Use `psutil` in conjuction with `dmidecode` to determine `ac_state` (#168)

* use psutil to determine ac_state

auto_cpufreq/core.py

@@ -135,31 +135,24 @@ def charging():
     power_dir = "/sys/class/power_supply/"
 
     computer_type = getoutput('dmidecode --string chassis-type')
-    
-    # Most common types for laptops, source: https://twitter.com/fooctrl/status/1357230198857564160
     if computer_type in [ "Notebook", "Laptop", "Convertible", "Portable" ]:
         # AC adapter states: 0, 1, unknown
         ac_info = getoutput(f"grep . {power_dir}A*/online").splitlines()
         # if there's one ac-adapter on-line, ac_state is True
         ac_state = any(['1' in ac.split(':')[-1] for ac in ac_info])
     else:
-        # if desktop ac_state is true
-        ac_state = True
-
-    # Possible values: Charging, Discharging, Unknown
-    battery_info = getoutput(f"grep . {power_dir}BAT*/status")
-
-    # need to explicitly check for each state in this order
-    # considering multiple batteries
-    if "Discharging" in battery_info:
-        battery_state = False
-    elif "Charging" in battery_info:
-        battery_state = True
-    else:
-        battery_state = None
+        has_battery = psutil.sensors_battery() is not None
+        if has_battery == True:
+            power_pluggedin = psutil.sensors_battery().power_plugged
+            if power_pluggedin == True:
+                ac_state = True
+            else:
+                ac_state = False
+        else:
+            ac_state = True
 
     # if both ac-adapter and battery states are unknown default to not charging
-    return ac_state or battery_state
+    return ac_state
 
 
 def get_avail_gov():