import { PayloadRequest } from "payload";

export const bulkMailEndpointHandler = async (req: PayloadRequest) => {
  try {
    let body: any = {};
    if (req.body) {
      try {
        body = (await req.json?.()) || {};
      } catch (_e) {
        body = req.body;
      }
    }

    const { contactIds, instructions, isTest } = body;

    if (!req.user) {
      return Response.json(
        { success: false, error: "Unauthorized" },
        { status: 401 },
      );
    }

    if (!Array.isArray(contactIds) || contactIds.length === 0) {
      return Response.json(
        { success: false, error: "No contacts selected" },
        { status: 400 },
      );
    }

    const OPENROUTER_KEY =
      process.env.OPENROUTER_KEY || process.env.OPENROUTER_API_KEY;
    if (!OPENROUTER_KEY) {
      return Response.json(
        { success: false, error: "Missing OPENROUTER_API_KEY" },
        { status: 500 },
      );
    }

    const sentEmails = [];
    const interactions = [];

    for (const contactId of contactIds) {
      // Fetch contact with account populated
      const contact = await req.payload.findByID({
        collection: "crm-contacts",
        id: contactId,
        depth: 1,
      });

      if (!contact || !contact.email) continue;

      const account = contact.account as any;
      const accountInfo = account
        ? `
Company Name: ${account.name || "Unknown"}
Website: ${account.website || "Unknown"}
Industry: ${account.industry || "Unknown"}
Website Status: ${account.websiteStatus || "Unknown"}
Internal Notes: ${account.notes || "None"}
      `
        : "No company information available.";

      const prompt = `You are an expert sales/business development AI assistant. Write a professional, personalized German B2B outreach email ("Anschreiben").
      
CONTEXT ABOUT THE CONTACT:
Name: ${contact.fullName || contact.firstName || "Unknown"}
Role: ${contact.role || "Unknown"}

CONTEXT ABOUT THEIR COMPANY:
${accountInfo}

USER INSTRUCTIONS / GOAL OF THE EMAIL:
${instructions}

CRITICAL INSTRUCTIONS:
1. Write the email subject on the FIRST line as: "SUBJECT: <Your Subject>"
2. The rest of the message should be the email body.
3. Keep it professional and natural in German (Sie-form unless you think Du is appropriate based on the industry, but prefer Sie).
4. Output only the email text, no markdown code blocks around it. No extra chit-chat.
`;

      const res = await fetch("https://openrouter.ai/api/v1/chat/completions", {
        method: "POST",
        headers: {
          Authorization: `Bearer ${OPENROUTER_KEY}`,
          "Content-Type": "application/json",
        },
        body: JSON.stringify({
          model: "google/gemini-3-flash-preview",
          messages: [{ role: "user", content: prompt }],
        }),
      });

      const data = await res.json();
      const generatedText = data.choices?.[0]?.message?.content?.trim() || "";

      if (!generatedText) {
        console.error("AI Generation failed for contact", contactId);
        continue;
      }

      // Parse subject and body
      const lines = generatedText.split("\n");
      let subject = "Information von Mintel";
      let bodyText = generatedText;

      if (lines[0].startsWith("SUBJECT:")) {
        subject = lines[0].replace("SUBJECT:", "").trim();
        bodyText = lines.slice(1).join("\n").trim();
      }

      // Use a simple HTML wrapper to preserve line breaks
      const htmlBody = `<p>${bodyText.replace(/\n/g, "<br/>")}</p>`;

      const targetEmail = isTest ? req.user.email : contact.email;

      // Send the email
      await req.payload.sendEmail({
        to: targetEmail,
        subject: (isTest ? "[TEST] " : "") + subject,
        html: htmlBody,
      });

      sentEmails.push({ contactId, email: targetEmail });

      if (!isTest) {
        // Log interaction
        const interaction = await req.payload.create({
          collection: "crm-interactions",
          data: {
            type: "email",
            subject: `Outbound AI Mail: ${subject}`,
            date: new Date().toISOString(),
            contact: contact.id,
            account: account?.id,
            content: {
              root: {
                type: "root",
                format: "",
                indent: 0,
                version: 1,
                direction: "ltr",
                children: [
                  {
                    type: "paragraph",
                    format: "",
                    indent: 0,
                    version: 1,
                    direction: "ltr",
                    children: [
                      {
                        type: "text",
                        mode: "normal",
                        style: "",
                        detail: 0,
                        format: 0,
                        text: bodyText,
                        version: 1,
                      },
                    ],
                  },
                ],
              },
            },
          },
        });
        interactions.push(interaction.id);

        // Update lead temperature to "warm" if it's currently cold and the status is lead
        if (
          account &&
          account.status === "lead" &&
          account.leadTemperature === "cold"
        ) {
          await req.payload.update({
            collection: "crm-accounts",
            id: account.id,
            data: {
              leadTemperature: "warm",
            },
          });
        }
      }
    }

    return Response.json({ success: true, sentEmails, testMode: isTest });
  } catch (e: any) {
    console.error("Bulk Mail error", e);
    return Response.json({ success: false, error: e.message }, { status: 500 });
  }
};