" Author: Eddie Lebow https://github.com/elebow
" Description: eruby checker using `erubi`

function! ale_linters#eruby#erubi#CheckErubi(buffer) abort
    return 'ruby -r erubi/capture_end -e ' . ale#Escape('""')
endfunction

function! ale_linters#eruby#erubi#GetCommand(buffer, check_erubi_output) abort
    let l:rails_root = ale#ruby#FindRailsRoot(a:buffer)

    if (!empty(a:check_erubi_output))
        " The empty command in CheckErubi returns nothing if erubi runs and
        " emits an error if erubi is not present
        return ''
    endif

    if empty(l:rails_root)
        return 'ruby -r erubi/capture_end -e ' . ale#Escape('puts Erubi::CaptureEndEngine.new($stdin.read).src') . '< %t | ruby -c'
    endif

    " Rails-flavored eRuby does not comply with the standard as understood by
    " Erubi, so we'll have to do some substitution. This does not reduce the
    " effectiveness of the linter---the translated code is still evaluated.
    return 'ruby -r erubi/capture_end -e ' . ale#Escape('puts Erubi::CaptureEndEngine.new($stdin.read.gsub(%{<%=},%{<%}), nil, %{-}).src') . '< %t | ruby -c'
endfunction

call ale#linter#Define('eruby', {
\   'name': 'erubi',
\   'executable': 'ruby',
\   'command_chain': [
\     {'callback': 'ale_linters#eruby#erubi#CheckErubi'},
\     {'callback': 'ale_linters#eruby#erubi#GetCommand', 'output_stream': 'stderr'},
\   ],
\   'callback': 'ale#handlers#ruby#HandleSyntaxErrors',
\})