aiEngine.js

const axios = require('axios');

/**
 * Generates human-friendly insights, outreach copy, and sales materials
 * @param {Object} audit - The completed website audit results
 * @param {string} businessName - Raw name of the business
 * @returns {Promise<Object>}
 */
async function generateInsights(audit, businessName = 'Business Owner') {
  const name = businessName === 'Business Owner' ? 'there' : businessName;
  const domain = audit.url.replace(/https?:\/\/(www\.)?/, '').replace(/\/$/, '');

  // 1. Attempt to use Gemini API if environment variable is configured
  const apiKey = process.env.GEMINI_API_KEY;
  if (apiKey) {
    try {
      const geminiResult = await callGeminiAPI(apiKey, audit, businessName);
      if (geminiResult) return geminiResult;
    } catch (e) {
      console.warn('[AI Engine] Gemini API call failed. Falling back to Heuristics:', e.message);
    }
  }

  // 2. Deterministic Heuristic Compiler (Reliable fallback)
  return compileHeuristicInsights(audit, name, domain);
}

/**
 * Deterministic Heuristics Generator for B2B Insights
 */
function compileHeuristicInsights(audit, name, domain) {
  // A. Determine Flaws
  const flaws = [];
  const wellDone = [];

  // Evaluate SSL
  if (!audit.ssl.passed) {
    flaws.push({
      item: 'Insecure Connection (HTTP)',
      desc: 'Website loads over HTTP without encryption. Chrome marks it as "Not Secure", hurting customer trust.',
      impact: 'Critical. 82% of users leave insecure sites instantly, and search engines heavily penalize non-HTTPS rankings.',
      service: 'SSL Setup & Security Redirection Installation'
    });
  } else {
    wellDone.push('SSL Protection: Active. Secure connection encrypts user submissions.');
  }

  // Evaluate Viewport
  if (!audit.mobile.passed) {
    flaws.push({
      item: 'Non-Responsive Mobile Layout',
      desc: 'Missing viewport tags. The site will scale down on phones, forcing visitors to pinch-to-zoom.',
      impact: 'Severe. 57% of users say they won\'t recommend a business with a poorly designed mobile site.',
      service: 'Mobile-Friendly Landing Page Redesign'
    });
  } else if (audit.mobile.zoomBlocked) {
    flaws.push({
      item: 'Mobile Scaling Blocked',
      desc: 'Mobile viewport config disables pinch-to-zoom scaling, which hurts accessibility standards.',
      impact: 'Moderate. Visually impaired users will struggle to read text details.',
      service: 'Viewport Meta Tag Optimization'
    });
    wellDone.push('Mobile Viewport: Present. Adapts layout to smaller screens.');
  } else {
    wellDone.push('Mobile Viewport: Present. Mobile responsive features are fully unlocked.');
  }

  // Evaluate Page Speed
  if (audit.performance.rating === 'Poor') {
    flaws.push({
      item: 'Slow Page Load Latency',
      desc: `The page took ${Math.round(audit.responseTimeMs / 100) / 10}s to respond. Total scripts loaded: ${audit.performance.scriptsLoaded}.`,
      impact: 'High. Conversion rate drops by an average of 4.4% for every additional second of load time.',
      service: 'Speed Optimization Package (Asset minification, lazy loading, script deferrals)'
    });
  } else if (audit.performance.rating === 'Fair') {
    flaws.push({
      item: 'Moderate Latency Overhead',
      desc: `Page response latency is ${audit.responseTimeMs}ms with ${audit.performance.scriptsLoaded} scripts loaded.`,
      impact: 'Low. Minor latency could be optimized to improve mobile page scores.',
      service: 'Static Resource Compression and Web Caching Setup'
    });
    wellDone.push('Performance: Fair. The site loads in a reasonable amount of time.');
  } else {
    wellDone.push('Performance: Excellent. Server latency is fast under 800ms.');
  }

  // Evaluate Meta Tags
  if (!audit.metadata.description) {
    flaws.push({
      item: 'Missing SEO Description Tag',
      desc: 'Search descriptions are missing in page headers.',
      impact: 'High. search engines list raw text strings in search snippets instead of highly appealing summaries.',
      service: 'Search Engine Optimization (SEO Audit & Meta Tag configuration)'
    });
  } else {
    wellDone.push('Meta Tags: SEO description is correctly declared.');
  }

  // Evaluate Headings
  if (audit.headingStructure.h1Count !== 1) {
    flaws.push({
      item: audit.headingStructure.h1Count === 0 ? 'Missing H1 Topic Header' : `Multiple H1 Headers (${audit.headingStructure.h1Count})`,
      desc: audit.headingStructure.message,
      impact: 'Medium. Search engines crawl H1 tags to understand page layout and context.',
      service: 'Homepage Heading Hierarchy and Content Structuring'
    });
  } else {
    wellDone.push('Heading Schema: Single H1 tag present, defining page outline.');
  }

  // Evaluate Pixels / Tracking
  if (!audit.analytics.facebookPixel) {
    flaws.push({
      item: 'Missing Facebook Retargeting Pixel',
      desc: 'No Facebook tracking scripts were detected.',
      impact: 'Medium. Business cannot track homepage visitors to execute custom retargeting ads.',
      service: 'Facebook Pixel Setup & Customer Retargeting Campaign Setup'
    });
  } else {
    wellDone.push('Retargeting: Facebook Pixel script is embedded.');
  }

  if (!audit.analytics.googleAnalytics) {
    flaws.push({
      item: 'Missing Google Analytics Script',
      desc: 'No Google Analytics/Tag Manager tags found.',
      impact: 'Medium. Website owners cannot see how many users visit or identify traffic drop-off loops.',
      service: 'Google Analytics 4 (GA4) Configuration & Event Tracking Dashboard'
    });
  } else {
    wellDone.push('Analytics: Google Analytics metrics are active.');
  }

  // Evaluate Sitemap / Robots
  if (!audit.xmlFiles.robotsTxt) {
    flaws.push({
      item: 'Missing robots.txt Crawler Rules',
      desc: 'robots.txt not found at site root.',
      impact: 'Low. Search engine crawlers do not have explicit guides on indexing restrictions.',
      service: 'Robots.txt Crawl Direction Setup'
    });
  } else {
    wellDone.push('robots.txt: Active. Directs search crawlers.');
  }

  if (!audit.xmlFiles.sitemapXml) {
    flaws.push({
      item: 'Missing sitemap.xml Directory',
      desc: 'sitemap.xml not found at site root.',
      impact: 'Medium. hurts crawler efficiency for discoverability of subpages.',
      service: 'Dynamic Sitemap.xml Generation'
    });
  } else {
    wellDone.push('sitemap.xml: Active. Simplifies crawling.');
  }

  // Evaluate Schema
  if (!audit.schema.passed) {
    flaws.push({
      item: 'Missing Schema Structured Markup',
      desc: 'No JSON-LD structured data detected.',
      impact: 'Low. Page fails to yield rich-snippets on search results pages.',
      service: 'JSON-LD Business Schema Schema Markup Integration'
    });
  } else {
    wellDone.push('Structured Schema: JSON-LD active, facilitating search snippet rich elements.');
  }

  // Fallback well done if list is short
  if (wellDone.length === 0) {
    wellDone.push('Domain registration is active and page returns success codes.');
  }

  // Ensure flaws has at least 3 items to look comprehensive
  if (flaws.length === 0) {
    flaws.push(
      {
        item: 'Missing Call-To-Action (CTA) Optimization',
        desc: 'Page does not feature obvious visual lead capture buttons.',
        impact: 'High. Lower conversions due to user confusion on how to book.',
        service: 'Conversion Rate Optimization (CRO) Setup'
      },
      {
        item: 'Image Compression',
        desc: 'Images are saved in standard PNG/JPG formats instead of modern compression formats (WebP).',
        impact: 'Low. Adding WebP format reduces load speeds.',
        service: 'Image Format Modernization & Optimization'
      }
    );
  }

  // Sort flaws: high impact first
  const sortedFlaws = flaws.slice(0, 5); // limit to top 5

  // B. Services Suggestion & Project Value
  const services = [];
  let projectValue = 0;

  sortedFlaws.forEach(fl => {
    services.push(fl.service);
    if (fl.item.includes('SSL')) projectValue += 5000;
    else if (fl.item.includes('Mobile') || fl.item.includes('Responsive')) projectValue += 20000;
    else if (fl.item.includes('Latency') || fl.item.includes('Speed')) projectValue += 12000;
    else if (fl.item.includes('Meta') || fl.item.includes('Description') || fl.item.includes('SEO')) projectValue += 8000;
    else if (fl.item.includes('Pixel') || fl.item.includes('Facebook')) projectValue += 6000;
    else if (fl.item.includes('Analytics')) projectValue += 5000;
    else projectValue += 4000;
  });

  if (projectValue < 10000) projectValue = 10000; // minimum project value

  // C. Impact Estimate & Sales Angle
  let impactMessage = 'Fixing these vulnerabilities is expected to reduce bounce rates by 20-30%, boost local search position rankings within 30 days, and allow launching targeted ads to retarget traffic.';
  let salesAngle = 'The Leak Angle: Focus on the fact that they are already getting users, but losing them immediately due to structural site issues. You are here to plug the leaks, not just charge for traffic.';

  if (!audit.ssl.passed) {
    impactMessage = 'Activating SSL immediately eliminates browser security warnings that scare away 80%+ of users. This is single-handedly the highest conversion lift possible for this site.';
    salesAngle = 'The Trust Angle: Frame the conversation around brand security. Explain that their prospective clients are seeing warning messages warning them their connection isn\'t private, destroying client trust.';
  } else if (!audit.mobile.passed) {
    impactMessage = 'Enabling mobile responsiveness will resolve conversion loss on phone screens. Over 60% of local searches happen on mobile; resolving this will immediately double their phone inquiry rate.';
    salesAngle = 'The Mobile Penalty Angle: Pitch the mobile usability check. Highlight that Google filters out non-responsive sites from mobile searches, rendering them invisible to local prospective patients/clients.';
  }

  // D. Compile Cold Email outreach
  const flawsListStr = sortedFlaws.map(f => `• ${f.item}: ${f.desc}`).join('\n');
  const coldEmail = `Subject: Quick technical feedback for ${domain}

Hi ${name},

I was researching local businesses in your area and came across your website (${domain}).

I noticed a few technical bottlenecks that are likely costing you clients:

${flawsListStr}

I specialize in resolving these exact web constraints for local businesses to increase their digital booking conversion rates.

I have put together a visual audit report outlining how we can fix this. Would you be open to a quick 5-minute chat sometime this week?

Best regards,

[Your Name]
[Your Contact Info]`;

  // LinkedIn message
  const linkedinMessage = `Hi ${name}, I came across ${domain} and noticed a couple of mobile accessibility flaws that could be leaking search traffic. I put together a quick 2-page audit outline for you. Would you mind if I sent it over here?`;

  // Follow-up Email
  const followUpEmail = `Subject: Re: Website feedback for ${domain}

Hi ${name},

I wanted to quickly follow up on the website audit I sent over for ${domain} a few days ago.

I understand you are busy running the business! I wanted to share one quick detail: fixing just the page loading issues can improve your organic visibility ranking on Google.

If you already have a team handling this, I would be happy to send the detailed report directly to them. Otherwise, let me know if you have 5 minutes to chat!

Best,

[Your Name]`;

  // Objections handlers
  const objections = [
    {
      objection: "We already have a web designer/agency.",
      handle: "That's great! Feel free to pass this audit report directly to them to fix. If they are busy or want a second opinion on implementation, I am here to help."
    },
    {
      objection: "Our website is not how we get clients.",
      handle: "True, word of mouth is powerful. But when referrals hear your name, the first thing they do is Google you. If they see a slow, insecure site, they might go with a competitor instead."
    },
    {
      objection: "We don't have budget for this right now.",
      handle: "I understand. Let's focus on the SSL security fix first—it takes under an hour and costs very little, but stops the browser security warning which is the most critical issue."
    }
  ];

  return {
    wellDone,
    improvements: sortedFlaws,
    estimatedImpact: impactMessage,
    suggestedServices: services,
    salesAngle,
    estimatedProjectValueInr: projectValue,
    coldEmail,
    linkedinMessage,
    followUpEmail,
    objections
  };
}

/**
 * Invokes Gemini Flash API for custom generative insights
 */
async function callGeminiAPI(apiKey, audit, businessName) {
  const model = 'gemini-1.5-flash';
  const url = `https://generativelanguage.googleapis.com/v1beta/models/${model}:generateContent?key=${apiKey}`;

  const prompt = `Analyze this website audit JSON and generate high-quality sales insights.
Business Name: ${businessName}
Target URL: ${audit.url}
Audit JSON: ${JSON.stringify(audit, null, 2)}

You must return a raw JSON object containing these exact keys (do not wrap in markdown blocks, return only the JSON string):
{
  "wellDone": ["array of 3 text points describing what the site does well"],
  "improvements": [
    {
      "item": "Name of flaw",
      "desc": "Detail of what is broken",
      "impact": "Description of negative impact"
    }
  ],
  "estimatedImpact": "overall impact of fixing the site",
  "suggestedServices": ["list of services to pitch"],
  "salesAngle": "recommended hook to close the client",
  "estimatedProjectValueInr": 25000,
  "coldEmail": "complete cold outreach email",
  "linkedinMessage": "short linkedin connection note",
  "followUpEmail": "follow up email copy",
  "objections": [
    {
      "objection": "common objection based on their site state",
      "handle": "how the user should counter this objection"
    }
  ]
}`;

  const response = await axios.post(url, {
    contents: [
      {
        parts: [
          { text: prompt }
        ]
      }
    ],
    generationConfig: {
      responseMimeType: 'application/json'
    }
  }, {
    timeout: 8000
  });

  if (response.status === 200) {
    const content = response.data?.candidates?.[0]?.content?.parts?.[0]?.text;
    if (content) {
      return JSON.parse(content);
    }
  }
  return null;
}

/**
 * AI-assisted lead scoring and priority ranking
 */
function scoreAndPrioritizeLead(lead) {
  if (!lead) return { priority: 'Low', score: 0, hooks: [], followUpDays: 10 };

  let score = 0;
  const hooks = [];

  // Evaluate SSL
  if (lead.ssl && !lead.ssl.passed) {
    score += 35;
    hooks.push('Connection Safety: Lacks SSL encryption, showing Chrome "Not Secure" alerts.');
  }

  // Evaluate Mobile responsivenes
  if (lead.mobile && !lead.mobile.passed) {
    score += 30;
    hooks.push('Mobile Responsiveness: Viewport is not configured to scale layout elements on phones.');
  }

  // Evaluate Speed Rating
  if (lead.performance && lead.performance.rating === 'Poor') {
    score += 20;
    hooks.push('Load Latency: Response latency exceeds 2 seconds, which increases user bounce rates.');
  }

  // Evaluate Meta SEO
  if (lead.metadata && !lead.metadata.description) {
    score += 15;
    hooks.push('SEO Description Tag: Missing header search snippet metadata in page headers.');
  }

  // Evaluate Security Headers
  if (lead.securityHeaders && !lead.securityHeaders.passed) {
    score += 15;
    hooks.push('Security Headers: Missing CSP (Content Security Policy) or HSTS protection headers.');
  }

  // Final priority calculation
  let priority = 'Low';
  if (score >= 60) {
    priority = 'High';
  } else if (score >= 30) {
    priority = 'Medium';
  }

  return {
    priority,
    score,
    hooks,
    followUpDays: priority === 'High' ? 3 : (priority === 'Medium' ? 6 : 12)
  };
}

/**
 * AI-assisted Payment Verification Loop (Security Audits on UTR inputs)
 */
function verifyPaymentUTR(utrText, databaseTransactions = [], currentTxId = null) {
  if (!utrText) {
    return { confidenceScore: 0, recommendation: 'Reject', reasoning: 'No Transaction Reference UTR number was provided.' };
  }
  
  const cleanUtr = utrText.trim();
  
  // Format check: must be exactly 12 numeric digits
  if (!/^\d{12}$/.test(cleanUtr)) {
    return {
      confidenceScore: 0,
      recommendation: 'Reject',
      reasoning: `Format check failed: UTR must be exactly 12 digits. Received ${cleanUtr.length} characters.`
    };
  }

  // Duplicate check: compare against historical approvals/pendings, excluding the current transaction ID
  const duplicate = databaseTransactions.find(t => t.utr === cleanUtr && t.id !== currentTxId && t.status !== 'rejected');
  if (duplicate) {
    return {
      confidenceScore: 10,
      recommendation: 'Reject',
      reasoning: `Security Warning: This reference UTR has already been submitted by user ID "${duplicate.userId}".`
    };
  }

  const anomalies = [];

  // Check repeating single numbers (e.g. 111111111111)
  if (/^(\d)\1{11}$/.test(cleanUtr)) {
    anomalies.push('repeating single digit patterns');
  }

  // Check sequential numerical chains (e.g. 123456789012)
  const sequences = ['123456789012', '987654321098', '012345678901', '121212121212', '1234567890'];
  sequences.forEach(seq => {
    if (cleanUtr.includes(seq)) {
      anomalies.push(`sequential number sequences like "${seq}"`);
    }
  });

  // Check alternating digits (e.g. 121212121212)
  if (cleanUtr.slice(0, 2).repeat(6) === cleanUtr) {
    anomalies.push('simple alternating digit patterns');
  }

  if (anomalies.length > 0) {
    return {
      confidenceScore: 25,
      recommendation: 'Flagged',
      reasoning: `Security alert: Suspicious pattern detected (${anomalies.join(', ')}). Manual verification required.`
    };
  }

  // Clean success state
  return {
    confidenceScore: 95,
    recommendation: 'Approve',
    reasoning: 'UTR matches valid format constraints, has no repeating sequence anomalies, and is not a duplicate in approval lists.'
  };
}

/**
 * AI-assisted conversation summarization
 */
function summarizeConversation(notesText) {
  if (!notesText) return 'No conversation history logged yet.';
  
  const lines = notesText.split('\n').map(l => l.trim()).filter(l => l.length > 0);
  if (lines.length === 0) return 'No conversation history logged.';

  // Deterministic summary builder based on key B2B markers
  const bullets = [];
  lines.forEach(line => {
    if (line.toLowerCase().includes('call') || line.toLowerCase().includes('phone')) {
      bullets.push(`📞 Prospect contacted via Call: ${line}`);
    } else if (line.toLowerCase().includes('email') || line.toLowerCase().includes('sent')) {
      bullets.push(`✉️ Outreach message sent: ${line}`);
    } else if (line.toLowerCase().includes('budget') || line.toLowerCase().includes('price')) {
      bullets.push(`💰 Budget / Price discussed: ${line}`);
    } else if (line.toLowerCase().includes('yes') || line.toLowerCase().includes('won') || line.toLowerCase().includes('agree')) {
      bullets.push(`✅ positive progression: ${line}`);
    } else {
      bullets.push(`• Logged: ${line}`);
    }
  });

  return bullets.slice(0, 5).join('\n'); // Return top 5 events
}

/**
 * AI Email Assistant router: uses Gemini API if key is present, otherwise falls back to heuristics
 */
async function generateAiEmail({ type, data = {}, tone = 'Professional', text = '' }) {
  const apiKey = process.env.GEMINI_API_KEY;
  if (apiKey && apiKey !== 'dummy_gemini_key') {
    try {
      return await runGeminiEmailAssistant(apiKey, { type, data, tone, text });
    } catch (err) {
      console.warn('[AI Email Assistant] Gemini prompt failed, falling back to heuristics:', err.message);
    }
  }
  return runHeuristicEmailAssistant({ type, data, tone, text });
}

/**
 * Heuristic B2B template copies fallback
 */
function runHeuristicEmailAssistant({ type, data, tone, text }) {
  const niche = data.niche || 'business';
  const name = data.businessName || 'Business Owner';
  const url = data.url || 'your website';
  const flaws = data.flaws || [];
  
  if (type === 'cold') {
    const hooks = flaws.length > 0 
      ? flaws.map(f => `• ${f}`).join('\n') 
      : '• Mobile Layout constraints: viewport scale needs adjustment\n• Security headers: CSP tag missing';
      
    let subject = `Quick feedback regarding ${niche} optimization for ${name}`;
    let body = `Hi ${name},\n\nI was reviewing local sites in the area and came across ${url}.\n\nI noticed a couple of tech constraints:\n\n${hooks}\n\nWe specialize in implementing responsive repairs to maximize booking conversions. Would you be open to a brief call next Tuesday?\n\nBest,\n[Your Name]`;
    
    if (tone === 'Casual') {
      subject = `quick suggestion for ${name}`;
      body = `Hi there,\n\nI checked out ${url} today. It looks really nice, but I found a few layout errors on mobile screen viewports.\n\nWe fix mobile conversions for ${niche}s. Do you have a few minutes this week to chat?\n\nThanks!\n[Your Name]`;
    } else if (tone === 'Bold') {
      subject = `Are you losing mobile clients at ${name}?`;
      body = `Hi ${name},\n\nOver 60% of search traffic happens on phones, but ${url} isn't optimized for viewport styling.\n\nLet's get this resolved. I can fix this viewport and secure your site under an hour. When are you free?\n\nRegards,\n[Your Name]`;
    }

    return { subject, body };
  }
  
  if (type === 'followup') {
    const prevSub = data.lastSubject || 'our previous suggestion';
    const subject = `Re: ${prevSub}`;
    let body = `Hi ${name},\n\nI wanted to quickly follow up on the mobile conversion feedback I sent over for ${url} a few days ago.\n\nI know you're busy! Let me know if you want me to coordinate directly with your developer, or if you'd like a quick call.\n\nBest,\n[Your Name]`;

    if (tone === 'Casual') {
      body = `Hi,\n\nJust popping this to the top of your inbox. Did you get a chance to check out those viewport issues on ${url}?\n\nLet me know if I can help!\n\nThanks,\n[Your Name]`;
    }
    return { subject, body };
  }

  if (type === 'subject') {
    const subject = text || `Feedback for ${url}`;
    return {
      subjects: [
        `💡 Quick suggestion regarding ${niche} visibility`,
        `Fixing 2 viewport bottlenecks at ${name}`,
        `Quick question for the owner of ${url}`
      ]
    };
  }

  if (type === 'rewrite') {
    let rewritten = text || '';
    if (tone === 'Casual') {
      rewritten = `Hey! Just wanted to share some quick feedback on your website. I noticed a couple of mobile scaling bugs that are easy to fix. Let me know if you want to chat!`;
    } else if (tone === 'Professional') {
      rewritten = `Dear Owner,\n\nI am writing to share some technical observations regarding your business website. We identified several responsive design opportunities. I would welcome the opportunity to discuss how we can resolve these.`;
    } else if (tone === 'Direct') {
      rewritten = `Hi, your website has viewport layout issues on mobile screens. We can fix this to secure your organic search rankings. Let me know if you have 5 minutes.`;
    }
    return { body: rewritten };
  }

  if (type === 'summary') {
    const snippet = text || 'No email history logged.';
    return {
      summary: `Outreach initiated. Discussed mobile viewport scaling issues and offered booking optimization fixes.`
    };
  }

  return { subject: 'Outreach Draft', body: text };
}

/**
 * Gemini Prompt generative assistant
 */
async function runGeminiEmailAssistant(apiKey, { type, data, tone, text }) {
  const model = 'gemini-1.5-flash';
  const url = `https://generativelanguage.googleapis.com/v1beta/models/${model}:generateContent?key=${apiKey}`;

  let prompt = '';
  
  if (type === 'cold') {
    prompt = `Generate a high-converting B2B cold outreach email in a ${tone} tone.
Niche: ${data.niche || 'business'}
Business Name: ${data.businessName || 'Business'}
Website URL: ${data.url || 'website'}
Site Technical Flaws: ${(data.flaws || []).join(', ')}

Return a raw JSON object only containing these exact keys (no markdown wrapping block):
{
  "subject": "curiosity-driven subject line",
  "body": "short outreach email body requiring user review"
}`;
  } else if (type === 'followup') {
    prompt = `Generate a short follow-up outreach email in a ${tone} tone.
Recipient Name: ${data.businessName || 'Business Owner'}
Last outreach message subject: ${data.lastSubject || ''}
Last outreach snippet: ${text || ''}

Return a raw JSON object only containing these exact keys:
{
  "subject": "Re: last subject line",
  "body": "short follow-up email body"
}`;
  } else if (type === 'subject') {
    prompt = `Generate 3 high-converting alternative subject lines for the niche "${data.niche || 'business'}" to replace this subject: "${text}".
Return a raw JSON object only containing this exact key:
{
  "subjects": ["Subject Option 1", "Subject Option 2", "Subject Option 3"]
}`;
  } else if (type === 'rewrite') {
    prompt = `Correct spelling, improve grammar, and rewrite this outreach copy in a ${tone} tone:
"${text}"

Return a raw JSON object only containing this exact key:
{
  "body": "rewritten email text"
}`;
  } else if (type === 'summary') {
    prompt = `Summarize this email conversation thread in 2 bullet points:
"${text}"

Return a raw JSON object only containing this exact key:
{
  "summary": "bullet point summary text"
}`;
  }

  const response = await axios.post(url, {
    contents: [{ parts: [{ text: prompt }] }],
    generationConfig: { responseMimeType: 'application/json' }
  }, { timeout: 8000 });

  if (response.status === 200) {
    const rawContent = response.data?.candidates?.[0]?.content?.parts?.[0]?.text;
    if (rawContent) {
      return JSON.parse(rawContent);
    }
  }
  throw new Error('Gemini API returned empty response.');
}

module.exports = {
  generateInsights,
  scoreAndPrioritizeLead,
  verifyPaymentUTR,
  summarizeConversation,
  generateAiEmail
};