import re
import dearpygui.dearpygui as dpg

from vrutil.utils import loaded, store, write_to_file

_GPU_POWER_PROFILE_MODE_FILE = '/sys/class/drm/card0/device/pp_power_profile_mode'
_GPU_PERFORMANCE_LEVEL_FILE = '/sys/class/drm/card0/device/power_dpm_force_performance_level'


class GpuSettings:
    """GPU related settings"""

    def __init__(self):
        self._power_profile_item = None
        self._performance_level_item = None

    def create_views(self):
        with dpg.collapsing_header(label='GPU', default_open=True):
            self._power_profile_item = dpg.add_combo(
                label='Power Profile',
                items=self._get_available_profiles(),
                default_value=self._get_selected_profile(),
                width=200,
                callback=self._select_profile,
            )
            self._performance_level_item = dpg.add_combo(
                label='Performance Level',
                items=self._get_available_levels(),
                default_value=self._get_selected_level(),
                width=200,
                callback=self._select_level,
            )

            dpg.add_spacer(height=10)

    def update(self):
        dpg.set_value(self._power_profile_item, self._get_selected_profile())
        dpg.set_value(self._performance_level_item, self._get_selected_level())

    # region Power Profile

    def _get_available_profiles(self):
        return tuple(map(lambda profile: profile[1], self._raw_gpu_profiles()))

    def _get_selected_profile(self):
        active_profile = next(filter(lambda profile: profile[2] == '*', self._raw_gpu_profiles()), None)
        loaded('GPU Profile', active_profile)
        return active_profile[1] if active_profile is not None else None

    def _select_profile(self, _sender, app_data, _user_data):
        selected_profile = next(filter(lambda profile: profile[1] == app_data, self._raw_gpu_profiles()), None)
        store('GPU Profile', selected_profile)
        if selected_profile is not None:
            write_to_file(_GPU_POWER_PROFILE_MODE_FILE, selected_profile[0])
        self.update()

    @staticmethod
    def _raw_gpu_profiles():
        rex = re.compile('^ *(\\d) +(\\w+)([ *]):$', flags=re.MULTILINE)
        with open(_GPU_POWER_PROFILE_MODE_FILE, 'r') as f:
            matches = re.findall(rex, f.read())
        return matches

    # endregion

    # region Performance Level

    @staticmethod
    def _get_available_levels():
        return 'auto', 'high'

    @staticmethod
    def _get_selected_level():
        with open(_GPU_PERFORMANCE_LEVEL_FILE, 'r') as f:
            level = f.readline().strip()
        loaded('GPU Level', level)
        return level

    def _select_level(self, _sender, level, _user_data):
        store('GPU Level', level)
        if level is not None:
            write_to_file(_GPU_PERFORMANCE_LEVEL_FILE, level)
        self.update()

    # endregion