From 19f925775a04dde24b7f30cb2ecf20643670d248 Mon Sep 17 00:00:00 2001
From: Oliver Hartmann <oliver.hartmann@freiewildbahn.de>
Date: Thu, 9 Sep 2021 22:23:07 +0200
Subject: [PATCH] Get snippets running

---
 init.lua         | 37 +++++++++++++++++++++++++++++++++----
 lua/cmp_plug.lua | 33 ++++++++++++++++++---------------
 2 files changed, 51 insertions(+), 19 deletions(-)

diff --git a/init.lua b/init.lua
index bd180ca..275eed3 100644
--- a/init.lua
+++ b/init.lua
@@ -73,12 +73,12 @@ utils.map('n', '<leader>b', '<cmd>Telescope buffers<cr>')
 utils.map('n', '<space>r', '<cmd>Telescope lsp_references<cr>')
 utils.map('n', '<C-S-o>', '<cmd>Telescope lsp_document_symbols<cr>')
 -------------------- LSP -----------------------------------
-local lsp = require 'lspconfig'
+local nvim_lsp = require 'lspconfig'
 
 -- We use the default settings for ccls and pylsp: the option table can stay empty
-lsp.ccls.setup {}
-lsp.pyright.setup{}
-lsp.clangd.setup{}
+nvim_lsp.ccls.setup {}
+nvim_lsp.pyright.setup{}
+nvim_lsp.clangd.setup{}
 
 utils.map('n', '<space>,', '<cmd>lua vim.lsp.diagnostic.goto_prev()<CR>')
 utils.map('n', '<space>;', '<cmd>lua vim.lsp.diagnostic.goto_next()<CR>')
@@ -94,6 +94,33 @@ utils.map('n', '<C-t>', '<cmd>lua vim.lsp.buf.workspace_symbol()<CR>')
 
 utils.map('n', '<A-o>', ':ClangdSwitchSourceHeader<CR>')
 
+-- Add additional capabilities supported by nvim-cmp
+local capabilities = vim.lsp.protocol.make_client_capabilities()
+capabilities.textDocument.completion.completionItem.documentationFormat = { 'markdown', 'plaintext' }
+capabilities.textDocument.completion.completionItem.snippetSupport = true
+capabilities.textDocument.completion.completionItem.preselectSupport = true
+capabilities.textDocument.completion.completionItem.insertReplaceSupport = true
+capabilities.textDocument.completion.completionItem.labelDetailsSupport = true
+capabilities.textDocument.completion.completionItem.deprecatedSupport = true
+capabilities.textDocument.completion.completionItem.commitCharactersSupport = true
+capabilities.textDocument.completion.completionItem.tagSupport = { valueSet = { 1 } }
+capabilities.textDocument.completion.completionItem.resolveSupport = {
+  properties = {
+    'documentation',
+    'detail',
+    'additionalTextEdits',
+  },
+}
+
+-- Enable some language servers with the additional completion capabilities offered by nvim-cmp
+local servers = { 'clangd', 'pyright', 'rust_analyzer', 'tsserver' }
+for _, lsp in ipairs(servers) do
+  nvim_lsp[lsp].setup {
+    -- on_attach = my_custom_on_attach,
+    capabilities = capabilities,
+  }
+end
+
 -------------------- GITSIGNS ------------------------------
 -- require('gitsigns').setup()
 -------------------- LIGHTBULB -----------------------------
@@ -132,3 +159,5 @@ require'nvim-treesitter.configs'.setup {
     -- termcolors = {} -- table of colour name strings
   }
 }
+-------------------- LUASNIP -------------------------------
+require("luasnip.loaders.from_vscode").load()
diff --git a/lua/cmp_plug.lua b/lua/cmp_plug.lua
index 767e9ad..502ab1f 100644
--- a/lua/cmp_plug.lua
+++ b/lua/cmp_plug.lua
@@ -1,4 +1,5 @@
 local cmp = require('cmp')
+local luasnip = require("luasnip")
 
 local t = function(str)
     return vim.api.nvim_replace_termcodes(str, true, true, true)
@@ -45,26 +46,28 @@ cmp.setup {
         }),
         ["<Tab>"] = cmp.mapping(function(fallback)
             if vim.fn.pumvisible() == 1 then
-                if vim.fn["UltiSnips#CanExpandSnippet"]() == 1 or
-                    vim.fn["UltiSnips#CanJumpForwards"]() == 1 then
-                    return vim.fn.feedkeys(t(
-                                               "<C-R>=UltiSnips#ExpandSnippetOrJump()<CR>"))
-                end
-
-                vim.fn.feedkeys(t("<C-n>"), "n")
-            elseif check_back_space() then
-                vim.fn.feedkeys(t("<tab>"), "n")
+              vim.api.nvim_feedkeys(t("<C-n>"), "n", true)
+            elseif luasnip.expand_or_jumpable() then
+              vim.api.nvim_feedkeys(t("<Plug>luasnip-expand-or-jump"), "", true)
             else
-                fallback()
+              fallback()
             end
-        end, {"i", "s"}),
-        ["<S-Tab>"] = cmp.mapping(function(fallback)
+          end, {
+            "i",
+            "s",
+          }),
+          ["<S-Tab>"] = cmp.mapping(function(fallback)
             if vim.fn.pumvisible() == 1 then
-                vim.fn.feedkeys(t("<C-p>"), "n")
+              vim.api.nvim_feedkeys(t("<C-p>"), "n", true)
+            elseif luasnip.jumpable(-1) then
+              vim.api.nvim_feedkeys(t("<Plug>luasnip-jump-prev"), "", true)
             else
-                fallback()
+              fallback()
             end
-        end, {"i", "s"})
+          end, {
+            "i",
+            "s",
+          }),
     },
     snippet = {
       expand = function(args)