/* Schedule any workflow reminder that falls within 72 hours for email */
import { WorkflowActions, WorkflowMethods, WorkflowTemplates } from "@prisma/client";
import client from "@sendgrid/client";
import sgMail from "@sendgrid/mail";
import type { NextApiRequest, NextApiResponse } from "next";

import dayjs from "@calcom/dayjs";
import { defaultHandler } from "@calcom/lib/server";
import prisma from "@calcom/prisma";
import { Prisma, WorkflowReminder } from "@calcom/prisma/client";
import { bookingMetadataSchema } from "@calcom/prisma/zod-utils";

import customTemplate, { VariablesType } from "../lib/reminders/templates/customTemplate";
import emailReminderTemplate from "../lib/reminders/templates/emailReminderTemplate";

const sendgridAPIKey = process.env.SENDGRID_API_KEY as string;
const senderEmail = process.env.SENDGRID_EMAIL as string;

sgMail.setApiKey(sendgridAPIKey);

async function handler(req: NextApiRequest, res: NextApiResponse) {
  const apiKey = req.headers.authorization || req.query.apiKey;
  if (process.env.CRON_API_KEY !== apiKey) {
    res.status(401).json({ message: "Not authenticated" });
    return;
  }

  if (!process.env.SENDGRID_API_KEY || !process.env.SENDGRID_EMAIL) {
    res.status(405).json({ message: "No SendGrid API key or email" });
    return;
  }

  //delete all scheduled email reminders where scheduled is past current date
  await prisma.workflowReminder.deleteMany({
    where: {
      method: WorkflowMethods.EMAIL,
      scheduledDate: {
        lte: dayjs().toISOString(),
      },
    },
  });

  //cancel reminders for cancelled/rescheduled bookings that are scheduled within the next hour
  const remindersToCancel = await prisma.workflowReminder.findMany({
    where: {
      cancelled: true,
      scheduledDate: {
        lte: dayjs().add(1, "hour").toISOString(),
      },
    },
  });

  try {
    const workflowRemindersToDelete: Prisma.Prisma__WorkflowReminderClient<WorkflowReminder, never>[] = [];

    for (const reminder of remindersToCancel) {
      await client.request({
        url: "/v3/user/scheduled_sends",
        method: "POST",
        body: {
          batch_id: reminder.referenceId,
          status: "cancel",
        },
      });

      const workflowReminderToDelete = prisma.workflowReminder.delete({
        where: {
          id: reminder.id,
        },
      });

      workflowRemindersToDelete.push(workflowReminderToDelete);
    }
    await Promise.all(workflowRemindersToDelete);
  } catch (error) {
    console.log(`Error cancelling scheduled Emails: ${error}`);
  }

  //find all unscheduled Email reminders
  const unscheduledReminders = await prisma.workflowReminder.findMany({
    where: {
      method: WorkflowMethods.EMAIL,
      scheduled: false,
      scheduledDate: {
        lte: dayjs().add(72, "hour").toISOString(),
      },
    },
    include: {
      workflowStep: true,
      booking: {
        include: {
          eventType: true,
          user: true,
          attendees: true,
        },
      },
    },
  });

  if (!unscheduledReminders.length) {
    res.status(200).json({ message: "No Emails to schedule" });
    return;
  }

  for (const reminder of unscheduledReminders) {
    try {
      let sendTo;

      switch (reminder.workflowStep.action) {
        case WorkflowActions.EMAIL_HOST:
          sendTo = reminder.booking?.user?.email;
          break;
        case WorkflowActions.EMAIL_ATTENDEE:
          sendTo = reminder.booking?.attendees[0].email;
          break;
        case WorkflowActions.EMAIL_ADDRESS:
          sendTo = reminder.workflowStep.sendTo;
      }

      const name =
        reminder.workflowStep.action === WorkflowActions.EMAIL_ATTENDEE
          ? reminder.booking?.attendees[0].name
          : reminder.booking?.user?.name;

      const attendeeName =
        reminder.workflowStep.action === WorkflowActions.EMAIL_ATTENDEE
          ? reminder.booking?.user?.name
          : reminder.booking?.attendees[0].name;

      const timeZone =
        reminder.workflowStep.action === WorkflowActions.EMAIL_ATTENDEE
          ? reminder.booking?.attendees[0].timeZone
          : reminder.booking?.user?.timeZone;

      const locale =
        reminder.workflowStep.action === WorkflowActions.EMAIL_ATTENDEE ||
        reminder.workflowStep.action === WorkflowActions.SMS_ATTENDEE
          ? reminder.booking?.attendees[0].locale
          : reminder.booking?.user?.locale;

      let emailContent = {
        emailSubject: reminder.workflowStep.emailSubject || "",
        emailBody: {
          text: reminder.workflowStep.reminderBody || "",
          html: `<body style="white-space: pre-wrap;">${reminder.workflowStep.reminderBody || ""}</body>`,
        },
      };

      switch (reminder.workflowStep.template) {
        case WorkflowTemplates.REMINDER:
          emailContent = emailReminderTemplate(
            reminder.booking?.startTime.toISOString() || "",
            reminder.booking?.endTime.toISOString() || "",
            reminder.booking?.eventType?.title || "",
            timeZone || "",
            attendeeName || "",
            name || ""
          );
          break;
        case WorkflowTemplates.CUSTOM:
          const variables: VariablesType = {
            eventName: reminder.booking?.eventType?.title || "",
            organizerName: reminder.booking?.user?.name || "",
            attendeeName: reminder.booking?.attendees[0].name,
            attendeeEmail: reminder.booking?.attendees[0].email,
            eventDate: dayjs(reminder.booking?.startTime).tz(timeZone),
            eventTime: dayjs(reminder.booking?.startTime).tz(timeZone),
            timeZone: timeZone,
            location: reminder.booking?.location || "",
            additionalNotes: reminder.booking?.description,
            customInputs: reminder.booking?.customInputs,
            meetingUrl: bookingMetadataSchema.parse(reminder.booking?.metadata || {})?.videoCallUrl,
          };
          const emailSubject = await customTemplate(
            reminder.workflowStep.emailSubject || "",
            variables,
            locale || ""
          );
          emailContent.emailSubject = emailSubject.text;
          emailContent.emailBody = await customTemplate(
            reminder.workflowStep.reminderBody || "",
            variables,
            locale || ""
          );
          break;
      }
      if (emailContent.emailSubject.length > 0 && emailContent.emailBody.text.length > 0 && sendTo) {
        const batchIdResponse = await client.request({
          url: "/v3/mail/batch",
          method: "POST",
        });

        const batchId = batchIdResponse[1].batch_id;

        if (reminder.workflowStep.action !== WorkflowActions.EMAIL_ADDRESS) {
          await sgMail.send({
            to: sendTo,
            from: {
              email: senderEmail,
              name: reminder.workflowStep.sender || "Cal.com",
            },
            subject: emailContent.emailSubject,
            text: emailContent.emailBody.text,
            html: emailContent.emailBody.html,
            batchId: batchId,
            sendAt: dayjs(reminder.scheduledDate).unix(),
            replyTo: reminder.booking?.user?.email || senderEmail,
          });
        }

        await prisma.workflowReminder.update({
          where: {
            id: reminder.id,
          },
          data: {
            scheduled: true,
            referenceId: batchId,
          },
        });
      }
    } catch (error) {
      console.log(`Error scheduling Email with error ${error}`);
    }
  }
  res.status(200).json({ message: "Emails scheduled" });
}

export default defaultHandler({
  POST: Promise.resolve({ default: handler }),
});