# Context
App users (landlord) can assign `tenantEmail` to a `BillingLocation`.

This is a e-mail address will be used to notify the tenant when the rent is due and/or the utility bills are due.

## E-mail verification
To prevent missuse and ensure that the e-mail is correct, before an e-mail address can be used by the automatic notification system, the tenant needs to verifies that he/she accepts to receive notifications.

This verification is done via a link sent to the tenant in a verification-request e-mail, which is sent to the tenant automatically when the landloard (app user) assigns this e-mail address to a BillingLocation.

Sending of this verification-request e-mail is handled by a system separate from NextJS app in `web-app` workspace. It detects newly assigned addresses from their status bein equal `EmailStatus.Unverified`. The two systems don't talk to each other at all - what's holding them together is the DB.

### Implementation details
Verification link points to the NextJS app in `web-app` workspace at path `/email/verify/[share-id]` (share-id is calculated using `generateShareId` from `/home/kneecola/projects/evidencija-rezija/web-app/app/lib/shareChecksum.ts`).

The web page served at this path cerifies if the [share-id] is correct and if not it shows 404 page.

The web page served at this path contains an text explanation and "Verify e-mail" button.

The text includes the following information:
* what the web app is about - very short into
* why the e-mail was sent = because the landloard of the property `BillingLocation.name` configured the rent (`BillingLocation.rentDueNotification`) and/or utility bills (`BillingLocation.billFwdStrategy`) to be delivered to that e-mail address
* what will hapen if he/she clicks on the "Verify e-mail" button = they will be receiving rent due (`BillingLocation.rentDueNotification`) or utility bills due (`BillingLocation.billFwdStrategy`) notification or both - 2x a month - depending on the config set by the landloard
* opt-out infomation (they can ignore this e-mail, but can also opt-out at any moment)

If the user clicks the button "Verify e-mail" this triggers update of `BillingLocation.tenantEmailStatus`.

Here's the expected stats flow:

* landloard/app user assigns an an new address to  `BillingLocation` -> `BillingLocation.tenantEmailStatus` is set to `EmailStatus.Unverified`
* an automated system detects that a new address was set (as indicated by `EmailStatus.Unverified` status), it then sets verification-email -> `BillingLocation.tenantEmailStatus` is set to `EmailStatus.VerificationPending`
* tenant click the link from the verification-requets e-mail  -> `BillingLocation.tenantEmailStatus` is set to `EmailStatus.Verified`

**Note:** status is updated for the `BillingLocation` inidcated by locationID (decoded from `[share-id]` param), and all subsequent (later in time) matching `BillingLocation` records (matched by comparing `BillingLocation.name`,  `BillingLocation.userId` and `BillingLocation.tenantEmail`). Similar pattern is already implemented in `updateOrAddLocation` fn in `locationAction.ts` (`updateScope === "subsequent"`).

## E-mail unsubscribe
Tenant can out-out from receiving e-mail notifications at any time via an `unsubscribe` link included at the end of every mail sent to the tenant.

### Implementation details
Verification link points to the NextJS app in `web-app` workspace at path `/email/unsubscribe/[share-id]` (share-id is calculated using `generateShareId` from `/home/kneecola/projects/evidencija-rezija/web-app/app/lib/shareChecksum.ts` ... search of examples of how this function is used).

The web page served at this path contains an text explanation and "Confirm unsubscribe" button.

The text includes the following information:
* what the web app is about - very short into
* why are they receiveing e-mails from this page = because their landlord for property `BillingLocation.name` has configured the app to deliver rent due or utility bills due notification or both to that address
* what will hapen if they click on "Confirm unsubscribe" = they will no longer receive rent due / utility bull due reminders

E-mail address's verification status is tracked via `BillingLocation.tenantEmailStatus`, which is set to `EmailStatus.Unsubscribed`.

**Note:** status is updated for the `BillingLocation` inidcated by locationID (decoded from `[share-id]` param), and all subsequent (later in time) matching `BillingLocation` records (matched by comparing `BillingLocation.name`, `BillingLocation.userId` and `BillingLocation.tenantEmail`). Similar pattern is already implemented in `updateOrAddLocation` fn in `locationAction.ts` (`updateScope === "subsequent"`).

## E-mail status in `LocationCard.tsx`

If the e-mail is not in `EmailStatus.Verified` state for a given location, then this will be indicated in `LocationCard.tsx` as a sibling of `total-payed-label` block (`<div className="flex ml-1">`)

## E-mail status in `LocationEditForm.tsx`

Current e-mail status will be indicated as a sibling of:
```
  {/* Email status indicator should go here */}
  <div id="tenantEmail-error" aria-live="polite" aria-atomic="true">
  ...
```

Use appropriate utf-8 icon for each status.

# Logical Units of work

Work will be split in logical units of work:

* implement e-mail verification DB logic
* implement e-mail verification page
    * create text both in croatian (hr.json) and english (en.json)
    * implement share-id verification (see /home/kneecola/projects/evidencija-rezija/web-app/app/[locale]/share/proof-of-payment/per-bill/[id]/route.tsx)
* implement e-mail unsubscribe DB logic
* implement e-mail unsubscribe page
    * create text both in croatian (hr.json) and english (en.json)
    * implement share-id verification (see /home/kneecola/projects/evidencija-rezija/web-app/app/[locale]/share/proof-of-payment/per-bill/[id]/route.tsx)
* add email status to `LocationCard.tsx`
* add email status to `LocationEditForm.tsx`

Each logical unit of work will be commited separatley.