-- Diagnostics
local special_sources = {
  lua_ls = 'lua',
}
vim.diagnostic.config({
  underline = true,
  severity_sort = true,
  virtual_text = {
    format = function(diagnostic)
      local src = diagnostic.source and (special_sources[diagnostic.source] or diagnostic.source)
      if src then
        return string.format('%s: %s', src, diagnostic.message)
      end
      return diagnostic.message
    end,
  },
  float = {
    border = 'rounded',
    header = '',
    format = function(diagnostic)
      local src = diagnostic.source and (special_sources[diagnostic.source] or diagnostic.source)
      if src then
        return string.format('%s: %s', src, diagnostic.message)
      end
      return diagnostic.message
    end,
  },
})

-- Override the virtual text diagnostic handler so that the most severe diagnostic is shown first.
local show_handler = vim.diagnostic.handlers.virtual_text.show
assert(show_handler)
local hide_handler = vim.diagnostic.handlers.virtual_text.hide
vim.diagnostic.handlers.virtual_text = {
  show = function(ns, bufnr, diagnostics, opts)
    table.sort(diagnostics, function(diag1, diag2)
      return diag1.severity > diag2.severity
    end)
    return show_handler(ns, bufnr, diagnostics, opts)
  end,
  hide = hide_handler,
}