From 6e4130fd265030612050c40d3db27069d981c87f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Geoffrey=20=E2=80=9CFrogeye=E2=80=9D=20Preud=27homme?=
 <geoffrey@frogeye.fr>
Date: Tue, 9 Jan 2024 21:53:00 +0100
Subject: [PATCH] vim: Better snippets (and split completion file)

---
 hm/common.nix             |  2 +-
 hm/vim/completion.nix     | 54 +++++++++++++++++++++++++++++++++++++++
 hm/vim/completion_pre.lua | 32 +++++++++++++++++++++++
 hm/vim/default.nix        | 39 ++++------------------------
 4 files changed, 92 insertions(+), 35 deletions(-)
 create mode 100644 hm/vim/completion.nix
 create mode 100644 hm/vim/completion_pre.lua

diff --git a/hm/common.nix b/hm/common.nix
index 30e6818..0efd9aa 100644
--- a/hm/common.nix
+++ b/hm/common.nix
@@ -29,7 +29,7 @@
       };
       commonShellAliases = {
         # Replacement commands
-        ls = "lsd";
+        # ls = "lsd"; # lsd is suuuper slow for large directories
         cat = "bat -pp";
 
         # Completion for existing commands
diff --git a/hm/vim/completion.nix b/hm/vim/completion.nix
new file mode 100644
index 0000000..693ff21
--- /dev/null
+++ b/hm/vim/completion.nix
@@ -0,0 +1,54 @@
+{ pkgs, lib, config, ... }:
+{
+  config = {
+    # Completion
+    programs.nixvim = {
+      extraConfigLuaPre = builtins.readFile ./completion_pre.lua;
+      plugins = {
+        # Snippets
+        # UltiSnips should be the better snippet engine, but:
+        # - Not built-in into Nixvim yet (UPST?)
+        # - Couldn't manage to make it work with friendly-snippets, which seems to give better snippets for Python at least
+        # - Tab switching between fields seems hard to configure
+        luasnip = {
+          enable = true;
+          fromVscode = [
+            { paths = "${pkgs.vimPlugins.friendly-snippets}"; }
+            # { paths = "${pkgs.vimPlugins.vim-snippets}"; } # UPST Needs snipmate support
+          ];
+        };
+
+        # Completion
+        nvim-cmp = {
+          enable = true;
+          mapping = {
+            # Proposed example, since there's no default
+            "<C-Space>" = "cmp.mapping.complete()";
+            "<C-d>" = "cmp.mapping.scroll_docs(-4)";
+            "<C-e>" = "cmp.mapping.close()";
+            "<C-f>" = "cmp.mapping.scroll_docs(4)";
+            "<CR>" = "cmp.mapping.confirm({ select = true })";
+            "<S-Tab>" = {
+              action = "nvim_cmp_stab";
+              modes = [ "i" "s" ];
+            };
+            "<Tab>" = {
+              action = "nvim_cmp_tab";
+              modes = [ "i" "s" ];
+            };
+          };
+          sources = [
+            # Respective plugins will get installed automatically
+            { name = "buffer"; }
+            { name = "calc"; }
+            { name = "nvim_lsp"; }
+            { name = "path"; }
+            { name = "luasnip"; }
+          ];
+          snippet.expand = "luasnip";
+        };
+        lspkind.enable = true; # Add icons to LSP completions
+      };
+    };
+  };
+}
diff --git a/hm/vim/completion_pre.lua b/hm/vim/completion_pre.lua
new file mode 100644
index 0000000..24cfa9b
--- /dev/null
+++ b/hm/vim/completion_pre.lua
@@ -0,0 +1,32 @@
+-- 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
diff --git a/hm/vim/default.nix b/hm/vim/default.nix
index f556afc..1a5fac5 100644
--- a/hm/vim/default.nix
+++ b/hm/vim/default.nix
@@ -1,5 +1,6 @@
 { pkgs, lib, config, ... }:
 let
+  # UPST
   vim-shot-f = pkgs.vimUtils.buildVimPlugin {
     pname = "vim-shot-f";
     version = "2016-02-05";
@@ -78,33 +79,6 @@ in
         # Tabline
         barbar.enable = true;
 
-        # Completion
-        nvim-cmp = {
-          enable = true;
-          mapping = { # Proposed example, since there's no default
-            "<C-Space>" = "cmp.mapping.complete()";
-            "<C-d>" = "cmp.mapping.scroll_docs(-4)";
-            "<C-e>" = "cmp.mapping.close()";
-            "<C-f>" = "cmp.mapping.scroll_docs(4)";
-            "<CR>" = "cmp.mapping.confirm({ select = true })";
-            "<S-Tab>" = {
-              action = "cmp.mapping.select_prev_item()";
-              modes = [ "i" "s" ];
-            };
-            "<Tab>" = {
-              action = "cmp.mapping.select_next_item()";
-              modes = [ "i" "s" ];
-            };
-          };
-          sources = [ # Respective plugins will get installed automatically
-            { name = "buffer"; }
-            { name = "calc"; }
-            { name = "nvim_lsp"; }
-            { name = "path"; }
-            { name = "vsnip"; }
-          ];
-        };
-        lspkind.enable = true; # Add icons to LSP completions
 
         # Go to whatever
         telescope = {
@@ -254,12 +228,6 @@ in
         # Language server
         lsp_signature-nvim # Show argument definition when typing a function
 
-        # Snippets
-        vim-vsnip 
-        vim-vsnip-integ
-        friendly-snippets
-        # TODO luasnip seems to be in Lua and more integrated with Nix.
-
         # Git
         fugitive-gitlab-vim # Open files in GitLab
         # TODO Connect it!
@@ -291,7 +259,6 @@ in
 
         " vim-gutentags
         let g:gutentags_cache_dir = expand('~/.cache/nvim/tags')
-
       '' + lib.optionalString config.frogeye.extra ''
         " languagetool
         let g:languagetool_cmd = "${pkgs.languagetool}/bin/languagetool-commandline"
@@ -368,4 +335,8 @@ in
       ];
     };
   };
+
+  imports = [
+    ./completion.nix
+  ];
 }