local M = {}

local function t(str)
    return vim.api.nvim_replace_termcodes(str, true, true, true)
end

function _G.format_mode(mode)
  local map_table = {
    ["n"] = "normal",
    ["no"] = "normal·operator pending",
    ["v"] = "visual",
    ["V"] = "visual(line)",
    [t('<C-v>')] = "visual(block)",
    ["s"] = "select",
    ["S"] = "select(line)",
    [t('<C-s>')] = "select(block)",
    ["i"] = "insert",
    ["R"] = "replace",
    ["Rv"] = "v·replace",
    ["c"] = "command",
    ["cv"] = "vim ex",
    ["ce"] = "ex",
    ["r"] = "prompt",
    ["rm"] = "more",
    ["r?"] = "confirm",
    ["!" ] = "shell",
    ["t"] = "terminal",
  }

  local output = map_table[mode]

  if output == nil then
    output = mode
  end

  return string.upper(output)
end

local function setHighlight(str)
  return string.format("%%#%s#", str)
end

function M.output()
  local palette = {
    cyan    = "#7dcfff",
    blue    = "#7aa2f7",
    magenta = "#bb9af7",
    black   = "#414868",
    bg      = "#15161e",
    none    = "NONE",
  }

  local statuslineMode        = "StatuslineMode"
  local statuslineTransparent = "StatuslineTransparent"
  local statuslineBlueText    = "StatuslineBlueText"
  local statuslineMagentaText = "StatuslineMagentaText"

  local theme = {
    [statuslineMode]        = {fg = palette["black"], bg = palette["cyan"], bold = true},
    [statuslineTransparent] = {bg = palette["none"]},
    [statuslineBlueText]    = {bg = palette["bg"], fg = palette["blue"], bold = true},
    [statuslineMagentaText] = {bg = palette["bg"], fg = palette["magenta"], bold = true},
  }

  local ns = vim.api.nvim_create_namespace("statusline")
  vim.api.nvim__set_hl_ns(ns)

  for name, settings in pairs(theme) do
    vim.api.nvim_set_hl(ns, name, settings)
  end

  local separator   = "▒▒"
  local mode        = " %{%v:lua.format_mode(v:lua.vim.fn.mode())%} "
  local open_file   = " %r%t %m"
  local buf_nr      = "[%n] "
  local right_align = "%="
  local file_format = " %{&ff}"
  local file_type   = "%y "
  local encoding    = "%{''.(&fenc!=''?&fenc:&enc).''} "
  local line_no     = " line: %03l/%03L "
  local percentage  = "[%3p%%] "

  return table.concat{
    setHighlight(statuslineMode),
    mode,
    setHighlight(statuslineBlueText),
    separator,
    open_file,
    buf_nr,
    separator,
    setHighlight(statuslineTransparent),
    right_align,
    setHighlight(statuslineBlueText),
    separator,
    file_format,
    file_type,
    encoding,
    setHighlight(statuslineMagentaText),
    separator,
    line_no,
    percentage,
    separator,
  }
end

return M