1{lib, ...}: {
 2  den.aspects.core.shell.fish = {
 3    includes = [
 4      ({user, ...}: {
 5        persistUser = {
 6          files = lib.optional (!(lib.elem "homeManager" user.classes)) ".local/share/fish/fish_history";
 7        };
 8        persistHome = {config, ...}: {
 9          files = ["${config.xdg.dataHome}/fish/fish_history"];
10        };
11      })
12    ];
13
14    nixos = {
15      programs.fish = {
16        enable = true;
17        useBabelfish = true;
18
19        shellInit = ''
20          set -U fish_greeting
21        '';
22      };
23    };
24
25    homeManager = {pkgs, ...}: {
26      programs.fish = {
27        enable = true;
28        generateCompletions = true;
29        plugins = with pkgs.fishPlugins; [
30          {
31            inherit (puffer) src;
32            name = "puffer";
33          }
34          {
35            inherit (autopair) src;
36            name = "autopair";
37          }
38        ];
39
40        shellInit = ''
41          set -U fish_greeting
42        '';
43      };
44    };
45  };
46
47  den.aspects.core.shell.fish.themes = {
48    catppuccin = {
49      homeManager = {pkgs, ...}: {
50        programs.fish = {
51          shellInit = ''
52            fish_config theme choose catppuccin-mocha
53          '';
54        };
55        xdg.configFile."fish/themes/catppuccin-mocha.theme".source = pkgs.fetchurl {
56          pname = "fish-theme-catppuccin-mocha.theme";
57          url = "https://github.com/catppuccin/fish/raw/5fc5ae9c2ec22eb376cb03ce76f0d262a38960f3/themes/static/catppuccin-mocha.theme";
58          hash = "sha256-sAn4eJy6tmloWbN0p+mBdku3CK5TUeKVtVsaH/CBnGk=";
59        };
60      };
61    };
62  };
63
64  den.aspects.core.shell.fish.bashOverlay = {
65    nixos = {config, ...}: {
66      programs.bash = {
67        interactiveShellInit = ''
68          # "check if parent process is not fish" && "make nested shells work properly"
69          if grep -qv fish /proc/$PPID/comm && [[ $SHLVL == [12] ]]; then
70              # set $SHELL for better integration with programs like nix shell, tmux, etc.
71              SHELL=${config.programs.fish.package}/bin/fish exec fish
72          fi
73        '';
74      };
75    };
76  };
77}