import sys, os, shutil
from lib import util, make


def _asymptote(in_path, out_path, asymptote_dir, working_dir):
    args = [os.environ['ASYMPTOTE'], '-vv', '-f', 'pdf', '-o', out_path, in_path]
    
    with util.command_context(args, set_env={'ASYMPTOTE_DIR': asymptote_dir}, working_dir=working_dir, use_stderr=True) as process:
        def get_loaded_file(line):
            if any(line.startswith(j) for j in ['Loading ', 'Including ']):
                parts = line.rstrip('\n').split(' ')
                
                if len(parts) == 4:
                    _, _, from_, path = parts
                    
                    if from_ == 'from':
                        return path
            
            return None
        
        def iter_loaded_files():
            for i in process.stderr:
                loaded_file = get_loaded_file(i)
                
                if loaded_file is not None:
                    yield loaded_file
                elif not any(i.startswith(j) for j in ['cd ', 'Using configuration ']):
                    print >> sys.stderr, i,
        
        loaded_files = list(iter_loaded_files())
    
    return loaded_files


@util.main
def main(in_path, out_path):
    try:
        _, out_suffix = os.path.splitext(out_path)
        
        with util.TemporaryDirectory() as temp_dir:
            absolute_in_path = os.path.abspath(in_path)
            temp_out_path = os.path.join(temp_dir, 'out.pdf')

            # Asymptote creates A LOT of temp files (presumably when invoking
            #  LaTeX) and leaves some of them behind. Thus we run asymptote
            # in a temporary directory.
            loaded_files = _asymptote(
                absolute_in_path,
                'out',
                os.path.dirname(absolute_in_path),
                temp_dir)
            
            if not os.path.exists(temp_out_path):
                raise util.UserError('Asymptote did not generate a PDF file.', in_path)
            
            # All dependencies as paths relative to the project root.
            dependencies = set(map(os.path.relpath, loaded_files))
            
            # Write output files.
            make.write_dependencies(out_path + '.d', out_path, dependencies - {in_path})
            shutil.copyfile(temp_out_path, out_path)
    except util.UserError as e:
        raise util.UserError('While processing {}: {}', in_path, e)