Frontend updates: caching basic data (json) from CDragon

Implement caching in the patch_detector, consume the cache from API routes in frontend

patch_detector/index.ts

@@ -1,18 +1,66 @@
 import { MongoClient } from 'mongodb'
+import { writeFile, mkdir } from 'fs/promises'
+import { existsSync } from 'fs'
+import { join } from 'path'
+
+// CDragon base URL for specific patch
+const CDRAGON_BASE = 'https://raw.communitydragon.org/'
+
+// Assets to cache for each patch
+const CDRAGON_ASSETS = [
+  {
+    name: 'items.json',
+    path: 'plugins/rcp-be-lol-game-data/global/default/v1/items.json'
+  },
+  {
+    name: 'perks.json',
+    path: 'plugins/rcp-be-lol-game-data/global/default/v1/perks.json'
+  },
+  {
+    name: 'perkstyles.json',
+    path: 'plugins/rcp-be-lol-game-data/global/default/v1/perkstyles.json'
+  },
+  {
+    name: 'summoner-spells.json',
+    path: 'plugins/rcp-be-lol-game-data/global/default/v1/summoner-spells.json'
+  },
+  {
+    name: 'champion-summary.json',
+    path: 'plugins/rcp-be-lol-game-data/global/default/v1/champion-summary.json'
+  }
+]
 
 main()
 
 async function main() {
-  const client = await connectToDatabase()
-  const newPatch = await fetchLatestPatch()
+  // In dev mode, get patch from database (the one we have match data for)
+  if (process.env.NODE_ENV === 'development') {
+    console.log('Development mode: downloading cache for database patch')
+    const client = await connectToDatabase()
+    const dbPatch = await getLatestPatchFromDatabase(client)
+    await client.close()
 
-  console.log('Latest patch is: ' + newPatch)
-
-  const newDate = new Date()
-  if (!(await compareLatestSavedPatch(client, newPatch, newDate))) {
-    downloadAssets()
+    if (dbPatch) {
+      console.log('Latest patch in database: ' + dbPatch)
+      await downloadAssets(dbPatch)
+    } else {
+      console.log('No patch found in database, fetching latest from game...')
+      const latestPatch = await fetchLatestPatch()
+      console.log('Latest game patch: ' + latestPatch)
+      await downloadAssets(latestPatch)
+    }
+    return
   }
 
+  // Production mode: check database and update if new patch
+  const newPatch = await fetchLatestPatch()
+  console.log('Latest patch is: ' + newPatch)
+
+  const client = await connectToDatabase()
+  const newDate = new Date()
+  if (!(await compareLatestSavedPatch(client, newPatch, newDate))) {
+    await downloadAssets(newPatch)
+  }
   await client.close()
 }
 
@@ -58,4 +106,66 @@ async function compareLatestSavedPatch(client: MongoClient, newPatch: string, ne
   return true
 }
 
-async function downloadAssets() {}
+async function getLatestPatchFromDatabase(client: MongoClient): Promise<string | null> {
+  const database = client.db('patches')
+  const patches = database.collection('patches')
+  const latestPatch = await patches.find().limit(1).sort({ date: -1 }).next()
+
+  if (latestPatch == null) {
+    return null
+  }
+
+  return latestPatch.patch
+}
+
+async function downloadAssets(patch: string) {
+  // Convert patch format for CDragon: "16.4.1" -> "16.4"
+  // CDragon uses patch format without the last minor version
+  const cdragonPatch = patch.split('.').slice(0, 2).join('.')
+  console.log(`Downloading CDragon assets for patch ${cdragonPatch} (from ${patch})...`)
+
+  // Get cache directory from environment or use default
+  const cacheDir = process.env.CDRAGON_CACHE_DIR || '/cdragon'
+  const patchDir = join(cacheDir, cdragonPatch)
+
+  // Create patch directory if it doesn't exist
+  if (!existsSync(patchDir)) {
+    await mkdir(patchDir, { recursive: true })
+    console.log(`Created directory: ${patchDir}`)
+  }
+
+  // Download each asset
+  for (const asset of CDRAGON_ASSETS) {
+    const url = `${CDRAGON_BASE}${cdragonPatch}/${asset.path}`
+    const filePath = join(patchDir, asset.name)
+
+    try {
+      console.log(`Downloading ${asset.name}...`)
+      const response = await fetch(url)
+
+      if (!response.ok) {
+        console.error(`Failed to download ${asset.name}: ${response.status} ${response.statusText}`)
+        continue
+      }
+
+      const data = await response.json()
+      await writeFile(filePath, JSON.stringify(data, null, 2))
+      console.log(`Saved ${asset.name} to ${filePath}`)
+    } catch (error) {
+      console.error(`Error downloading ${asset.name}:`, error)
+    }
+  }
+
+  // Create a symlink or copy to 'latest' directory for easy access
+  const latestDir = join(cacheDir, 'latest')
+  const latestFile = join(latestDir, 'patch.txt')
+
+  if (!existsSync(latestDir)) {
+    await mkdir(latestDir, { recursive: true })
+  }
+
+  await writeFile(latestFile, patch)
+  console.log(`Updated latest patch reference to ${patch}`)
+
+  console.log('CDragon assets download complete!')
+}