shop-manager-challenge pr

README.md

@@ -1,94 +1,32 @@
 Shop Manager Project
 =================
 
-* Feel free to use Google, your notes, books, etc. but work on your own
-* If you refer to the solution of another coach or student, please put a link to that in your README
-* If you have a partial solution, **still check in a partial solution**
-* You must submit a pull request to this repo with your code next Monday morning
+Welcome to the Shop Manager!
 
-Challenge:
--------
-
-Please start by [forking this repo](https://github.com/makersacademy/shop-manager-challenge/fork), then clone your fork to your local machine. Work into that directory.
-
-We are going to write a small terminal program allowing the user to manage a shop database containing some items and orders.
-
-User stories:
--------
+You can run the program using:
 
 ```
-As a shop manager
-So I can know which items I have in stock
-I want to keep a list of my shop items with their name and unit price.
-
-As a shop manager
-So I can know which items I have in stock
-I want to know which quantity (a number) I have for each item.
-
-As a shop manager
-So I can manage items
-I want to be able to create a new item.
-
-As a shop manager
-So I can know which orders were made
-I want to keep a list of orders with their customer name.
+ruby app.rb
+```
 
-As a shop manager
-So I can know which orders were made
-I want to assign each order to their corresponding item.
+The program will continuously ask for actions to perform on the database until you select option 7 to exit the program
 
-As a shop manager
-So I can know which orders were made
-I want to know on which date an order was placed. 
+### Database
 
-As a shop manager
-So I can manage orders
-I want to be able to create a new order.
+You will need to have a database running locally named 'items_orders'.
+This can be achieved by running the following in the terminal
 ```
-
-Here's an example of the terminal output your program should generate (yours might be slightly different — that's totally OK):
-
+createdb items_orders
 ```
-Welcome to the shop management program!
-
-What do you want to do?
-  1 = list all shop items
-  2 = create a new item
-  3 = list all orders
-  4 = create a new order
-
-1 [enter]
-
-Here's a list of all shop items:
-
- #1 Super Shark Vacuum Cleaner - Unit price: 99 - Quantity: 30
- #2 Makerspresso Coffee Machine - Unit price: 69 - Quantity: 15
- (...)
+To initialise the tables run the following:
 ```
-
-Technical Approach:
------
-
-In this unit, you integrated a database by using the `PG` gem, and test-driving and building Repository classes. You can continue to use this approach when building this challenge.
-
-[You'll also need to mock IO](https://github.com/makersacademy/golden-square/blob/main/mocking_bites/05_unit_testing_terminal_io_bite.md) in your integration or unit tests, since the program will ask for user input.
-
-Notes on test coverage
-----------------------
-
-Please ensure you have the following **AT THE TOP** of your spec_helper.rb in order to have test coverage stats generated
-on your pull request:
-
-```ruby
-require 'simplecov'
-require 'simplecov-console'
-
-SimpleCov.formatter = SimpleCov::Formatter::MultiFormatter.new([
-  SimpleCov::Formatter::Console,
-  # Want a nice code coverage website? Uncomment this next line!
-  # SimpleCov::Formatter::HTMLFormatter
-])
-SimpleCov.start
+psql -h 127.0.0.1 items_orders < spec/seeds_create.sql
+```
+If you want to import some existing data into this table you can use the provided seed by entering the following into the terminal:
+```
+psql -h 127.0.0.1 items_orders < spec/seeds.sql
 ```
+>hint: this will also refresh the table with the starter data if you wish to restart after adding data!
+### WARNING
 
-You can see your test coverage when you run your tests. If you want this in a graphical form, uncomment the `HTMLFormatter` line and see what happens!
+Incorrect data entry wasn't in the scope of the program and can cause errors - **DOUBLE CHECK YOUR DATA ENTRY**

app.rb

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+Dir["./lib/*.rb"].each {|file| require file}
+
+app = Application.new(
+  'items_orders',
+  Kernel,
+  ItemRepository.new,
+  OrderRepository.new
+)
+app.run

lib/application.rb

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+class Application
+
+  # The Application class initializer
+  # takes four arguments:
+  #  * The database name to call `DatabaseConnection.connect`
+  #  * the Kernel object as `io` (so we can mock the IO in our tests)
+  #  * the ItemRepository object (or a double of it)
+  #  * the OrderRepository object (or a double of it)
+  def initialize(database_name, io, item_repository, order_repository)
+    DatabaseConnection.connect(database_name)
+    @io = io
+    @item_repository = item_repository
+    @order_repository = order_repository
+  end
+
+  # "Runs" the terminal application
+  def run
+    loop do
+      print_menu
+      selection = @io.gets.chomp
+      do_selection(selection)
+    end
+  end
+
+  # Takes the user's selection and perfoms the appropriate action
+  def do_selection(selection)
+    case selection
+    when "1"
+      print_items
+    when "2"
+      print_items_by_order
+    when "3"
+      create_item
+    when "4"
+      print_orders
+    when "5"
+      print_orders_by_item
+    when "6"
+      create_order
+    when "7"
+      @io.exit
+    end
+  end
+
+  # Prints the menu
+  def print_menu
+    @io.puts "Welcome to the shop!"
+    @io.puts "What would you like to do?"
+    @io.puts "1 - List all items"
+    @io.puts "2 - List all items attached to an order"
+    @io.puts "3 - Create a new item"
+    @io.puts "4 - List all orders"
+    @io.puts "5 - List all orders that contain a specific item"
+    @io.puts "6 - Create a new order"
+    @io.puts "7 - Exit"
+  end
+
+  # Prints all the items
+  def print_items
+    @io.puts "All items:"
+    @item_repository.all.each do |item|
+      print_item(item)
+    end
+  end
+
+  # Prints all the items attached to an order
+  def print_items_by_order
+    @io.puts "What order do you want to see the items for?"
+    order_id = @io.gets.chomp.to_i
+    @item_repository.find_by_order(order_id).each do |item|
+      print_item(item)
+    end
+  end
+
+  # Creates an item
+  def create_item
+    item = Item.new
+
+    @io.print "Name: "
+    item.name = @io.gets.chomp
+
+    @io.print "Price: "
+    item.unit_price = @io.gets.chomp.to_f
+
+    @io.print "Quantity: "
+    item.quantity = @io.gets.chomp.to_i
+
+    @item_repository.create(item)
+    @io.puts("Item created!")
+  end
+
+  # Prints all the orders
+  def print_orders
+    @io.puts "All orders:"
+    @order_repository.all.each do |order|
+      print_order(order)
+    end
+  end
+
+  # Prints all orders that have an item
+  def print_orders_by_item
+    @io.puts "What item do you want to see the orders for?"
+    item_id = @io.gets.chomp.to_i
+
+    @order_repository.find_by_item(item_id).each do |order|
+      print_order(order)
+    end
+  end
+
+  # Creates a new item
+  def create_order
+    order = Order.new
+
+    @io.print "Name: "
+    order.customer_name = @io.gets.chomp
+
+    @io.print "Date: "
+    order.date = @io.gets.chomp
+
+    @order_repository.create(order)
+    @io.puts "Order created!"
+  end
+
+  # Prints a single item
+  def print_item(item)
+    @io.puts "#{item.name} - Price: £#{sprintf('%.2f',item.unit_price)} - Quantity: #{item.quantity}"
+  end
+
+  # Prints a single order
+  def print_order(order)
+    @io.puts "#{order.customer_name} - #{order.date}"
+  end
+end

lib/database_connection.rb

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+require 'pg'
+
+# This class is a thin "wrapper" around the
+# PG library. We'll use it in our project to interact
+# with the database using SQL.
+
+class DatabaseConnection
+  # This method connects to PostgreSQL using the 
+  # PG gem. We connect to 127.0.0.1, and select
+  # the database name given in argument.
+  def self.connect(database_name)
+    @connection = PG.connect({ host: '127.0.0.1', dbname: database_name })
+  end
+
+  # This method executes an SQL query 
+  # on the database, providing some optional parameters
+  # (you will learn a bit later about when to provide these parameters).
+  def self.exec_params(query, params)
+    if @connection.nil?
+      raise 'DatabaseConnection.exec_params: Cannot run a SQL query as the connection to'\
+      'the database was never opened. Did you make sure to call first the method '\
+      '`DatabaseConnection.connect` in your app.rb file (or in your tests spec_helper.rb)?'
+    end
+    @connection.exec_params(query, params)
+  end
+end

lib/item.rb

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+class Item
+  attr_accessor :id, :name, :unit_price, :quantity
+end

lib/item_repository.rb

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+class ItemRepository
+
+  # Selecting all records
+  def all
+    # Executes the SQL query:
+    sql = "SELECT * FROM items;"
+
+    result_set = DatabaseConnection.exec_params(sql, [])
+
+    return result_set_to_items(result_set)
+  end
+
+  # Adding an item to the table
+  # item: Item - item to add to table
+  def create(item)
+    # Executes the SQL query:
+    sql = 'INSERT INTO items (name, unit_price, quantity) VALUES ($1,$2,$3)'
+    sql_params = [item.name,item.unit_price,item.quantity]
+
+    DatabaseConnection.exec_params(sql, sql_params)
+
+    return nil
+  end
+
+  # Find all the items attached to an order
+  # order_id: int - the id of the order to filter by
+  def find_by_order(order_id)
+    sql =  
+      'SELECT 
+	      items.id,
+	      items.name,
+	      items.unit_price,
+	      items.quantity
+	    FROM items
+	    JOIN items_orders
+	      ON items.id = items_orders.item_id
+	    JOIN orders
+	      ON items_orders.order_id = orders.id
+	    WHERE order_id = $1;'
+
+    sql_params = [order_id]
+    result_set = DatabaseConnection.exec_params(sql, sql_params)
+
+    # Returns an array of item objects. 
+    return result_set_to_items(result_set)
+  end
+
+  # Converts an SQL result set into a list of items
+  # result_set: tuple - whats returned when querying a table
+  def result_set_to_items(result_set)
+    items = []
+
+    result_set.each do |record|
+      item = Item.new
+      item.id = record['id'].to_i
+      item.name = record['name']
+      item.unit_price = record['unit_price'].to_f
+      item.quantity = record['quantity'].to_i
+
+      items << item
+    end
+
+    return items
+  end
+end

lib/order.rb

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+class Order
+  attr_accessor :id, :customer_name, :date
+end