1 files changed, 166 insertions, 0 deletions
diff --git a/modules/flake/githubWorkflow.nix b/modules/flake/githubWorkflow.nix
new file mode 100644
index 0000000..bb36bf7
--- /dev/null
+++ b/modules/flake/githubWorkflow.nix
@@ -0,0 +1,166 @@
+{
+  config,
+  lib,
+  self,
+  ...
+}: let
+  cfg = config.githubWorkflowGenerator;
+
+  inherit
+    (builtins)
+    attrNames
+    filter
+    ;
+
+  inherit
+    (lib)
+    elem
+    flatten
+    getAttrs
+    literalExpression
+    mapAttrsToList
+    mdDoc
+    mkOption
+    types
+    ;
+
+  supportedOutputs = [
+    "apps"
+    "checks"
+    "devShells"
+    "darwinConfigurations"
+    "homeConfigurations"
+    "nixosConfigurations"
+    "packages"
+  ];
+
+  platformMap = {
+    options = {
+      arch = mkOption {
+        description = mdDoc "the architecture of a system";
+        type = types.str;
+        default = null;
+        example = literalExpression "x86_64";
+      };
+
+      os = mkOption {
+        description = mdDoc "the name of an os supported by github runners";
+        type = types.str;
+        default = null;
+        example = literalExpression "ubuntu-latest";
+      };
+    };
+  };
+
+  overrides = {
+    options = {
+      systems = mkOption {
+        description = mdDoc "list of systems to build an output for";
+        type = types.listOf types.str;
+        default = builtins.attrNames cfg.platforms;
+      };
+    };
+  };
+
+  mkMatrix = {
+    output,
+    systems ? (attrNames cfg.platforms),
+  }:
+    if (lib.elem output ["nixosConfigurations" "darwinConfigurations"])
+    then
+      mkMatrixFlat {
+        inherit output;
+        suffix = ".config.system.build.toplevel";
+      }
+    else if (output == "homeConfigurations")
+    then
+      mkMatrixFlat {
+        inherit output;
+        suffix = ".activationPackage";
+      }
+    else
+      flatten (
+        mapAttrsToList
+        (
+          system:
+            mapAttrsToList (
+              attr: _: {
+                inherit (cfg.platforms.${system}) os arch;
+                attr = "${output}.${system}.${attr}";
+              }
+            )
+        )
+        (getAttrs systems self.${output})
+      );
+
+  mkMatrixFlat = {
+    output,
+    suffix ? "",
+  }:
+    mapAttrsToList (
+      attr: deriv: {
+        inherit (cfg.platforms.${deriv.pkgs.system}) os arch;
+        attr = "${output}.${attr}${suffix}";
+      }
+    )
+    self.${output};
+
+  jobs = let
+    self' = getAttrs cfg.outputs self;
+  in
+    flatten (
+      mapAttrsToList (
+        output: _:
+          mkMatrix ({inherit output;} // cfg.overrides.${output} or {})
+      )
+      self'
+    );
+in {
+  options = {
+    githubWorkflowGenerator = {
+      outputs = mkOption {
+        description = mdDoc "outputs to include in workflow";
+        type = types.listOf types.str;
+        default = filter (output: elem output supportedOutputs) (attrNames self);
+      };
+
+      platforms = mkOption {
+        description = mdDoc ''
+          an attrset that can map a nix system to an architecture and os supported by github
+        '';
+        type = types.attrsOf (types.submodule platformMap);
+        default = {
+          "x86_64-linux" = {
+            arch = "x86_64";
+            os = "ubuntu-latest";
+          };
+
+          "aarch64-linux" = {
+            arch = "aarch64";
+            os = "ubuntu-latest";
+          };
+
+          "x86_64-darwin" = {
+            arch = "x86_64";
+            os = "macos-latest";
+          };
+        };
+      };
+
+      overrides = mkOption {
+        description = mdDoc "overrides for mkMatrix args";
+        type = types.attrsOf (types.submodule overrides);
+        default = {};
+        example = literalExpression ''
+          {
+            githubworkflowGenerator.overrides = {
+              checks.systems = [ "x86_64-linux" ];
+            };
+          }
+        '';
+      };
+    };
+  };
+
+  config.flake.githubWorkflow = {matrix.include = jobs;};
+}