# Mutual-credit zome

## Assumptions
- Transactor zomes
- Every transaction is public in the DHT
- This zome can be used in many different contexts -> scales (networks of 10 to 1000 nodes)

## Entries

#[hdk_entry(visibility = "public")]
struct Transaction {
    spender_balance: isize
    recipient_balance: isize
    
    amount: usize
    timestamp: Timestamp
    
    recipient: AgentPubKey
    spender: AgentPubKey
    
    spender_last_transaction: EntryHash
    recipient_last_transaction: EntryHash
}

Roberto->Hedayat: EntryHash3
Hedayat->Guillem: EntryHash1
Roberto->Thomas: EntryHash2
Guillem->Roberto: {
spender_last_transaction: EntryHash1
recipient_last_transaction: EntryHash2
}

graph TD
subgraph paths
end

## ZomeFunctions

Request Credits

sequenceDiagram

participant receiver_UI
participant receiver_transactor
participant sender_transactor

receiver_UI->>receiver_transactor: request_credits(amount, sender)
receiver_transactor-->>receiver_transactor: create entry with signature in DHT
receiver_transactor-->>receiver_transactor: create_link from sender_pub_key
receiver_transactor-->>receiver_transactor: create_link from receiver_pub_key
receiver_transactor-->>sender_transactor: remote_signal(request_hash)

Accept Request

sequenceDiagram

participant sender_UI
participant sender_transactor
participant receiver_transactor

sender_UI->>sender_transactor: accept_request(request_hash)
sender_transactor-->>sender_transactor: create transaction and publish it (with the receiver signature inside the request)
sender_transactor-->>sender_transactor: create_link from sender_pub_key
sender_transactor-->>sender_transactor: create_link from receiver_pub_key
sender_transactor-->>sender_transactor: remote_signal(receiver)

Reject Request

sequenceDiagram

participant sender_UI
participant sender_transactor
participant receiver_transactor

sender_UI->>sender_transactor: reject_request(request_hash)
sender_transactor-->>sender_transactor: deletes request
sender_transactor-->>sender_transactor: deletes link from receiver
sender_transactor-->>sender_transactor: deletes link from sender
sender_transactor-->>sender_transactor: remote_signal(sender)

## MVP features

- Core flow (request, accept, reject)
- Balance transaction
- UI + Notifications?
-

## 3rd horizon (Ideas to revisit downstream)
- exchange proposals
- others paying for your credit (accepting) => Gift?
-