Get a daily report of unanswered emails from actual humans, using Gemini

@Gmail find the emails I haven't replied to

function sendEmailRecapWithGemini() {
  const REPORT_RECIPIENT = "[email protected]";
 
  // 1. Emails from the last 24 hours
  const query = "newer_than:1d";
  const threads = GmailApp.search(query);
  if (threads.length === 0) {
    Logger.log("No new email in the last 24 hours.");
    return;
  }
 
  const emailsToAnalyze = [];
 
  for (let i = 0; i < threads.length; i++) {
    const thread = threads[i];
    const messages = thread.getMessages();
    const lastMessage = messages[messages.length - 1];
 
    // Skip if I already replied (last message in the thread is mine)
    const sender = lastMessage.getFrom();
    if (sender.includes(GmailApp.getAliases()[0]) ||
        sender.includes(Session.getActiveUser().getEmail())) {
      continue;
    }
 
    // Body excerpt, to stay within token limits
    const bodyText = lastMessage.getPlainBody().substring(0, 1500);
 
    emailsToAnalyze.push({
      id: i,
      sender: sender,
      subject: lastMessage.getSubject(),
      excerpt: bodyText,
      link: thread.getPermalink()
    });
  }
 
  if (emailsToAnalyze.length === 0) {
    Logger.log("No pending emails after preliminary checks.");
    return;
  }
 
  // 2. The fuzzy prompt
  const prompt = `Act as an extremely smart personal assistant. Analyze this list of emails received in the last 24 hours.
Your only goal is to identify ONLY the emails written by real people (clients, colleagues, partners, friends) that require a reply, an action or my attention.
 
Strictly exclude:
- News, update or marketing newsletters.
- Automated transactional emails (purchase receipts, booking confirmations, platform notifications, system alerts).
- Social notifications or generic messages from commercial bots.
 
For each email you genuinely believe requires a human reply, fill in this JSON schema. Reply EXCLUSIVELY with valid JSON, no text before or after:
[
  {
    "id": ,
    "reason": ""
  }
]
 
Here is the list of emails to analyze:
${JSON.stringify(emailsToAnalyze, null, 2)}`;
 
  // 3. Calling Gemini
  let selectedEmails = [];
  try {
    const apiKey = PropertiesService.getScriptProperties().getProperty("GEMINI_KEY");
    if (!apiKey) {
      Logger.log("Error: GEMINI_KEY not found in script properties.");
      return;
    }
 
    const url = `https://generativelanguage.googleapis.com/v1beta/models/gemini-1.5-flash:generateContent?key=${apiKey}`;
 
    const payload = {
      contents: [{ parts: [{ text: prompt }] }],
      generationConfig: { responseMimeType: "application/json" } // forces clean JSON
    };
 
    const response = UrlFetchApp.fetch(url, {
      method: "POST",
      contentType: "application/json",
      payload: JSON.stringify(payload),
      muteHttpExceptions: true
    });
 
    const jsonResponse = JSON.parse(response.getContentText());
    if (jsonResponse.candidates && jsonResponse.candidates[0].content.parts[0].text) {
      const modelText = jsonResponse.candidates[0].content.parts[0].text;
      selectedEmails = JSON.parse(modelText);
    } else {
      Logger.log("Unexpected response from Gemini: " + response.getContentText());
      return;
    }
  } catch (error) {
    Logger.log("Error while calling Gemini: " + error);
    return;
  }
 
  // 4. The final report
  if (selectedEmails && selectedEmails.length > 0) {
    let body = "Hi,\n\nGemini went through the mailbox and isolated these emails from real people waiting for a reply:\n\n";
    selectedEmails.forEach((sel, idx) => {
      const e = emailsToAnalyze.find(x => x.id === sel.id);
      if (e) {
        body += `${idx + 1}. From: ${e.sender}\n   Subject: ${e.subject}\n   Context: ${sel.reason}\n   Reply: ${e.link}\n\n`;
      }
    });
    GmailApp.sendEmail(
      REPORT_RECIPIENT,
      `[Smart Report] ${selectedEmails.length} emails to reply to`,
      body
    );
    Logger.log("Smart report sent.");
  } else {
    Logger.log("No human emails to report today.");
  }
}