format.lua

local pattern = require("copilot_cmp.pattern")
local format= {}

local label_text = function (text)
  local text_len = vim.fn.strchars(text)
  local shorten = function (str)
    local short_prefix = vim.fn.strcharpart(str, 0, 20)
    local short_suffix = vim.fn.strcharpart(str, text_len - 15, text_len)
    local delimiter = " ... "
    return short_prefix .. delimiter .. short_suffix
  end
  text = text:gsub("^%s*", "")
  return text_len > 40 and shorten(text) or text
end

format.get_indent_string = function (text)
  return string.match(text, '^%s*')
end

format.get_newline_char = function (text)
  if string.find(text, '\n') ~= nil then
    return '\n'
  else
    return nil
  end
end

-- deindents all lines and sets relative indent level to indent_level spaces
format.deindent = function(text, user_indent)
  local indent = string.match(text, '^%s*')
  if not indent then return text end

  local deindented = string.gsub(string.gsub(string.gsub(text, '^' .. indent, ''), '\n' .. indent, '\n'), '[\r|\n]$', '')

  if #indent == 0 or not user_indent or user_indent == indent then
    return deindented
  end

  local lines = format.split(deindented, '\n')
  for k, v in ipairs(lines) do
    lines[k] = string.gsub(v, '^' .. indent, user_indent)
  end
  return table.concat(lines, '\n')
end

format.add_indent = function(text, user_indent, indent_level)
  if not indent_level or indent_level == 0 then return text end

  local lines = format.split(text, '\n')
  local indent_str = string.rep(user_indent, indent_level)
  for k, v in ipairs(lines) do
    lines[k] = indent_str .. v
  end
  return table.concat(lines, '\n')
end

format.remove_leading_whitespace = function (text)
  return text:gsub("^%s*", "")
end

format.split = function (inputstr, sep)
  sep = sep or inputstr:find('\r') and '\r' or '\n'
  if sep == nil then sep = "\n" end
  if not string.find(inputstr, '[\r|\n]') then
    return {inputstr}
  end
  local t={}
  for str in string.gmatch(inputstr, "([^"..sep.."]+)") do
    table.insert(t, str)
  end
  return t
end

format.get_indent_offset = function(text)
  return #text - #format.remove_leading_whitespace(text)
end

format.to_multi_line = function (item, ctx)
  -- get indent on line before cursor
  local indent_offset = format.get_indent_offset(ctx.cursor_before_line)
  local user_indent = string.match(ctx.cursor_before_line, '^%s')

  -- if there is no indent on line before cursor, detect via expandtab settings
  -- have to do this to correcly force compliance with shiftwidth for multilines
  if user_indent == nil then
    user_indent = vim.bo.expandtab and ' ' or '\t'
  end

  -- if tabs , indent offset is the same as indent level
  local indent_level = indent_offset
  -- if spaces, force compliance with shiftwidth
  if user_indent == ' ' then
    user_indent = string.rep(' ', vim.o.shiftwidth)
    indent_level = math.floor(indent_offset/vim.o.shiftwidth)
  end

  -- deindent everything and set all relative indents vim.o.shiftwidth spaces or one tab char
  local preview = format.deindent(item.text, user_indent)
  local text = preview

  -- add indent equal to whitespace before cursor to every line
  if user_indent ~= nil then
    text = format.add_indent(preview, user_indent, indent_level)
  end

  -- get abbreviated label
  local label = label_text(text)
  local splitText = format.split(text)
  local offset = {
    start = {
      line = item.range.start.line,
      character = item.range.start.character
    },
    ['end'] = {
      line = item.range['end'].line,
      character = #splitText[1]
    }
  }
  return {
    preview = preview,
    label = label,
    text = text,
    insert = offset,
    replace = offset
  }
end

local function handle_suffix(text, suffix)
  local tbl = format.split(text)
  tbl[1] = pattern.set_suffix(tbl[1], suffix)
  local res = ''
  for i, v in ipairs(tbl) do
    res = res .. v
    if i < #tbl then
      res = res .. '\n'
    end
  end
  return res
end

format.format_item = function(item, ctx, opts)
  if opts.fix_pairs then
    item.text = handle_suffix(item.text, ctx.cursor_after_line)
    item.displayText = handle_suffix(item.displayText, ctx.cursor_after_line)
  end

  local multi_line = format.to_multi_line(item, ctx)

  return {
    copilot = true, -- for comparator, only availiable in panel, not cycling
    score = item.score or nil,
    label = multi_line.label,
    filterText = multi_line.newText,
    kind = 1,
    cmp = {
      kind_hl_group = "CmpItemKindCopilot",
      kind_text = 'Copilot',
    },
    textEdit = {
      -- use trim text here so it doesn't add extra indent
      newText = multi_line.text,
      insert = multi_line.insert,
      replace = multi_line.replace,
    },
    documentation = {
      kind = "markdown",
      value = "```" .. vim.bo.filetype .. "\n" .. multi_line.preview .. "\n```"
    },
    dup = 0,
  }
end

return format