BETTERZON-57: Adding utility sql functions

.gitignore

@@ -27,6 +27,7 @@ speed-measure-plugin*.json
 !Backend.iml
 !CucumberTests.iml
 !Crawler.iml
+!Crawler-Loadbalancer.iml
 
 # Include IntelliJ modules
 !/.idea/modules.xml

.idea/modules.xml

@@ -5,6 +5,7 @@
       <module fileurl="file://$PROJECT_DIR$/Backend/Backend.iml" filepath="$PROJECT_DIR$/Backend/Backend.iml" />
       <module fileurl="file://$PROJECT_DIR$/Betterzon.iml" filepath="$PROJECT_DIR$/Betterzon.iml" />
       <module fileurl="file://$PROJECT_DIR$/Crawler/Crawler.iml" filepath="$PROJECT_DIR$/Crawler/Crawler.iml" />
+      <module fileurl="file://$PROJECT_DIR$/Crawler-Loadbalancer/Crawler-Loadbalancer.iml" filepath="$PROJECT_DIR$/Crawler-Loadbalancer/Crawler-Loadbalancer.iml" />
       <module fileurl="file://$PROJECT_DIR$/CucumberTests/CucumberTests.iml" filepath="$PROJECT_DIR$/CucumberTests/CucumberTests.iml" />
       <module fileurl="file://$PROJECT_DIR$/Frontend/Frontend.iml" filepath="$PROJECT_DIR$/Frontend/Frontend.iml" />
     </modules>

Crawler-Loadbalancer/Crawler-Loadbalancer.iml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="PYTHON_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$" />
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

Crawler-Loadbalancer/requirements.txt

@@ -0,0 +1,2 @@
+pymysql
+logging

Crawler-Loadbalancer/sql.py

@@ -0,0 +1,42 @@
+import pymysql
+import os
+import logging
+
+
+def __getConnection__() -> pymysql.Connection:
+    """
+    Opens a new pymysql connection and returns it
+    :return: A pymysql Connection object
+    """
+    logger = logging.getLogger()
+    try:
+        conn = pymysql.connect(
+            user=os.environ['BETTERZON_CRAWLER_USER'],
+            password=os.environ['BETTERZON_CRAWLER_PASSWORD'],
+            host=os.environ['BETTERZON_CRAWLER_HOST'],
+            port=3306,
+            database=os.environ['BETTERZON_CRAWLER_DB']
+        )
+
+        return conn
+    except pymysql.Error as e:
+        logger.error('SQL Connection error: %s', e)
+        return
+
+
+def getShopsToCrawl() -> [int]:
+    """
+    Queries the list of vendor IDs and returns them
+    :return: The list of IDs
+    """
+    conn = __getConnection__()
+    cur = conn.cursor()
+
+    query = 'SELECT vendor_id FROM vendors'
+
+    cur.execute(query)
+
+    # Extract the IDs from the returned tuples into a list
+    vendor_ids = list(map(lambda x: x[0], cur.fetchall()))
+
+    return vendor_ids

Crawler/Crawler.iml

@@ -2,13 +2,13 @@
 <module type="WEB_MODULE" version="4">
   <component name="FacetManager">
     <facet type="Python" name="Python">
-      <configuration sdkName="Python 3.9 (venv)" />
+      <configuration sdkName="Python 3.9" />
     </facet>
   </component>
   <component name="NewModuleRootManager" inherit-compiler-output="true">
     <exclude-output />
     <content url="file://$MODULE_DIR$" />
     <orderEntry type="sourceFolder" forTests="false" />
-    <orderEntry type="library" name="Python 3.9 (venv) interpreter library" level="application" />
+    <orderEntry type="library" name="Python 3.9 interpreter library" level="application" />
   </component>
 </module>

Crawler/requirements.txt

@@ -1,4 +1,5 @@
 pymysql
 flask
 flask-sqlalchemy
-flask_restful
+flask_restful
+logging

Crawler/sql.py

@@ -0,0 +1,70 @@
+import logging
+
+import pymysql
+import os
+
+
+def __getConnection__() -> pymysql.Connection:
+    """
+    Opens a new pymysql connection and returns it
+    :return: A pymysql Connection object
+    """
+    logger = logging.getLogger()
+    try:
+        conn = pymysql.connect(
+            user=os.environ['BETTERZON_CRAWLER_USER'],
+            password=os.environ['BETTERZON_CRAWLER_PASSWORD'],
+            host=os.environ['BETTERZON_CRAWLER_HOST'],
+            port=3306,
+            database=os.environ['BETTERZON_CRAWLER_DB']
+        )
+
+        return conn
+    except pymysql.Error as e:
+        logger.error('SQL Connection error: %s', e)
+        return
+
+
+def getProductsForShop(vendor_id: int) -> [{}]:
+    """
+    Queries the product links for all products of the given shop
+    :param vendor_id: The vendor / shop to query products for
+    :return: A list of product objects, each having the following parameters:
+                product_id, vendor_id, url
+    """
+    conn = __getConnection__()
+    cur = conn.cursor()
+
+    query = 'SELECT product_id, url FROM product_links WHERE vendor_id = %s'
+
+    cur.execute(query, (vendor_id,))
+
+    products = list(map(lambda x: {'product_id': x[0], 'vendor_id': vendor_id, 'url': x[1]}, cur.fetchall()))
+
+    return products
+
+
+def insertShopData(data_to_insert: [tuple]) -> bool:
+    """
+    Inserts the given list of tuples into the DB
+    :param dataToInsert: A list of tuples, where each tuple has to contain product id, vendor id and the price
+                         in exactly this order
+    :return: If the insert was successful
+    """
+    conn = __getConnection__()
+    cur = conn.cursor()
+
+    query = 'INSERT INTO prices (product_id, vendor_id, price_in_cents, timestamp) VALUES (%s, %s, %s, NOW())'
+
+    affectedRows = cur.executemany(query, data_to_insert)
+
+    if affectedRows != len(data_to_insert):
+        # Something went wrong, revert the changes
+        conn.rollback()
+    else:
+        conn.commit()
+
+    cur.close()
+    conn.close()
+
+    return affectedRows == len(data_to_insert)