{ ... }:

{
  programs.fish.enable = true;

  programs.fish.shellAbbrs =
    { e  = "nvim";
      l  = "ls -lh";
      ip = "ip -c";
      iftop = "iftop -m 70M";
    };

  programs.fish.shellAliases =
    { namecoin-cli = "namecoin-cli -conf=$XDG_CONFIG_HOME/namecoin"; };

  programs.fish.loginShellInit =
    ''
      # Start abduco in ssh
      if set -q SSH_CLIENT
        # start abduco on ssh
        if not set -q ABDUCO_SESSION
          exec abduco -A ssh fish
        else if test $SHLVL -eq 1
          tput rmcup
        end
      end
    '';

  programs.fish.interactiveShellInit =
    ''
      ## Fish settings

      # mixed emacs/vi
      fish_hybrid_key_bindings

      # kj to normal mode
      bind -M insert kj "
        if commandline -P;
          commandline -f cancel;
        else;
          set fish_bind_mode default;
          commandline -f backward-char repaint-mode;
        end"

      # fix unquoted URLs
      set -U fish_features ampersand-nobg-in-token qmark-noglob
      # change default cursor
      set fish_cursor_insert underscore


      ## Color scheme

      # syntax highlighting
      set fish_color_command      green
      set fish_color_param        normal
      set fish_color_comment      brcyan
      set fish_color_operator     purple
      set fish_color_escape       bryellow
      set fish_color_redirection  blue
      set fish_color_selection    --background=black

      # completion/history
      set fish_pager_color_prefix       yellow
      set fish_pager_color_description  brblue
      set fish_pager_color_progress     brblack --background=black
      set fish_color_search_match       --background=black

      # man pages colors
      # bold, blink stop
      set -x LESS_TERMCAP_md (set_color -o bryellow)
      set -x LESS_TERMCAP_mb (set_color -u magenta)
      set -x LESS_TERMCAP_me (set_color normal)
      # standout start/stop
      set -x LESS_TERMCAP_so (set_color brblue -b black)
      set -x LESS_TERMCAP_se (set_color normal -b normal)
      # underline start/stop
      set -x LESS_TERMCAP_us (set_color -u brmagenta)
      set -x LESS_TERMCAP_ue (set_color normal)

      # used default LS_COLORS
      eval (dircolors | sed 's/\(\w\+\)=/set \1 /')


      ## Aliases

      # start process and detach
      function start
        nohup $argv > /dev/null 2>&1 &; disown
      end

      # start process without network access
      function nnet
        unshare -nc fish -ic "$argv"
      end

      # interactively rename files
      function vimv
        set tmp (mktemp --tmpdir -d vimv.XXX)
        if set -q argv[1]
          # directory listing
          find $argv[1] -maxdepth 1 | sort | cat -n | tee $tmp/before > $tmp/after
        else
          # read from stdin
          cat -n - | tee $tmp/before > $tmp/after
        end
        $EDITOR $tmp/after
        # only print differing lines
        awk '
          NR==FNR { line=$0; sub($1, "", line); sub(/\s+/, "", line); lines[$1]=line; next }
          NR!=FNR { line=$0; sub($1, "", line); sub(/\s+/, "", line);
            if (!($1 in lines)) { printf("rm -vr \"%s\"\n", line); next }
            if (lines[$1] != line) printf("mv -vin \"%s\" \"%s\"\n", line, lines[$1])
          }
        ' $tmp/after $tmp/before | sh
        rm -r $tmp
      end
    '';

  programs.fish.promptInit =
    ''
      # Outputs colored text
      function color
        set_color $argv[1]
        for i in $argv[2..-1]
          echo -n $i
        end
        set_color normal
      end

      # Git branch info
      function git_branch
        if not test -f .git/HEAD
          return
        end

        set branch (git rev-parse --abbrev-ref HEAD 2> /dev/null)
        if test $status -ne 0
          set branch (cut -f 3 -d '/' .git/HEAD)
        else if test $branch = HEAD
          set branch (head -c 10 .git/HEAD)
        end

        timeout 0.1 git diff-files --quiet 2>/dev/null
        if test $status -eq 1
          set branch (color yellow $branch'*')
        else
          set branch (color green $branch)
        end

        timeout 0.1 git status --porcelain 2>/dev/null 1>| read untracked
        if test -n "$untracked"
          set dirty (color red '*')
        end

        echo " <$branch$dirty>"
      end

      # Left prompt
      function fish_prompt
        if fish_is_root_user
          set prompt (color blue Λ)
          set user   (color red (whoami))
        else
          set prompt (color blue λ)
          set user   (color green (whoami))
        end

        if test \( "$LINES" -lt 10 \) -o \( "$COLUMNS" -lt 30 \)
          echo "$prompt "
          return
        end

        if set -q SSH_CLIENT
          set host (color yellow (hostname))
        else
          set host (color green (hostname))
        end

        set git  (git_branch)
        set path (color cyan (prompt_pwd))

        switch $fish_bind_mode
          case default
            set mode (color blue n)
          case insert
            set mode (color red i)
          case visual
            set mode (color yellow v)
        end

        echo "$user@$host $mode$path$git"
        echo "$prompt "
      end

      # Right prompt
      function fish_right_prompt
        set code $status
        if test $code -ne 0
          set exitcode (color red $code" ⏎")
        end
        if string match -q '/nix*' $PATH[1]
          set nix " <"(color blue nix)">"
        end
        echo "$exitcode$nix"
      end

      function fish_mode_prompt; end
      function fish_greeting; end
  '';

}