esphome-dev/esphome/helpers.py

from __future__ import print_function

import codecs
import logging
import os

from esphome.py_compat import char_to_byte, text_type

_LOGGER = logging.getLogger(__name__)


def ensure_unique_string(preferred_string, current_strings):
    test_string = preferred_string
    current_strings_set = set(current_strings)

    tries = 1

    while test_string in current_strings_set:
        tries += 1
        test_string = u"{}_{}".format(preferred_string, tries)

    return test_string


def indent_all_but_first_and_last(text, padding=u'  '):
    lines = text.splitlines(True)
    if len(lines) <= 2:
        return text
    return lines[0] + u''.join(padding + line for line in lines[1:-1]) + lines[-1]


def indent_list(text, padding=u'  '):
    return [padding + line for line in text.splitlines()]


def indent(text, padding=u'  '):
    return u'\n'.join(indent_list(text, padding))


# From https://stackoverflow.com/a/14945195/8924614
def cpp_string_escape(string, encoding='utf-8'):
    def _should_escape(byte):  # type: (int) -> bool
        if not 32 <= byte < 127:
            return True
        if byte in (char_to_byte('\\'), char_to_byte('"')):
            return True
        return False

    if isinstance(string, text_type):
        string = string.encode(encoding)
    result = ''
    for character in string:
        character = char_to_byte(character)
        if _should_escape(character):
            result += '\\%03o' % character
        else:
            result += chr(character)
    return '"' + result + '"'


def color(the_color, message=''):
    from colorlog.escape_codes import escape_codes, parse_colors

    if not message:
        res = parse_colors(the_color)
    else:
        res = parse_colors(the_color) + message + escape_codes['reset']

    return res


def run_system_command(*args):
    import subprocess

    p = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    stdout, stderr = p.communicate()
    rc = p.returncode
    return rc, stdout, stderr


def mkdir_p(path):
    import errno

    try:
        os.makedirs(path)
    except OSError as exc:
        if exc.errno == errno.EEXIST and os.path.isdir(path):
            pass
        else:
            raise


def is_ip_address(host):
    parts = host.split('.')
    if len(parts) != 4:
        return False
    try:
        for p in parts:
            int(p)
        return True
    except ValueError:
        return False


def _resolve_with_zeroconf(host):
    from esphome.core import EsphomeError
    from esphome.zeroconf import Zeroconf

    try:
        zc = Zeroconf()
    except Exception:
        raise EsphomeError("Cannot start mDNS sockets, is this a docker container without "
                           "host network mode?")
    try:
        info = zc.resolve_host(host + '.')
    except Exception as err:
        raise EsphomeError("Error resolving mDNS hostname: {}".format(err))
    finally:
        zc.close()
    if info is None:
        raise EsphomeError("Error resolving address with mDNS: Did not respond. "
                           "Maybe the device is offline.")
    return info


def resolve_ip_address(host):
    from esphome.core import EsphomeError
    import socket

    try:
        ip = socket.gethostbyname(host)
    except socket.error as err:
        if host.endswith('.local'):
            ip = _resolve_with_zeroconf(host)
        else:
            raise EsphomeError("Error resolving IP address: {}".format(err))

    return ip


def get_bool_env(var, default=False):
    return bool(os.getenv(var, default))


def is_hassio():
    return get_bool_env('ESPHOME_IS_HASSIO')


def copy_file_if_changed(src, dst):
    src_text = read_file(src)
    if os.path.isfile(dst):
        dst_text = read_file(dst)
    else:
        dst_text = None
    if src_text == dst_text:
        return
    write_file(dst, src_text)


def read_file(path):
    try:
        with codecs.open(path, 'r', encoding='utf-8') as f_handle:
            return f_handle.read()
    except OSError:
        from esphome.core import EsphomeError
        raise EsphomeError(u"Could not read file at {}".format(path))


def write_file(path, text):
    try:
        mkdir_p(os.path.dirname(path))
        with codecs.open(path, 'w+', encoding='utf-8') as f_handle:
            f_handle.write(text)
    except OSError:
        from esphome.core import EsphomeError
        raise EsphomeError(u"Could not write file at {}".format(path))


def write_file_if_changed(text, dst):
    src_content = None
    if os.path.isfile(dst):
        src_content = read_file(dst)
    if src_content != text:
        write_file(dst, text)