Bulk Discounts

This project is an extension of the Little Esty Shop group project. You will add functionality for merchants to create bulk discounts for their items. A “bulk discount” is a discount based on the quantity of items the customer is buying, for example “20% off orders of 10 or more items”.

Learning Goals

• Write migrations to create tables and relationships between tables
• Implement CRUD functionality for a resource using forms (form_tag or form_with), buttons, and links
• Use MVC to organize code effectively, limiting the amount of logic included in views and controllers
• Use built-in ActiveRecord methods to join multiple tables of data, make calculations, and group data based on one or more attributes
• Write model tests that fully cover the data logic of the application
• Write feature tests that fully cover the functionality of the application

Setup

This project is an extension of Little Esty Shop. Students have two options for setup:

1. If your Little Esty Shop project is complete, you can use it as a starting point for this project. If you are not the repo owner, fork the project to your account. If you are the repo owner, you can work off the repo without forking, just make sure your teammates have a chance to fork before pushing any commits to your repo
2. If your Little Esty Shop project is not complete, fork this repo as a starting point for this project.

Rubric

Bulk Discounts

Bulk Discounts are subject to the following criteria:

• Bulk discounts should have a percentage discount as well as a quantity threshold
• Bulk discounts should belong to a Merchant
• A Bulk discount is eligible for all items that the merchant sells. Bulk discounts for one merchant should not affect items sold by another merchant
• Merchants can have multiple bulk discounts
  • If an item meets the quantity threshold for multiple bulk discounts, only the one with the greatest percentage discount should be applied
• Bulk discounts should apply on a per-item basis
  • If the quantity of an item ordered meets or exceeds the quantity threshold, then the percentage discount should apply to that item only. Other items that did not meet the quantity threshold will not be affected.
  • The quantities of items ordered cannot be added together to meet the quantity thresholds, e.g. a customer cannot order 1 of Item A and 1 of Item B to meet a quantity threshold of 2. They must order 2 or Item A and/or 2 of Item B

Examples

Example 1

• Merchant A has one Bulk Discount
  • Bulk Discount A is 20% off 10 items
• Invoice A includes two of Merchant A’s items
  • Item A is ordered in a quantity of 5
  • Item B is ordered in a quantity of 5

In this example, no bulk discounts should be applied.

Example 2

• Merchant A has one Bulk Discount
  • Bulk Discount A is 20% off 10 items
• Invoice A includes two of Merchant A’s items
  • Item A is ordered in a quantity of 10
  • Item B is ordered in a quantity of 5

In this example, Item A should be discounted at 20% off. Item B should not be discounted.

Example 3

• Merchant A has two Bulk Discounts
  • Bulk Discount A is 20% off 10 items
  • Bulk Discount B is 30% off 15 items
• Invoice A includes two of Merchant A’s items
  • Item A is ordered in a quantity of 12
  • Item B is ordered in a quantity of 15

In this example, Item A should discounted at 20% off, and Item B should discounted at 30% off.

Example 4

• Merchant A has two Bulk Discounts
  • Bulk Discount A is 20% off 10 items
  • Bulk Discount B is 15% off 15 items
• Invoice A includes two of Merchant A’s items
  • Item A is ordered in a quantity of 12
  • Item B is ordered in a quantity of 15

In this example, Both Item A and Item B should discounted at 20% off. Additionally, there is no scenario where Bulk Discount B can ever be applied.

Example 5

• Merchant A has two Bulk Discounts
  • Bulk Discount A is 20% off 10 items
  • Bulk Discount B is 30% off 15 items
• Merchant B has no Bulk Discounts
• Invoice A includes two of Merchant A’s items
  • Item A1 is ordered in a quantity of 12
  • Item A2 is ordered in a quantity of 15
• Invoice A also includes one of Merchant B’s items
  • Item B is ordered in a quantity of 15

In this example, Item A1 should discounted at 20% off, and Item A2 should discounted at 30% off. Item B should not be discounted.

User Stories

Merchant Bulk Discounts Index

As a merchant
When I visit my merchant dashboard
Then I see a link to view all my discounts
When I click this link
Then I am taken to my bulk discounts index page
Where I see all of my bulk discounts including their
percentage discount and quantity thresholds
And each bulk discount listed includes a link to its show page

As a merchant
When I visit the discounts index page
I see a section with a header of "Upcoming Holidays"
In this section the name and date of the next 3 upcoming US holidays are listed.

Use the Next Public Holidays Endpoint in the [Nager.Date API](https://date.nager.at/swagger/index.html)

Merchant Bulk Discount Create

As a merchant
When I visit my bulk discounts index
Then I see a link to create a new discount
When I click this link
Then I am taken to a new page where I see a form to add a new bulk discount
When I fill in the form with valid data
Then I am redirected back to the bulk discount index
And I see my new bulk discount listed

Merchant Bulk Discount Delete

As a merchant
When I visit my bulk discounts index
Then next to each bulk discount I see a link to delete it
When I click this link
Then I am redirected back to the bulk discounts index page
And I no longer see the discount listed

Merchant Bulk Discount Show

As a merchant
When I visit my bulk discount show page
Then I see the bulk discount's quantity threshold and percentage discount

Merchant Bulk Discount Edit

As a merchant
When I visit my bulk discount show page
Then I see a link to edit the bulk discount
When I click this link
Then I am taken to a new page with a form to edit the discount
And I see that the discounts current attributes are pre-poluated in the form
When I change any/all of the information and click submit
Then I am redirected to the bulk discount's show page
And I see that the discount's attributes have been updated

Merchant Invoice Show Page: Total Revenue includes discounts

As a merchant
When I visit my merchant invoice show page
Then I see that the total revenue for my merchant includes bulk discounts in the calculation

Merchant Invoice Show Page: Link to applied discounts

As a merchant
When I visit my merchant invoice show page
Next to each invoice item I see a link to the show page for the bulk discount that was applied (if any)

Admin Invoice Show Page: Total Revenue includes discounts

As an admin
When I visit an admin invoice show page
Then I see that the total revenue includes bulk discounts in the calculation

Extensions

• When an invoice is pending, a merchant should not be able to delete or edit a bulk discount that applies to any of their items on that invoice.
• When an Admin marks an invoice as “completed”, then the discount percentage should be stored on the invoice item record so that it can be referenced later
• Merchants should not be able to create/edit bulk discounts if they already have a discount in the system that would prevent the new discount from being applied (see example 4)
• Holiday Discount Extensions

Create a Holiday Discount

As a merchant,
when I visit the discounts index page,
In the Holiday Discounts section, I see a `create discount` button next to each of the 3 upcoming holidays.
When I click on the button I am taken to a new discount form that has the form fields auto populated with the following:

Discount name: <name of holiday> discount
Percentage Discount: 30
Quantity Threshold: 2

I can leave the information as is, or modify it before saving.
I should be redirected to the discounts index page where I see the newly created discount added to the list of discounts.

View a Holiday Discount

As a merchant (if I have created a holiday discount for a specific holiday),
when I visit the discount index page,
within the `Upcoming Holidays` section I should not see the button to 'create a discount' next to that holiday,
instead I should see a `view discount` link.
When I click the link I am taken to the discount show page for that holiday discount.