-- menuone: show also for just one code suggestion
-- noinsert: only insert text when selection confirmed
-- noselect: force to select from suggestion
-- preview: show more details
vim.opt.completeopt = {'menuone', 'noselect', 'noinsert', 'preview'}

-- shortmess is used to reduce verbocity
-- vim.opt.shortmess = vim.opt.shortmess + { c = true }

local cmp = require'cmp'
cmp.setup( {
	-- configuration 
 snippet = {
   expand = function(args)
     vim.fn["UltiSnips#Anon"](args.body)
   end,
 },
	-- mapping 
	  mapping = {
    -- Shift+TAB to go to the Previous Suggested item
    ['<C-s-k>'] = cmp.mapping.select_prev_item(),
    -- Tab to go to the next suggestion
    ['<C-k>'] = cmp.mapping.select_next_item(),
    -- CTRL+SHIFT+f to scroll backwards in description
    ['<C-S-f>'] = cmp.mapping.scroll_docs(-4),
    -- CTRL+F to scroll forwards in the description
    ['<C-f>'] = cmp.mapping.scroll_docs(4),
    -- CTRL+SPACE to bring up completion at current Cursor location
    ['<C-Space>'] = cmp.mapping.complete(),
    -- CTRL+e to exit suggestion and close it
    ['<C-e>'] = cmp.mapping.close(),
    -- CR (enter or return) to CONFIRM the currently selection suggestion
    -- We set the ConfirmBehavior to insert the Selected suggestion
    ['<CR>'] = cmp.mapping.confirm({
    behavior = cmp.ConfirmBehavior.Insert,
      select = true,
    })
  },

	-- installed sources for code suggestion
  sources = {
      { name = 'path' },
      { name = 'nvim_lsp', keyword_length = 3 },
      { name = 'nvim_lsp_signature_help'}, 
      { name = 'nvim_lua', keyword_length = 2},
      { name = 'buffer', keyword_length = 2 },
      { name = 'ultisnips', keyword_length = 2 },
      { name = 'calc' },
      { name = "lua-latex-symbols", option = { cache = true } }
 },

 -- Add borders to the windows
 window = {
   completion = cmp.config.window.bordered(),
   documentation = cmp.config.window.bordered(),
 },
 -- add formating of the different sources
   formatting = {
   fields = {'menu', 'abbr', 'kind'},
   format = function(entry, item)
     local menu_icon ={
       nvim_lsp = 'λ',
       ultisnips = '⋗',
       buffer = 'b',
       path = 'p',
       calc = 'Σ',
       lualatexsymbols = 'L'
     }
     item.menu = menu_icon[entry.source.name]
       return item
   end,
  }
} )

-- Set configuration for specific filetype.
cmp.setup.filetype('gitcommit', {
  sources = cmp.config.sources({
    { name = 'cmp_git' }, -- You can specify the `cmp_git` source if you were installed it.
  }, {
    { name = 'buffer' },
  })
})



-- Use cmdline & path source for ':' (if you enabled `native_menu`, this won't work anymore).
cmp.setup.cmdline(':', {
  mapping = cmp.mapping.preset.cmdline(),
  sources = cmp.config.sources({
    { name = 'path' }
  }, {
    { name = 'cmdline' }
  })
})