flake: initial commit

flake.nix

@@ -0,0 +1,174 @@
+{
+  inputs.flake-utils.url = "github:numtide/flake-utils";
+
+  outputs = {
+    self,
+    nixpkgs,
+    flake-utils,
+  }: let
+    mapOverlayOverride = namespace: overlay: final: prev: let
+      overlayPkgs = overlay final prev;
+    in
+      {
+        "${namespace}" = builtins.removeAttrs overlayPkgs ["override"];
+      }
+      // (overlayPkgs.override or {});
+  in
+    flake-utils.lib.eachDefaultSystem (system: {
+      formatter = (import nixpkgs {inherit system;}).alejandra;
+    })
+    // {
+      overlays = let
+        overlay = mapOverlayOverride "trivium" (import ./pkgs);
+      in {
+        default = overlay;
+        trivium = overlay;
+      };
+
+      lib = {
+        mkSystemFlake = {
+          flakes,
+          system,
+          formatter ? "alejandra",
+          localOverlayPath ? null,
+          nixpkgsConfigPath ? null,
+          nixosSourcePath ? null,
+          nixosPlatformsPath ?
+            if nixosSourcePath != null
+            then nixosSourcePath + /platform
+            else null,
+          hmSourcePath ? null,
+          hmPlatformsPath ?
+            if hmSourcePath != null
+            then hmSourcePath + /platform
+            else null,
+        }: let
+          optionalFlake = name:
+            if flakes ? "${name}"
+            then flakes.${name}
+            else null;
+
+          requireFlake = name:
+            if flakes ? "${name}"
+            then flakes.${name}
+            else throw "Required flake input '${name}' is required but was not provided";
+
+          nur = optionalFlake "nur";
+          nixpkgs = requireFlake "nixpkgs";
+          unstable = optionalFlake "unstable";
+
+          home-manager =
+            if hmSourcePath != null
+            then requireFlake "home-manager"
+            else null;
+
+          pkgs = importPkgs nixpkgs;
+
+          importPkgs = flake:
+            import flake ({
+                inherit system;
+
+                config = import ./pkgs/config nixpkgs.lib;
+                overlays = let
+                  conditions = [
+                    {
+                      overlay = nur.overlays.default;
+                      condition = nur != null;
+                    }
+                    # NB: Preserve the relative order
+                    {
+                      overlay = self.overlays.trivium;
+                      condition = true;
+                    }
+                    {
+                      overlay = flakes.self.overlays.default;
+                      condition = true;
+                    }
+                  ];
+                in
+                  builtins.map (cond: cond.overlay) (builtins.filter (cond: cond.condition) conditions);
+              }
+              // (
+                if nixpkgsConfigPath != null
+                then {
+                  config = import nixpkgsConfigPath {inherit (nixpkgs) lib;};
+                }
+                else {}
+              ));
+
+          inherit (pkgs.trivium.lib) importAll;
+        in
+          with pkgs.lib;
+            {
+              formatter.${system} =
+                if formatter == "alejandra"
+                then pkgs.alejandra
+                else if formatter == "nixpkgs-fmt"
+                then pkgs.nixpkgs-fmt
+                else throw "Unknown formatter: '${formatter}'";
+
+              packages.${system} = pkgs.local;
+
+              overlays.default = final: prev: let
+                overlay =
+                  if localOverlayPath != null
+                  then import localOverlayPath
+                  else (final: prev: {});
+              in
+                mapOverlayOverride "local" overlay final prev
+                // optionalAttrs (unstable != null) {
+                  unstable = importPkgs unstable;
+                };
+            }
+            // optionalAttrs (nixosSourcePath != null) {
+              nixosConfigurations = let
+                nixosSystem = {modules}:
+                  makeOverridable nixpkgs.lib.nixosSystem {
+                    inherit modules pkgs system;
+
+                    specialArgs = {
+                      inherit flakes;
+                    };
+                  };
+
+                hostConfig = platform:
+                  nixosSystem {
+                    modules = [
+                      ./nixos
+                      nixosSourcePath
+                      platform
+                    ];
+                  };
+              in
+                mapAttrs (_: hostConfig) (importAll {root = nixosPlatformsPath;});
+            }
+            // optionalAttrs (hmSourcePath != null) {
+              homeConfigurations = let
+                registry = {...}: {
+                  config.nix.registry =
+                    mapAttrs
+                    (_: value: {flake = value;})
+                    flakes;
+                };
+
+                home = name: platform:
+                  home-manager.lib.homeManagerConfiguration {
+                    inherit pkgs;
+
+                    extraSpecialArgs = {
+                      inherit flakes;
+                    };
+
+                    modules = [
+                      ./hm
+                      hmSourcePath
+                      platform
+                      registry
+                    ];
+                  };
+              in
+                mapAttrs home (importAll {root = hmPlatformsPath;});
+            };
+      };
+    };
+}

hm/default.nix

@@ -0,0 +1 @@
+{}

nixos/default.nix

@@ -0,0 +1 @@
+{}

pkgs/default.nix

@@ -0,0 +1,8 @@
+final: prev:
+with prev.lib; let
+  inherit (final) callPackage;
+in {
+  lib = callPackage ./lib {};
+
+  override = {};
+}

pkgs/lib/default.nix

@@ -0,0 +1,3 @@
+{callPackage}: {
+  importAll = callPackage ./importAll.nix {};
+}

pkgs/lib/importAll.nix

@@ -0,0 +1,20 @@
+{lib}: {
+  root,
+  exclude ? [],
+}:
+with builtins;
+with lib;
+# http://chriswarbo.net/projects/nixos/useful_hacks.html
+  let
+    basename = removeSuffix ".nix";
+
+    isMatch = name: type:
+      (hasSuffix ".nix" name || type == "directory")
+      && ! elem name (map basename exclude);
+
+    entry = name: _: {
+      name = basename name;
+      value = import (root + "/${name}");
+    };
+  in
+    mapAttrs' entry (filterAttrs isMatch (readDir root))