"=============================================================================
" shell.vim --- SpaceVim shell layer
" Copyright (c) 2016-2023 Wang Shidong & Contributors
" Author: Wang Shidong < wsdjeg@outlook.com >
" URL: https://spacevim.org
" License: GPLv3
"=============================================================================

""
" @section shell, layers-shell
" @parentsection layers
" SpaceVim uses deol.nvim for shell support in neovim and uses vimshell for
" vim. For more info, read |deol| and |vimshell|.
"
" @subsection layer options
"
" 1. `default_shell`: config the default shell to be used by shell layer.
"
" @subsection key bindings
" >
"   Key bindings    Description
"   SPC '           Open or switch to terminal windows
"   q               Hide terminal windows in normal mode
"   ctrl-`          Hide terminal window in terminal mode
" <

let s:SYSTEM = SpaceVim#api#import('system')
let s:FLOAT = SpaceVim#api#import('neovim#floating')
let s:WIN = SpaceVim#api#import('vim#window')

function! SpaceVim#layers#shell#plugins() abort
  let plugins = []
  if has('nvim')
    call add(plugins,['Shougo/deol.nvim'])
  endif
  call add(plugins,['Shougo/vimshell.vim',                { 'on_cmd':['VimShell']}])
  return plugins
endfunction

let s:file = expand('<sfile>:~')
let s:lnum = expand('<slnum>') + 2
function! SpaceVim#layers#shell#config() abort
  call SpaceVim#mapping#space#def('nnoremap', ["'"], 'call call('
        \ . string(function('s:open_default_shell')) . ', [0])',
        \ ['open-shell',
        \ [
          \ "[SPC '] is to open or jump to default shell window",
          \ '',
          \ 'Definition: ' . s:file . ':' . s:lnum,
          \ ]
          \ ], 1)
  call SpaceVim#mapping#space#def('nnoremap', ["\""], 'call call('
        \ . string(function('s:open_default_shell')) . ', [1])',
        \ ['open-shell-in-buffer-dir',
        \ [
          \ "[SPC \"] is to open or jump to default shell window with the current file's pwd",
          \ '',
          \ 'Definition: ' . s:file . ':' . s:lnum,
          \ ]
          \ ], 1)

  if has('nvim') || exists(':tnoremap') == 2
    exe 'tnoremap <silent><C-Right> <C-\><C-n>:<C-u>wincmd l<CR>'
    exe 'tnoremap <silent><C-Left>  <C-\><C-n>:<C-u>wincmd h<CR>'
    exe 'tnoremap <silent><C-Up>    <C-\><C-n>:<C-u>wincmd k<CR>'
    exe 'tnoremap <silent><C-Down>  <C-\><C-n>:<C-u>wincmd j<CR>'
    exe 'tnoremap <silent><M-Left>  <C-\><C-n>:<C-u>bprev<CR>'
    exe 'tnoremap <silent><M-Right>  <C-\><C-n>:<C-u>bnext<CR>'
    exe 'tnoremap <silent><C-`>     <C-\><C-n>:q<Cr>'
    if s:SYSTEM.isWindows
      exe 'tnoremap <expr><silent><C-d>  SpaceVim#layers#shell#terminal()'
      exe 'tnoremap <expr><silent><C-u>  SpaceVim#layers#shell#ctrl_u()'
      exe 'tnoremap <expr><silent><C-w>  SpaceVim#layers#shell#ctrl_w()'
      exe 'tnoremap <expr><silent><C-r>  SpaceVim#layers#shell#ctrl_r()'
    endif
  endif

  if has('nvim')
    augroup spacevim_layer_shell
      au!
      au WinEnter,BufWinEnter term://* startinsert
      au TermOpen * call s:on_term_open()
      if has('timers')
        au TermClose * let g:_spacevim_termclose_abuf = expand('<abuf>') | call timer_start(5, 'SpaceVim#mapping#close_term_buffer')
      else
        au TermClose * let g:_spacevim_termclose_abuf = expand('<abuf>') | call SpaceVim#mapping#close_term_buffer()
      endif
    augroup END
  endif

endfunction


function! s:on_term_open() abort
  startinsert
  let &l:statusline = SpaceVim#layers#core#statusline#get(1)
endfunction

" FIXME: 
func! SpaceVim#layers#shell#terminal() abort
  let line = getline('.')
  if isdirectory(line[:-2])
    return "exit\<CR>"
  endif
  return ''
endf
func! SpaceVim#layers#shell#ctrl_u() abort
  let line = getline('.')
  let prompt = getcwd() . '>'
  return repeat("\<BS>", len(line) - len(prompt) + 2)
endfunction

func! SpaceVim#layers#shell#ctrl_r() abort
  let reg = getchar()
  if reg == 43
    return @+
  endif
  return "\<C-r>"
endfunction


func! SpaceVim#layers#shell#ctrl_w() abort
  let cursorpos = getcurpos()
  let line = getline(cursorpos[1])[:cursorpos[2]-1]
  let str = matchstr(line, '[^ ]*\s*$')
  return repeat("\<BS>", len(str))
endfunction


let s:default_shell = 'terminal'
let s:default_position = 'top'
let s:default_height = 30
" the shell should be cached base on the root of a project, cache the terminal
" buffer id in: s:shell_cached_br 
let s:enable_project_shell = 1
let s:shell_cached_br = {}

function! SpaceVim#layers#shell#set_variable(var) abort
  let s:default_shell = get(a:var, 'default_shell', 'terminal')
  let s:default_position = get(a:var, 'default_position', 'top')
  let s:default_height = get(a:var, 'default_height', 30)
  let s:enable_project_shell = get(a:var, 'enable_project_shell', 1)
endfunction

function! SpaceVim#layers#shell#get_options() abort

  return ['default_shell', 'default_position', 'default_height',]

endfunction

let s:open_terminals_buffers = []
" shell windows shoud be toggleable, and can be hide.
function! s:open_default_shell(open_with_file_cwd) abort
  if a:open_with_file_cwd
    if getwinvar(winnr(), '&buftype') ==# 'terminal'
      let path = getbufvar(winbufnr(winnr()), '_spacevim_shell_cwd', SpaceVim#plugins#projectmanager#current_root())
    else
      let path = expand('%:p:h')
    endif
  else
    let path = SpaceVim#plugins#projectmanager#current_root()
    " if the current file is not in a project, the projectmanager return empty
    " string. Then use current directory as default cwd.
    if empty(path)
      let path  = getcwd()
    endif
  endif

  " look for already opened terminal windows
  let windows = [] 
  windo call add(windows, winnr()) 
  for window in windows
    if getwinvar(window, '&buftype') ==# 'terminal'
      exe window .  'wincmd w'
      if getbufvar(winbufnr(window), '_spacevim_shell_cwd') ==# l:path
        " startinsert do not work in gvim
        if has('nvim')
          startinsert
        else
          normal! a
        endif
        return
      else
        " the opened terminal window is not the one we want.
        " close it, we're gonna open a new terminal window with the given l:path
        exe 'wincmd c'
        break
      endif
    endif
  endfor

  if s:default_position ==# 'float' && exists('*nvim_open_win')
    let s:term_win_id =  s:FLOAT.open_win(bufnr('%'), v:true,
          \ {
            \ 'relative': 'editor',
            \ 'width'   : &columns, 
            \ 'height'  : &lines * s:default_height / 100,
            \ 'row': 0,
            \ 'col': &lines - (&lines * s:default_height / 100) - 2
            \ })

    exe win_id2win(s:term_win_id) .  'wincmd w'
  elseif s:default_position ==# 'center-float' && exists('*nvim_open_win')
    let s:term_win_id =  nvim_open_win(bufnr('%'), v:true,
          \ {
            \ 'relative': 'editor',
            \ 'width'   : &columns - 10, 
            \ 'height'  : &lines - 10,
            \ 'row': 5,
            \ 'border' : 'single',
            \ 'col': 5
            \ })

    exe win_id2win(s:term_win_id) .  'wincmd w'

  call nvim_set_option_value('winhighlight', 'NormalFloat:Normal,FloatBorder:WinSeparator', { 'win' : s:term_win_id})
  else
    " no terminal window found. Open a new window
    let cmd = s:default_position ==# 'float' ?
          \ 'topleft split' :
          \ s:default_position ==# 'top' ?
          \ 'topleft split' :
          \ s:default_position ==# 'bottom' ?
          \ 'botright split' :
          \ s:default_position ==# 'right' ?
          \ 'rightbelow vsplit' : 'leftabove vsplit'
    exe cmd
    let lines = &lines * s:default_height / 100
    if lines < winheight(0) && (s:default_position ==# 'top' || s:default_position ==# 'bottom')
      exe 'resize ' . lines
    endif
  endif
  let w:shell_layer_win = 1
  for open_terminal in s:open_terminals_buffers
    if bufexists(open_terminal)
      if getbufvar(open_terminal, '_spacevim_shell_cwd') ==# l:path
        exe 'silent b' . open_terminal
        " clear the message 
        if has('nvim')
          startinsert
        else
          normal! a
        endif
        return
      endif
    else
      " remove closed buffer from list
      call remove(s:open_terminals_buffers, 0)
    endif
  endfor

  " no terminal window with l:path as cwd has been found, let's open one
  if s:default_shell ==# 'terminal'
    if exists(':terminal')
      if has('nvim')
        if s:SYSTEM.isWindows
          let shell = empty($SHELL) ? 'cmd.exe' : $SHELL
        else
          let shell = empty($SHELL) ? 'bash' : $SHELL
        endif
        enew
        call termopen(shell, {'cwd': l:path})
        " @bug cursor is not cleared when open terminal windows.
        " in neovim-qt when using :terminal to open a shell windows, the orgin
        " cursor position will be highlighted. switch to normal mode and back
        " is to clear the highlight.
        " This seem a bug of neovim-qt in windows.
        "
        " cc @equalsraf
        if s:SYSTEM.isWindows && has('nvim')
          stopinsert
          startinsert
        endif
        let s:term_buf_nr = bufnr('%')
        call extend(s:shell_cached_br, {getcwd() : s:term_buf_nr})
      else 
        " handle vim terminal
        if s:SYSTEM.isWindows
          let shell = empty($SHELL) ? 'cmd.exe' : $SHELL
        else
          let shell = empty($SHELL) ? 'bash' : $SHELL
        endif
        let s:term_buf_nr = term_start(shell, {'cwd': l:path, 'curwin' : 1, 'term_finish' : 'close'})
      endif
      call add(s:open_terminals_buffers, s:term_buf_nr)
      let b:_spacevim_shell = shell
      let b:_spacevim_shell_cwd = l:path

      " use WinEnter autocmd to update statusline
      doautocmd WinEnter
      setlocal nobuflisted nonumber norelativenumber

      " use q to hide terminal buffer in vim, if vimcompatible mode is not
      " enabled, and smart quit is on.
      if !empty(g:spacevim_windows_smartclose)  && !g:spacevim_vimcompatible
        exe 'nnoremap <buffer><silent> ' . g:spacevim_windows_smartclose . ' :hide<CR>'
      endif
      startinsert
    else
      echo ':terminal is not supported in this version'
    endif
  elseif s:default_shell ==# 'VimShell'
    VimShell
    imap <buffer> <C-d> exit<esc><Plug>(vimshell_enter)
  endif
endfunction

function! SpaceVim#layers#shell#close_terminal() abort
  for terminal_bufnr in s:open_terminals_buffers
    if bufexists(terminal_bufnr)
      exe 'silent bd!' . terminal_bufnr
    endif
  endfor
endfunction

function! SpaceVim#layers#shell#health() abort
  call SpaceVim#layers#shell#plugins()
  call SpaceVim#layers#shell#config()
  return 1
endfunction

function! SpaceVim#layers#shell#loadable() abort

  return 1

endfunction