Merge pull request 'feature/parse-config-file' (#1) from feature/parse-config-file into master

Reviewed-on: #1

.gitignore

@@ -234,4 +234,5 @@ fabric.properties
 # ---> Custom
 .idea/deployment.xml
 .idea/misc.xml
-.idea/remote-mappings.xml
+.idea/remote-mappings.xml
+.idea/mvw-dl.iml

.idea/mvw-dl.iml

@@ -1,8 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<module type="PYTHON_MODULE" version="4">
-  <component name="NewModuleRootManager">
-    <content url="file://$MODULE_DIR$" />
-    <orderEntry type="inheritedJdk" />
-    <orderEntry type="sourceFolder" forTests="false" />
-  </component>
-</module>

config.ini

@@ -11,6 +11,11 @@ state_file_name_suffix = .log
 min_duration = 1200
 max_duration = 2700
 query = @maus-query.json
-query = {"queries":[{"fields":["topic"],"query":"die sendung mit der maus"},{"fields":["channel"],"query":"ARD"}],"sortBy":"timestamp","sortOrder":"desc","future":false,"offset":0,"size":50}
+# query = {"queries":[{"fields":["topic"],"query":"die sendung mit der maus"},{"fields":["channel"],"query":"ARD"}],"sortBy":"timestamp","sortOrder":"desc","future":false,"offset":0,"size":50}
 # state_file_name = maus
-# tmp_base_dir = %(tmp_base_dir)s/maus
+# tmp_base_dir = %(tmp_base_dir)s/maus
+
+[test]
+min_duration = 100
+max_duration = 200
+query = {"queries":[{"fields":["topic"],"query":"die sendung mit der maus"},{"fields":["channel"],"query":"ARD"}],"sortBy":"timestamp","sortOrder":"desc","future":false,"offset":0,"size":50}

main.py

@@ -1,3 +1,135 @@
+import configparser
+import logging
+import os
+import sys
+from rich.logging import RichHandler
+
+
+# Exit codes
+# 1: Config file invalid, it has no sections
+# 2: Config file invalid, sections must define at least CONST.CFG_MANDATORY
+
+
+class CONST(object):
+    __slots__ = ()
+    LOG_FORMAT = "%(message)s"
+    CFG_DEFAULT_FILENAME = "config.ini"
+    CFG_DEFAULT_ABS_PATH = os.path.join(os.getcwd(), CFG_DEFAULT_FILENAME)
+    CFG_MANDATORY = "query"
+
+
+CONST = CONST()
+logging.basicConfig(
+    level="NOTSET",
+    format=CONST.LOG_FORMAT,
+    datefmt="[%X]",
+    handlers=[RichHandler(
+        show_time=False if "SYSTEMD_EXEC_PID" in os.environ else True,
+        rich_tracebacks=True
+    )]
+)
+log = logging.getLogger("rich")
+log.setLevel(logging.DEBUG)
+
+
+class ConfigParser(configparser.ConfigParser):
+    """Can get options() without defaults
+
+    Taken from https://stackoverflow.com/a/12600066.
+    """
+
+    def options(self, section, no_defaults=False, **kwargs):
+        if no_defaults:
+            try:
+                return list(self._sections[section].keys())
+            except KeyError:
+                raise configparser.NoSectionError(section)
+        else:
+            return super().options(section)
+
+
+ini_defaults = []
+internal_defaults = {
+    "self_name": "mvw-dl",
+    "tmp_base_dir": "/tmp/%(self_name)s",
+    "state_base_dir": "/var/lib/%(self_name)s",
+    "state_files_dir": "%(state_base_dir)s/state",
+    "state_file_retention": "50",
+    "state_file_name_prefix": "state-",
+    "state_file_name_suffix": ".log"
+}
+config = ConfigParser(defaults=internal_defaults)
+config.read(CONST.CFG_DEFAULT_FILENAME)
+
+
+def print_section_header(header: str) -> str:
+    return f"Loading config section '[{header}]' ..."
+
+
+def validate_default_section(config_obj: configparser.ConfigParser()) -> None:
+    log.debug(f"Loading config from file '{CONST.CFG_DEFAULT_ABS_PATH}' ...")
+    if not config_obj.sections():
+        log.error(f"No config sections found in '{CONST.CFG_DEFAULT_ABS_PATH}'. Exiting 1 ...")
+        sys.exit(1)
+    if config.defaults():
+        log.debug(f"Symbol legend:\n"
+                  f"* Global default from section '[{config_obj.default_section}]'\n"
+                  f"~ Local option, doesn't exist in '[{config_obj.default_section}]'\n"
+                  f"+ Local override of a value from '[{config_obj.default_section}]'\n"
+                  f"= Local override, same value as in '[{config_obj.default_section}]'")
+        log.debug(print_section_header(config_obj.default_section))
+        for default in config_obj.defaults():
+            ini_defaults.append({default: config_obj[config_obj.default_section][default]})
+            log.debug(f"* {default} = {config_obj[config_obj.default_section][default]}")
+    else:
+        log.debug(f"No defaults defined")
+
+
+def config_has_valid_section(config_obj: configparser.ConfigParser()) -> bool:
+    has_valid_section = False
+    for config_obj_section in config_obj.sections():
+        if CONST.CFG_MANDATORY in config_obj.options(config_obj_section):
+            has_valid_section = True
+            break
+    return has_valid_section
+
+
+def is_default(config_key: str) -> bool:
+    return any(config_key in ini_default for ini_default in ini_defaults)
+
+
+def is_same_as_default(config_kv_pair: dict) -> bool:
+    return config_kv_pair in ini_defaults
+
+
+def validate_config_sections(config_obj: configparser.ConfigParser()) -> None:
+    for section in config_obj.sections():
+        log.debug(print_section_header(section))
+        if CONST.CFG_MANDATORY not in config_obj.options(section, no_defaults=True):
+            log.warning(f"Config section '[{section}]' does not have mandatory option '{CONST.CFG_MANDATORY}' set, "
+                        f"skipping section ...")
+            config_obj.remove_section(section)
+        else:
+            for key in config_obj.options(section, no_defaults=True):
+                kv_prefix = "~"
+                if is_default(key):
+                    kv_prefix = "+"
+                    if is_same_as_default({key: config_obj[section][key]}):
+                        kv_prefix = "="
+                log.debug(f"{kv_prefix} {key} = {config_obj[section][key]}")
+
+
+validate_default_section(config)
+if config_has_valid_section(config):
+    validate_config_sections(config)
+else:
+    log.error(f"No valid config section found. A valid config section has at least the '{CONST.CFG_MANDATORY}' "
+              f"option set. Exiting 2 ...")
+    sys.exit(2)
+
+quit()
+
+
 # This is a sample Python script.
 
 # Press Umschalt+F10 to execute it or replace it with your code.

requirements.in

@@ -0,0 +1 @@
+rich

requirements.txt

@@ -0,0 +1,12 @@
+#
+# This file is autogenerated by pip-compile with python 3.10
+# To update, run:
+#
+#    pip-compile
+#
+commonmark==0.9.1
+    # via rich
+pygments==2.11.2
+    # via rich
+rich==12.0.0
+    # via -r requirements.in