-- nvim-hardline
-- By Olivier Roques
-- github.com/ojroques

-------------------- VARIABLES -----------------------------
local api, cmd, vim = vim.api, vim.cmd, vim
local wo = vim.wo
local common = require('hardline.common')
local M = {}

-------------------- OPTIONS -------------------------------
M.options = {
  theme = 'default',
  events = {
    active = {
      'WinEnter',
    },
    inactive = {
      'WinLeave',
    },
  },
  sections = {
    -- {class = 'mode', item = require('hardline.parts.mode').item}, ' ',
    -- {class = 'high', item = require('hardline.parts.git').item}, ' ',
    {class = 'med', item = require('hardline.parts.filename').item}, ' ',
    '%=',
    -- {class = 'high', item = require('hardline.parts.filetype').item}, ' ',
    -- {class = 'mode', item = require('hardline.parts.line').item},
  },
}

-------------------- STATUSLINE ----------------------------
local function color_item(item, class)
  if not class then return item end
  if not M.options.theme[class] then return item end
  return string.format('%%#Hardline_%s_%s#%s%%*', class, 'active', item)
end

local function update_section(section)
  if type(section) == 'function' then
    return section()
  elseif type(section) == 'string' then
    return section
  elseif type(section) == 'table' then
    return color_item(update_section(section.item), section.class)
  end
  common.echo('WarningMsg', 'Invalid section.')
  return ''
end

function M.update()
  return table.concat(vim.tbl_map(update_section, M.options.sections))
end

-------------------- SETUP -----------------------------
local function set_autocmds()
  cmd 'augroup hardline'
  cmd 'autocmd!'
  for mode, events in pairs(M.options.events) do
    for _, event in ipairs(events) do
      local raw_str = 'autocmd %s * lua require("hardline").set_statusline()'
      cmd(string.format(raw_str, event))
    end
  end
  cmd 'augroup END'
end

local function set_hlgroups()
  for class, attr in pairs(M.options.theme) do
    for mode, args in pairs(attr) do
      local a = {}
      for k, v in pairs(args) do
        table.insert(a, string.format('%s=%s', k, v))
      end
      a = table.concat(a, ' ')
      cmd(string.format('hi Hardline_%s_%s %s', class, mode, a))
    end
  end
end

local function set_theme()
  if type(M.options.theme) == 'string' then
    local theme = require(string.format('hardline.themes.%s', M.options.theme))
    M.options.theme = theme
  end
end

function M.set_statusline()
  wo.statusline = [[%!luaeval('require("hardline").update()')]]
end

function M.setup(user_options)
  M.options = vim.tbl_extend('force', M.options, user_options)
  set_theme()
  set_hlgroups()
  set_autocmds()
  M.set_statusline()
end

------------------------------------------------------------
return M