Add grounded Ollama rewrite flow for chatbot

server.js

@@ -55,6 +55,15 @@ const BACKUP_RETENTION_DAYS = 30
 const BACKUP_INTERVAL_MS = 24 * 60 * 60 * 1000
 const ADMIN_SESSION_TTL_MS = 7 * 24 * 60 * 60 * 1000
 const ADMIN_PASSWORD = process.env.ADMIN_PASSWORD ?? 'change-me-admin-password'
+const CHATBOT_LLM_ENABLED = process.env.CHATBOT_LLM_ENABLED === 'true'
+const CHATBOT_LLM_BASE_URL = process.env.CHATBOT_LLM_BASE_URL ?? 'http://127.0.0.1:11434'
+const CHATBOT_LLM_MODEL = process.env.CHATBOT_LLM_MODEL ?? 'qwen2.5:3b-instruct'
+const CHATBOT_LLM_TIMEOUT_MS = Number(process.env.CHATBOT_LLM_TIMEOUT_MS) > 0
+  ? Number(process.env.CHATBOT_LLM_TIMEOUT_MS)
+  : 25000
+const CHATBOT_LLM_NUM_CTX = Number(process.env.CHATBOT_LLM_NUM_CTX) > 0
+  ? Number(process.env.CHATBOT_LLM_NUM_CTX)
+  : 2048
 
 const EMPTY_VISITOR_STATS = {
   totalVisits: 0,
@@ -784,12 +793,173 @@ async function refreshChatbotFromDiskIfChanged() {
   }
 }
 
+function normalizeChatbotLlmContext(chunks) {
+  if (!Array.isArray(chunks)) return []
+
+  return chunks
+    .filter(chunk => chunk && typeof chunk.content === 'string')
+    .slice(0, 4)
+    .map((chunk, index) => {
+      const title = typeof chunk.title === 'string' ? chunk.title.trim().slice(0, 160) : `Context ${index + 1}`
+      const sourceLabel = typeof chunk.sourceLabel === 'string' && chunk.sourceLabel.trim()
+        ? chunk.sourceLabel.trim().slice(0, 200)
+        : title
+      const content = chunk.content.trim().slice(0, 1400)
+
+      return {
+        title,
+        sourceLabel,
+        content,
+      }
+    })
+    .filter(chunk => chunk.content.length > 0)
+}
+
+function buildGroundedRewritePrompt({ question, draftAnswer, sources, contextChunks }) {
+  const sourceList = Array.isArray(sources) && sources.length > 0
+    ? sources.slice(0, 6).map(source => `- ${String(source).slice(0, 220)}`).join('\n')
+    : '- No explicit source labels provided'
+
+  const contextBlock = contextChunks.length > 0
+    ? contextChunks
+      .map((chunk, index) => (
+        `Context ${index + 1}: ${chunk.sourceLabel}\nTitle: ${chunk.title}\nExcerpt: ${chunk.content}`
+      ))
+      .join('\n\n')
+    : 'No context excerpts were provided.'
+
+  return [
+    'You are rewriting a Bible-study chatbot answer.',
+    'Hard rules:',
+    '1) Use ONLY facts in DRAFT ANSWER and CONTEXT EXCERPTS.',
+    '2) If DRAFT ANSWER is uncertain or says content is missing, keep that uncertainty and do not fill gaps.',
+    '3) Do not add verses, names, history, or claims not present in the provided text.',
+    '4) Keep a warm pastoral tone but concise.',
+    '5) Return plain text only. No markdown headers, no bullets unless needed for clarity.',
+    '',
+    `QUESTION:\n${question}`,
+    '',
+    `DRAFT ANSWER:\n${draftAnswer}`,
+    '',
+    `SOURCES:\n${sourceList}`,
+    '',
+    `CONTEXT EXCERPTS:\n${contextBlock}`,
+  ].join('\n')
+}
+
+async function rewriteWithChatbotLlm({ question, draftAnswer, sources, contextChunks }) {
+  const controller = new AbortController()
+  const timeout = setTimeout(() => controller.abort(), CHATBOT_LLM_TIMEOUT_MS)
+
+  try {
+    const prompt = buildGroundedRewritePrompt({
+      question,
+      draftAnswer,
+      sources,
+      contextChunks,
+    })
+
+    const response = await fetch(`${CHATBOT_LLM_BASE_URL.replace(/\/$/, '')}/api/chat`, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      signal: controller.signal,
+      body: JSON.stringify({
+        model: CHATBOT_LLM_MODEL,
+        stream: false,
+        options: {
+          temperature: 0.2,
+          num_ctx: CHATBOT_LLM_NUM_CTX,
+        },
+        messages: [
+          {
+            role: 'system',
+            content: 'Rewrite grounded answers faithfully. Never add information not present in the provided draft/context.',
+          },
+          {
+            role: 'user',
+            content: prompt,
+          },
+        ],
+      }),
+    })
+
+    if (!response.ok) {
+      const text = await response.text()
+      throw new Error(`LLM request failed (${response.status}): ${text.slice(0, 220)}`)
+    }
+
+    const payload = await response.json()
+    const rewritten = typeof payload?.message?.content === 'string'
+      ? payload.message.content.trim()
+      : ''
+
+    if (!rewritten) {
+      throw new Error('LLM returned an empty response')
+    }
+
+    return rewritten.slice(0, 3500)
+  } finally {
+    clearTimeout(timeout)
+  }
+}
+
 // Public: return all chatbot entries for client-side matching
 app.get('/api/chatbot-content', async (req, res) => {
   await refreshChatbotFromDiskIfChanged()
   res.json(chatbotEntries)
 })
 
+// Optional: grounded rewrite endpoint for local Ollama usage.
+app.post('/api/chatbot-grounded-rewrite', async (req, res) => {
+  if (!CHATBOT_LLM_ENABLED) {
+    res.status(503).json({
+      ok: false,
+      message: 'Chatbot LLM is disabled. Set CHATBOT_LLM_ENABLED=true to enable.',
+    })
+    return
+  }
+
+  const question = typeof req.body?.question === 'string' ? req.body.question.trim() : ''
+  const draftAnswer = typeof req.body?.draftAnswer === 'string' ? req.body.draftAnswer.trim() : ''
+  const sources = Array.isArray(req.body?.sources)
+    ? req.body.sources.filter(source => typeof source === 'string').slice(0, 8)
+    : []
+  const contextChunks = normalizeChatbotLlmContext(req.body?.contextChunks)
+
+  if (!question) {
+    res.status(400).json({ ok: false, message: 'Missing required field: question' })
+    return
+  }
+
+  if (!draftAnswer) {
+    res.status(400).json({ ok: false, message: 'Missing required field: draftAnswer' })
+    return
+  }
+
+  try {
+    const rewrittenAnswer = await rewriteWithChatbotLlm({
+      question,
+      draftAnswer,
+      sources,
+      contextChunks,
+    })
+
+    res.json({
+      ok: true,
+      text: rewrittenAnswer,
+      model: CHATBOT_LLM_MODEL,
+      grounded: true,
+    })
+  } catch (err) {
+    console.error('[chatbot-llm] rewrite failed:', err)
+    res.status(502).json({
+      ok: false,
+      message: 'LLM rewrite failed. Returning deterministic draft is recommended.',
+      error: String(err),
+    })
+  }
+})
+
 // Admin: get all entries
 app.get('/api/admin/chatbot-content', async (req, res) => {
   if (!isValidAdminSession(req)) { res.status(401).json({ message: 'Not authenticated.' }); return }