const fs = require("fs");
const User = require("../models/user.js");
const asyncHandler = require("express-async-handler");
const { body, validationResult } = require("express-validator");
const { default: mongoose } = require("mongoose");
const bcrypt = require("bcryptjs");
const passport = require("passport");
const multer = require("multer");
const storage = multer.memoryStorage();
const upload = multer({
  storage: storage,
  limits: { fileSize: 1840000 },
});

exports.new_get = (req, res, next) => {
  res.render("newuser", { errors: false });
};

exports.new_post = [
  // this goes first as it replaces bodyparser to some extent
  upload.single("avatar"),

  // Validate and sanitize fields
  body("username", "Please enter a username!")
    .trim()
    .escape()
    .isLength({ min: 1 })
    .custom(async (value) => {
      const found = await User.findOne({ username: value }).lean().exec();
      if (found) throw new Error("User already exists!");
      else return value;
    }),

  body("password", "Please enter a password!")
    .trim()
    .escape()
    .isLength({ min: 1 }),

  body("confirm", "Please confirm password!")
    .trim()
    .escape()
    .isLength({ min: 1 })
    .custom((value, { req }) => {
      if (value !== req.body.password)
        throw new Error("Passwords don't match!");
      else return value;
    }),

  // Process request after validation and sanitization.
  asyncHandler(async (req, res, next) => {
    // Extract the validation errors from a request.
    const errors = validationResult(req);
    // if there are validation errors
    if (!errors.isEmpty()) {
      // Render the creation form again with sanitized values/error messages.
      res.render("newuser", {
        errors: errors.array(),
      });
      return;
    }
    if (!req.file) {
      const error = {
        msg: "Avatar not uploaded",
      };
      // add to errors array
      errArr = [error];
      // Render the creation form again with error message.
      res.render("newuser", {
        errors: errArr,
      });
      return;
    }
    // else data is valid
    // create new user with hashed password
    const user = new User({
      username: req.body.username,
      password: await bcrypt.hash(req.body.password, 10),
      _id: new mongoose.Types.ObjectId(),
      avatar: req.file.buffer,
    });

    // save to mongo
    await user.save();

    // saved. Redirect to login page
    res.redirect(`/user/login`);
  }),
];

exports.login_get = (req, res, next) => {
  res.render("login", { error: false });
};

exports.login_post = (req, res, next) => {
  passport.authenticate("local", (err, user, options) => {
    if (!user) {
      return res.render("login", { error: options.message });
    }
    req.login(user, (error) => {
      if (error) {
        console.log(error);
      }
      return res.redirect("/");
    });
  })(req, res, next);
};

exports.logout = (req, res, next) => {
  req.logout(() => {
    res.redirect("/");
  });
};

exports.get = asyncHandler(async (req, res, next) => {
  const user = await User.findById(req.params.userID).exec();
  res.render("user", {
    user: user,
    currentUser: req.user,
  });
});

exports.put_get = asyncHandler(async (req, res, next) => {
  const user = await User.findById(req.params.userID).lean().exec();
  res.render("edituser", {
    user: user,
    errors: false,
  });
});

exports.put = [
  // this goes first as it replaces bodyparser to some extent
  upload.single("avatar"),

  // Validate and sanitize fields
  // username cannot be changed for security/impersonation reasons

  body("oldpassword", "Please enter current password to authorize changes!")
    .trim()
    .escape()
    .isLength({ min: 1 })
    .custom(async (value, { req }) => {
      const dbUser = await User.findById(req.params.userID).lean().exec();
      const match = await bcrypt.compare(value, dbUser.password);
      if (!match) {
        return Promise.reject();
      }
    })
    .withMessage("Incorrect password!"),

  body("password", "Please enter new password!").optional().trim().escape(),

  // Process request after validation and sanitization.
  asyncHandler(async (req, res, next) => {
    // find existing user in DB
    const dbUser = await User.findById(req.params.userID).lean().exec();

    // Extract the validation errors from a request.
    const errors = validationResult(req);
    // if there are validation errors
    if (!errors.isEmpty()) {
      // Render the creation form again with sanitized values/error messages.
      res.render("edituser", {
        errors: errors.array(),
        user: dbUser,
      });
      return;
    }
    // else data is valid

    // ascertain which fields have been changed by the user
    let password = (image = false);
    let user = null;

    // check for password field
    if (
      req.body.password &&
      req.body.password != "" &&
      req.body.password != "null" &&
      req.body.password !== null
    ) {
      password = true;
    }
    // check for image
    if (req.file) image = true;

    // if there is a password
    if (password) {
      // if there is an image
      if (image) {
        // make new user with new avatar and password
        user = new User({
          username: dbUser.username,
          password: await bcrypt.hash(req.body.password, 10),
          _id: dbUser._id,
          avatar: req.file.buffer,
        });
      }
      // if there is not an image
      else {
        // make new user with new password only
        user = new User({
          username: dbUser.username,
          password: await bcrypt.hash(req.body.password, 10),
          _id: dbUser._id,
          avatar: dbUser.avatar,
        });
      }
    }
    // if there is not a password but there is an image
    else if (image) {
      // make new user with new image only
      user = new User({
        username: dbUser.username,
        password: dbUser.password,
        _id: dbUser._id,
        avatar: req.file.buffer,
      });
    }
    // if nothing was passed, user stays null

    // update user in DB to new user if needed
    if (user != null) {
      await User.findByIdAndUpdate(dbUser._id, user, {});
      // saved. logout and redirect to log in again
      req.logout((err) => {
        if (err) {
          return next(err);
        }
        res.redirect("/user/login");
      });
      return;
    }

    // if nothing updated, redirect to edit page with error
    const error = {
      msg: "Nothing updated",
    };
    // add to errors array
    errArr = [error];
    // render error
    res.render("edituser", {
      user: dbUser,
      errors: errArr,
    });
    return;
  }),
];

exports.delete = asyncHandler(async (req, res, next) => {
  await User.findByIdAndDelete(req.params.userID);
  req.logout((err) => {
    if (err) {
      return next(err);
    }
    res.redirect("/user/login");
  });
});