Use Cases
Guest Checkout
Unique email id and contact no? sorted
Email id and contact no already used by same customer? sorted
Email id used but not contact no - not allowed, change contact no after email authentication? Figure out UX.
Contact no used but not email - Not allowed. Use different phone number, or login into previous account with phone number and change email id.
Email id and contact no already used by 2 separate customers - Same as c.
Address selection for guest checkout. TBD with UX, Algo and manual.
Logged in Checkout
Unique contact no - sorted
Contact no already used by another customer - 1.d
Unified cart across platforms?
Unified cart across devices? Yes.
Unified cart across cities? TBD with UX
Merge carts after login? TBD with UX
Order Source?

Schema Changes for Web
to be deleted(move to panem)
Users - Remove from web
Delivery_addresses - Remove from web
Referral_codes - Remove from web
Bookings and associations - remove from web
Wishlist
Devices
 to be modified
Customers - keep temporarily until kyc migration
Payments - add panem user_id, remove all other user credentials
Carts - add panem user_id and delivery_address_id, will be empty for guest checkouts until panem user created.
Orders - add panem user_id



Ghost User Workflow on Web/Mobile
On first visit, ask user for city and create a ghost user.
POST /ghost_users
Request
:city_id
:medium
:device_params
:device_id
:device_name
device_os
:device_os_version
:device_app_version
:track_params
:source
:campaign
:medium
Response - This would return the ghost_identifier
Save ghost user identifier in cookie/local storage.
Cookie Name - furlenco_ghost_identifier
Header Name - X-Ghost-Identifier
All subsequent calls will include this ghost user identifier.
When user logins, Panem Token is returned, which is stored on cookie/local storage
Cookie Name - furlenco_panem_token
Header Name - X-Panem-Token
All subsequent calls should contain this token

Guest Checkout Workflow on Web/Mobile
User enters email_id and contact_no for guest checkout.
Get the user_id from panem and update cart
POST /guest_user
Request
email_id
contact_no
Response
If user for email_id exists
if user has same contact_no as given, user is returned and user_id is updated in cart.
If user has different contact_no as given, error - "The email id you provided - #{email_id} already has a contact no - #{masked_contact_no} saved. Proceed if you wish to use the same contact no. You might choose to change it after logging in into your account."
If user doesn’t have contact_no, contact_no is updated, user id returned, and user_id is saved in cart
if user for contact_no is present(obviously it’ll have a different email_id since we dealt the previous case earlier), error - "The contact no you provided - #{contact_no} already has a email id - #{masked_email_id} saved. Proceed if you wish to use the same email id. You might choose to change it after logging in into your account."
if email_id and contact_no are unique, user created, returned and user_id is updated in cart.
The user has to keep trying until the above step is successful.
After this, get all delivery_addresses of user(masked since he’s not logged in)
GET cart/user/delivery_addresses
Response - [
 { id: 1, full_address: `full masked address of user` },
 { id: 2, full_address: `full masked address of user` }
]
Now the user has the option to either choose one of these addresses or create a new one.
Choose one delivery_address, this would validate whether it belongs to the user.
PUT /cart/delivery_addresses
Request
delivery_address_id
Create a delivery_address
POST cart/delivery_addresses
Request
city_id
pincode
address
The delivery_address_id is updated in the cart.
Now he can checkout.