From e95c1c3e95f9f093457806921ddb065cba5cae6a Mon Sep 17 00:00:00 2001
From: Peter Tim Soriano <chops10@my.yorku.ca>
Date: Wed, 21 Apr 2021 01:00:26 -0400
Subject: [PATCH] behavioral pattern (state)

---
 scraping/webscraper.py               |  26 ++-----
 scraping/webscraper_state_pattern.py | 107 +++++++++++++++++++++++++++
 2 files changed, 114 insertions(+), 19 deletions(-)
 create mode 100644 scraping/webscraper_state_pattern.py

diff --git a/scraping/webscraper.py b/scraping/webscraper.py
index 556b1c01..fd9ef906 100644
--- a/scraping/webscraper.py
+++ b/scraping/webscraper.py
@@ -30,6 +30,7 @@
 import json
 import os.path
 import logging
+from webscraper_state import Context, ConcreteSaveState, ConcreteConnectState
 
 
 mydb = None
@@ -74,28 +75,14 @@ def localtime_to_ust(datetime):
 
 def connect():
     global mydb
-
-    # populate this from env file
-    path_to_json = "./db.json"
-
-    with open(path_to_json, "r") as handler:
-        info = json.load(handler)
-        print(info)
-
-        mydb = mysql.connector.connect(
-            host=info["host"],
-            user=info["user"],
-            passwd=info["passwd"],
-            database=info["database"],
-        )
-
-    print(mydb)
+    
+    context = Context(ConcreteConnectState())
+    context.request_connect()
 
 
 def save_to_db():
-    connect()
-    for newsObject in newsObject_stack:
-        insert(newsObject)
+    context = Context(ConcreteSaveState())
+    context.request_connect()
 
 
 def insert(data_dict):
@@ -143,6 +130,7 @@ def insert(data_dict):
 
 
 key = ["新型コロナウイルス", "新型肺炎", "新型ウィルス", "武漢肺炎", "新型冠狀病毒"]
+global newsObject_stack
 newsObject_stack = []
 
 NEWS_URLs = {
diff --git a/scraping/webscraper_state_pattern.py b/scraping/webscraper_state_pattern.py
new file mode 100644
index 00000000..9a35849e
--- /dev/null
+++ b/scraping/webscraper_state_pattern.py
@@ -0,0 +1,107 @@
+from __future__ import annotations
+from abc import ABC, abstractmethod
+import json
+import mysql.connector
+from webscraper import insert
+
+
+class Context:
+    """
+    The Context defines the interface of interest to clients. It also maintains
+    a reference to an instance of a State subclass, which represents the current
+    state of the Context.
+    """
+
+    _state = None
+    """
+    A reference to the current state of the Context.
+    """
+
+    def __init__(self, state: State) -> None:
+        self.transition_to(state)
+
+    def transition_to(self, state: State):
+        """
+        The Context allows changing the State object at runtime.
+        """
+
+        print(f"Context: Transition to {type(state).__name__}")
+        self._state = state
+        self._state.context = self
+
+    """
+    The Context delegates part of its behavior to the current State object.
+    """
+
+    def request_connect(self):
+        self._state.connectDB()
+
+    def request_save_to_db(self):
+        self._state.saveDB()
+
+
+class State(ABC):
+    """
+    The base State class declares methods that all Concrete State should
+    implement and also provides a backreference to the Context object,
+    associated with the State. This backreference can be used by States to
+    transition the Context to another State.
+    """
+
+    @property
+    def context(self) -> Context:
+        return self._context
+
+    @context.setter
+    def context(self, context: Context) -> None:
+        self._context = context
+
+    @abstractmethod
+    def connectDB(self) -> None:
+        pass
+
+    @abstractmethod
+    def saveDB(self) -> None:
+        pass
+
+
+"""
+Concrete States implement various behaviors, associated with a state of the
+Context.
+"""
+
+
+class ConcreteConnectState(State):
+    def connectDB(self) -> None:
+        path_to_json = "./db.json"
+
+        with open(path_to_json, "r") as handler:
+            info = json.load(handler)
+            print(info)
+
+        mydb = mysql.connector.connect(
+            host=info["host"],
+            user=info["user"],
+            passwd=info["passwd"],
+            database=info["database"],
+        )
+
+        print(mydb)
+        print("ConcreteStateA handles request1.")
+        print("ConcreteStateA wants to change the state of the context.")
+        self.context.transition_to(ConcreteSaveState())
+
+    def saveDB(self) -> None:
+        print("ConcreteStateA handles request2.")
+
+
+class ConcreteSaveState(State):
+    def connectDB(self) -> None:
+        print("ConcreteStateB handles request1.")
+
+    def saveDB(self, newsObject_stack) -> None:
+        for newsObject in newsObject_stack:
+            insert(newsObject)
+        print("ConcreteStateB handles request2.")
+        print("ConcreteStateB wants to change the state of the context.")
+        self.context.transition_to(ConcreteConnectState())
\ No newline at end of file