Watch for events on Pocketbase

watch.ts

import PocketBase from "pocketbase";
import eventsource from "eventsource";

global.EventSource = eventsource as unknown as typeof EventSource;
const pb = new PocketBase(process.env.POCKETBASE_URL);

// Store the initial states of all records in a cache
const previousRecords: { [recordId: string]: any } = {};

async function watchCollectionChanges(collection: string) {
  // Optionally, pre-cache initial states of all records
  const initialRecords = await pb.collection(collection).getFullList();

  // Populate previousRecords cache
  initialRecords.forEach(record => {
    previousRecords[record.id] = record;
  });

  // Subscribe to real-time updates on all records in the collection
  pb.collection(collection).subscribe("*", (e) => {
    const updatedRecord = e.record;

    if (e.action === "update" || e.action === "create") {
      const recordId = updatedRecord.id;
      const previousRecord = previousRecords[recordId] || {};

      // Compare fields to detect changes
      Object.keys(updatedRecord).forEach((field) => {
        // Ignore `created`, `updated`, and `id` fields
        if (["created", "updated", "id"].includes(field)) {
          return;
        }

        switch (field) {
          case "data":
          case "photos":
            if (updatedRecord[field] === null && previousRecord[field] === null) return;

            // Handle `data` field logic here
            if (field === "data" && updatedRecord[field] !== previousRecord[field]) {
              if (updatedRecord[field] === null && previousRecord[field] !== null) {
                console.log(`Record ID: ${recordId} - New record created.`);
                return;
              } else if (previousRecord[field] === null) {
                console.log(`Record ID: ${recordId} - Record updated.`);
                return;
              } else {
                const differences: string[] = [];

                // Compare JSON objects
                if (typeof updatedRecord[field] === "object" && typeof previousRecord[field] === "object") {
                  for (const key in updatedRecord[field]) {
                    if (Object.prototype.hasOwnProperty.call(updatedRecord[field], key)) {
                      if (updatedRecord[field][key] !== previousRecord[field][key]) {
                        differences.push(`${key}: ${previousRecord[field][key]} -> ${updatedRecord[field][key]}`);
                      }
                    }
                  }
                }

                if (differences.length > 0) {
                  if (differences.some((diff) => diff.includes("L_Photo_Updt_Date"))) {
                    console.log(`Time to update photos for record ID: ${recordId}.`);
                    //return;
                  }
                  console.log(`Record ID: ${recordId} - Field "${field}" changed: ${differences.join(", ")}`);
                }
              }
            }
            break;

          case "class":
            if (updatedRecord[field] !== previousRecord[field]) {
              if (previousRecord[field] === undefined && updatedRecord[field] === "") return;
              console.log(`Record ID: ${recordId} - Class Type changed from ${previousRecord[field]} to ${updatedRecord[field]}`);
            }
            break;

          default:
            if (updatedRecord[field] !== previousRecord[field]) {
              console.log(`Record ID: ${recordId} - Field "${field}" changed from ${previousRecord[field]} to ${updatedRecord[field]}`);
            }
            break;
        }
      });

      // Update the cache for this record
      previousRecords[recordId] = updatedRecord;
    }

    if (e.action === "delete") {
      console.log(`Record ID: ${e.record.id} was deleted.`);
      delete previousRecords[e.record.id];
    }
  });
}

// Use the function to watch an entire collection
watchCollectionChanges("listings");