From 8e643a37f78d3da2a6016f62a2d276a03666dcc1 Mon Sep 17 00:00:00 2001
From: Rokas Puzonas <rokas.puz@gmail.com>
Date: Mon, 1 Nov 2021 17:55:53 +0200
Subject: [PATCH] fix: setup luasnip to work with cmp

---
 lua/config/cmp.lua | 33 +++++++++++++++++++++++++++++----
 1 file changed, 29 insertions(+), 4 deletions(-)

diff --git a/lua/config/cmp.lua b/lua/config/cmp.lua
index 550fc55..cf582ce 100644
--- a/lua/config/cmp.lua
+++ b/lua/config/cmp.lua
@@ -3,6 +3,12 @@ local lspkind = require('lspkind')
 lspkind.init()
 
 local cmp = require('cmp')
+local luasnip = require("luasnip")
+
+local has_words_before = function()
+  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
 
 cmp.setup{
 	completion = { completeopt = 'menu,menuone,noinsert' },
@@ -12,8 +18,6 @@ cmp.setup{
 		end,
 	},
 	mapping = {
-		-- ['<C-n>'] = cmp.mapping.select_next_item({ behavior = cmp.SelectBehavior.Insert }),
-		-- ['<C-p>'] = cmp.mapping.select_prev_item({ behavior = cmp.SelectBehavior.Insert }),
 		['<C-d>'] = cmp.mapping.scroll_docs(-4),
 		['<C-f>'] = cmp.mapping.scroll_docs(4),
 		['<C-Space>'] = cmp.mapping.complete(),
@@ -21,7 +25,29 @@ cmp.setup{
 		['<CR>'] = cmp.mapping.confirm({
 			behavior = cmp.ConfirmBehavior.Insert,
 			select = true,
-		})
+		}),
+
+		["<C-n>"] = cmp.mapping(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, { "i", "s" }),
+
+		["<C-p>"] = cmp.mapping(function(fallback)
+			if cmp.visible() then
+				cmp.select_prev_item()
+			elseif luasnip.jumpable(-1) then
+				luasnip.jump(-1)
+			else
+				fallback()
+			end
+		end, { "i", "s" }),
 	},
 	sources = {
 		{ name = 'emoji', max_item_count = 10, keyword_length = 5 },
@@ -53,7 +79,6 @@ cmp.setup{
 	}
 }
 
-
 -- Use buffer source for `/`.
 cmp.setup.cmdline('/', {
 	sources = {