From fdac477d09b1a8bcfb12b9de6500746ecfe7bf40 Mon Sep 17 00:00:00 2001
From: Jan Losinski <losinski@wh2.tu-dresden.de>
Date: Tue, 5 Feb 2019 21:16:48 +0100
Subject: [PATCH] Change config to use dataclasses

This means that we depend on python 3.7 now. But it gives an easier
possibility to distinguish between required and optional parameters. It
also allows to pecify the type of the option drectly and access it via
the dataclasses fields.

This might fix #2
---
 wallabag_kindle_consumer/config.py | 63 +++++++++++++-----------------
 1 file changed, 28 insertions(+), 35 deletions(-)

diff --git a/wallabag_kindle_consumer/config.py b/wallabag_kindle_consumer/config.py
index a2087ce..542a6be 100644
--- a/wallabag_kindle_consumer/config.py
+++ b/wallabag_kindle_consumer/config.py
@@ -1,36 +1,29 @@
-import os
+import dataclasses
 import configparser
+import os
 
 from logbook import Logger
 
 logger = Logger(__name__)
 
 
+@dataclasses.dataclass
 class Config:
-    known_values = ["wallabag_host", "db_uri", "client_id", "client_secret", "domain", "smtp_from", "smtp_host",
-                    "smtp_port", "smtp_user", "smtp_passwd", "tag", "refresh_grace", "consume_interval",
-                    "interface_host", "interface_port"]
-    required_values = ["wallabag_host", "db_uri", "client_id", "client_secret", "domain", "smtp_from", "smtp_host",
-                       "smtp_port", "smtp_user", "smtp_passwd"]
-
-    def __init__(self, wallabag_host, db_uri, client_id, client_secret, domain, smtp_from, smtp_host, smtp_port,
-                 smtp_user, smtp_passwd, tag='kindle', refresh_grace=120, consume_interval=30,
-                 interface_host="127.0.0.1", interface_port=8080):
-        self.wallabag_host = wallabag_host
-        self.db_uri = db_uri
-        self.client_id = client_id
-        self.client_secret = client_secret
-        self.domain = domain
-        self.smtp_from = smtp_from
-        self.smtp_host = smtp_host
-        self.smtp_port = smtp_port
-        self.smtp_user = smtp_user
-        self.smtp_passwd = smtp_passwd
-        self.tag = tag
-        self.refresh_grace = refresh_grace
-        self.consume_interval = consume_interval
-        self.interface_host = interface_host
-        self.interface_port = interface_port
+    wallabag_host: str
+    db_uri: str
+    client_id: str
+    client_secret: str
+    domain: str
+    smtp_from: str
+    smtp_host: str
+    smtp_port: int
+    smtp_user: str
+    smtp_passwd: str
+    tag: str = "kindle"
+    refresh_grace: int = 120
+    consume_interval: int = 30
+    interface_host: str = "127.0.0.1"
+    interface_port: int = 8080
 
     @staticmethod
     def from_file(filename):
@@ -51,12 +44,12 @@ class Config:
 
         tmp = {}
         missing = []
-        for key in Config.known_values:
-            if key in dflt:
-                tmp[key] = dflt[key]
+        for field in dataclasses.fields(Config):
+            if field.name in dflt:
+                tmp[field.name] = field.type(dflt[field.name])
             else:
-                if key in Config.required_values:
-                    missing.append(key)
+                if field.default is dataclasses.MISSING:
+                    missing.append(field.name)
 
         if 0 != len(missing):
             logger.warn("Config file {filename} does not contain configs for: {lst}", filename=filename,
@@ -70,12 +63,12 @@ class Config:
         logger.info("Read config from environment")
         tmp = {}
         missing = []
-        for key in Config.known_values:
-            if key.upper() in os.environ:
-                tmp[key] = os.environ[key.upper()]
+        for field in dataclasses.fields(Config):
+            if field.name.upper() in os.environ:
+                tmp[field.name] = field.type(os.environ[field.name.upper()])
             else:
-                if key in Config.required_values:
-                    missing.append(key.upper())
+                if field.default is dataclasses.MISSING:
+                    missing.append(field.name.upper())
 
         if 0 != len(missing):
             logger.warn("Environment config does not contain configs for: {lst}", lst=", ".join(missing))