viminal2/lua/scripts/intellitab.lua

-- `intellitab.nvim` by Pedro Alves (https://github.com/pta2002)
-- URL: https://github.com/pta2002/intellitab.nvim?tab=MIT-1-ov-file
-- Copyright 2021 Pedro Alves. Licensed under MIT.

local v = vim.api

local treesitter = require("nvim-treesitter")

local function get_line_indent(line, sw)
  local indent = 0

  for c in line:gmatch("%s") do
    if c == "\t" then
      indent = indent + sw
    else
      indent = indent + 1
    end
  end

  return indent
end

local function indent()
  local cursor = v.nvim_win_get_cursor(0)
  local line = v.nvim_buf_get_lines(0, cursor[1] - 1, cursor[1], false)[1]

  local indentexpr = v.nvim_get_option_value("indentexpr", { buf = 0 })
  local expand = v.nvim_get_option_value("expandtab", { buf = 0 })
  local shiftwidth = v.nvim_eval("shiftwidth()")
  local tab_char = v.nvim_replace_termcodes("<Tab>", true, true, true)
  local indent_goal

  if treesitter ~= nil and treesitter.get_indent ~= nil then
    indent_goal = treesitter.get_indent(line)
  end

  if indent_goal == nil or indent_goal < 0 then
    if indentexpr ~= "" then
      indent_goal = v.nvim_eval(indentexpr)
    elseif v.nvim_get_option_value("cindent", { buf = 0 }) then
      indent_goal = v.nvim_call_function("cindent", { cursor[1] })
    else
      indent_goal = v.nvim_call_function("indent", { cursor[1] })
    end
  end

  if indent_goal == -1 and cursor[1] ~= 1 then
    local prev_line = v.nvim_buf_get_lines(0, cursor[1] - 2, cursor[1] - 1, false)[1]
    indent_goal = get_line_indent(prev_line, shiftwidth)
  end

  -- Reset the cursor, since the functions are free to move it
  v.nvim_win_set_cursor(0, cursor)

  if cursor[2] == 0 and line == "" and indent_goal ~= nil and indent_goal > 0 then
    local i = 0
    while i < indent_goal do
      if expand then
        v.nvim_feedkeys(" ", "n", true)
        i = i + 1
      else
        v.nvim_feedkeys(tab_char, "n", true)
        i = i + shiftwidth
      end
    end
    print(i, indent_goal)
  else
    v.nvim_feedkeys(tab_char, "n", true)
  end
end

return { indent = indent }