separator: path: value:
+      if isDerivation value
+      then {
+        ${concatStringsSep separator path} = value;
+      }
+      else if isAttrs value
+      then concatMapAttrs (name: flattenPkgs separator (path ++ [name])) value
+      else
+        # Ignore the functions which makeScope returns
+        {};
+
+    inputsScope = makeScope pkgs.newScope (_: {
+      inherit inputs;
+      inherit (self) pins;
+    });
+
+    scopeFromDirectory = directory:
+      packagesFromDirectoryRecursive {
+        inherit directory;
+        inherit (inputsScope) newScope callPackage;
       };
 
+    legacyPackages = scopeFromDirectory ./pkgs/by-name;
+  in {
+    packages =
+      (flattenPkgs "/" [] legacyPackages)
+      // {
         inherit (docs.manual) htmlOpenTool;
+
         # Documentation
         docs = docs.manual.html;
         docs-html = docs.manual.html;

flake/pkgs/by-name/avante-nvim/package.nix

@@ -1,4 +1,5 @@
 {
+  pins,
   openssl,
   pkg-config,
   rustPlatform,
@@ -6,11 +7,17 @@
   vimUtils,
   makeWrapper,
   pkgs,
-  version,
-  src,
   ...
 }: let
-  inherit version src;
+  # From npins
+  pin = pins.avante-nvim;
+  version = pin.branch;
+  src = pkgs.fetchFromGitHub {
+    inherit (pin.repository) owner repo;
+    rev = pin.revision;
+    sha256 = pin.hash;
+  };
+
   avante-nvim-lib = rustPlatform.buildRustPackage {
     pname = "avante-nvim-lib";
     inherit version src;
@@ -48,10 +55,9 @@ in
       ext = stdenv.hostPlatform.extensions.sharedLibrary;
     in ''
       mkdir -p $out/build
-      ln -s ${avante-nvim-lib}/lib/libavante_repo_map${ext} $out/build/avante_repo_map${ext}
-      ln -s ${avante-nvim-lib}/lib/libavante_templates${ext} $out/build/avante_templates${ext}
-      ln -s ${avante-nvim-lib}/lib/libavante_tokenizers${ext} $out/build/avante_tokenizers${ext}
-      ln -s ${avante-nvim-lib}/lib/libavante_html2md${ext} $out/build/avante_html2md${ext}
+      for lib in avante_repo_map avante_templates avante_tokenizers avante_html2md; do
+        ln -s ${avante-nvim-lib}/lib/lib$lib${ext} $out/build/$$lib${ext}
+      done
     '';
 
     nvimSkipModules = [