local previewers = require('telescope.previewers')
local Job = require('plenary.job')
local new_maker = function(filepath, bufnr, opts)
  filepath = vim.fn.expand(filepath)
  Job:new({
    command = 'file',
    args = { '--mime-type', '-b', filepath },
    on_exit = function(j)
      local mime_type = vim.split(j:result()[1], '/')[1]
      if mime_type == "text" then
        previewers.buffer_previewer_maker(filepath, bufnr, opts)
      else
        -- maybe we want to write something to the buffer here
        vim.schedule(function()
          vim.api.nvim_buf_set_lines(bufnr, 0, -1, false, { 'BINARY' })
        end)
      end
    end
  }):sync()
end

require('telescope').setup {
  defaults = {
    buffer_previewer_maker = new_maker,
    file_ignore_patterns = {"**/*.pdf"},
  }
}

local map = vim.api.nvim_set_keymap
-- Find files using Telescope command-line sugar.
map('n', '<leader>e', '<cmd>Telescope find_files<cr>', {})
map('n', '<leader>g', '<cmd>Telescope live_grep<cr>', {})
map('n', '<leader>b', '<cmd>Telescope buffers<cr>', {})
map('n', '<leader>h', '<cmd>Telescope help_tags<cr>', {})