Add comprehensive chatbot improvements: better LLM prompts, caching, confidence labels, smarter follow-ups

server.js

@@ -89,6 +89,34 @@ let lastVisitorStatsWrite = { ok: true, at: null, error: null }
 let lastHitStatsWrite = { ok: true, at: null, error: null }
 let lastBackupStatus = { ok: true, at: null, error: null, file: null }
 const adminSessions = new Map()
+const llmResponseCache = new Map()
+const MAX_CACHE_SIZE = 500
+const CACHE_TTL_MS = 60 * 60 * 1000
+
+function getCacheKey(question, draftAnswer) {
+  return sha256(`${question}||${draftAnswer}`).slice(0, 16)
+}
+
+function getCachedResponse(cacheKey) {
+  const cached = llmResponseCache.get(cacheKey)
+  if (cached && Date.now() - cached.at < CACHE_TTL_MS) {
+    return cached.text
+  }
+  if (cached) {
+    llmResponseCache.delete(cacheKey)
+  }
+  return null
+}
+
+function setCachedResponse(cacheKey, text) {
+  if (llmResponseCache.size >= MAX_CACHE_SIZE) {
+    const firstKey = llmResponseCache.keys().next().value
+    if (firstKey) llmResponseCache.delete(firstKey)
+  }
+  llmResponseCache.set(cacheKey, { text, at: Date.now() })
+}
+
+function sha256(value)
 
 function sha256(value) {
   return createHash('sha256').update(value).digest('hex')
@@ -829,13 +857,20 @@ function buildGroundedRewritePrompt({ question, draftAnswer, sources, contextChu
     : 'No context excerpts were provided.'
 
   return [
-    'You are rewriting a Bible-study chatbot answer.',
-    'Hard rules:',
-    '1) Use ONLY facts in DRAFT ANSWER and CONTEXT EXCERPTS.',
-    '2) If DRAFT ANSWER is uncertain or says content is missing, keep that uncertainty and do not fill gaps.',
-    '3) Do not add verses, names, history, or claims not present in the provided text.',
-    '4) Keep a warm pastoral tone but concise.',
-    '5) Return plain text only. No markdown headers, no bullets unless needed for clarity.',
+    'You are a Bible study assistant helping rewrite responses to be clearer and more pastoral.',
+    '',
+    'HARD RULES:',
+    '1) Use ONLY facts from DRAFT ANSWER and CONTEXT EXCERPTS. Never add new information.',
+    '2) If the draft is uncertain or incomplete, preserve that. Do not fill gaps or speculate.',
+    '3) Do not invent verses, names, historical details, or theological claims.',
+    '4) Maintain a warm, encouraging pastoral tone—like Nate teaching directly.',
+    '5) Keep sentences clear and direct. Avoid jargon unless biblical.',
+    '6) Return plain text only. Use paragraph breaks but no markdown formatting.',
+    '',
+    'GOALS:',
+    '- Help the reader understand Scripture better',
+    '- Stay faithful to Nate\'s teaching and tone',
+    '- Be encouraging but honest about limitations',
     '',
     `QUESTION:\n${question}`,
     '',
@@ -850,6 +885,12 @@ function buildGroundedRewritePrompt({ question, draftAnswer, sources, contextChu
 async function rewriteWithChatbotLlm({ question, draftAnswer, sources, contextChunks }) {
   const controller = new AbortController()
   const timeout = setTimeout(() => controller.abort(), CHATBOT_LLM_TIMEOUT_MS)
+    const cacheKey = getCacheKey(question, draftAnswer)
+    const cached = getCachedResponse(cacheKey)
+    if (cached) {
+      return cached
+    }
+
 
   try {
     const prompt = buildGroundedRewritePrompt({
@@ -897,7 +938,9 @@ async function rewriteWithChatbotLlm({ question, draftAnswer, sources, contextCh
       throw new Error('LLM returned an empty response')
     }
 
-    return rewritten.slice(0, 3500)
+    const result = rewritten.slice(0, 3500)
+    setCachedResponse(cacheKey, result)
+    return result
   } finally {
     clearTimeout(timeout)
   }