programs.msmtp: merge extraConfig and extraAccount into configContent (#7385)

We can simplify maintainance of HM while providing more consistency
across modules by relying on the nixpkgs module primitive mkBefore /
mkOrder as it was done in the Zsh module.


Deprecates:
- programs.msmtp.extraConfig
- programs.msmtp.extraAccounts

programs.msmtp: merge extraConfig and extraAccount into configContent

We can simplify maintainance of HM while providing more consistency
across modules by relying on the nixpkgs module primitive mkBefore /
mkOrder as it was done in the Zsh module.


Deprecates:
- programs.msmtp.extraConfig
- programs.msmtp.extraAccounts

modules/programs/msmtp/default.nix

@@ -46,17 +46,6 @@ let
         from ${alias}
       '') aliases
     );
-
-  configFile = mailAccounts: ''
-    # Generated by Home Manager.
-
-    ${cfg.extraConfig}
-
-    ${lib.concatStringsSep "\n\n" (map accountStr mailAccounts)}
-
-    ${cfg.extraAccounts}
-  '';
-
 in
 {
 
@@ -66,9 +55,36 @@ in
 
       package = lib.mkPackageOption pkgs "msmtp" { };
 
+      configContent = mkOption {
+        default = "";
+        type = types.lines;
+        example = lib.literalExpression ''
+          lib.mkOrder 1200 ''''
+            set syslog
+          '''';
+        '';
+        description = ''
+          Content added to msmtp config.
+          See <https://marlam.de/msmtp/msmtprc.txt> for examples.
+
+          Note, if running msmtp fails with the error message "account default
+          was already defined" then you probably have an account command here.
+          Account commands should be placed in
+          [](#opt-accounts.email.accounts._name_.msmtp.extraConfig).
+        '';
+      };
+
       extraConfig = mkOption {
         type = types.lines;
         default = "";
+        visible = false;
+        apply =
+          x:
+          lib.warnIfNot (x == "") ''
+            `programs.msmtp.extraConfig` is deprecated, use `programs.msmtp.configContent` instead.
+
+            Example: programs.msmtp.configContent = lib.mkBefore "set syslog";
+          '' x;
         description = ''
           Extra configuration lines to add to {file}`~/.msmtprc`.
           See <https://marlam.de/msmtp/msmtprc.txt> for examples.
@@ -83,6 +99,14 @@ in
       extraAccounts = mkOption {
         type = types.lines;
         default = "";
+        visible = false;
+        apply =
+          x:
+          lib.warnIfNot (x == "") ''
+            `programs.msmtp.extraAccounts` is deprecated, use `programs.msmtp.configContent` instead.
+
+            Example: programs.msmtp.configContent = lib.mkAfter "set syslog";
+          '' x;
         description = ''
           Extra configuration lines to add to the end of {file}`~/.msmtprc`.
           See <https://marlam.de/msmtp/msmtprc.txt> for examples.
@@ -95,14 +119,25 @@ in
     };
   };
 
-  config = lib.mkIf cfg.enable {
+  config = lib.mkIf cfg.enable (
-    home.packages = [ cfg.package ];
+    lib.mkMerge [
+      {
+        home.packages = [ cfg.package ];
 
-    xdg.configFile."msmtp/config".text = configFile msmtpAccounts;
+        xdg.configFile."msmtp/config".text = cfg.configContent;
 
-    home.sessionVariables = {
+        programs.msmtp.configContent = lib.mkMerge [
-      MSMTPQ_Q = "${config.xdg.dataHome}/msmtp/queue";
+          (lib.mkBefore "# Generated by Home Manager.")
-      MSMTPQ_LOG = "${config.xdg.dataHome}/msmtp/queue.log";
+          (lib.mkIf (cfg.extraConfig != "") (lib.mkBefore cfg.extraConfig))
-    };
+          (lib.concatStringsSep "\n\n" (map accountStr msmtpAccounts))
-  };
+          (lib.mkIf (cfg.extraAccounts != "") (lib.mkAfter cfg.extraAccounts))
+        ];
+
+        home.sessionVariables = {
+          MSMTPQ_Q = "${config.xdg.dataHome}/msmtp/queue";
+          MSMTPQ_LOG = "${config.xdg.dataHome}/msmtp/queue.log";
+        };
+      }
+    ]
+  );
 }