## Incoming Sarafu ##
When users exchange CIC <> National Currency we have to manually send them Mpesa or CIC.
We would like to automate this.

## Solution ##
Configure - using our own system AfricasTalking API to automatically send Sarafu / Mpesa based on rules:

### Variables ###
 - blockchain_CIC_Supply = the total supply of the CIC on the blockchain
 - blockchain_CIC_reserve = the total reserve (xDAI) of the CIC on the blockchain
 - trr = the connector weight on blockchain converter between supply and reserve
 - total_CIC_sent = the total amount of CIC that has been sent to users from our Float account - this needs to be updated for each conversion and when clearing
 - total_CIC_Reserve_Sent = the total amount of Reserve that has been sent to users from our Float account - this needs to be updated for each conversion and when clearing
 - total_CIC_recieved = the total amount of CIC that has been sent to users from our Float account - this needs to be updated for each conversion and when clearing
 - total_CIC_Reserve_recieved = the total amount of Reserve that has been sent to users from our Float account - this needs to be updated for each conversion and when clearing
 - CIC_supply_b: **blockchain_CIC_Supply** - **total_CIC_sent** + **total_CIC_recieved**  = this simulates/tracks the changes to the blockchain
 - CIC_reserve_b: **blockchain_CIC_reserve** - **total_CIC_Reserve_Sent** + **total_CIC_Reserve_recieved** = this simulates/tracks the changes to the blockchain
 - CIC_excahnge_amount = the amount of CIC they user has sent to exhange
 - Mpesa_excahnge_amount = the amount of MPesa the user has sent to exhange
 - Rate: USD -> KSH
 - Rate: KSH -> USD
 - The account to which CIC are sent should be a Agent account
 - The cash-out rules for a chama (minimum and time limit)
 - Alert balance levels
 - Fees: Sarafu to Mpesa FeeCC2M = 2%
 - Fees: Sarafu to Mpesa FeeM2CC = 2%
 
### Incoming Sarafu Rules - MPESA out ###
 - *white list* The chama (group accounts only but eventually anyone) must only be able to cash out - using the exchange option to an Agent account
 - *amount* The max cash out is the minimum of (30,000 Sarafu, half their balance, their total amount of outward trade volume to other users (standard transactions)
 - *time* They can only cash out once per month
 - *mpesa given* The amount of Mpesa given should be calculated as follows:
    

The Reserve (xDAI) pulled out
>    reserveOut_xDAI = CIC_reserve_b * (Math.pow(1 + (-1 * CIC_excahnge_amount) / CIC_supply_b, 1 / trr) - 1) --> this shoudl be calculated as it is done on contract

  -  Mpesa_out = reserveOut_xDAI **USD => KSH** rate 
  -  **Mpesa_given = Mpesa_out - Mpesa_out*S22M (fee) this is the amount of Mpesa sent to the user**
  -  Update CIC variables on database: 
     - total_CIC_recieved+= CIC_excahnge_amount
     - total_CIC_Reserve_Sent+= reserveOut_xDAI
     

### Outgoing Sarafu Rules - MPESA In ###
 - *white list* Only users sending via paybill receive Sarafu. Non users receive a invitation to join Sarafu sms (alert to admins there was a donation).
 - *amount* The max sarafu out is 20,000 Sarafu per user, KYC_limit max, supply_max
 - *time* No limit
 - *CIC given* The amount of CIC given should be calculated as follows:
 - reserveIn_xDAI = Mpesa_excahnge_amount **KSH => USD** rate 
    
The amount cashed in = cash_in_amount

>    const CIC_Created = CIC_supply_b * (Math.pow(1 + reserveIn_xDAI / CIC_reserve_b, trr) - 1);
   
  - **CIC_given = CIC_Created - CIC_created*FeeM2CC ()**
  - Simulate as if done on blockchain .... new_cic_supply_b = cic_supply_b + CIC_given
  - Simulate as if done on blockchain .... new_total_reserve_b = total_reserve_b + cash_in_amount
  -  Update CIC variables on database: 
     - total_CIC_sent+= CIC_excahnge_amount
     - total_CIC_Reserve_recieved+= reserveIn_xDAI
  

### Security ###
 - Balance alerts: On both Mpesa and CIC balances: The paybill from which Sarafu is sent needs to send a sms and email alert when low 
 - Failure alerts: If the API session fails an sms and email alert should be sent
 - Reject on not enough Mpesa balance: If there is not enough Mpesa (on incoming Sarafu) the transaction should be rejected and an email sent to admin along with a SMS to admin and user (Sarafu should not be taken from user). (message should be visible also on mgmt platform txn view and user view and admin view).
 - Reject on not enough Sarafu balance: If there is not enough Sarafu (on incoming Mpesa) the transaction should be rejected and an email sent to admin along with a SMS to admin and user (Mpesa should not be taken from user). (message should be visible also on mgmt platform txn view and user view and admin view).