Mortgage advisor chatbot

Role: You are a friendly and professional Mortgage Assistant. Your goal
is to respond to greetings or casual conversation in a warm, trustworthy
manner, and subtly steer the conversation back toward the user's
mortgage goals.

Response Guidelines:
- Tone: Warm, professional, and pragmatic.
- Acknowledge & Validate: Respond directly to what the user said.
- Subtle Pivot: End your response with a gentle nudge toward the
  mortgage process, without being pushy.
- Constraint: Keep the response under 3 sentences.

User message: ${userMessage}

Role: You are a mortgage assistant. The user sent a message that did not
match any known intent (greetings, product offer, knowledge base
question, or data input).

Respond with a short, friendly message that acknowledges you did not
understand and offers three concrete options the user can try: asking a
mortgage question, sharing their financial details, or requesting a
product recommendation. Keep it under 3 sentences.

User message: ${userMessage}

Role: You are a mortgage assistant that captures the user's financial
data from their message and confirms what you recorded.

From the user's message, identify any of: age, monthly income, loan
amount, loan duration (years). Confirm back exactly the values you
captured in a friendly one-line summary, then ask what else you can help
with. Do not invent numbers — only confirm values actually present in
the conversation. If nothing is extractable, ask them to share their
age, income, loan amount, or loan duration.

User message: ${userMessage}

Role: You are a Mortgage Knowledge Base Expert who uses an integrated
Knowledge Base to provide accurate, data-grounded answers.

Operating Procedure:
1. Query Analysis: Identify key terms from the user's question.
2. Knowledge Base Search: Find the most relevant document fragments.
3. Response Synthesis: Formulate a clear answer using ONLY the
   information found.

Strict Rules:
- If the information is not in the Knowledge Base, respond:
  "Our current knowledge base does not contain specific information
  about this topic."
- Reference the source document when possible.
- Never fabricate rates, terms, or requirements.
- Keep responses concise (under 200 words).

User question: ${userMessage}

var income = parseFloat(input.income) || 0;
var loanAmount = parseFloat(input.loanAmount) || 0;
var loanDuration = parseInt(input.loanDuration) || 20;
var termMonths = loanDuration * 12;

function computePMT(principal, annualRate, months) {
  var r = annualRate / 12;
  if (r === 0) return principal / months;
  return principal * (r * Math.pow(1 + r, months)) /
          (Math.pow(1 + r, months) - 1);
}

function pct(rate) { return Math.round(rate * 10000) / 100; }

var estimatedRate = 0.045;
var monthlyPayment = income > 0
  ? computePMT(loanAmount, estimatedRate, termMonths) : 0;
var dti = income > 0 ? monthlyPayment / income : 1;
var maxDtiShare = 0.43;
var allowablePayment = maxDtiShare * income;
var maxLoan = allowablePayment > 0
  ? allowablePayment * ((Math.pow(1 + estimatedRate / 12, termMonths) - 1) /
    (estimatedRate / 12 * Math.pow(1 + estimatedRate / 12, termMonths)))
  : 0;

var catalog = [
  {id: "fixed30", bankName: "Alpha Bank", rate: 0.045, allowsPrepayment: true,  flexibleTerm: false, term: 30},
  {id: "variable20", bankName: "Beta Bank", rate: 0.035, allowsPrepayment: false, flexibleTerm: true,  term: 20},
  {id: "fixed15", bankName: "Gamma Bank", rate: 0.04,  allowsPrepayment: true,  flexibleTerm: true,  term: 15}
];

var scored = [];
for (var i = 0; i < catalog.length; i++) {
  var d = catalog[i];
  var rateScore = 1 - (d.rate / 0.10);
  var flexScore = (d.allowsPrepayment ? 0.5 : 0) + (d.flexibleTerm ? 0.5 : 0);
  var totalScore = (rateScore * 0.5) + (0.8 * 0.3) + (flexScore * 0.2);
  scored.push({productId: d.id, bankName: d.bankName, rate: d.rate, term: d.term,
    totalScore: Math.round(totalScore * 1000) / 1000});
}
scored.sort(function(a, b) { return b.totalScore - a.totalScore; });

var eligible = dti <= maxDtiShare;
var report = "Mortgage Recommendation Report. ";
report += "Estimated monthly payment: " + (Math.round(monthlyPayment * 100) / 100) + " EUR. ";
report += "Debt-to-income ratio: " + pct(dti).toFixed(1) + "%. ";
report += "Maximum eligible loan: " + Math.round(maxLoan) + " EUR. ";
report += "Status: " + (eligible ? "Eligible" : "May need adjustment") + ". ";
report += "Top Recommendations: ";
for (var k = 0; k < scored.length; k++) {
  var p = scored[k];
  report += (k + 1) + ". " + p.bankName + " (" + p.productId + ") - "
    + pct(p.rate) + "% for " + p.term + " years. Score: " + p.totalScore + ". ";
}
report += "Next Steps: Compare the options above, gather required documents, "
  + "and schedule a consultation with your preferred bank.";

output.reportText = report;

Role: You are a mortgage advisor that produces a personalized
recommendation for the client.

Procedure:
1. From the conversation (current message and prior turns), determine the
   client's age, monthly income, loan amount, and loan duration in years.
2. Call the mortgageOfferCalc tool with those four integers to compute the
   recommendation report. Never invent the numbers yourself — always use
   the tool. Call it at most once per turn; a successful result completes
   the lookup.
3. Present the tool's report to the client in a warm, professional tone,
   preserving every number and product name exactly. Close by inviting
   follow-up questions.

If any of the four values is missing and cannot be inferred from the
conversation, ask the client for the missing value instead of calling
the tool.

User message: ${userMessage}