dotfiles/modules/nixos/apps/neovim/default.nix

{
  options,
  config,
  lib,
  pkgs,
  ...
}:
with lib; let
  cfg = config.aa.apps.neovim;
in {
  options.aa.apps.neovim = with types; {
    enable = mkEnableOption "neovim";

    tmuxThemePath = mkOption {
      type = str;
      default = "vim-tmuxline/tmux_theme";
      description = "Where to store tmux theme generated by vim-tmuxline";
    };
  };

  config = mkIf cfg.enable {
    environment.systemPackages = with pkgs; [fzf fd nil];

    aa.home.dataFile = {
      ${cfg.tmuxThemePath}.source = ./tmux_theme;
    };
    aa.home.extraOptions = {
      programs.neovim = {
        enable = true;
        withNodeJs = true;
        withPython3 = true;
        extraPython3Packages = ps: with ps; [black isort flake8 ipdb];
        #extraPackages = with pkgs; [];
        plugins = with pkgs.vimPlugins; [
          # tree-sitter (code parser)
          nvim-treesitter.withAllGrammars

          # git integration
          gitgutter
          fugitive
          rhubarb

          # coc plugins
          coc-json
          coc-yaml
          coc-pyright
          coc-spell-checker
          coc-rust-analyzer

          # Eye candy
          nvim-web-devicons
          base16-nvim

          markdown-preview-nvim

          {
            plugin = lualine-nvim;
            type = "lua";
            config = ''
              require('lualine').setup {
              options = {
                icons_enabled = true,
                theme = 'auto',
                component_separators = { left = '', right = ''},
                section_separators = { left = '', right = ''},
                disabled_filetypes = {
                statusline = {},
                winbar = {},
                },
                ignore_focus = {},
                always_divide_middle = true,
                globalstatus = false,
                refresh = {
                statusline = 1000,
                tabline = 1000,
                winbar = 1000,
                }
              },
              sections = {
                lualine_a = {'mode'},
                lualine_b = {'branch', 'diff', 'diagnostics'},
                lualine_c = {'filename'},
                lualine_x = {'encoding', 'fileformat', 'filetype'},
                lualine_y = {'progress'},
                lualine_z = {'location'}
              },
              inactive_sections = {
                lualine_a = {},
                lualine_b = {},
                lualine_c = {'filename'},
                lualine_x = {'location'},
                lualine_y = {},
                lualine_z = {}
              },
              tabline = {},
              winbar = {},
              inactive_winbar = {},
              extensions = {}
              }
            '';
          }

          # TODO: Only install these if tmux is enabled
          # tmux integration
          tmux-navigator
          tmuxline-vim

          vim-obsession
          vim-nix

          # Telescope (fuzzy finding)
          telescope-nvim # Config for this in `extraConfig` since it depends on <leader> and I override that. (Generated config places plugin config above contents of extraConfig
          {
            plugin = telescope-file-browser-nvim;
            type = "lua";
            config = ''
              vim.api.nvim_set_keymap(
                "n",
                "<space>fb",
                ":Telescope file_browser<CR>",
                { noremap = true }
              )
              require("telescope").load_extension("file_browser")
            '';
          }
          {
            plugin = telescope-coc-nvim;
            type = "lua";
            config = ''
              require("telescope").setup({
                extensions = {
                  coc = {
                    prefer_locations = true;
                  }
                }
              })
              require("telescope").load_extension("coc")

              vim.api.nvim_set_keymap(
                "n",
                "<leader>coc",
                ":Telescope coc<CR>",
                { noremap = true }
              )
            '';
          }
        ];

        coc = {
          enable = true;
          settings = {
            "coc.preferences.formatOnSave" = true;
            "python.formatting.provider" = "black";
            "languageserver" = {
              "nix" = {
                "command" = "nil";
                "rootPatterns" = ["flake.nix"];
                "filetypes" = ["nix"];
              };
            };
          };

          # Copied the below from coc's README
          pluginConfig =
            ''
              " Some servers have issues with backup files, see #649.
              set nobackup
              set nowritebackup

              " Having longer updatetime (default is 4000 ms = 4 s) leads to noticeable
              " delays and poor user experience.
              set updatetime=300

              " Always show the signcolumn, otherwise it would shift the text each time
              " diagnostics appear/become resolved.
              set signcolumn=yes

              " Use tab for trigger completion with characters ahead and navigate.
              " NOTE: There's always complete item selected by default, you may want to enable
              " no select by `"suggest.noselect": true` in your configuration file.
              " NOTE: Use command ':verbose imap <tab>' to make sure tab is not mapped by
              " other plugin before putting this into your config.
              inoremap <silent><expr> <TAB>
                  \ coc#pum#visible() ? coc#pum#next(1) :
                  \ CheckBackspace() ? "\<Tab>" :
                  \ coc#refresh()
              inoremap <expr><S-TAB> coc#pum#visible() ? coc#pum#prev(1) : "\<C-h>"

              " Make <CR> to accept selected completion item or notify coc.nvim to format
              " <C-g>u breaks current undo, please make your own choice.
              inoremap <silent><expr> <CR> coc#pum#visible() ? coc#pum#confirm()
                                          \: "\<C-g>u\<CR>\<c-r>=coc#on_enter()\<CR>"

              function! CheckBackspace() abort
                let col = col('.') - 1
                return !col || getline('.')[col - 1]  =~# '\s'
              endfunction

              " Use <c-space> to trigger completion.
              if has('nvim')
                inoremap <silent><expr> <c-space> coc#refresh()
              else
                inoremap <silent><expr> <c-@> coc#refresh()
              endif

              " Use `[g` and `]g` to navigate diagnostics
              " Use `:CocDiagnostics` to get all diagnostics of current buffer in location list.
              nmap <silent> [g <Plug>(coc-diagnostic-prev)
              nmap <silent> ]g <Plug>(coc-diagnostic-next)

              " GoTo code navigation.
              nmap <silent> gd <Plug>(coc-definition)
              nmap <silent> gy <Plug>(coc-type-definition)
              nmap <silent> gi <Plug>(coc-implementation)
              nmap <silent> gr <Plug>(coc-references)

              " Use K to show documentation in preview window.
              nnoremap <silent> K :call ShowDocumentation()<CR>

              function! ShowDocumentation()
                if CocAction('hasProvider', 'hover')
                call CocActionAsync('doHover')
                else
                call feedkeys('K', 'in')
                endif
              endfunction

              " Highlight the symbol and its references when holding the cursor.
              autocmd CursorHold * silent call CocActionAsync('highlight')

              " Symbol renaming.
              nmap <leader>rn <Plug>(coc-rename)

              " Formatting selected code.
              xmap <leader>f  <Plug>(coc-format-selected)
              nmap <leader>f  <Plug>(coc-format-selected)

              augroup mygroup
                autocmd!
                " Setup formatexpr specified filetype(s).
                autocmd FileType typescript,json setl formatexpr=CocAction('formatSelected')
                " Update signature help on jump placeholder.
                autocmd User CocJumpPlaceholder call CocActionAsync('showSignatureHelp')
              augroup end

              " Applying codeAction to the selected region.
              " Example: `<leader>aap` for current paragraph
              xmap <leader>a  <Plug>(coc-codeaction-selected)
              nmap <leader>a  <Plug>(coc-codeaction-selected)

              " Remap keys for applying codeAction to the current buffer.
              nmap <leader>ac  <Plug>(coc-codeaction)
              " Apply AutoFix to problem on the current line.
              nmap <leader>qf  <Plug>(coc-fix-current)

              " Run the Code Lens action on the current line.
              nmap <leader>cl  <Plug>(coc-codelens-action)

              " Map function and class text objects
              " NOTE: Requires 'textDocument.documentSymbol' support from the language server.
              xmap if <Plug>(coc-funcobj-i)
              omap if <Plug>(coc-funcobj-i)
              xmap af <Plug>(coc-funcobj-a)
              omap af <Plug>(coc-funcobj-a)
              xmap ic <Plug>(coc-classobj-i)
              omap ic <Plug>(coc-classobj-i)
              xmap ac <Plug>(coc-classobj-a)
              omap ac <Plug>(coc-classobj-a)

              " Remap <C-f> and <C-b> for scroll float windows/popups.
              if has('nvim-0.4.0') || has('patch-8.2.0750')
                nnoremap <silent><nowait><expr> <C-f> coc#float#has_scroll() ? coc#float#scroll(1) : "\<C-f>"
                nnoremap <silent><nowait><expr> <C-b> coc#float#has_scroll() ? coc#float#scroll(0) : "\<C-b>"
                inoremap <silent><nowait><expr> <C-f> coc#float#has_scroll() ? "\<c-r>=coc#float#scroll(1)\<cr>" : "\<Right>"
                inoremap <silent><nowait><expr> <C-b> coc#float#has_scroll() ? "\<c-r>=coc#float#scroll(0)\<cr>" : "\<Left>"
                vnoremap <silent><nowait><expr> <C-f> coc#float#has_scroll() ? coc#float#scroll(1) : "\<C-f>"
                vnoremap <silent><nowait><expr> <C-b> coc#float#has_scroll() ? coc#float#scroll(0) : "\<C-b>"
              endif

              " Use CTRL-S for selections ranges.
              " Requires 'textDocument/selectionRange' support of language server.
              nmap <silent> <C-s> <Plug>(coc-range-select)
              xmap <silent> <C-s> <Plug>(coc-range-select)

              " Add `:Format` command to format current buffer.
              command! -nargs=0 Format :call CocActionAsync('format')

              " Add `:Fold` command to fold current buffer.
              command! -nargs=? Fold :call     CocAction('fold', <f-args>)

              " Add `:OR` command for organize imports of the current buffer.
              command! -nargs=0 OR   :call     CocActionAsync('runCommand', 'editor.action.organizeImport')

              " Add (Neo)Vim's native statusline support.
              " NOTE: Please see `:h coc-status` for integrations with external plugins that
              " provide custom statusline: lightline.vim, vim-airline.
                    set statusline^=%{coc#status()}%{get(b:,'coc_current_function',''
            + "''"
            + ''              )}

                  " Mappings for CoCList
                  " Show all diagnostics.
                  nnoremap <silent><nowait> <space>a  :<C-u>CocList diagnostics<cr>
                  " Manage extensions.
                  nnoremap <silent><nowait> <space>e  :<C-u>CocList extensions<cr>
                  " Show commands.
                  nnoremap <silent><nowait> <space>c  :<C-u>CocList commands<cr>
                  " Find symbol of current document.
                  nnoremap <silent><nowait> <space>o  :<C-u>CocList outline<cr>
                  " Search workspace symbols.
                  nnoremap <silent><nowait> <space>s  :<C-u>CocList -I symbols<cr>
                  " Do default action for next item.
                  nnoremap <silent><nowait> <space>j  :<C-u>CocNext<CR>
                  " Do default action for previous item.
                  nnoremap <silent><nowait> <space>k  :<C-u>CocPrev<CR>
                  " Resume latest coc list.
                  nnoremap <silent><nowait> <space>p  :<C-u>CocListResume<CR>

            ''
            # The below is custom and did not come from coc's README
            + ''
              " GoTo code navigation.
              nmap <silent> gd <Plug>(coc-definition)
              nmap <silent> gs :call CocAction('jumpDefinition', 'split')<CR>
              nmap <silent> gv :call CocAction('jumpDefinition', 'vsplit')<CR>
              nmap <silent> gn :call CocAction('jumpDefinition', 'tabe')<CR>
              nmap <silent> gy <Plug>(coc-type-definition)
              nmap <silent> gi <Plug>(coc-implementation)
              nmap <silent> gr <Plug>(coc-references)
            '';
        };

        extraConfig = ''
          set tabstop=4
          set shiftwidth=4
          set mouse=a
          set expandtab
          set number
          set relativenumber
          set autoindent
          set termguicolors
          syntax on
          let mapleader = "`"

          " Eye Candy (selects theme and sets up transparency)
          colorscheme base16-darktooth
          hi Normal guibg=none ctermbg=none
          hi NormalNC guibg=NONE
          hi LineNr guibg=none ctermbg=none
          hi Folded guibg=none ctermbg=none
          hi NonText guibg=none ctermbg=none
          hi SpecialKey guibg=none ctermbg=none
          hi VertSplit guibg=none ctermbg=none
          hi SignColumn guibg=none ctermbg=none
          hi EndOfBuffer guibg=none ctermbg=none

          " Toggle line highlighting based on focus
          autocmd BufEnter * setlocal cursorline
          autocmd BufLeave * setlocal nocursorline

          " Toggle relative line numbers
          nmap <leader>num :set invrelativenumber<CR>

          " Bindings for telescope-nvim
          nnoremap <leader>ff <cmd>lua require('telescope.builtin').find_files()<cr>
          nnoremap <leader>fg <cmd>lua require('telescope.builtin').live_grep()<cr>
          nnoremap <leader>fb <cmd>lua require('telescope.builtin').buffers()<cr>
          nnoremap <leader>fh <cmd>lua require('telescope.builtin').help_tags()<cr>

          " coc
          nnoremap <Leader>cmd :CocCommand<CR>
          nnoremap <Leader>cfg :CocConfig<CR>
          nnoremap <Leader>def :call CocAction('jumpDefinition')<CR>
          nnoremap <Leader>fmt :call CocActionAsync('format')<CR>
          vmap <leader>a <Plug>(coc-codeaction-selected)
          nmap <leader>a <Plug>(coc-codeaction-selected)

          " rhubarb
          noremap <Leader>bro :GBrowse<CR>

          " Tab completion
          set wildmode=longest,list,full
          set wildmenu
        '';
      };
    };
  };
}