check if items disappeared since last run (AGAIN WITH AI)

.gitignore

@@ -32,3 +32,6 @@ report.[0-9]_.[0-9]_.[0-9]_.[0-9]_.json
 
 # Finder (MacOS) folder config
 .DS_Store
+
+wishlist.json
+missing_items.json

getWishlist.mjs

@@ -1,12 +1,25 @@
 import bcfetch from 'bandcamp-fetch';
-const fs = require("fs");
+import fs from 'fs/promises'; // Using the promise-based version of fs for clean async/await
 
 const username = 'noschxl';
 
 async function fetchEntireWishlist() {
-  let allWishlistItems = [];
+  let previousWishlist = [];
   
-  // Set the initial parameters using the username
+  // 1. Try to load the previous wishlist to compare against
+  try {
+    const fileData = await fs.readFile('wishlist.json', 'utf8');
+    previousWishlist = JSON.parse(fileData);
+    console.log(`Loaded ${previousWishlist.length} previous items from wishlist.json for comparison.`);
+  } catch (error) {
+    if (error.code === 'ENOENT') {
+      console.log('No existing wishlist.json found. This must be the first run!');
+    } else {
+      console.error('Error reading wishlist.json:', error);
+    }
+  }
+
+  let allWishlistItems = [];
   let currentParams = {
     target: username,
     imageFormat: 'art_app_large'
@@ -15,47 +28,64 @@ async function fetchEntireWishlist() {
   let hasMorePages = true;
   let pageCount = 1;
 
-  console.log(`Starting wishlist scrape for user: ${username}...`);
+  console.log(`\nStarting wishlist scrape for user: ${username}...`);
 
-  // Loop will keep running as long as Bandcamp returns a continuation token
+  // 2. Scrape the current wishlist
   while (hasMorePages) {
     console.log(`Fetching page ${pageCount}...`);
     
     try {
       const result = await bcfetch.fan.getWishlist(currentParams);
 
-      // Add the items from the current page to our master list
-      // (Assuming the library returns the array inside an 'items' property)
       if (result && result.items) {
         allWishlistItems.push(...result.items);
       }
 
-      // Check if there are more pages to fetch
       if (result.continuation) {
-        // Update the target with the continuation object for the next loop iteration
         currentParams.target = result.continuation;
         pageCount++;
       } else {
-        // No continuation token means we've hit the end of the wishlist
         hasMorePages = false;
       }
     } catch (error) {
       console.error(`Error fetching page ${pageCount}:`, error);
-      break; // Exit the loop if something goes wrong
+      break; 
     }
   }
 
   console.log(`\nDone! Successfully scraped ${allWishlistItems.length} items from your wishlist.`);
   
-  // You can now write `allWishlistItems` to a JSON file using Node's 'fs' module
-  // console.log(JSON.stringify(allWishlistItems, null, 2));
-  fs.writeFile('wishlist.json', JSON.stringify(allWishlistItems, null, 2), (err) => {
-    if (err) {
-        console.error('Error writing to file', err);
+  // 3. Compare the old list against the new list
+  if (previousWishlist.length > 0) {
+    // Create a Set of all the current IDs for fast, easy lookup
+    const currentIds = new Set(allWishlistItems.map(item => item.id));
+
+    // Filter the previous list to find items whose IDs are missing from the current scrape
+    const missingItems = previousWishlist.filter(item => !currentIds.has(item.id));
+
+    if (missingItems.length > 0) {
+      console.log(`\nWARNING: ${missingItems.length} item(s) have disappeared since the last run!`);
+      
+      missingItems.forEach(item => {
+        console.log(`- ${item.artist.name} : ${item.name}`);
+        console.log(`  Old URL: ${item.url}\n`);
+      });
+
+      // Optional: Save the missing items to a separate file so you don't lose their metadata
+      await fs.writeFile('missing_items.json', JSON.stringify(missingItems, null, 2));
+      console.log('Saved missing items to missing_items.json');
     } else {
-        console.log('Data written to file');
+      console.log('\nAll good! No items have disappeared since your last run.');
+    }
+  }
+
+  // 4. Overwrite wishlist.json with the new, up-to-date data for the next run
+  try {
+    await fs.writeFile('wishlist.json', JSON.stringify(allWishlistItems, null, 2));
+    console.log('Successfully updated wishlist.json with current data.');
+  } catch (error) {
+    console.error('Error writing to wishlist.json:', error);
   }
-  })
 }
 
 fetchEntireWishlist();