Initial commit

flake.nix

@@ -0,0 +1,50 @@
+# flake.nix
+{
+  description = "Dev shell + runnable app for merge_pdfs.py";
+
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.05";
+
+  outputs = { self, nixpkgs }:
+  let
+    systems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];
+    forEachSystem = f: nixpkgs.lib.genAttrs systems (system:
+      let
+        pkgs = import nixpkgs { inherit system; };
+        python = pkgs.python311.withPackages (ps: [ ps.pypdf2 ]);
+        # Small wrapper so `nix run` works: it uses the Python with PyPDF2 and your script.
+        merge-pdfs = pkgs.writeShellScriptBin "merge-pdfs" ''
+          exec ${python}/bin/python ${./merge_pdfs.py} "$@"
+        '';
+      in f pkgs python merge-pdfs
+    );
+  in {
+    devShells = forEachSystem (pkgs: python: merge-pdfs: {
+      default = pkgs.mkShell {
+        packages = [
+          python            # Python 3.11 with PyPDF2
+          pkgs.ruff         # optional: linter
+          pkgs.pyright      # optional: type checker
+        ];
+        shellHook = ''
+          echo "✅ Dev shell ready. Try:"
+          echo "  python merge_pdfs.py output.pdf a.pdf b.pdf"
+        '';
+      };
+    });
+
+    # `nix run` makes it easy to use from anywhere:
+    apps = forEachSystem (pkgs: python: merge-pdfs: {
+      default = {
+        type = "app";
+        program = "${merge-pdfs}/bin/merge-pdfs";
+      };
+    });
+
+    # expose the tiny wrapper as a package if you want `nix build .#merge-pdfs`
+    packages = forEachSystem (pkgs: python: merge-pdfs: {
+      default = merge-pdfs;
+      merge-pdfs = merge-pdfs;
+    });
+  };
+}
+