modularize git

modules/default.nix

@@ -14,6 +14,7 @@
         ./home/programs/foot
         ./home/programs/fuzzel
         ./home/programs/ghostty
+        ./home/programs/git
         ./home/programs/helix
         ./home/programs/hyprlock
         ./home/programs/jujutsu

modules/home/programs/git/default.nix

@@ -0,0 +1,59 @@
+{
+  config,
+  pkgs,
+  lib,
+  ...
+}: let
+  inherit (lib) mkIf mkEnableOption;
+  cfg = config.home.programs.git;
+in {
+  options = {
+    home.programs.git.enable = mkEnableOption "Enables git";
+  };
+  config = mkIf cfg.enable {
+    home.packages = [pkgs.gh];
+    programs.git = {
+      enable = true;
+      userName = config.accounts.username;
+      userEmail = config.accounts.mail;
+      delta = {
+        enable = true;
+        options.dark = true;
+      };
+      extraConfig = {
+        # user.signingkey = "${config.home.homeDirectory}/.ssh/id_ed25519.pub";
+        user.signingkey = "${config.home.homeDirectory}/.config/git/allowed_signers";
+        signing = {
+          format = lib.mkDefault "ssh";
+          key = "${config.home.homeDirectory}/.ssh/id_ed25519";
+          signByDefault = true;
+        };
+        gpg = {
+          # format = lib.mkDefault "ssh";
+          ssh.allowedSignersFile = config.home.homeDirectory + "/" + config.xdg.configFile."git/allowed_signers".target;
+        };
+        commit = {
+          verbose = true;
+          gpgSign = false;
+        };
+        init.defaultBranch = "main";
+        merge.conflictStyle = "diff3";
+        diff.algorithm = "histogram";
+        log.date = "iso";
+        column.ui = "auto";
+        branch.sort = "committerdate";
+        push.autoSetupRemote = true;
+        rerere.enabled = true;
+      };
+      lfs.enable = true;
+      ignores = [
+        ".direnv"
+        "result"
+        ".jj"
+      ];
+    };
+    xdg.configFile."git/allowed_signers".text = ''
+      ${config.accounts.mail} namespaces="git" ${config.accounts.sshKey}
+    '';
+  };
+}

modules/options/accounts/default.nix

@@ -4,6 +4,24 @@
   ...
 }: let
   inherit (lib) mkOption types;
+
+  sshKeys = {
+    cnixpad = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIXCjkKouZrsMoswMIeueO8X/c3kuY3Gb0E9emvkqwUv cnst@cnixpad";
+    cnixlab = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAICiNcNex+/hrEQJYJJTj89uPXocSfChU38E5TujWdxaM cnstlab@cnixlab";
+    cnixtop = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIEUub8vbzUn2f39ILhAJ2QeH8xxLSjiyUuo8xvHGx/VB adam@cnst.dev";
+    toothpc = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIGu5vZbb5ExampleKeyHereGfDF9c5 toothpick@toothpc";
+  };
+
+  keyName = config.accounts.sshUser or null;
+
+  selectedKey =
+    if keyName != null
+    then
+      lib.attrByPath [keyName] (
+        builtins.abort "No SSH key defined for hostname/key '${toString keyName}'"
+      )
+      sshKeys
+    else builtins.abort "No accounts.sshUser provided, cannot select SSH key.";
 in {
   options.accounts = {
     username = mkOption {
@@ -11,10 +29,21 @@ in {
       default = "cnst";
       description = "Set the desired username";
     };
-    hostname = mkOption {
+    mail = mkOption {
       type = types.str;
-      default = "cnix";
-      description = "Set the desired hostname";
+      default = "adam@cnst.dev";
+      description = "Set the desired email";
+    };
+    sshKey = lib.mkOption {
+      type = lib.types.str;
+      default = selectedKey;
+      description = "Host-specific SSH key";
+      readOnly = true;
+    };
+    sshUser = lib.mkOption {
+      type = lib.types.nullOr lib.types.str;
+      default = null;
+      description = "Optional override for selecting an SSH key by name";
     };
   };
 }