## Purpose of this document
Provide the necessary technical information for the engineering team to deliver the Prism SaaS solution MVP.

## Decisions
### `prism-node` service is deployed in the in-memory mode

Expected outcome:
- deployment simplification
- environment cost optimization
- `prism-agent` configuration is simple

Constraints:
- Prism DID is not published to the blockchain
- absence of interoperability with other SSI systems

Mitigation:
- Cardano stack can be added later

### `prism-node` service is shared among all `prism-agent` instances
Expected outcome:
- deployment simplification
- cost optimization
- Cardano Wallet is not a part of SaaS
- `prism-agent` configuration is simple

Constraints:
- `prism-node` is a single point of failure

Mitigation:
- mitigate the SPOF later
- switch to Demeter Cadrano infrastructure

### `prism-agent` service uses Postgresql as a Secrets Store
Expected outcome:
- deployment simplification (the Vault is not needed)
- cost optimization

Constraints:
- the key materials are stored in not secure location

Mitigation:
- Switch to the Vault service after multi-tenancy implementation

### `prism-mediator` and mediator database are shared among all `prism-agent` instances
Expected outcome:
- deployment simplification
- cost optimization
- `prism-agent` configuration is simple

Constraints:
- `prism-mediator` is a SPOF

Mitigation:
- mitigate the SPOF after SaaS MVP

### `provisioning-backend` is implemented using TypeScript + Node.js

Expected outcome:
- engineers with TS experience implement provisioning backend
- provisioning backend is simple and maintainable

### Manage App and Enterprise Services are shared among all the `prism-agent` instances
Javier says that it's possible and the work to implement it is in progress.

Expected outcome:
- deployment simplification
- cost optimization

Constraints:
- Enterprise service is SPOF

## Architecture questions to figure out
### How to use the Cardano Wallet in SaaS offering?
//out of scope for now

### What Identity and Access Management (IAM) system should be used?
// the Keycloak, the Vault, something other

### How to configure the cluster management for the SaaS solution
There are the following options:
#### ??? ArgoCD + Postgresql + ArgoCD REST API
// Platform Engineering task - with @David Poltorak.

## New Components for the SaaS MVP

### Provisioning-backend
Purpose:
- orchestrate the resources of the SaaS environment
- communicate with the underlying infrastructure systems
- expose the REST API for resource orchestration

### IAM system
Purpose:
- provide the authentication method for the SaaS
- manage the users (create, activate, deactivate, update, get information)

## Admin UI (optional for MVP)
Purpose:
- observe the status of the SaaS environment
- manage the SaaS environment

ArgoCD + Grafana + Prometheus can be used so far

## Deployment Diagram
This diagram is exported from the Structurizr

graph LR
  linkStyle default fill:#ffffff

  subgraph diagram [Prism SaaS - Containers]
    style diagram fill:#ffffff,stroke:#ffffff

    1["<div style='font-weight: bold'>User</div><div style='font-size: 70%; margin-top: 0px'>[Person]</div>"]
    style 1 fill:#08427b,stroke:#052e56,color:#ffffff
    2["<div style='font-weight: bold'>Admin</div><div style='font-size: 70%; margin-top: 0px'>[Person]</div>"]
    style 2 fill:#08427b,stroke:#052e56,color:#ffffff

    subgraph 3 [Prism SaaS]
      style 3 fill:#ffffff,stroke:#0b4884,color:#0b4884

      subgraph group1 [Infrastructure Services]
        style group1 fill:#ffffff,stroke:#cccccc,color:#cccccc,stroke-dasharray:5

        21("<div style='font-weight: bold'>Admin App</div><div style='font-size: 70%; margin-top: 0px'>[Container]</div>")
        style 21 fill:#438dd5,stroke:#2e6295,color:#ffffff
        23("<div style='font-weight: bold'>Platform Backend</div><div style='font-size: 70%; margin-top: 0px'>[Container]</div>")
        style 23 fill:#438dd5,stroke:#2e6295,color:#ffffff
        26("<div style='font-weight: bold'>Argo CD</div><div style='font-size: 70%; margin-top: 0px'>[Container]</div>")
        style 26 fill:#438dd5,stroke:#2e6295,color:#ffffff
        28("<div style='font-weight: bold'>Platform DB</div><div style='font-size: 70%; margin-top: 0px'>[Container]</div>")
        style 28 fill:#438dd5,stroke:#2e6295,color:#ffffff
      end

      subgraph group2 [Prism Enterprise Services]
        style group2 fill:#ffffff,stroke:#cccccc,color:#cccccc,stroke-dasharray:5

        10("<div style='font-weight: bold'>Manage App</div><div style='font-size: 70%; margin-top: 0px'>[Container]</div>")
        style 10 fill:#438dd5,stroke:#2e6295,color:#ffffff
        12("<div style='font-weight: bold'>Enterprise Service Backend</div><div style='font-size: 70%; margin-top: 0px'>[Container]</div>")
        style 12 fill:#438dd5,stroke:#2e6295,color:#ffffff
      end

      subgraph group3 [Prism Mediator Services]
        style group3 fill:#ffffff,stroke:#cccccc,color:#cccccc,stroke-dasharray:5

        14("<div style='font-weight: bold'>Prism Mediator</div><div style='font-size: 70%; margin-top: 0px'>[Container]</div>")
        style 14 fill:#438dd5,stroke:#2e6295,color:#ffffff
        16("<div style='font-weight: bold'>MongoDB</div><div style='font-size: 70%; margin-top: 0px'>[Container]</div>")
        style 16 fill:#438dd5,stroke:#2e6295,color:#ffffff
      end

      subgraph group4 [Prism Platform Dynamic Services]
        style group4 fill:#ffffff,stroke:#cccccc,color:#cccccc,stroke-dasharray:5

        31("<div style='font-weight: bold'>Prism Agent DB</div><div style='font-size: 70%; margin-top: 0px'>[Container]</div>")
        style 31 fill:#438dd5,stroke:#2e6295,color:#ffffff
        32("<div style='font-weight: bold'>Prism Agent #1</div><div style='font-size: 70%; margin-top: 0px'>[Container]</div>")
        style 32 fill:#438dd5,stroke:#2e6295,color:#ffffff
        38("<div style='font-weight: bold'>Prism Agent #2</div><div style='font-size: 70%; margin-top: 0px'>[Container]</div>")
        style 38 fill:#438dd5,stroke:#2e6295,color:#ffffff
      end

      subgraph group5 [Prism Platform Identity Services]
        style group5 fill:#ffffff,stroke:#cccccc,color:#cccccc,stroke-dasharray:5

        18("<div style='font-weight: bold'>Prism Node</div><div style='font-size: 70%; margin-top: 0px'>[Container]</div>")
        style 18 fill:#438dd5,stroke:#2e6295,color:#ffffff
        19("<div style='font-weight: bold'>Prism Node DB</div><div style='font-size: 70%; margin-top: 0px'>[Container]</div>")
        style 19 fill:#438dd5,stroke:#2e6295,color:#ffffff
      end

      4("<div style='font-weight: bold'>APISIX API Gateway</div><div style='font-size: 70%; margin-top: 0px'>[Container]</div>")
      style 4 fill:#438dd5,stroke:#2e6295,color:#ffffff
      7("<div style='font-weight: bold'>Teleport Gateway</div><div style='font-size: 70%; margin-top: 0px'>[Container]</div>")
      style 7 fill:#438dd5,stroke:#2e6295,color:#ffffff
    end

    4-. "<div>Calls</div><div style='font-size: 70%'></div>" .->10
    10-. "<div>Calls REST API</div><div style='font-size: 70%'></div>" .->12
    4-. "<div>Calls REST/DIDComm API</div><div style='font-size: 70%'></div>" .->14
    14-. "<div>Store the state</div><div style='font-size: 70%'></div>" .->16
    18-. "<div>Store state</div><div style='font-size: 70%'></div>" .->19
    7-. "<div>Calls</div><div style='font-size: 70%'></div>" .->21
    12-. "<div>Call REST API</div><div style='font-size: 70%'></div>" .->23
    21-. "<div>Call REST API</div><div style='font-size: 70%'></div>" .->23
    23-. "<div>Manage Agents</div><div style='font-size: 70%'></div>" .->26
    26-. "<div>Stores the topoloy of the<br />environment</div><div style='font-size: 70%'></div>" .->28
    23-. "<div>Stores the state of the<br />environment</div><div style='font-size: 70%'></div>" .->28
    4-. "<div>Calls REST API</div><div style='font-size: 70%'></div>" .->32
    26-. "<div>Manage the instance lifecycle</div><div style='font-size: 70%'></div>" .->32
    32-. "<div>Communicate over gRPC API</div><div style='font-size: 70%'></div>" .->18
    32-. "<div>Store the state</div><div style='font-size: 70%'></div>" .->31
    32-. "<div>Communicate over DIDComm</div><div style='font-size: 70%'></div>" .->14
    4-. "<div>Calls REST API</div><div style='font-size: 70%'></div>" .->38
    26-. "<div>Manage the instance lifecycle</div><div style='font-size: 70%'></div>" .->38
    38-. "<div>Communicate over gRPC API</div><div style='font-size: 70%'></div>" .->18
    38-. "<div>Store the state</div><div style='font-size: 70%'></div>" .->31
    38-. "<div>Communicate over DIDComm</div><div style='font-size: 70%'></div>" .->14
    1-. "<div>Calls</div><div style='font-size: 70%'></div>" .->4
    2-. "<div>Calls</div><div style='font-size: 70%'></div>" .->7
  end