import os


def FlagsForFile(filename, **kwargs):
    client_data = kwargs['client_data']
    cwd = client_data['getcwd()']

    flags = [
        '-Wall',
        # '-Wextra',
        # '-Wshadow',
        # '-Werror',
        # '-Wc++98-compat',
        # '-Wno-long-long',
        # '-Wno-variadic-macros',
        # '-fexceptions',
        # '-DNDEBUG',
        '-std=c++11',
        '-stdlib=libstdc++',
        '-x', 'c++',
        '-I', '.',
        '-I', './include',
    ]
    flags += rospack()
    relative_to = cwd
    final_flags = MakeRelativePathsInFlagsAbsolute(flags, relative_to)

    return {
        'flags': final_flags,
        'do_cache': True
    }

# This function makes it easy to pull in additional flags from rospack
def rospack():
    cmd = ['rospack', 'cflags-only-I']
    try:
        out = subprocess.Popen(cmd, shell=False, stdout=subprocess.PIPE).stdout
    except:
        return []
    line = out.readline()[:-1].split(" ")
    includes = []
    for include in line:
        if include.startswith(os.path.expanduser('~')):
            includes += ['-I', include]
        else:
            includes += ['-isystem', include]
    return filter(lambda a: a != ' ', includes)


def DirectoryOfThisScript():
    return os.path.dirname(os.path.abspath(__file__))


def MakeRelativePathsInFlagsAbsolute(flags, working_directory):
    if not working_directory:
        return list(flags)
    new_flags = []
    make_next_absolute = False
    path_flags = ['-isystem', '-I', '-iquote', '--sysroot=']
    for flag in flags:
        new_flag = flag

        if make_next_absolute:
            make_next_absolute = False
            if not flag.startswith('/'):
                new_flag = os.path.join(working_directory, flag)

        for path_flag in path_flags:
            if flag == path_flag:
                make_next_absolute = True
                break

            if flag.startswith(path_flag):
                path = flag[len(path_flag):]
                new_flag = path_flag + os.path.join(working_directory, path)
                break

        if new_flag:
            new_flags.append(new_flag)
    return new_flags