" .vimrc - vim configuration
" based on: https://stackoverflow.com/questions/1218390
"           https://trofi.github.io/posts/277-from-mcedit-to-vim.html

" appearance

set showmode        " show current mode (insert/append/etc.) in status bar
set showcmd         " show typed command in status bar
set number          " show line numbers
set ruler           " show cursor position in status bar
set background=dark " dark background (for tmux)
                    " from: https://unix.stackexchange.com/a/363374
"set laststatus=2    " always show the status bar at the bottom
"set showtabline=2   " show the tab bar even only one file is open
"set cul             " highlight current line

" window splitting

set splitbelow      " new horizontal splits are on the bottom
set splitright      " new vertical splits are on the right

" indenting / wrapping

set smartindent     " smart auto indenting
set copyindent      " copy indentation style of prior line
set shiftwidth=4    " 4 spaces for auto indents
set tabstop=4       " 4 spaces per tab
set expandtab       " turn tabs into spaces
set tw=72           " set text width (for hardwrapping) to 70 columns

" disable history
set viminfo=
let g:netrw_dirhistmax=0

" enhanced searching
" https://www.twilio.com/blog/5-quality-of-life-vim-tricks-for-your-vimrc

set hlsearch        " highlight search terms
set incsearch       " highlight search terms as you type them
set showmatch       " highlight matching parentheses
set ignorecase      " case insensitive searching
set smartcase       " case sensitive if uppercase characters are provided
nnoremap <CR> :noh<CR>

" highlight trailing white space in red
" requires vim-runtime on Debian
" https://stackoverflow.com/questions/356126

highlight ExtraWhitespace ctermbg=red guibg=red
match ExtraWhitespace /\s\+$/

" highlight non-ascii characters in red
" may require vim-runtime on Debian
" https://stackoverflow.com/questions/16987362/

highlight nonascii guibg=Red ctermbg=1 term=standout
au BufReadPost * syntax match nonascii "[^\u0000-\u007F]"

" enable builtin spellchecking
" https://vimtricks.com/p/vim-spell-check/
" https://www.linux.com/training-tutorials/using-spell-checking-vim/
" https://unix.stackexchange.com/questions/12889
" https://vi.stackexchange.com/questions/15578

let s:spellingState=0
function! ToggleSpelling()
    if s:spellingState
       set nospell
    else
       set spell spelllang=en_us
    endif
    let s:spellingState = !s:spellingState
endfunction
nnoremap <C-s> :call ToggleSpelling()<CR>

" remove trailing whitespace
" https://vimtricks.com/p/vim-remove-trailing-whitespace/
" https://github.com/Omar12/dotfiles/blob/master/.vimrc

function! StripWhitespace()
    let save_cursor = getpos(".")
	let old_query = getreg('/')
    :%s/\s\+$//e
    call setpos('.', save_cursor)
    call setreg('/', old_query)
endfunction
nnoremap ss :call StripWhitespace()<CR>