Week3 Shop Manager Challenge

README.md

@@ -1,3 +1,10 @@
+Note:
+-------
+I did not get to TDD this project as I wished for due to lack of time, it just seemed more important to me at this time to imagine and put in practice a whole shop_manager with the relevant classes, methods and DB access. I will definetly do a lot more on the testing next time. What a lovely jouney it has been to see it work in the end so close to what a real app would do.
+
+
+
+
 Shop Manager Project
 =================
 

lib/item.rb

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+class Item 
+  def initialize(name, unit_price, quantity, item_id = 0)
+   @name = name
+   @unit_price = unit_price
+   @quantity = quantity
+   @item_id = item_id
+  end
+
+  def name
+    @name
+  end
+
+  def unit_price
+    @unit_price
+  end
+
+  def quantity
+    @quantity
+  end
+
+  def item_id
+    @item_id
+  end
+end

lib/order.rb

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+class Order
+  def initialize(customer_name, item, order_id = 0)
+    @customer_name = customer_name
+    @item = item
+    @order_id = order_id
+  end
+
+  def customer_name
+    @customer_name
+  end
+
+  def item
+    @item
+  end
+
+  def order_id
+   @order_id
+  end
+end

lib/shop_manager.rb

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+require_relative './item'
+require_relative './order'
+require 'pg'
+
+class ShopManager
+  WHAT_TO_DO = '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'
+
+  def initialize
+    db_connect
+    initiate_menu
+  end
+
+  def initiate_menu(initial = true)
+    puts "
+    Welcome to the shop management program!
+    " if initial == true
+    puts "
+    #{WHAT_TO_DO}
+    "
+    answer = gets.chomp
+    case answer
+    when '1'
+      print_all_items(all_items)
+    when '2'
+      new_item_collect_data
+    when '3'
+      all_orders
+    when '4'
+      new_order_collect_data
+    else
+      initiate_menu(false)
+    end
+  end
+
+  def new_item_collect_data
+    while true do
+      puts 'Enter the name for the new Item'
+      name = gets.chomp
+      break if name.count("a-zA-Z") > 0
+    end
+    while true do
+      puts "Enter the price for the #{name}"
+      unit_price = gets.chomp
+      break if unit_price.to_i.is_a? Integer
+    end
+    while true do
+      puts "Enter the quantity for the #{name}"
+      quantity = gets.chomp
+      break if quantity.to_i.is_a? Integer
+    end
+    item = Item.new(name, unit_price, quantity)
+    new_item(item)
+  end
+
+  def new_item(item)
+    # add item to items table
+    query = "INSERT INTO items(name, unit_price, quantity) 
+    VALUES('#{item.name}', #{item.unit_price.to_i}, #{item.quantity.to_i});"
+    result = @conn_db.exec(query)
+    puts "Your item has been added succesfully"
+  end
+
+  def db_connect()
+    @conn_db = PG.connect({ host: '127.0.0.1', dbname: 'shop_manager' })
+  end
+
+  def new_order_collect_data
+    while true do
+      puts 'New Order, please enter your name'
+      customer_name = gets.chomp
+      break if customer_name.count("a-zA-Z") > 4 && customer_name.split(' ').count >= 2
+    end
+    items = all_items
+    while true do
+      puts "Please select you item's id"
+      item_id = gets.chomp
+      if item_id.to_i.is_a? Integer
+        return_item = items.find { |curr_item| curr_item.item_id == item_id }
+        if !return_item.nil?
+          item = Item.new(return_item.name, return_item.unit_price, return_item.quantity, return_item.item_id)
+          order = Order.new(customer_name, item)
+          new_order(order)
+        end
+      end
+      break unless return_item.nil?
+    end
+  end
+
+  def new_order(order)
+    # add order to orders table
+    query = "INSERT INTO orders(customer_name, item_id) 
+    VALUES('#{order.customer_name}', '#{order.item.item_id}') RETURNING *;"
+    @conn_db.exec(query)
+    puts "Your order has been placed succesfully, thank you!"
+  end
+
+  private
+  def get_select_query(table)
+    "SELECT * FROM #{table};"
+  end
+
+  def all_items
+    query = get_select_query('items')
+    items = @conn_db.exec(query)
+    items = items.map do |item|
+      Item.new(item['name'], item['unit_price'], item['quantity'], item['item_id'])
+    end
+
+    items
+  end
+
+  def orders_all
+    query = get_select_query('orders')
+    @conn_db.exec(query)
+  end
+
+  def all_orders
+    items = all_items
+    orders = orders_all
+    orders = orders.map do |order|
+      item = items.find { |curr_item| curr_item.item_id == order['item_id'] }
+      Order.new(order["customer_name"], item, order["order_id"])
+    end
+    print_all_orders(orders)
+  end
+
+  def print_all_items(items)
+    puts "Here's a list of all shop items:"
+    #1 Super Shark Vacuum Cleaner - Unit price: 99 - Quantity: 30
+    items.each do |item|
+      puts "Item id: #{item.item_id} - #{item.name} - Unit price: £#{item.unit_price}.00 - Quantity: #{item.quantity}"
+    end
+  end
+
+  def print_all_orders(orders)
+    puts "Here's a list of all shop orders:"
+    #1 Super Shark Vacuum Cleaner - Unit price: 99 - Quantity: 30
+    orders.each do |order|
+      puts "Order id: #{order.order_id} - #{order.customer_name} - Item: #{order.item.name} - Price: £#{order.item.unit_price}.00"
+    end
+  end
+end
+
+ShopManager.new
+

recipe.md

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+# Two Tables (Many-to-Many) Design Recipe Template
+
+_Copy this recipe template to design and create two related database tables having a Many-to-Many relationship._
+
+## 1. Extract nouns from the user stories or specification
+
+```ruby
+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.
+
+As a shop manager
+So I can know which orders were made
+I want to assign each order to their corresponding item.
+
+As a shop manager
+So I can know which orders were made
+I want to know on which date an order was placed. 
+
+As a shop manager
+So I can manage orders
+I want to be able to create a new order.
+
+```
+Nouns:
+
+items, item_name, unit_price
+```
+
+## 2. Infer the Table Name and Columns
+
+Put the different nouns in this table. Replace the example with your own nouns.
+
+| Record                | Properties          |
+| --------------------- | ------------------  |
+| posts                 | title, content
+| tags                  | name
+
+1. Name of the first table (always plural): `posts` 
+
+    Column names: `title`, `content`
+
+2. Name of the second table (always plural): `tags` 
+
+    Column names: `name`
+
+## 3. Decide the column types.
+
+[Here's a full documentation of PostgreSQL data types](https://www.postgresql.org/docs/current/datatype.html).
+
+Most of the time, you'll need either `text`, `int`, `bigint`, `numeric`, or `boolean`. If you're in doubt, do some research or ask your peers.
+
+Remember to **always** have the primary key `id` as a first column. Its type will always be `SERIAL`.
+
+```
+# EXAMPLE:
+
+Table: posts
+id: SERIAL
+title: text
+content: text
+
+Table: tags
+id: SERIAL
+name: text
+```
+
+## 4. Design the Many-to-Many relationship
+
+Make sure you can answer YES to these two questions:
+
+1. Can one [TABLE ONE] have many [TABLE TWO]? (Yes/No)
+2. Can one [TABLE TWO] have many [TABLE ONE]? (Yes/No)
+
+```
+# EXAMPLE
+
+1. Can one tag have many posts? YES
+2. Can one post have many tags? YES
+```
+
+_If you would answer "No" to one of these questions, you'll probably have to implement a One-to-Many relationship, which is simpler. Use the relevant design recipe in that case._
+
+## 5. Design the Join Table
+
+The join table usually contains two columns, which are two foreign keys, each one linking to a record in the two other tables.
+
+The naming convention is `table1_table2`.
+
+```
+# EXAMPLE
+
+Join table for tables: posts and tags
+Join table name: posts_tags
+Columns: post_id, tag_id
+```
+
+## 4. Write the SQL.
+
+```sql
+-- EXAMPLE
+-- file: posts_tags.sql
+
+-- Replace the table name, columm names and types.
+
+-- Create the first table.
+CREATE TABLE items (
+  item_id SERIAL PRIMARY KEY,
+  name text,
+  unit_price int,
+  quantity int
+);
+
+-- Create the second table.
+CREATE TABLE orders (
+  order_id SERIAL PRIMARY KEY,
+  custumer_name text,
+  date TIMESTAMP not null defaul now(),
+  item_id int
+);
+
+-- Create the join table.
+CREATE TABLE items_orders (
+  item_id int,
+  order_id int,
+  constraint fk_item foreign key(item_id) references items(id) on delete cascade,
+  constraint fk_order foreign key(order_id) references orders(id) on delete cascade,
+  PRIMARY KEY (item_id, order_id)
+);
+
+```
+
+## 5. Create the tables.
+
+```bash
+psql -h 127.0.0.1 database_name < posts_tags.sql
+```