PSEUDO.md

What is needed?

• a schema that contains users, chats and messages
• a seed script that creates users, chats and message
• a frontend app that uses classic Prisma Client to read and display messages from the db
• a sidecar Prisma client that connects to a local server that polls the db to check for changes
• the frontend app also uses the sidecar client to subscribe to get new messages live

Frontend app

• just show a list of current messages
• have a subscription that automatically updates the view with new messages

Sidecar app methods:

• ENUM operation = ['CREATED', 'UPDATED']

• prisma_sub.message.$subscribe({operation: [operation], where: MessageWhereInput}) : Message[] to subscribe to messages.

• prisma_sub.chat.$subscribe({operation: [operation], where: ChatWhereInput}) : Chat[] to subscribe to chats.

• prisma_sub.user.$subscribe({operation: [operation], where: UserWhereInput}) : User[] to subscribe to users.

• payload to endpoint: {model, operation, where}

• payload from endpoint: {operation, model[]}

• On method call it:

1. connects to hardcoded prisma_sub endpoint
2. submits operation and where input to the endpoint
3. gets a websocket endpoint to connect to in response
4. offers some iterator magic to get the data from the websocket endpoint and close it when done

Prisma subscription server

• exposes endpoint where it listens for subscription requests
• when a request comes in:

1. it spins off a process
2. in there it creates a websocket endpoint and sends that back to the requester
3. it retrieves the model, operation and the where from the request
4. it creates one new where per operation
   • CREATED: where: { AND: [where, createdAt_gt: timestamp] }
   • UPDATED: where: { AND: [where, updatedAt_gt: timestamp] }
5. in a 1 sec loop it:
   • resets timestamp to current time
   • queries the db once per defined operation prisma.model.findMany({where: where})
   • sends the results to the websocket endpoint if the result is non-empty {operation, model[]}
   • abort loop if the websocket endpoint is closed