flake compatibility + index management (#11)

* compatibility to flake based systems

  - add flake.nix
  - provide interface for updating the index

* pin nix to version 2.3

* Update ,

Co-authored-by: Artturi <Artturin@artturin.com>

* remove db outdated error

Co-authored-by: Artturi <Artturin@artturin.com>

,

@@ -25,6 +25,9 @@ fi
 if [[ "$1" == "--install" ]] || [[ "$1" == "-i" ]]; then
   install=1
   shift
+elif [[ "$1" == "--update" ]] || [[ "$1" == "-u" ]]; then
+  ${UPDATE_SCRIPT}
+  exit
 else
   install=""
 fi
@@ -55,8 +58,16 @@ if [[ -z $attr ]]; then
   exit 1
 fi
 
+# on flake based installations nixpkgs is specified via
+# flake input and therefore NIX_PATH might be unset
+if echo $NIX_PATH | grep -q "nixpkgs="; then
+  nixArgs=""
+else
+  nixArgs="-I nixpkgs=${NIXPKGS}"
+fi
+
 if [[ -n $install ]]; then
-  nix-env -iA "nixpkgs.${attr%%.*}"
+  nix-env $nixArgs -iA "nixpkgs.${attr%%.*}"
 else
   nix_version_greater_or_equal() {
     local nix_version
@@ -65,7 +76,7 @@ else
   }
 
   if nix_version_greater_or_equal "2.4"; then
-    nix --extra-experimental-features 'nix-command flakes' shell "nixpkgs#${attr}" -c "${argv0}" "$@"
+    nix --extra-experimental-features 'nix-command flakes' shell "${NIXPKGS}#${attr}" -c "${argv0}" "$@"
   else
     nix run "nixpkgs.${attr}" -c "${argv0}" "$@"
   fi

default.nix

@@ -8,6 +8,7 @@
 , fzy ? pkgs.fzy
 , makeWrapper ? pkgs.makeWrapper
 , runCommand ? pkgs.runCommand
+, updateScript ? import ./update-index.nix { inherit pkgs; }
 , linkFarm ? pkgs.linkFarm
 
 # We use this to add matchers for stuff that's not in upstream nixpkgs, but is
@@ -48,6 +49,8 @@ stdenv.mkDerivation rec {
     chmod +x $out/bin/,
     wrapProgram $out/bin/, \
       --set PREBUILT_NIX_INDEX_DB ${nixIndexDB} \
+      --set NIXPKGS ${pkgs.path} \
+      --set UPDATE_SCRIPT ${updateScript} \
       --prefix PATH : ${nix-index}/bin \
       --prefix PATH : ${nix}/bin \
       --prefix PATH : ${fzy}/bin

flake.lock

@@ -0,0 +1,26 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1638110343,
+        "narHash": "sha256-hQaow8sGPyUrXgrqgDRsfA+73uR0vms2goTQNxIAaRQ=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "942eb9a335b4cd22fa6a7be31c494e53e76f5637",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixos-unstable",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,36 @@
+{
+  description = "Comma runs software without installing it";
+
+  inputs = {
+    nixpkgs.url = "nixpkgs/nixos-unstable";
+  };
+
+  outputs = { self, nixpkgs, }:
+  let
+    b = builtins;
+    lib = nixpkgs.lib;
+    supportedSystems = [ "x86_64-linux" "x86_64-darwin" ];
+    forAllSystems = f: lib.genAttrs supportedSystems
+      (system: f system (import nixpkgs { inherit system; }));
+  in
+  rec {
+
+    packages = forAllSystems
+      (system: pkgs: {
+        comma = import ./default.nix {
+          inherit pkgs;
+          updateScript = apps."${system}".update-index.program;
+        };
+      });
+
+    defaultPackage = forAllSystems (system: pkgs: packages."${system}".comma);
+
+    apps = forAllSystems
+      (system: pkgs: {
+        update-index = {
+          type = "app";
+          program = b.toString (pkgs.callPackage ./update-index.nix {});
+        };
+      });
+  };
+}

update-index.nix

@@ -0,0 +1,28 @@
+{
+  pkgs ? import <nixpkgs> {},
+
+  coreutils ? pkgs.coreutils,
+  gnugrep ? pkgs.gnugrep,
+  lib ? pkgs.lib,
+  nix-index ? pkgs.nix-index,
+  writeScript ? pkgs.writeScript,
+}:
+
+writeScript "update-index" ''
+  PATH=${lib.makeBinPath [
+    coreutils
+    gnugrep
+    nix-index
+  ]}
+
+  # on flake based installations nixpkgs is specified via
+  # flake input and therefore NIX_PATH might be unset
+  if echo $NIX_PATH | grep -q "nixpkgs="; then
+    nixpkgs=""
+  else
+    nixpkgs="-I nixpkgs=${pkgs.path}"
+  fi
+
+  mkdir -p $HOME/.cache/comma/
+  nix-index -d $HOME/.cache/nix-index -f $nixpkgs
+''