Editing command line with scrollback using kitty and fish

edit_command_buffer_with_scrollback.fish

# This is a modified version of `edit_command_buffer` distributed with fish.
function edit_command_buffer_with_scrollback --description 'Edit the command buffer in an external editor'
    set -l f (mktemp)
    or return 1
    if set -q f[1]
        command mv $f $f.fish
        set f $f.fish
    else
        # We should never execute this block but better to be paranoid.
        if set -q TMPDIR
            set f $TMPDIR/fish.$fish_pid.fish
        else
            set f /tmp/fish.$fish_pid.fish
        end
        command touch $f
        or return 1
    end

    commandline -b >$f

    # compute cursor line/column
    set -l offset (commandline --cursor)
    set -l lines (commandline)\n
    set -l line 1
    while test $offset -ge (string length -- $lines[1])
        set offset (math $offset - (string length -- $lines[1]))
        set line (math $line + 1)
        set -e lines[1]
    end
    set col (math $offset + 1)

    __fish_disable_bracketed_paste
    vim                             \
        +"set previewwindow"        \
        +"norm! G"                  \
        +"wincmd j"                 \
        +"call cursor($line, $col)" \
        +"resize 12" -o (begin; history --reverse; kitten @ get-text --extent all; end | psub) $f
    set -l editor_status $status
    __fish_enable_bracketed_paste

    # Here we're checking the exit status of the editor.
    if test $editor_status -eq 0 -a -s $f
        # Set the command to the output of the edited command and move the cursor to the
        # end of the edited command.
        commandline -r -- (command cat $f)
        commandline -C 999999
    else
        echo
        echo (_ "Ignoring the output of your editor since its exit status was non-zero")
        echo (_ "or the file was empty")
    end
    command rm $f
    # We've probably opened something that messed with the screen.
    # A repaint seems in order.
    commandline -f repaint
end

Update: added fish history at the beginning of the scrollback buffer.