"""Utilities and helper functions."""

import collections
import errno
import functools
import logging
import os
from pathlib import Path
import re
import sys
import threading

import click
import update_checker
import yaml

import aprsd
from aprsd import plugin


LOG_LEVELS = {
    "CRITICAL": logging.CRITICAL,
    "ERROR": logging.ERROR,
    "WARNING": logging.WARNING,
    "INFO": logging.INFO,
    "DEBUG": logging.DEBUG,
}

DEFAULT_LOG_FORMAT = (
    "[%(asctime)s] [%(threadName)-12s] [%(levelname)-5.5s]"
    " %(message)s - [%(pathname)s:%(lineno)d]"
)

DEFAULT_DATE_FORMAT = "%m/%d/%Y %I:%M:%S %p"

# an example of what should be in the ~/.aprsd/config.yml
DEFAULT_CONFIG_DICT = {
    "ham": {"callsign": "NOCALL"},
    "aprs": {
        "login": "NOCALL",
        "password": "00000",
        "host": "rotate.aprs2.net",
        "port": 14580,
    },
    "aprsd": {
        "logfile": "/tmp/aprsd.log",
        "logformat": DEFAULT_LOG_FORMAT,
        "dateformat": DEFAULT_DATE_FORMAT,
        "trace": False,
        "enabled_plugins": plugin.CORE_MESSAGE_PLUGINS,
        "units": "imperial",
        "watch_list": {
            "enabled": False,
            # Who gets the alert?
            "alert_callsign": "NOCALL",
            # 43200 is 12 hours
            "alert_time_seconds": 43200,
            # How many packets to save in a ring Buffer
            # for a particular callsign
            "packet_keep_count": 10,
            "callsigns": [],
            "enabled_plugins": plugin.CORE_NOTIFY_PLUGINS,
        },
        "web": {
            "enabled": True,
            "logging_enabled": True,
            "host": "0.0.0.0",
            "port": 8001,
            "users": {
                "admin": "password-here",
            },
        },
        "email": {
            "enabled": True,
            "shortcuts": {
                "aa": "5551239999@vtext.com",
                "cl": "craiglamparter@somedomain.org",
                "wb": "555309@vtext.com",
            },
            "smtp": {
                "login": "SMTP_USERNAME",
                "password": "SMTP_PASSWORD",
                "host": "smtp.gmail.com",
                "port": 465,
                "use_ssl": False,
                "debug": False,
            },
            "imap": {
                "login": "IMAP_USERNAME",
                "password": "IMAP_PASSWORD",
                "host": "imap.gmail.com",
                "port": 993,
                "use_ssl": True,
                "debug": False,
            },
        },
    },
    "services": {
        "aprs.fi": {"apiKey": "APIKEYVALUE"},
        "openweathermap": {"apiKey": "APIKEYVALUE"},
        "opencagedata": {"apiKey": "APIKEYVALUE"},
        "avwx": {"base_url": "http://host:port", "apiKey": "APIKEYVALUE"},
    },
}

home = str(Path.home())
DEFAULT_CONFIG_DIR = f"{home}/.config/aprsd/"
DEFAULT_SAVE_FILE = f"{home}/.config/aprsd/aprsd.p"
DEFAULT_CONFIG_FILE = f"{home}/.config/aprsd/aprsd.yml"


def synchronized(wrapped):
    lock = threading.Lock()

    @functools.wraps(wrapped)
    def _wrap(*args, **kwargs):
        with lock:
            return wrapped(*args, **kwargs)

    return _wrap


def env(*vars, **kwargs):
    """This returns the first environment variable set.
    if none are non-empty, defaults to '' or keyword arg default
    """
    for v in vars:
        value = os.environ.get(v, None)
        if value:
            return value
    return kwargs.get("default", "")


def mkdir_p(path):
    """Make directory and have it work in py2 and py3."""
    try:
        os.makedirs(path)
    except OSError as exc:  # Python >= 2.5
        if exc.errno == errno.EEXIST and os.path.isdir(path):
            pass
        else:
            raise


def insert_str(string, str_to_insert, index):
    return string[:index] + str_to_insert + string[index:]


def end_substr(original, substr):
    """Get the index of the end of the <substr>.

    So you can insert a string after <substr>
    """
    idx = original.find(substr)
    if idx != -1:
        idx += len(substr)
    return idx


def dump_default_cfg():
    return add_config_comments(
        yaml.dump(
            DEFAULT_CONFIG_DICT,
            indent=4,
        ),
    )


def add_config_comments(raw_yaml):
    end_idx = end_substr(raw_yaml, "aprs:")
    if end_idx != -1:
        # lets insert a comment
        raw_yaml = insert_str(
            raw_yaml,
            "\n    # Get the passcode for your callsign here: "
            "\n    # https://apps.magicbug.co.uk/passcode",
            end_idx,
        )

    end_idx = end_substr(raw_yaml, "aprs.fi:")
    if end_idx != -1:
        # lets insert a comment
        raw_yaml = insert_str(
            raw_yaml,
            "\n        # Get the apiKey from your aprs.fi account here:  "
            "\n        # http://aprs.fi/account",
            end_idx,
        )

    end_idx = end_substr(raw_yaml, "opencagedata:")
    if end_idx != -1:
        # lets insert a comment
        raw_yaml = insert_str(
            raw_yaml,
            "\n        # (Optional for TimeOpenCageDataPlugin) "
            "\n        # Get the apiKey from your opencagedata account here:  "
            "\n        # https://opencagedata.com/dashboard#api-keys",
            end_idx,
        )

    end_idx = end_substr(raw_yaml, "openweathermap:")
    if end_idx != -1:
        # lets insert a comment
        raw_yaml = insert_str(
            raw_yaml,
            "\n        # (Optional for OWMWeatherPlugin) "
            "\n        # Get the apiKey from your "
            "\n        # openweathermap account here: "
            "\n        # https://home.openweathermap.org/api_keys",
            end_idx,
        )

    end_idx = end_substr(raw_yaml, "avwx:")
    if end_idx != -1:
        # lets insert a comment
        raw_yaml = insert_str(
            raw_yaml,
            "\n        # (Optional for AVWXWeatherPlugin) "
            "\n        # Use hosted avwx-api here: https://avwx.rest "
            "\n        # or deploy your own from here: "
            "\n        # https://github.com/avwx-rest/avwx-api",
            end_idx,
        )

    return raw_yaml


def create_default_config():
    """Create a default config file."""
    # make sure the directory location exists
    config_file_expanded = os.path.expanduser(DEFAULT_CONFIG_FILE)
    config_dir = os.path.dirname(config_file_expanded)
    if not os.path.exists(config_dir):
        click.echo(f"Config dir '{config_dir}' doesn't exist, creating.")
        mkdir_p(config_dir)
    with open(config_file_expanded, "w+") as cf:
        cf.write(dump_default_cfg())


def get_config(config_file):
    """This tries to read the yaml config from <config_file>."""
    config_file_expanded = os.path.expanduser(config_file)
    if os.path.exists(config_file_expanded):
        with open(config_file_expanded) as stream:
            config = yaml.load(stream, Loader=yaml.FullLoader)
            return config
    else:
        if config_file == DEFAULT_CONFIG_FILE:
            click.echo(
                f"{config_file_expanded} is missing, creating config file",
            )
            create_default_config()
            msg = (
                "Default config file created at {}.  Please edit with your "
                "settings.".format(config_file)
            )
            click.echo(msg)
        else:
            # The user provided a config file path different from the
            # Default, so we won't try and create it, just bitch and bail.
            msg = f"Custom config file '{config_file}' is missing."
            click.echo(msg)

        sys.exit(-1)


def conf_option_exists(conf, chain):
    _key = chain.pop(0)
    if _key in conf:
        return conf_option_exists(conf[_key], chain) if chain else conf[_key]


def check_config_option(config, chain, default_fail=None):
    result = conf_option_exists(config, chain.copy())
    if not result:
        raise Exception(
            "'{}' was not in config file".format(
                chain,
            ),
        )
    else:
        if default_fail:
            if result == default_fail:
                # We have to fail and bail if the user hasn't edited
                # this config option.
                raise Exception(
                    "Config file needs to be edited from provided defaults for {}.".format(
                        chain,
                    ),
                )
        else:
            return config


# This method tries to parse the config yaml file
# and consume the settings.
# If the required params don't exist,
# it will look in the environment
def parse_config(config_file):
    # for now we still use globals....ugh
    global CONFIG

    def fail(msg):
        click.echo(msg)
        sys.exit(-1)

    def check_option(config, chain, default_fail=None):
        try:
            config = check_config_option(config, chain, default_fail=default_fail)
        except Exception as ex:
            fail(repr(ex))
        else:
            return config

    config = get_config(config_file)

    # special check here to make sure user has edited the config file
    # and changed the ham callsign
    check_option(
        config,
        [
            "ham",
            "callsign",
        ],
        default_fail=DEFAULT_CONFIG_DICT["ham"]["callsign"],
    )
    check_option(
        config,
        ["services", "aprs.fi", "apiKey"],
        default_fail=DEFAULT_CONFIG_DICT["services"]["aprs.fi"]["apiKey"],
    )
    check_option(
        config,
        ["aprs", "login"],
        default_fail=DEFAULT_CONFIG_DICT["aprs"]["login"],
    )
    check_option(
        config,
        ["aprs", "password"],
        default_fail=DEFAULT_CONFIG_DICT["aprs"]["password"],
    )

    # Ensure they change the admin password
    if config["aprsd"]["web"]["enabled"] is True:
        check_option(
            config,
            ["aprsd", "web", "users", "admin"],
            default_fail=DEFAULT_CONFIG_DICT["aprsd"]["web"]["users"]["admin"],
        )

    if config["aprsd"]["watch_list"]["enabled"] is True:
        check_option(
            config,
            ["aprsd", "watch_list", "alert_callsign"],
            default_fail=DEFAULT_CONFIG_DICT["aprsd"]["watch_list"]["alert_callsign"],
        )

    if config["aprsd"]["email"]["enabled"] is True:
        # Check IMAP server settings
        check_option(config, ["aprsd", "email", "imap", "host"])
        check_option(config, ["aprsd", "email", "imap", "port"])
        check_option(
            config,
            ["aprsd", "email", "imap", "login"],
            default_fail=DEFAULT_CONFIG_DICT["aprsd"]["email"]["imap"]["login"],
        )
        check_option(
            config,
            ["aprsd", "email", "imap", "password"],
            default_fail=DEFAULT_CONFIG_DICT["aprsd"]["email"]["imap"]["password"],
        )

        # Check SMTP server settings
        check_option(config, ["aprsd", "email", "smtp", "host"])
        check_option(config, ["aprsd", "email", "smtp", "port"])
        check_option(
            config,
            ["aprsd", "email", "smtp", "login"],
            default_fail=DEFAULT_CONFIG_DICT["aprsd"]["email"]["smtp"]["login"],
        )
        check_option(
            config,
            ["aprsd", "email", "smtp", "password"],
            default_fail=DEFAULT_CONFIG_DICT["aprsd"]["email"]["smtp"]["password"],
        )

    return config


def human_size(bytes, units=None):
    """Returns a human readable string representation of bytes"""
    if not units:
        units = [" bytes", "KB", "MB", "GB", "TB", "PB", "EB"]
    return str(bytes) + units[0] if bytes < 1024 else human_size(bytes >> 10, units[1:])


def strfdelta(tdelta, fmt="{hours}:{minutes}:{seconds}"):
    d = {"days": tdelta.days}
    d["hours"], rem = divmod(tdelta.seconds, 3600)
    d["minutes"], d["seconds"] = divmod(rem, 60)
    return fmt.format(**d)


def _check_version():
    # check for a newer version
    try:
        check = update_checker.UpdateChecker()
        result = check.check("aprsd", aprsd.__version__)
        if result:
            # Looks like there is an updated version.
            return 1, result
        else:
            return 0, "APRSD is up to date"
    except Exception:
        # probably can't get in touch with pypi for some reason
        # Lets put up an error and move on.  We might not
        # have internet in this aprsd deployment.
        return 1, "Couldn't check for new version of APRSD"


def flatten_dict(d, parent_key="", sep="."):
    """Flatten a dict to key.key.key = value."""
    items = []
    for k, v in d.items():
        new_key = parent_key + sep + k if parent_key else k
        if isinstance(v, collections.MutableMapping):
            items.extend(flatten_dict(v, new_key, sep=sep).items())
        else:
            items.append((new_key, v))
    return dict(items)


def parse_delta_str(s):
    if "day" in s:
        m = re.match(
            r"(?P<days>[-\d]+) day[s]*, (?P<hours>\d+):(?P<minutes>\d+):(?P<seconds>\d[\.\d+]*)",
            s,
        )
    else:
        m = re.match(r"(?P<hours>\d+):(?P<minutes>\d+):(?P<seconds>\d[\.\d+]*)", s)
    return {key: float(val) for key, val in m.groupdict().items()}


class RingBuffer:
    """class that implements a not-yet-full buffer"""

    def __init__(self, size_max):
        self.max = size_max
        self.data = []

    class __Full:
        """class that implements a full buffer"""

        def append(self, x):
            """Append an element overwriting the oldest one."""
            self.data[self.cur] = x
            self.cur = (self.cur + 1) % self.max

        def get(self):
            """return list of elements in correct order"""
            return self.data[self.cur :] + self.data[: self.cur]

    def append(self, x):
        """append an element at the end of the buffer"""

        self.data.append(x)
        if len(self.data) == self.max:
            self.cur = 0
            # Permanently change self's class from non-full to full
            self.__class__ = self.__Full

    def get(self):
        """Return a list of elements from the oldest to the newest."""
        return self.data

    def __len__(self):
        return len(self.data)