import os

from lib import util, make


def _openscad(in_path, out_path, deps_path):
    util.command([os.environ['OPENSCAD'], '-o', out_path, '-d', deps_path, in_path])


@util.main
def main(in_path, out_path):
    cwd = os.getcwd()
    
    def relpath(path):
        return os.path.relpath(path, cwd)
    
    with util.TemporaryDirectory() as temp_dir:
        temp_deps_path = os.path.join(temp_dir, 'deps')
        temp_mk_path = os.path.join(temp_dir, 'mk')
        temp_files_path = os.path.join(temp_dir, 'files')
        
        _, out_ext = os.path.splitext(out_path)
        
        # OpenSCAD requires the output file name to end in .stl or .dxf.
        temp_out_path = os.path.join(temp_dir, 'out' + out_ext)
        
        _openscad(in_path, temp_out_path, temp_deps_path)
        
        mk_content = '%:; echo "$@" >> {}'.format(util.bash_escape_string(temp_files_path))
        
        # Use make to parse the dependency makefile written by OpenSCAD.
        util.write_file(temp_mk_path, mk_content.encode())
        util.command(
            ['make', '-s', '-B', '-f', temp_mk_path, '-f', temp_deps_path],
            remove_env=['MAKELEVEL', 'MAKEFLAGS'])
        
        # All dependencies as paths relative to the project root.
        deps = set(map(relpath, util.read_file(temp_files_path).decode().splitlines()))
        
        # Relative paths to all files that should not appear in the
        # dependency makefile.
        ignored_files = set(map(relpath, [in_path, temp_deps_path, temp_mk_path, temp_out_path]))
        
        # Write output files.
        make.write_dependencies(out_path + '.d', out_path, deps - ignored_files)
        util.rename_atomic(temp_out_path, out_path)