Implement Pre-Transaction Workflow

[gitfelipegomes]

Context

A pre-transaction is a mechanism for pre-processing values. It performs validation of the accounts involved in the transaction, reserves the amounts in the source accounts (on_hold), and keeps the transaction in a pending state, awaiting a subsequent call for confirmation (commit) or cancellation (cancel).

In the case of confirmation, the balances are effectively transferred to the destination accounts, and the corresponding debit and credit operations are recorded.

In the event of cancellation, the previously reserved amounts are returned to the available balance of the source accounts.

How to do it

Workflow

stateDiagram-v2
    state validate <<choice>>
    [*] --> validate: pre-transaction
    validate --> PRE_APPROVED: account validation success
    validate --> ERROR: account validation fail
    PRE_APPROVED --> APPROVED: commit
    PRE_APPROVED --> CANCELED: cancel
    APPROVED --> [*]
    CANCELED --> [*]

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Step: Create Transaction

1. Validate transaction
2. Move the balance from the source accounts to on_hold
3. Set transaction status to PRE_APPROVED

Action: Commit

1. Transfer the reserved balances to the destination accounts
2. Record the credit and debit operations
3. Set status to APPROVED

Action: Cancel

1. Return the reserved balances from the source accounts to the available balance
2. Set status to CANCELED

To-do

• Add pending:boolean field on transaction body
• Create new column int the transaction database to store transaction JSON
• Create transaction commit endpoint
• Create transaction cancel endpoint

[fredcamaral]

(syncing github issues with jira)