depot/packages/modules/devshell.nix

{ lib, ... }:

{
  perSystem = { config, inputs', system, ... }:
  with lib;
  let
    inherit (inputs'.devshell.legacyPackages) mkShell;

    wrapInAttrs = value: if builtins.isAttrs value then value else { inherit value; };

    wrapPackage = package: { inherit package; };

    injectAttrName = name: value: { inherit name; } // wrapInAttrs value;

    mkNamedAttrs = builtins.mapAttrs injectAttrName;

    attrsToNamedList = attrs: builtins.attrValues (mkNamedAttrs attrs);

    mkProjectShell = 
    {
      packages ? [],
      tools ? [],
      commands ? {},
      env ? {},
      config ? {}
    }:
    mkShell {
      imports = [
        config
        {
          commands = map wrapPackage tools;
        }
        {
          inherit packages;
          commands = attrsToNamedList commands;
          env = attrsToNamedList env;
        }
      ];
    };
  in {
    options.projectShells = mkOption {
      default = {};
      type = types.attrsOf (types.submodule {
        options = {
          packages = mkOption {
            default = [];
            type = types.listOf types.package;
          };
          tools = mkOption {
            default = [];
            type = types.listOf types.package;
          };
          commands = mkOption {
            default = {};
            type = types.attrsOf types.attrs;
          };
          env = mkOption {
            default = {};
            type = with types; attrsOf (oneOf [ attrs str ] );
          };
          config = mkOption {
            default = {};
            type = types.anything;
          };
        };
      });
    };
    config.devShells = lib.mkIf (system == "x86_64-linux") (mapAttrs (_: mkProjectShell) config.projectShells);
  };
}