-- luasnip setup
local luasnip = require 'luasnip'
local cmp = require 'cmp'

cmp.setup {
    snippet = {
        expand = function(args) require('luasnip').lsp_expand(args.body) end
    },
    mapping = {
        ['<C-p>'] = cmp.mapping.select_prev_item(),
        ['<C-n>'] = cmp.mapping.select_next_item(),
        ['<C-d>'] = cmp.mapping.scroll_docs(-4),
        ['<C-f>'] = cmp.mapping.scroll_docs(4),
        ['<C-Space>'] = cmp.mapping.complete(),
        ['<C-e>'] = cmp.mapping.close(),
        ['<CR>'] = cmp.mapping.confirm {
            behavior = cmp.ConfirmBehavior.Replace,
            select = true
        },
        ['<Tab>'] = function(fallback)
            if vim.fn.pumvisible() == 1 then
                vim.fn.feedkeys(vim.api.nvim_replace_termcodes('<C-n>', true,
                                                               true, true), 'n')
            elseif luasnip.expand_or_jumpable() then
                vim.fn.feedkeys(vim.api.nvim_replace_termcodes(
                                    '<Plug>luasnip-expand-or-jump', true, true,
                                    true), '')
            else
                fallback()
            end
        end,
        ['<S-Tab>'] = function(fallback)
            if vim.fn.pumvisible() == 1 then
                vim.fn.feedkeys(vim.api.nvim_replace_termcodes('<C-p>', true,
                                                               true, true), 'n')
            elseif luasnip.jumpable(-1) then
                vim.fn.feedkeys(vim.api.nvim_replace_termcodes(
                                    '<Plug>luasnip-jump-prev', true, true, true),
                                '')
            else
                fallback()
            end
        end
    },
    sources = {
        {name = 'nvim_lsp'}, {name = 'luasnip'}, {name = "nvim_lua"},
        {name = 'path'}, {name = 'buffer'}, {name = 'calc'},
        {name = 'treesitter'}
    }
}