-- Setup nvim-cmp.
local cmp = require'cmp'
local lspkind = require'lspkind'

cmp.setup({
  snippet = {
    expand = function(args)
      -- For `ultisnips` user.
      vim.fn["UltiSnips#Anon"](args.body)
    end,
  },
  mapping = {
    ['<Tab>'] = {
      i = function(fallback)
        if cmp.visible() then
          cmp.select_next_item()
        else
          fallback()
        end
      end,
      c = cmp.config.disable
  },
    ['<S-Tab>'] = {
      i = function(fallback)
        if cmp.visible() then
          cmp.select_prev_item()
        else
          fallback()
        end
      end,
      c = cmp.config.disable
    },
    ['<Esc>'] = cmp.mapping.close(),
    ['<CR>'] = cmp.mapping.confirm({ select = true }),
    ['<C-d>'] = cmp.mapping.scroll_docs(-4),
    ['<C-f>'] = cmp.mapping.scroll_docs(4),
  },
  sources = {
    { name = 'nvim_lsp' }, -- For nvim-lsp
    { name = 'ultisnips' }, -- For ultisnips user.
    { name = 'nvim_lua' }, -- for nvim lua function
    { name = 'path' }, -- for path completion
    { name = 'buffer', keyword_length = 4 }, -- for buffer word completion
    { name = 'omni' },
    { name = 'emoji', insert = true, } -- emoji completion
  },
  completion = {
    keyword_length = 1,
    completeopt = "menu,noselect"
  },
  view = {
    entries = 'custom',
  },
  formatting = {
    format = lspkind.cmp_format({
      mode = "symbol_text",
      menu = ({
        nvim_lsp = "[LSP]",
        ultisnips = "[US]",
        nvim_lua = "[Lua]",
        path = "[Path]",
        buffer = "[Buffer]",
        emoji = "[Emoji]",
	      omni = "[Omni]",
      }),
    }),
  },
})

--  see https://github.com/hrsh7th/nvim-cmp/wiki/Menu-Appearance#how-to-add-visual-studio-code-dark-theme-colors-to-the-menu
vim.cmd[[
  highlight! link CmpItemMenu Comment
  " gray
  highlight! CmpItemAbbrDeprecated guibg=NONE gui=strikethrough guifg=#808080
  " blue
  highlight! CmpItemAbbrMatch guibg=NONE guifg=#569CD6
  highlight! CmpItemAbbrMatchFuzzy guibg=NONE guifg=#569CD6
  " light blue
  highlight! CmpItemKindVariable guibg=NONE guifg=#9CDCFE
  highlight! CmpItemKindInterface guibg=NONE guifg=#9CDCFE
  highlight! CmpItemKindText guibg=NONE guifg=#9CDCFE
  " pink
  highlight! CmpItemKindFunction guibg=NONE guifg=#C586C0
  highlight! CmpItemKindMethod guibg=NONE guifg=#C586C0
  " front
  highlight! CmpItemKindKeyword guibg=NONE guifg=#D4D4D4
  highlight! CmpItemKindProperty guibg=NONE guifg=#D4D4D4
  highlight! CmpItemKindUnit guibg=NONE guifg=#D4D4D4
]]