Configure explain log level via cli and config file

CONFIG.md

@@ -19,6 +19,8 @@ default values for the other sections.
   paths in the config file are interpreted relative to this path. If this path
   is relative, it is interpreted relative to the script's working dir. `~` is
   expanded to the current user's home directory. (Default: `.`)
+- `explain`: Whether PFERD should log and explain its actions and decisions in
+  detail. (Default: `no`)
 
 ## The `crawl:*` sections
 

PFERD/__main__.py

@@ -4,6 +4,7 @@ import configparser
 from pathlib import Path
 
 from .config import Config, ConfigDumpException, ConfigLoadException
+from .logging import log
 from .output_dir import OnConflict, Redownload
 from .pferd import Pferd
 from .version import NAME, VERSION
@@ -42,6 +43,13 @@ GENERAL_PARSER.add_argument(
     metavar="PATH",
     help="custom working directory"
 )
+GENERAL_PARSER.add_argument(
+    "--explain", "-e",
+    # TODO Use argparse.BooleanOptionalAction after updating to 3.9
+    action="store_const",
+    const=True,
+    help="log and explain in detail what PFERD is doing"
+)
 
 
 def load_general(
@@ -52,6 +60,8 @@ def load_general(
 
     if args.working_dir is not None:
         section["working_dir"] = str(args.working_dir)
+    if args.explain is not None:
+        section["explain"] = "true" if args.explain else "false"
 
 
 CRAWLER_PARSER = argparse.ArgumentParser(add_help=False)
@@ -217,6 +227,10 @@ def prune_crawlers(
 def main() -> None:
     args = PARSER.parse_args()
 
+    # Configure log levels set by command line arguments
+    if args.explain is not None:
+        log.output_explain = args.explain
+
     if args.version:
         print(f"{NAME} {VERSION}")
         exit()
@@ -226,6 +240,11 @@ def main() -> None:
     except ConfigLoadException:
         exit(1)
 
+    # Configure log levels set in the config file
+    # TODO Catch config section exceptions
+    if args.explain is None:
+        log.output_explain = config.default_section.explain()
+
     if args.dump_config is not None:
         try:
             if args.dump_config is True:

PFERD/config.py

@@ -50,6 +50,15 @@ class Section:
         self.error(key, "Missing value")
 
 
+class DefaultSection(Section):
+    def working_dir(self) -> Path:
+        pathstr = self.s.get("working_dir", ".")
+        return Path(pathstr).expanduser()
+
+    def explain(self) -> bool:
+        return self.s.getboolean("explain", fallback=False)
+
+
 class Config:
     @staticmethod
     def _default_path() -> Path:
@@ -62,6 +71,11 @@ class Config:
 
     def __init__(self, parser: ConfigParser):
         self._parser = parser
+        self._default_section = DefaultSection(parser[parser.default_section])
+
+    @property
+    def default_section(self) -> DefaultSection:
+        return self._default_section
 
     @staticmethod
     def _fail_load(path: Path, reason: str) -> None:
@@ -134,10 +148,6 @@ class Config:
     def dump_to_stdout(self) -> None:
         self._parser.write(sys.stdout)
 
-    @property
-    def default_section(self) -> SectionProxy:
-        return self._parser[self._parser.default_section]
-
     def crawler_sections(self) -> List[Tuple[str, SectionProxy]]:
         result = []
         for name, proxy in self._parser.items():
@@ -153,8 +163,3 @@ class Config:
                 result.append((name, proxy))
 
         return result
-
-    @property
-    def working_dir(self) -> Path:
-        pathstr = self.default_section.get("working_dir", ".")
-        return Path(pathstr).expanduser()

PFERD/crawler.py

@@ -184,7 +184,7 @@ class Crawler(ABC):
         self._transformer = Transformer(section.transform())
 
         self._output_dir = OutputDirectory(
-            config.working_dir / section.output_dir(name),
+            config.default_section.working_dir() / section.output_dir(name),
             section.redownload(),
             section.on_conflict(),
         )

PFERD/crawlers/local.py

@@ -46,7 +46,7 @@ class LocalCrawler(Crawler):
     ):
         super().__init__(name, section, config)
 
-        self._target = config.working_dir / section.target()
+        self._target = config.default_section.working_dir() / section.target()
         self._crawl_delay = section.crawl_delay()
         self._download_delay = section.download_delay()
         self._download_speed = section.download_speed()

PFERD/logging.py

@@ -52,9 +52,9 @@ class Log:
         self._lines: List[str] = []
 
         # Whether different parts of the output are enabled or disabled
-        self._enabled_explain = False
-        self._enabled_action = True
-        self._enabled_report = True
+        self.output_explain = False
+        self.output_action = True
+        self.output_report = True
 
     def _update_live(self) -> None:
         elements = []
@@ -66,11 +66,6 @@ class Log:
         group = RenderGroup(*elements)  # type: ignore
         self._live.update(group)
 
-    def configure(self, explain: bool, action: bool, report: bool) -> None:
-        self._enabled_explain = explain
-        self._enabled_action = action
-        self._enabled_report = report
-
     @contextmanager
     def show_progress(self) -> Iterator[None]:
         if self._showing_progress:
@@ -107,19 +102,19 @@ class Log:
             self.console.print(text)
 
     def explain_topic(self, text: str) -> None:
-        if self._enabled_explain:
+        if self.output_explain:
             self.print(f"[cyan]{escape(text)}")
 
     def explain(self, text: str) -> None:
-        if self._enabled_explain:
+        if self.output_explain:
             self.print(f"  {escape(text)}")
 
     def action(self, text: str) -> None:
-        if self._enabled_action:
+        if self.output_action:
             self.print(text)
 
     def report(self, text: str) -> None:
-        if self._enabled_report:
+        if self.output_report:
             self.print(text)
 
     @contextmanager