-- https://github.com/hrsh7th/nvim-cmp/wiki/Example-mappings#luasnip

local has_words_before = function()
    unpack = unpack or table.unpack
    local line, col = unpack(vim.api.nvim_win_get_cursor(0))
    return col ~= 0 and vim.api.nvim_buf_get_lines(0, line - 1, line, true)[1]:sub(col, col):match("%s") == nil
end

local luasnip = require("luasnip")
local cmp = require("cmp")

local nvim_cmp_tab = function(fallback)
    if cmp.visible() then
        cmp.select_next_item()
    elseif luasnip.expand_or_jumpable() then
        luasnip.expand_or_jump()
    elseif has_words_before() then
        cmp.complete()
    else
        fallback()
    end
end

local nvim_cmp_stab = function(fallback)
    if cmp.visible() then
        cmp.select_prev_item()
    elseif luasnip.jumpable(-1) then
        luasnip.jump(-1)
    else
        fallback()
    end
end