# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

import os
import platform
import re
import warnings

from abc import ABC, abstractclassmethod
from enum import Enum, unique
from pathlib import Path
from subprocess import check_output, CalledProcessError
from typing import Any, List, NamedTuple, Optional, Tuple  # noqa: F401

from libqtile import bar
from libqtile.log_utils import logger
from libqtile.images import Img  # noqa: F401
from libqtile.widget import base
from libqtile import images, configurable

from typing import Dict  # noqa: F401


@unique
class BatteryState(Enum):
    CHARGING = 1
    DISCHARGING = 2
    FULL = 3
    EMPTY = 4
    UNKNOWN = 5


BatteryStatus = NamedTuple("BatteryStatus", [
    ("state", BatteryState),
    ("percent", float),
    ("power", float),
    ("time", int),
])


class _Battery(ABC):
    """
        Battery interface class specifying what member functions a
        battery implementation should provide.
    """
    @abstractclassmethod
    def update_status(self) -> BatteryStatus:
        """Read the battery status

            Reads the battery status from the system and returns the result.

            Raises RuntimeError on error.
        """
        pass


def load_battery(**config) -> _Battery:
    """Default battery loading function

    Loads and returns the _Battery interface suitable for the current running
    platform.

    Parameters
    ----------
    config: Dictionary of config options that are passed to the generated
    battery.

    Return
    ------
    The configured _Battery for the current platform.
    """
    system = platform.system()
    if system == 'FreeBSD':
        return _FreeBSDBattery(str(config["battery"]))
    elif system == 'Linux':
        return _LinuxBattery(**config)
    else:
        raise RuntimeError('Unknown platform!')


class _FreeBSDBattery(_Battery):
    """
        A battery class compatible with FreeBSD. Reads battery status
        using acpiconf.

        Takes a battery setting containing the number of the battery
        that should be monitored.
    """

    def __init__(self, battery='0') -> None:
        self.battery = battery

    def update_status(self) -> BatteryStatus:
        try:
            info = check_output(['acpiconf', '-i', self.battery]).decode('utf-8')
        except CalledProcessError:
            raise RuntimeError('acpiconf exited incorrectly')

        stat = re.search(r'State:\t+([a-z]+)', info)

        if stat is None:
            raise RuntimeError('Could not get battery state!')

        stat = stat.group(1)
        if stat == 'charging':
            state = BatteryState.CHARGING
        elif stat == 'discharging':
            state = BatteryState.DISCHARGING
        elif stat == 'high':
            state = BatteryState.FULL
        else:
            state = BatteryState.UNKNOWN

        percent_re = re.search(r'Remaining capacity:\t+([0-9]+)', info)
        if percent_re:
            percent = int(percent_re.group(1)) / 100
        else:
            raise RuntimeError('Could not get battery percentage!')

        power_re = re.search(r'Present rate:\t+(?:[0-9]+ mA )*\(?([0-9]+) mW',
                             info)
        if power_re:
            power = float(power_re.group(1)) / 1000
        else:
            raise RuntimeError('Could not get battery power!')

        time_re = re.search(r'Remaining time:\t+([0-9]+:[0-9]+|unknown)',
                            info)
        if time_re:
            if time_re.group(1) == 'unknown':
                time = 0
            else:
                hours, _, minutes = time_re.group(1).partition(':')
                time = int(hours) * 3600 + int(minutes) * 60
        else:
            raise RuntimeError('Could not get remaining battery time!')

        return BatteryStatus(state, percent=percent, power=power, time=time)


class _LinuxBattery(_Battery, configurable.Configurable):
    defaults = [
        (
            'status_file',
            None,
            'Name of status file in /sys/class/power_supply/ACAD'
        ),
        (
            'energy_now_file',
            None,
            'Name of file with the current energy in /sys/class/power_supply/ACAD'
        ),
        (
            'energy_full_file',
            None,
            'Name of file with the maximum energy in /sys/class/power_supply/ACAD'
        ),
        (
            'power_now_file',
            None,
            'Name of file with the current power draw in /sys/class/power_supply/ACAD'
        )
    ]

    filenames = {}  # type: Dict

    BAT_DIR = '/sys/class/power_supply'

    BATTERY_INFO_FILES = {
        'energy_now_file': ['energy_now', 'charge_now'],
        'energy_full_file': ['energy_full', 'charge_full'],
        'power_now_file': ['power_now', 'current_now'],
        'voltage_now_file': ['voltage_now'],
        'status_file': ['status'],
    }

    def __init__(self, **config):
        _LinuxBattery.defaults.append(('battery',
                                       self._get_battery_name(),
                                       'ACPI name of a battery, usually BAT0'))

        configurable.Configurable.__init__(self, **config)
        self.add_defaults(_LinuxBattery.defaults)
        if isinstance(self.battery, int):
            self.battery = "BAT{}".format(self.battery)

    def _get_battery_name(self):
        if os.path.isdir(self.BAT_DIR):
            bats = [f for f in os.listdir(self.BAT_DIR) if f.startswith('BAT')]
            if bats:
                return bats[0]
        return 'BAT0'

    def _load_file(self, name) -> Optional[Tuple[str, str]]:
        try:
            path = os.path.join(self.BAT_DIR, self.battery, name)
            if 'energy' in name or 'power' in name:
                value_type = 'uW'
            elif 'charge' in name:
                value_type = 'uAh'
            elif 'current' in name:
                value_type = 'uA'
            else:
                value_type = ''

            with open(path, 'r') as f:
                return f.read().strip(), value_type
        except Exception:
            logger.exception("Failed to get %s" % name)
        return None

    def _get_param(self, name) -> Tuple[str, str]:
        if name in self.filenames and self.filenames[name]:
            result = self._load_file(self.filenames[name])
            if result is not None:
                return result

        # Don't have the file name cached, figure it out
        # Don't modify the global list! Copy with [:]
        file_list = self.BATTERY_INFO_FILES.get(name, [])[:]
        user_file_name = getattr(self, name, None)
        if user_file_name is not None:
            file_list.insert(0, user_file_name)

        # Iterate over the possibilities, and return the first valid value
        for filename in file_list:
            value = self._load_file(filename)
            if value is not None:
                self.filenames[name] = filename
                return value

        raise RuntimeError("Unable to read status for {}".format(name))

    def update_status(self) -> BatteryStatus:
        stat = self._get_param('status_file')[0]

        if stat == "Full":
            state = BatteryState.FULL
        elif stat == "Charging":
            state = BatteryState.CHARGING
        elif stat == "Discharging":
            state = BatteryState.DISCHARGING
        else:
            state = BatteryState.UNKNOWN

        now_str, now_unit = self._get_param('energy_now_file')
        full_str, full_unit = self._get_param('energy_full_file')
        power_str, power_unit = self._get_param('power_now_file')
        # the units of energy is uWh or uAh, multiply to get to uWs or uAs
        now = 3600 * float(now_str)
        full = 3600 * float(full_str)
        power = float(power_str)

        if now_unit != full_unit:
            raise RuntimeError("Current and full energy units do not match")
        if full == 0:
            percent = 0.
        else:
            percent = now / full

        if power_unit == 'uA':
            voltage = float(self._get_param('voltage_now_file')[0])
            power = voltage * power / 1e12
        elif power_unit == 'uW':
            power = power / 1e6

        if power == 0:
            time = 0
        elif state == BatteryState.DISCHARGING:
            time = int(now / power)
        else:
            time = int((full - now) / power)

        return BatteryStatus(state=state, percent=percent, power=power, time=time)


class Battery(base.ThreadPoolText):
    """A text-based battery monitoring widget currently supporting FreeBSD"""
    orientations = base.ORIENTATION_HORIZONTAL
    defaults = [
        ('charge_char', '^', 'Character to indicate the battery is charging'),
        ('discharge_char', 'V', 'Character to indicate the battery is discharging'),
        ('full_char', '=', 'Character to indicate the battery is full'),
        ('empty_char', 'x', 'Character to indicate the battery is empty'),
        ('unknown_char', '?', 'Character to indicate the battery status is unknown'),
        ('format', '{char} {percent:2.0%} {hour:d}:{min:02d} {watt:.2f} W', 'Display format'),
        ('hide_threshold', None, 'Hide the text when there is enough energy 0 <= x < 1'),
        ('show_short_text', True, 'Show "Full" or "Empty" rather than formated text'),
        ('low_percentage', 0.10, "Indicates when to use the low_foreground color 0 < x < 1"),
        ('low_foreground', 'FF0000', 'Font color on low battery'),
        ('update_interval', 60, 'Seconds between status updates'),
        ('battery', 0, 'Which battery should be monitored'),
    ]

    def __init__(self, **config) -> None:
        if "update_delay" in config:
            warnings.warn("Change from using update_delay to update_interval for battery widget, removed in 0.15",
                          DeprecationWarning)
            config["update_interval"] = config.pop("update_delay")

        base.ThreadPollText.__init__(self, "BAT", bar.CALCULATED, **config)
        self.add_defaults(self.defaults)

        self._battery = self._load_battery(**config)

    @staticmethod
    def _load_battery(**config):
        """Function used to load the Battery object

        Battery behavior can be changed by overloading this function in a base
        class.
        """
        return load_battery(**config)

    def poll(self) -> str:
        """Determine the text to display

        Function returning a string with battery information to display on the
        status bar. Should only use the public interface in _Battery to get
        necessary information for constructing the string.
        """
        try:
            status = self._battery.update_status()
        except RuntimeError as e:
            return 'Error: {}'.format(e)

        return self.build_string(status)

    def build_string(self, status: BatteryStatus) -> str:
        """Determine the string to return for the given battery state

        Parameters
        ----------
        status:
            The current status of the battery

        Returns
        -------
        str
            The string to display for the current status.
        """
        if self.hide_threshold is not None and status.percent > self.hide_threshold:
            return ''

        if self.layout is not None:
            if status.state == BatteryState.DISCHARGING and status.percent < self.low_percentage:
                self.layout.colour = self.low_foreground
            else:
                self.layout.colour = self.foreground

        if status.state == BatteryState.CHARGING:
            char = self.charge_char
        elif status.state == BatteryState.DISCHARGING:
            char = self.discharge_char
        elif status.state == BatteryState.FULL:
            if self.show_short_text:
                return "Full"
            char = self.full_char
        elif status.state == BatteryState.EMPTY or \
                (status.state == BatteryState.UNKNOWN and status.percent == 0):
            if self.show_short_text:
                return "Empty"
            char = self.empty_char
        else:
            char = self.unknown_char

        hour = status.time // 3600
        minute = (status.time // 60) % 60

        return self.format.format(
            char=char,
            percent=status.percent,
            watt=status.power,
            hour=hour,
            min=minute
        )


def default_icon_path() -> str:
    """Get the default path to battery icons"""
    dir_path = Path(__file__).resolve() / ".." / ".." / "resources" / "battery-icons"
    return str(dir_path.resolve())


class BatteryIcon(base._TextBox):
    """Battery life indicator widget."""

    orientations = base.ORIENTATION_HORIZONTAL
    defaults = [
        ('battery', 0, 'Which battery should be monitored'),
        ('update_interval', 60, 'Seconds between status updates'),
        ('theme_path', default_icon_path(), 'Path of the icons'),
    ]  # type: List[Tuple[str, Any, str]]

    icon_names = (
        'battery-missing',
        'battery-caution',
        'battery-low',
        'battery-good',
        'battery-full',
        'battery-caution-charging',
        'battery-low-charging',
        'battery-good-charging',
        'battery-full-charging',
        'battery-full-charged',
    )

    def __init__(self, **config) -> None:
        if "update_delay" in config:
            warnings.warn("Change from using update_delay to update_interval for battery widget, removed in 0.15",
                          DeprecationWarning)
            config["update_interval"] = config.pop("update_delay")

        base._TextBox.__init__(self, "BAT", bar.CALCULATED, **config)

        self.add_defaults(self.defaults)

        if self.theme_path:
            self.length_type = bar.STATIC
            self.length = 0
        self.surfaces = {}  # type: Dict[str, Img]
        self.current_icon = 'battery-missing'

        self._battery = self._load_battery(**config)

    @staticmethod
    def _load_battery(**config):
        """Function used to load the Battery object

        Battery behavior can be changed by overloading this function in a base
        class.
        """
        return load_battery(**config)

    def timer_setup(self) -> None:
        self.update()
        self.timeout_add(self.update_interval, self.timer_setup)

    def _configure(self, qtile, bar) -> None:
        base._TextBox._configure(self, qtile, bar)
        self.setup_images()

    def setup_images(self) -> None:
        d_imgs = images.Loader(self.theme_path)(*self.icon_names)
        new_height = self.bar.height - self.actual_padding
        for key, img in d_imgs.items():
            img.resize(height=new_height)
            if img.width > self.length:
                self.length = int(img.width + self.actual_padding * 2)
            self.surfaces[key] = img.pattern

    def update(self) -> None:
        status = self._battery.update_status()
        icon = self._get_icon_key(status)
        if icon != self.current_icon:
            self.current_icon = icon
            self.draw()

    def draw(self) -> None:
        if self.theme_path:
            self.drawer.clear(self.background or self.bar.background)
            self.drawer.ctx.set_source(self.surfaces[self.current_icon])
            self.drawer.ctx.paint()
            self.drawer.draw(offsetx=self.offset, width=self.length)
        else:
            self.text = self.current_icon[8:]
            base._TextBox.draw(self)

    @staticmethod
    def _get_icon_key(status: BatteryStatus) -> str:
        key = 'battery'

        percent = status.percent
        if percent < .2:
            key += '-caution'
        elif percent < .4:
            key += '-low'
        elif percent < .8:
            key += '-good'
        else:
            key += '-full'

        state = status.state
        if state == BatteryState.CHARGING:
            key += '-charging'
        elif state == BatteryState.FULL:
            key += '-charged'
        return key