" Vim indent file
" Language:		NSIS script
" Maintainer:		Ken Takata
" URL:			https://github.com/k-takata/vim-nsis
" Last Change:		2021-10-18
" Filenames:		*.nsi
" License:		VIM License

if exists("b:did_indent")
  finish
endif
let b:did_indent = 1

setlocal nosmartindent
setlocal noautoindent
setlocal indentexpr=GetNsisIndent(v:lnum)
setlocal indentkeys=!^F,o,O
setlocal indentkeys+==~${Else,=~${EndIf,=~${EndUnless,=~${AndIf,=~${AndUnless,=~${OrIf,=~${OrUnless,=~${Case,=~${Default,=~${EndSelect,=~${EndSwith,=~${Loop,=~${Next,=~${MementoSectionEnd,=~FunctionEnd,=~SectionEnd,=~SectionGroupEnd,=~PageExEnd,0=~!macroend,0=~!if,0=~!else,0=~!endif

let b:undo_indent = "setl ai< inde< indk< si<"

if exists("*GetNsisIndent")
  finish
endif

function! GetNsisIndent(lnum)
  " If this line is explicitly joined: If the previous line was also joined,
  " line it up with that one, otherwise add two 'shiftwidth'
  if getline(a:lnum - 1) =~ '\\$'
    if a:lnum > 1 && getline(a:lnum - 2) =~ '\\$'
      return indent(a:lnum - 1)
    endif
    return indent(a:lnum - 1) + shiftwidth() * 2
  endif

  " Grab the current line, stripping comments.
  let l:thisl = substitute(getline(a:lnum), '[;#].*$', '', '')
  " Check if this line is a conditional preprocessor line.
  let l:preproc = l:thisl =~? '^\s*!\%(if\|else\|endif\)'

  " Grab the previous line, stripping comments.
  " Skip preprocessor lines and continued lines.
  let l:prevlnum = a:lnum
  while 1
    let l:prevlnum = prevnonblank(l:prevlnum - 1)
    if l:prevlnum == 0
      " top of file
      return 0
    endif
    let l:prevl = substitute(getline(l:prevlnum), '[;#].*$', '', '')
    let l:prevpreproc = l:prevl =~? '^\s*!\%(if\|else\|endif\)'
    if l:preproc == l:prevpreproc && getline(l:prevlnum - 1) !~? '\\$'
      break
    endif
  endwhile
  let l:previ = indent(l:prevlnum)
  let l:ind = l:previ

  if l:preproc
    " conditional preprocessor
    if l:prevl =~? '^\s*!\%(if\%(\%(macro\)\?n\?def\)\?\|else\)\>'
      let l:ind += shiftwidth()
    endif
    if l:thisl =~? '^\s*!\%(else\|endif\)\?\>'
      let l:ind -= shiftwidth()
    endif
    return l:ind
  endif

  if l:prevl =~? '^\s*\%(\${\%(If\|IfNot\|Unless\|ElseIf\|ElseIfNot\|ElseUnless\|Else\|AndIf\|AndIfNot\|AndUnless\|OrIf\|OrIfNot\|OrUnless\|Select\|Case\|Case[2-5]\|CaseElse\|Default\|Switch\|Do\|DoWhile\|DoUntil\|For\|ForEach\|MementoSection\)}\|Function\>\|Section\>\|SectionGroup\|PageEx\>\|!macro\>\)'
    " previous line opened a block
    let l:ind += shiftwidth()
  endif
  if l:thisl =~? '^\s*\%(\${\%(ElseIf\|ElseIfNot\|ElseUnless\|Else\|EndIf\|EndUnless\|AndIf\|AndIfNot\|AndUnless\|OrIf\|OrIfNot\|OrUnless\|Loop\|LoopWhile\|LoopUntil\|Next\|MementoSectionEnd\)\>}\?\|FunctionEnd\>\|SectionEnd\>\|SectionGroupEnd\|PageExEnd\>\|!macroend\>\)'
    " this line closed a block
    let l:ind -= shiftwidth()
  elseif l:thisl =~? '^\s*\${\%(Case\|Case[2-5]\|CaseElse\|Default\)\>}\?'
    if l:prevl !~? '^\s*\${\%(Select\|Switch\)}'
      let l:ind -= shiftwidth()
    endif
  elseif l:thisl =~? '^\s*\${\%(EndSelect\|EndSwitch\)\>}\?'
    " this line closed a block
    if l:prevl =~? '^\s*\${\%(Select\|Switch\)}'
      let l:ind -= shiftwidth()
    else
      let l:ind -= shiftwidth() * 2
    endif
  endif

  return l:ind
endfunction

" vim: ts=8 sw=2 sts=2
