Move to a profile-based configuration where common

This patch makes it so common configuration is now located in shared/
and each host basically just becomes a bunch of import statements.

The exception here is host-specific configuration like the `*.linus.onl`
that live inside `hosts/ahmed/`.

Specifically I have:

- moved common configuration `shared/{nixos,home-manager,nix-darwin}`.
- moved `hosts/common.nix` to `shared/nixos/common-{nix,shell}-settings.nix`.
- split `hosts/muhammed/{dev-utils,neovim}` into per-language
  configuration.

This patch was done in preparation for the arrival of a new host, which
will need to share a lot of configuration with Muhammed.

5 files changed, 434 insertions, 0 deletions

diff --git a/shared/home-manager/neovim/completion.nix b/shared/home-manager/neovim/completion.nix
new file mode 100644
index 0000000..3776674
--- /dev/null
+++ b/shared/home-manager/neovim/completion.nix
@@ -0,0 +1,47 @@
+# This module sets up auto completion for Neovim.
+{pkgs, ...}: {
+  programs.neovim.plugins = with pkgs.vimPlugins; [
+    # This is the actual completion engine.
+    {
+      plugin = nvim-cmp;
+      type = "lua";
+      config = ''
+        local cmp = require("cmp")
+
+        cmp.setup({
+        	mapping = cmp.mapping.preset.insert({
+        		["<C-b>"] = cmp.mapping.scroll_docs(-4),
+        		["<C-f>"] = cmp.mapping.scroll_docs(4),
+        		["<C-j>"] = cmp.mapping.select_next_item(),
+        		["<C-k>"] = cmp.mapping.select_prev_item(),
+        		["<C-Space>"] = cmp.mapping.complete(),
+        		["<C-e>"] = cmp.mapping.abort(),
+        		["<Tab>"] = cmp.mapping.confirm({ select = true }), -- Accept currently selected item. Set `select` to `false` to only confirm explicitly selected items.
+        	}),
+        	sources = cmp.config.sources({
+        		{ name = "nvim_lsp" },
+        		{ name = "calc" },
+        		{ name = "path" },
+        		{ name = "buffer" },
+        	}),
+        	-- disable completion in comments
+        	enabled = function()
+        		local context = require("cmp.config.context")
+        		-- keep command mode completion enabled when cursor is in a comment
+        		if vim.api.nvim_get_mode().mode == "c" then
+        			return true
+        		else
+        			return not context.in_treesitter_capture("comment")
+        			   and not context.in_syntax_group("Comment")
+        		end
+        	end
+        })
+      '';
+    }
+    # The following are plugins for the... completion plugin.
+    cmp-nvim-lsp
+    cmp-calc
+    cmp-buffer
+    cmp-path
+  ];
+}
diff --git a/shared/home-manager/neovim/default.nix b/shared/home-manager/neovim/default.nix
new file mode 100644
index 0000000..63a7564
--- /dev/null
+++ b/shared/home-manager/neovim/default.nix
@@ -0,0 +1,28 @@
+# This file contains the HM configuration options for Neovim.
+{...}: {
+  imports = [
+    ./completion.nix
+    ./editing-plugins.nix
+    ./lsp.nix
+  ];
+
+  programs.neovim = {
+    enable = true;
+
+    # Import my existing config. I've been working on this for years and when
+    # my enthusiasm for Nix eventually dies off, I want to take it with me.
+    extraConfig = builtins.readFile ./init.vim;
+
+    # Typing `vi`, `vim`, or `vimdiff` will also run neovim.
+    viAlias = true;
+    vimAlias = true;
+    vimdiffAlias = true;
+  };
+
+  # Set Neovim as the default editor.
+  home.sessionVariables.EDITOR = "nvim";
+  home.sessionVariables.VISUAL = "nvim";
+
+  # Use neovim as man pager.
+  home.sessionVariables.MANPAGER = "nvim +Man!";
+}
diff --git a/shared/home-manager/neovim/editing-plugins.nix b/shared/home-manager/neovim/editing-plugins.nix
new file mode 100644
index 0000000..23c7d63
--- /dev/null
+++ b/shared/home-manager/neovim/editing-plugins.nix
@@ -0,0 +1,26 @@
+# This module sets up and configures various miscellaneous plugins.
+# TODO: I fear this file will become the utils.lua of my Neovim configuration. Remove it!
+{pkgs, ...}: {
+  programs.neovim.plugins = [
+    {
+      plugin = pkgs.vimPlugins.vim-localvimrc;
+      type = "viml";
+      config = ''
+        let g:localvimrc_persistent = 1
+        let g:localvimrc_name = [ "local.vim", "editors/local.vim" ]
+      '';
+    }
+    {
+      plugin = pkgs.vimPlugins.vim-sneak;
+      type = "viml";
+      config = ''
+        let g:sneak#s_next = 1
+        let g:sneak#use_ic_scs = 1
+        map f <Plug>Sneak_f
+        map F <Plug>Sneak_F
+        map t <Plug>Sneak_t
+        map T <Plug>Sneak_T
+      '';
+    }
+  ];
+}
diff --git a/shared/home-manager/neovim/init.vim b/shared/home-manager/neovim/init.vim
new file mode 100644
index 0000000..eeb6920
--- /dev/null
+++ b/shared/home-manager/neovim/init.vim
@@ -0,0 +1,274 @@
+" Settings
+"""""""""""""""""""""""""""
+
+" Leave boomer mode
+set nocompatible
+
+set history=1000
+
+" Backspace in insert mode
+set backspace=indent,eol,start
+
+" Hide buffer when abandoned (you can gd away, etc)
+set hid
+
+" Searching
+" NOTE: ignorecase and smartcase must be used together (see :h 'smartcase')
+set incsearch gdefault ignorecase smartcase nohlsearch
+
+" Only auto-continue comments when i_<cr> is pressed (not n_o)
+" Must be set after :filetype-plugin-on
+filetype plugin indent on
+au FileType * setlocal fo-=o fo+=r
+
+" Enable syntax highlighting
+syn on
+
+" Colorscheme
+" au VimEnter * ++nested colorscheme ansi_linus
+
+" Persistent undo
+set undofile
+
+" Give me some thinking time, jesus!
+set timeout timeoutlen=2000
+
+" Line numbers
+set number relativenumber
+
+" Improve macro performance
+set lazyredraw
+
+" Show matching brackets
+set showmatch
+set matchtime=2
+
+set listchars=tab:>-,eol:$,space:.,trail:@,nbsp:%
+
+" Enable mouse input for all modes but visual.
+"
+" I disable mouse in visual mode so I can select text in the terminal using
+" the mouse. This is useful when copying text from a remote instance of vim
+" SSH session where "* doesn't work.
+set mouse=nicr
+
+" sussy sus the sussy sus
+set nowrap
+
+" Mappings
+"""""""""""""""""""""""""""
+
+let g:mapleader = "\<space>"
+let g:maplocalleader = "\<space>"
+
+" Some keys are hard to press with the Danish layout. Luckily, we have some
+" spare keys! Note that ctrl and esc are swapped at the OS level.
+nnoremap æ $
+nnoremap Æ 0
+
+" Switching windows
+" TODO: make this work with iTerm2 panes
+" nnoremap <c-h> <c-w><c-h>
+" nnoremap <c-j> <c-w><c-j>
+" nnoremap <c-k> <c-w><c-k>
+" nnoremap <c-l> <c-w><c-l>
+" tnoremap <c-h> <c-\><c-n><c-w><c-h>
+" tnoremap <c-j> <c-\><c-n><c-w><c-j>
+" tnoremap <c-k> <c-\><c-n><c-w><c-k>
+" tnoremap <c-l> <c-\><c-n><c-w><c-l>
+
+" Resize windows
+nnoremap + <c-w>+
+nnoremap - <c-w>-
+
+" Switching tabs
+nnoremap <silent> <leader>tt     :tabnext<CR>
+nnoremap <silent> <leader>tn     :tabnew<CR>
+nnoremap <silent> <leader>to     :tabonly<CR>
+nnoremap <silent> <leader>tc     :tabclose<CR>
+nnoremap <silent> <leader>tm     :tabmove
+" Just use gt and gT
+" nnoremap <silent> <leader>tl     :tabn<CR>
+" nnoremap <silent> <leader>th     :tabN<CR>
+nnoremap <silent> <leader>t<S-L> :tabl<CR>
+nnoremap <silent> <leader>t<S-H> :tabr<CR>
+
+" Fast macros (qq to record)
+nnoremap Q @q
+vnoremap Q :norm! @q<cr>
+
+" Make Y act like C and D
+nnoremap <s-y> y$
+vnoremap <s-y> $y
+
+" Indent using tab key
+nnoremap <Tab>   >l
+nnoremap <S-Tab> <l
+vnoremap <Tab>   >gv
+vnoremap <S-Tab> <gv
+
+noremap! <C-j> <down>
+noremap! <C-k> <up>
+noremap! <C-h> <left>
+noremap! <C-l> <right>
+
+" Toggle showing 'listchars'
+nnoremap <silent> <leader>l :set list!<cr>
+
+" Escape in terminal mode
+tnoremap <esc><esc> <c-\><c-n>
+
+" Seamlessly enter/leave terminal buffer.
+tnoremap <c-w> <c-\><c-n><c-w>
+au BufEnter term://* norm! i
+
+" Join to end of line below
+" This is already used by the window switching mappings
+nnoremap <c-j> ddpkJ
+
+" Move window to the left and switch to the eastern window.
+" I do this move pretty frequently.
+nnoremap <c-w><c-w> <c-w>L<c-w>h
+
+" If the fzf executable is available, assume that the fzf plugin is going to
+" be loaded. In that case we want an easy way to load a file.
+if executable("fzf")
+	nnoremap <leader><leader> <CMD>FZF<CR>
+else
+	nnoremap <leader><leader> <CMD>echo "FZF not found!"<CR>
+endif
+
+" Define go-to-definition help pages, otherwise see the mappings in the hook
+" for LSP configuration.
+autocmd Filetype help nnoremap <buffer> gd <C-]>
+
+" Commands
+"""""""""""""""""""""""""""
+
+" Create a temporary buffer
+" NOTE: relied on by other commands
+command Temp       new | setlocal buftype=nofile bufhidden=wipe noswapfile nomodified nobuflisted
+command TempTab tabnew | setlocal buftype=nofile bufhidden=wipe noswapfile nomodified nobuflisted
+
+" Reverse lines
+command! -bar -range=% Reverse <line1>,<line2>g/^/m<line1>-1|nohl
+
+" Redraw screen
+" CTRL-L mapping is used in other thing
+command Redraw norm! 
+
+" Run buffer contents as vimscript
+command! -bar -range=% Run execute 'silent!' . <line1> . ',' . <line2> . 'y|@"'
+
+" Output the result of a command to the buf
+command! -nargs=+ -complete=command Output
+			\ redir => output               |
+			\ silent execute <q-args>       |
+			\ redir END                     |
+			\ tabnew                        |
+			\ setlocal buftype=nofile bufhidden=wipe noswapfile nobuflisted nomodified |
+			\ silent put=output             |
+			\ if <q-args> =~ ':!'           |
+			\ 	silent 1,2delete _      |
+			\ else                          |
+			\ 	silent 1,4delete _      |
+			\ endif
+
+" Copy buffer to system clipboard
+command! Copy silent w !pbcopy
+
+" Copy the location of the current file
+command! CopyDir !echo %:r | pbcopy
+
+" View in-memory changes before writing to disk
+command! DiffOnDisk
+	\ let orig_filetype=&ft                         |
+	\ vert new                                      |
+	\ read ++edit # | 0d_                           |
+	\ setlocal bt=nofile bh=wipe nobl noswf ro      |
+	\ let &l:filetype = orig_filetype               |
+	\ diffthis                                      |
+	\ wincmd p                                      |
+	\ diffthis
+
+command WrapItUp setlocal wrap
+               \| nnoremap <buffer> j gj
+               \| nnoremap <buffer> k gk
+               \| nnoremap <buffer> 0 g0
+               \| nnoremap <buffer> $ g$
+
+" Miscellaneous
+"""""""""""""""""""""""""""
+
+" Show the color column only if insert mode (and only if cc is set)
+augroup ShowCCInInsertMode
+        au!
+	au InsertEnter * if &tw != 0 | let &cc = &tw + 1 | endif
+	au InsertLeave * let &cc = 0
+augroup END
+
+" Auto-refresh vim config
+" au BufWritePost $XDG_CONFIG_HOME/*.{vim,lua} so %
+
+" Jump to last editing location when opening files
+au BufReadPost *
+	\ if line("'\"") > 0 && line("'\"") <= line("$") |
+	\ 	exe "normal! g'\"" |
+	\ endif
+
+augroup Sus
+	au!
+
+	" Add syntax groups if relevant. This conditional is compensating for
+	" the lack of negative matches in :au.
+	"
+	" See: https://vim.fandom.com/wiki/Highlight_unwanted_spaces
+	" See: https://stackoverflow.com/questions/6496778/vim-run-autocmd-on-all-filetypes-except
+	fun! s:AddSyntax()
+		if bufname() !~ 'term://\|man://'
+			" Any trailing whitespace at the end of lines.
+			syn match SusWhitespace /\s\+$/ containedin=ALL
+
+			" Any non-breaking spaces. These are generated by
+			" CMD+SPACE and deeply annoying.
+			syn match SusWhitespace /\%u00A0/ containedin=ALL
+
+			" Any characters beyond the maximum width of the text.
+			if &tw > 0
+				let reg = '\%' . (&tw + 1) . 'v.\+'
+				exe 'syn match SusWhitespace /'.reg.'/ containedin=ALL'
+			endif
+		endif
+	endfun
+
+	" Remove highligt group.
+	"
+	" Note that we have to do abit more work since the the syntax rules
+	" have changed under Vim's nose. Hopefully the perfomance
+	" characteristics don't come back to haunt us.
+	fun! s:RemoveSyntax()
+		syn clear SusWhitespace
+		syn sync fromstart
+	endfun
+
+	" Add a persistent highligt group, which matches are going to use.
+	au VimEnter,ColorScheme * hi SusWhitespace ctermbg=red guibg=red
+
+	" Create some persistent syntax highlighting groups.
+	au Syntax * call s:AddSyntax()
+
+	" When 'textwidth' changes, we may need to recalculate.
+	au OptionSet textwidth call s:RemoveSyntax()
+	                   \ | call s:AddSyntax()
+
+	" Temporarily remove the groups when in insert mode.
+	au InsertEnter * call s:RemoveSyntax()
+	au InsertLeave * call s:AddSyntax()
+augroup END
+
+" Allow for quick prototyping outside of NixOS/Home-Manager by loading some
+" extra configuration if relevant.
+let extra_vimrc = expand("~/extra-temporary.vimrc")
+if filereadable(extra_vimrc)
+	execute "source " . extra_vimrc
+endif
diff --git a/shared/home-manager/neovim/lsp.nix b/shared/home-manager/neovim/lsp.nix
new file mode 100644
index 0000000..bc10487
--- /dev/null
+++ b/shared/home-manager/neovim/lsp.nix
@@ -0,0 +1,59 @@
+# Installs and configures lspconfig. The actual LSPs are added in the per-language profiles.
+{pkgs, ...}: {
+  programs.neovim.plugins = [
+    {
+      plugin = pkgs.vimPlugins.nvim-lspconfig;
+      type = "lua";
+      config = ''
+        local lspconfig = require("lspconfig")
+        local util = require("lspconfig.util")
+
+        -- Mappings.
+        -- See `:help vim.diagnostic.*` for documentation on any of the below functions
+        local opts = { noremap=true, silent=true }
+        vim.keymap.set('n', '<leader>e', vim.diagnostic.open_float, opts)
+        vim.keymap.set('n', '[d', vim.diagnostic.goto_prev, opts)
+        vim.keymap.set('n', ']d', vim.diagnostic.goto_next, opts)
+        vim.keymap.set('n', '<leader>q', vim.diagnostic.setloclist, opts)
+
+        -- Use an on_attach function to only map the following keys
+        -- after the language server attaches to the current buffer
+        vim.api.nvim_create_autocmd("LspAttach", {
+          callback = function(args)
+            local bufnr = args.buf
+            local client = vim.lsp.get_client_by_id(args.data.client_id)
+
+            -- Enable completion triggered by <c-x><c-o>
+            if client.server_capabilities.completionProvider then
+              vim.bo[bufnr].omnifunc = "v:lua.vim.lsp.omnifunc"
+            end
+
+            -- XXX: What does this do?
+            if client.server_capabilities.definitionProvider then
+              vim.bo[bufnr].tagfunc = "v:lua.vim.lsp.tagfunc"
+            end
+
+            -- Mappings.
+            -- See `:help vim.lsp.*` for documentation on any of the below functions
+            local bufopts = { noremap=true, silent=true, buffer=bufnr }
+            vim.keymap.set('n', 'gD', vim.lsp.buf.declaration, bufopts)
+            vim.keymap.set('n', 'gd', vim.lsp.buf.definition, bufopts)
+            vim.keymap.set('n', 'K', vim.lsp.buf.hover, bufopts)
+            vim.keymap.set('n', 'gi', vim.lsp.buf.implementation, bufopts)
+            vim.keymap.set('n', '<C-k>', vim.lsp.buf.signature_help, bufopts)
+            vim.keymap.set('n', '<leader>wa', vim.lsp.buf.add_workspace_folder, bufopts)
+            vim.keymap.set('n', '<leader>wr', vim.lsp.buf.remove_workspace_folder, bufopts)
+            vim.keymap.set('n', '<leader>wl', function()
+              print(vim.inspect(vim.lsp.buf.list_workspace_folders()))
+            end, bufopts)
+            vim.keymap.set('n', '<leader>D', vim.lsp.buf.type_definition, bufopts)
+            vim.keymap.set('n', '<leader>rn', vim.lsp.buf.rename, bufopts)
+            vim.keymap.set('n', '<leader>ca', vim.lsp.buf.code_action, bufopts)
+            vim.keymap.set('n', 'gr', vim.lsp.buf.references, bufopts)
+            vim.keymap.set('n', '<leader>f', function() vim.lsp.buf.format { async = true } end, bufopts)
+          end,
+        })
+      '';
+    }
+  ];
+}