nvim pager for kitty history

kitty+page.lua

return function(INPUT_LINE_NUMBER, CURSOR_LINE, CURSOR_COLUMN)
  print('kitty sent:', INPUT_LINE_NUMBER, CURSOR_LINE, CURSOR_COLUMN)
  vim.opt.encoding='utf-8'
  vim.opt.clipboard = 'unnamed'
  vim.opt.compatible = false
  vim.opt.number = false
  vim.opt.relativenumber = false
  vim.opt.termguicolors = true
  vim.opt.showmode = false
  vim.opt.ruler = false
  vim.opt.laststatus = 0
  vim.o.cmdheight = 0
  vim.opt.showcmd = false
  vim.opt.scrollback = INPUT_LINE_NUMBER + CURSOR_LINE
  local term_buf = vim.api.nvim_create_buf(true, false);
  local term_io = vim.api.nvim_open_term(term_buf, {})
  vim.api.nvim_buf_set_keymap(term_buf, 'n', 'q', '<Cmd>q<CR>', { })
  vim.api.nvim_buf_set_keymap(term_buf, 'n', '<ESC>', '<Cmd>q<CR>', { })
  local group = vim.api.nvim_create_augroup('kitty+page', {})

  local setCursor = function()
    vim.api.nvim_feedkeys(tostring(INPUT_LINE_NUMBER) .. [[ggzt]], 'n', true)
    local line = vim.api.nvim_buf_line_count(term_buf)
    if (CURSOR_LINE <= line) then
      line = CURSOR_LINE
    end
    vim.api.nvim_feedkeys(tostring(line - 1) .. [[j]], 'n', true)
    vim.api.nvim_feedkeys([[0]], 'n', true)
    vim.api.nvim_feedkeys(tostring(CURSOR_COLUMN - 1) .. [[l]], 'n', true)
  end

  vim.api.nvim_create_autocmd('ModeChanged', {
    group = group,
    buffer = term_buf,
    callback = function()
      local mode = vim.fn.mode()
      if mode == 't' then
        vim.cmd.stopinsert()
        vim.schedule(setCursor)
      end
    end,
  })

  vim.api.nvim_create_autocmd('VimEnter', {
    group = group,
    pattern = '*',
    once = true,
    callback = function(ev)
        local current_win = vim.fn.win_getid()
        for _, line in ipairs(vim.api.nvim_buf_get_lines(ev.buf, 0, -2, false)) do
          vim.api.nvim_chan_send(term_io, line)
          vim.api.nvim_chan_send(term_io, '\r\n')
        end
        for _, line in ipairs(vim.api.nvim_buf_get_lines(ev.buf, -2, -1, false)) do
          vim.api.nvim_chan_send(term_io, line)
        end
        vim.api.nvim_win_set_buf(current_win, term_buf)
        vim.api.nvim_buf_delete(ev.buf, { force = true } )
        vim.schedule(setCursor)
    end
  })
end

kitty.conf

# ...
scrollback_pager nvim -u NONE -R -M -c 'lua require("kitty+page")(INPUT_LINE_NUMBER, CURSOR_LINE, CURSOR_COLUMN)' -  
# ...

This is my modified attempt, using @yusufshalaby solution with vim.defer_fn(setCursor, 10) to make sure the terminal has time to process the content and the buffer is ready.

/home/YOUR_USER/.config/nvim/lua/kitty+page.lua:

return function(INPUT_LINE_NUMBER)
    vim.opt.encoding='utf-8'
    -- Prevent auto-centering on click
    vim.opt.scrolloff = 0
    vim.opt.compatible = false
    vim.opt.number = false
    vim.opt.relativenumber = false
    vim.opt.termguicolors = true
    vim.opt.showmode = false
    vim.opt.ruler = false
    vim.opt.signcolumn=no
    vim.opt.showtabline=0
    vim.opt.laststatus = 0
    vim.o.cmdheight = 0
    vim.opt.showcmd = false
    vim.opt.scrollback = 100000
    vim.opt.clipboard:append('unnamedplus')
    local term_buf = vim.api.nvim_create_buf(true, false)
    local term_io = vim.api.nvim_open_term(term_buf, {})
    -- Map 'q' to first yank the visual selection (if any), which makes the copy selection work, and then quit.
    vim.api.nvim_buf_set_keymap(term_buf, 'v', 'q', 'y<Cmd>qa!<CR>', { })
    -- Regular quit mapping for normal mode
    vim.api.nvim_buf_set_keymap(term_buf, 'n', 'q', '<Cmd>qa!<CR>', { })
    local group = vim.api.nvim_create_augroup('kitty+page', {clear = true})

    local setCursor = function()
        local max_line_nr = vim.api.nvim_buf_line_count(term_buf)
        local input_line_nr = math.max(1, math.min(tonumber(INPUT_LINE_NUMBER), max_line_nr))

        -- It seems that both the view (view.topline) and the cursor (nvim_win_set_cursor) must be set
        -- for scrolling and cursor positioning to work reliably with terminal buffers.
        vim.fn.winrestview({topline = input_line_nr})
        vim.api.nvim_win_set_cursor(0, {input_line_nr, 0})
    end

  vim.api.nvim_create_autocmd('ModeChanged', {
    group = group,
    buffer = term_buf,
    callback = function()
      local mode = vim.fn.mode()
      if mode == 't' then
        vim.cmd.stopinsert()
        vim.schedule(setCursor)
      end
    end,
  })

  vim.api.nvim_create_autocmd('VimEnter', {
    group = group,
    pattern = '*',
    once = true,
    callback = function(ev)
        local current_win = vim.fn.win_getid()
        -- Instead of sending lines individually, concatenate them.
        local main_lines = vim.api.nvim_buf_get_lines(ev.buf, 0, -2, false)
        local content = table.concat(main_lines, '\r\n')
        vim.api.nvim_chan_send(term_io, content .. '\r\n')

        -- Process the last line separately (without trailing \r\n)
        local last_line = vim.api.nvim_buf_get_lines(ev.buf, -2, -1, false)[1]
        if last_line then
            vim.api.nvim_chan_send(term_io, last_line)
        end
        vim.api.nvim_win_set_buf(current_win, term_buf)
        vim.api.nvim_buf_delete(ev.buf, { force = true } )
        -- Use vim.defer_fn to make sure the terminal has time to process the content and the buffer is ready.
        vim.defer_fn(setCursor, 10)
    end
  })
end

On my kitty.conf:

scrollback_pager nvim -u NONE -R -M -c 'lua require("kitty+page")(INPUT_LINE_NUMBER)' -

This solution breaks long lines into multiple actual lines in the buffer, rather than using proper soft wrapping in Neovim. As a result, copying long lines becomes problematic.