From 9db851bb8227717b3cc2d4099c5fb43ee738e274 Mon Sep 17 00:00:00 2001
From: David Arnold <dar@xoe.solutions>
Date: Fri, 9 Oct 2020 11:27:23 -0500
Subject: [PATCH] Add command categories

---
 devshell.toml          |  2 ++
 docs/devshell.toml     |  2 ++
 docs/devshell.toml.md  |  1 +
 mkDevShell/options.nix | 50 +++++++++++++++++++++++++++++++-----------
 4 files changed, 42 insertions(+), 13 deletions(-)

diff --git a/devshell.toml b/devshell.toml
index 0dc0fa16..1955f9f7 100644
--- a/devshell.toml
+++ b/devshell.toml
@@ -47,8 +47,10 @@ command = "echo hello"
 help = "used to format Nix code"
 name = "nixpkgs-fmt"
 package = "nixpkgs-fmt"
+category = "formatters"
 
 [[commands]]
 help = "github utility"
 name = "hub"
 package = "gitAndTools.hub"
+category = "utilites"
diff --git a/docs/devshell.toml b/docs/devshell.toml
index da84d794..858a3029 100644
--- a/docs/devshell.toml
+++ b/docs/devshell.toml
@@ -47,8 +47,10 @@ command = "echo hello"
 help = "used to format Nix code"
 name = "nixpkgs-fmt"
 package = "nixpkgs-fmt"
+category = "formatters"
 
 [[commands]]
 help = "github utility"
 name = "hub"
 package = "gitAndTools.hub"
+category = "utilites"
diff --git a/docs/devshell.toml.md b/docs/devshell.toml.md
index 5e7cf2d0..a06969b3 100644
--- a/docs/devshell.toml.md
+++ b/docs/devshell.toml.md
@@ -55,6 +55,7 @@ command = "echo hello"
 help = "used to format Nix code"
 name = "nixpkgs-fmt"
 package = "nixpkgs-fmt"
+category = "formatters"
 
 [[commands]]
 help = "github utility"
diff --git a/mkDevShell/options.nix b/mkDevShell/options.nix
index ca5d53f2..11aff60c 100644
--- a/mkDevShell/options.nix
+++ b/mkDevShell/options.nix
@@ -20,10 +20,8 @@ let
 
   commandsToMenu = commands:
     let
-      commandsSorted = builtins.sort (a: b: a.name < b.name) commands;
-
       commandLengths =
-        map ({ name, ... }: builtins.stringLength name) commandsSorted;
+        map ({ name, ... }: builtins.stringLength name) commands;
 
       maxCommandLength =
         builtins.foldl'
@@ -32,18 +30,36 @@ let
           commandLengths
       ;
 
-      op = { name, help, ... }:
+      commandCategories = lib.unique (
+        (zipAttrsWithNames [ "category" ] (name: vs: vs) commands).category
+      );
+
+      commandByCategoriesSorted =
+        builtins.attrValues (lib.genAttrs
+          commandCategories
+          (category: lib.nameValuePair category (builtins.sort
+            (a: b: a.name < b.name)
+            (builtins.filter
+              (x: x.category == category)
+              commands
+            )
+          ))
+        );
+
+      opCat = { name, value }:
         let
-          len = maxCommandLength - (builtins.stringLength name);
+          opCmd = { name, help, ...}:
+            let
+              len = maxCommandLength - (builtins.stringLength name);
+            in
+            if help == null || help == "" then
+              name
+            else
+              "${pad name len} - ${help}";
         in
-        if help == null || help == "" then
-          name
-        else
-          "${pad name len} - ${help}"
-      ;
-
+         "\n[${name}]\n" + builtins.concatStringsSep "\n" (map opCmd value);
     in
-    builtins.concatStringsSep "\n" (map op commandsSorted)
+    builtins.concatStringsSep "\n" (map opCat commandByCategoriesSorted)
   ;
 
   # Because we want to be able to push pure JSON-like data into the
@@ -61,6 +77,15 @@ let
       '';
     };
 
+    category = mkOption {
+      type = types.str;
+      default = "general commands";
+      description = ''
+        Set a free text category under which this command is grouped
+        and shown in the help menu.
+      '';
+    };
+
     help = mkOption {
       type = types.nullOr types.str;
       default = null;
@@ -193,7 +218,6 @@ in
         help = "prints this menu";
         name = "menu";
         command = ''
-          echo "[commands]"
           cat <<'DEVSHELL_MENU'
           ${commandsToMenu config.commands}
           DEVSHELL_MENU