local cmp = require'cmp'
local snippy = require('snippy')

cmp.setup({
    
    snippet = {
        expand = function(args)
            snippy.expand_snippet(args.body)
        end
    },
    window = {
      completion = cmp.config.window.bordered(),
      documentation = cmp.config.window.bordered(),
    },
    mapping = cmp.mapping.preset.insert({
      ['<C-b>'] = cmp.mapping.scroll_docs(-4),
      ['<C-f>'] = cmp.mapping.scroll_docs(4),
      ['<C-Space>'] = cmp.mapping.complete(),
      ['<C-e>'] = cmp.mapping.abort(),
      -- Accept currently selected item. Set `select` to `false` to only confirm explicitly selected items.
      ['<CR>'] = cmp.mapping.confirm({ select = true }),
      ["<Tab>"] = cmp.mapping(function(fallback)
        if cmp.visible() then
          cmp.select_next_item()
        elseif snippy.can_expand_or_advance() then
          snippy.expand_or_advance()
        else
          fallback()
        end
      end, { "i", "s" }),

      ["<S-Tab>"] = cmp.mapping(function(fallback)
        if cmp.visible() then
          cmp.select_prev_item()
        elseif snippy.can_jump(-1) then
          snippy.previous()
        else
          fallback()
        end
      end, { "i", "s" }),
    }),
    sources = cmp.config.sources({
      { name = 'nvim_lsp' },
      { name = 'snippy' },
      { name = 'buffer' },
    }),
    formatting = {
        fields = {
            cmp.ItemField.Abbr,
            cmp.ItemField.Kind,
            cmp.ItemField.Menu,
        },
        format = function(entry, vim_item)
            vim_item.abbr = string.sub(vim_item.abbr, 1, 20)
            vim_item.kind = string.sub(vim_item.kind, 1, 10)
            if vim_item.menu then
                vim_item.menu = string.sub(vim_item.menu, 1, 10)
            end
            return vim_item
        end
    }
})