From 4bbfa49d6fb7502bec0eeda79581e4fdca5631e9 Mon Sep 17 00:00:00 2001
From: Marko Korhonen <marko@korhonen.cc>
Date: Wed, 28 Feb 2024 09:04:56 +0200
Subject: [PATCH] Nvim: Improve luasnip keymappings

---
 home/.config/nvim/lua/plugins/cmp.lua | 44 ++++++++++++++++++++++-----
 1 file changed, 37 insertions(+), 7 deletions(-)

diff --git a/home/.config/nvim/lua/plugins/cmp.lua b/home/.config/nvim/lua/plugins/cmp.lua
index 3891206..8af7348 100644
--- a/home/.config/nvim/lua/plugins/cmp.lua
+++ b/home/.config/nvim/lua/plugins/cmp.lua
@@ -26,6 +26,12 @@ return {
     local cmp = require("cmp")
     local luasnip = require("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
+
     -- Set completeopt to have a better completion experience
     vim.o.completeopt = "menuone,noselect"
 
@@ -46,20 +52,44 @@ return {
           behavior = cmp.ConfirmBehavior.Replace,
           select = true,
         }),
-        ["<Tab>"] = cmp.mapping(function(fallback)
-          if cmp.visible() then
-            cmp.select_next_item()
-          elseif luasnip.expand_or_jumpable() then
-            luasnip.expand_or_jump()
+        -- Snippet placeholder forward
+        ["<C-f>"] = cmp.mapping(function(fallback)
+          if luasnip.jumpable(1) then
+            luasnip.jump(1)
           else
             fallback()
           end
         end, { "i", "s" }),
+        -- Snippet placeholder backward
+        ["<C-b>"] = cmp.mapping(function(fallback)
+          if luasnip.jumpable(-1) then
+            luasnip.jump(-1)
+          else
+            fallback()
+          end
+        end, { "i", "s" }),
+        -- Completion menu forward
+        ["<Tab>"] = cmp.mapping(function(fallback)
+          if cmp.visible() then
+            -- If only one entry, select it
+            if #cmp.get_entries() == 1 then
+              cmp.confirm({ select = true })
+            else
+              cmp.select_next_item()
+            end
+          elseif has_words_before() then
+            cmp.complete()
+            if #cmp.get_entries() == 1 then
+              cmp.confirm({ select = true })
+            end
+          else
+            fallback()
+          end
+        end, { "i", "s" }),
+        -- Completion menu backward
         ["<S-Tab>"] = cmp.mapping(function(fallback)
           if cmp.visible() then
             cmp.select_prev_item()
-          elseif luasnip.jumpable(-1) then
-            luasnip.jump(-1)
           else
             fallback()
           end