const admin = require("firebase-admin");
const { FieldValue } = require("firebase-admin/firestore");
const {
  onDocumentDeleted,
  onDocumentCreated,
} = require("firebase-functions/firestore");
const { refList } = require("../index");
const { ORDER_TYPES, createOrderDocument } = require("./helpers/orders");
const { deleteFolder } = require("../helpers/firebase");
const { Resend } = require("resend");
const { welcomeTemplate } = require("../helpers/email");
const { RESEND_API_KEY } = require("../config/keys");
const { onRequest } = require("firebase-functions/https");

const resendClient = new Resend(RESEND_API_KEY);
const WELCOME_EMAIL_FROM =
  process.env.RESEND_FROM_EMAIL || "MusicLand <musicland@minuit.app>";
const WELCOME_EMAIL_SUBJECT = "Bienvenue sur MusicLand";

exports.testWelcomMail = onRequest(async (req, res) => {
  if (req.method !== "GET") {
    res.set("Allow", "GET");
    return res
      .status(405)
      .json({ success: false, error: "Method not allowed" });
  }
  try {
    const targetEmail = req.query.email || "tdtomthomas@gmail.com";
    const firstName = req.query.firstName || "Toto";
    const lastName = req.query.lastName || "Test";
    const { data, error } = await resendClient.emails.send({
      from: WELCOME_EMAIL_FROM,
      to: [targetEmail],
      subject: WELCOME_EMAIL_SUBJECT,
      html: welcomeTemplate({ firstName, lastName }),
    });
    if (error) {
      console.log("Failed to send welcome email:", error);
      return res
        .status(500)
        .json({ success: false, error: error.message || error.toString() });
    }
    console.log("Welcome email sent:", data);
    return res.status(200).json({ success: true, data });
  } catch (e) {
    console.log(e);
    return res
      .status(500)
      .json({ success: false, error: e.message || e.toString() });
  }
});

exports.onUserCreated = onDocumentCreated("users/{userID}", async (event) => {
  try {
    const {
      email = "",
      firstName = "",
      lastName = "",
    } = event?.data?.data() || {};

    const userId = event?.params?.userID;

    try {
      await createOrderDocument({
        userId,
        type: ORDER_TYPES.GIFT,
        amount: 10,
        metadata: { reason: "WELCOME_BONUS" },
        orderId: `welcome_${userId}`,
      });
    } catch (coinError) {
      console.warn(
        "[users-onUserCreated] Unable to grant welcome coins",
        event?.params?.userID,
        coinError?.message || coinError,
      );
    }
    if (email) {
      if (!resendClient) {
        console.warn("Resend API key not configured; skipping welcome email.");
        return;
      }
      try {
        console.log(`Sending welcome email to ${email}`);
        const { data, error } = await resendClient.emails.send({
          from: WELCOME_EMAIL_FROM,
          to: [email],
          subject: WELCOME_EMAIL_SUBJECT,
          html: welcomeTemplate({ firstName, lastName }),
        });
        if (error) {
          console.log("Failed to send welcome email:", error);
          return;
        }
        console.log("Welcome email sent:", data);
      } catch (error) {
        console.log("Failed to send welcome email:", error);
      }
    } else {
      throw new Error("User created with empty email");
    }
  } catch (e) {
    console.log(e);
  }
});

exports.onUserDelete = onDocumentDeleted("users/{userID}", async (event) => {
  try {
    const userID = event?.params?.userID;
    await clearAllUserData(userID);

    await deleteFolder(`users/${userID}/`);

    await admin.auth().deleteUser(userID);
    console.log(`User ${userID} deleted successfully`);
  } catch (e) {
    console.log(e);
  }
});

async function clearAllUserData(userID) {
  const deleteAll = async (ref, key, operator = "==") => {
    const snapshot = await ref.where(key, operator, userID).get();
    snapshot.forEach((item) => item.ref.delete());
  };
  const removeFromArray = async (ref, arrayName) => {
    const snapshot = await ref.where(arrayName, "array-contains", userID).get();
    snapshot.forEach((item) =>
      item.ref.update({
        [arrayName]: FieldValue.arrayRemove(userID),
      }),
    );
  };

  await deleteAll(refList.projects, "userId");
  await deleteAll(refList.playlists, "createdBy");
}