" Common.
set encoding=utf-8
set fileencoding=utf-8
set nobackup
set noswapfile

" Tabs.
" set expandtab
set tabstop=2
set shiftwidth=2

" Lines.
set number
set relativenumber
set cursorline
set colorcolumn=80

set list
set listchars=space:·,tab:‑→
" set listchars=space:·,tab:─→
" set listchars=space:·,tab:└→
" set listchars=space:◦,eol:$,tab:->,trail:~,extends:>,precedes:<

" Having longer updatetime (default is 4000 ms = 4s) 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

" Colors.
syntax on
colorscheme slate

" Plugins.
call plug#begin()
	Plug 'neoclide/coc.nvim', {'branch': 'release'}
call plug#end()

" COC
" ============================================================================ "

" 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 code actions to the selected code block
" Example: `<leader>aap` for current paragraph
xmap <leader>a <Plug>(coc-codeaction-selected)
nmap <leader>a <Plug>(coc-codeaction-selected)

" Remap keys for applying code actions at the cursor position
nmap <leader>ac <Plug>(coc-codeaction-cursor)
" Remap keys for apply code actions affect whole buffer
nmap <leader>as <Plug>(coc-codeaction-source)
" Apply the most preferred quickfix action to fix diagnostic on the current line
nmap <leader>qf <Plug>(coc-fix-current)

" Remap keys for applying refactor code actions
nmap <silent> <leader>re <Plug>(coc-codeaction-refactor)
xmap <silent> <leader>r <Plug>(coc-codeaction-refactor-selected)
nmap <silent> <leader>r <Plug>(coc-codeaction-refactor-selected)

" 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> to 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>
