ab3cfg: simplify entire class to one single function

Co-Authored-By: liushuyu <[email protected]>

Author: Cyanoxygen

acbs/ab3cfg.py

@@ -1,39 +1,20 @@
 import os
 
+from acbs.const import AUTOBUILD_CONF_DIR
 from acbs import bashvar
+from pyparsing import ParseException # type: ignore
 
-class AB3Cfg(object):
 
-    def __init__(self, path) -> None:
-        '''
-        Class representing autobuild3 config file.
-
-        :param path: path to the ab3cfg.sh file, with the filename
-        '''
-        self.cfgpath = path
-        self.vars = None
-        self.stage2 = False
-        try:
-            with open(self.cfgpath, 'rt') as cfgfile:
-                self.parse(cfgfile)
-        except Exception as e:
-            # You run ACBS then you should have AB3, eh?
-            raise RuntimeError(f'Autobuild3 config file {self.cfgpath} does not exist\n' +
-                               'Unable to read Autobuild3 config file.') from e
-
-    def parse(self, file):
-        '''
-        Parse the ab3cfg.sh file.
-        '''
-        try:
-            self.vars = bashvar.eval_bashvar(file.read(), filename=self.cfgpath)
-        except Exception as e:
-            raise RuntimeError(f'Error parsing autobuild3 config file: {e}.') from e
-
-    def is_in_stage2(self) -> bool:
-        '''
-        Return True if ab3 is in stage 2 mode.
-        '''
-        if self.vars:
-            self.stage2 = ((self.vars.get('ABSTAGE2') == '1') or False)
-        return self.stage2
+def is_in_stage2() -> bool:
+    ab3cfg_path: str = os.path.join(AUTOBUILD_CONF_DIR, 'ab3cfg.sh')
+    try:
+        with open(ab3cfg_path) as f:
+            vars = bashvar.eval_bashvar(f.read(), filename=ab3cfg_path)
+            stage2_val: str = vars.get('ABSTAGE2')
+            return True if stage2_val == '1' else False
+    except OSError as e:
+        raise RuntimeError(f'Unable to read Autobuild config file {ab3cfg_path}.') from e
+    except ParseException as e:
+        raise RuntimeError(f'Error occurred while parsing Autobuild config file {ab3cfg_path}.') from e
+    except Exception as e:
+        raise RuntimeError(f'Error occurred while checking whether stage 2 mode is enabled.') from e