app.js

//jshint esversion:6

const express = require("express");
const bodyParser = require("body-parser");
const mongoose = require("mongoose");
const _ = require("lodash");

const app = express();

app.set("view engine", "ejs");

app.use(bodyParser.urlencoded({ extended: true }));
app.use(express.static("public"));

mongoose.connect("mongodb://127.0.0.1:27017/todolistDB");

const itemsSchema = { name: String };

const Item = mongoose.model("Item", itemsSchema);

const item1 = new Item({ name: "Welcome to your todolist!" });
const item2 = new Item({ name: "Hit the + button to add a new item." });
const item3 = new Item({ name: "<-- Hit this to delete an item." });

const defaultItems = [item1, item2, item3];

const listSchema = {
  name: String,
  items: [itemsSchema]
};

const List = mongoose.model("List", listSchema);

app.get("/", function (req, res) {
  Item.find({}, function (err, foundItems) {
    if (foundItems.length === 0) {
      Item.insertMany(defaultItems, function (err) {
        if (err) {
          console.log(err);
        } else {
          console.log("Successfully saved default items to dB");
        }
      });
      res.redirect("/");
    } else {
      res.render("list", { listTitle: "Today", newListItems: foundItems });
    }
  });
});

app.post("/", function (req, res) {
  const itemName = req.body.newItem;
  const listName = req.body.list;

  const item = new Item({ name: itemName });
  if (listName === "Today") {
    item.save();
    res.redirect("/");
  } else {
    List.findOne({ name: listName }, function (err, foundList) {
      foundList.items.push(item);
      foundList.save();
    });
    res.redirect("/" + listName);
  }
});

app.post("/delete", function (req, res) {
  const checkedItemId = req.body.checkbox;
  const listName = req.body.listName;

  if (listName === "Today") {
    Item.findByIdAndRemove(checkedItemId, function (err) {
      if (!err) {
        console.log("Successfully deleted checked item.");
        res.redirect("/");
      }
    });
  } else {
    List.findOneAndUpdate({ name: listName }, { $pull: { items: { _id: checkedItemId } } }, function (err, foundList) {
      if (!err) {
        res.redirect("/" + listName);
      }
    });
  }

});

app.get("/:customListName", function (req, res) {
  const customListName = _.capitalize(req.params.customListName);

  List.findOne({ name: customListName }, function (err, foundList) {
    if (!err) {
      if (!foundList) {
        // Create a new list
        const list = new List({
          name: customListName,
          items: defaultItems
        });
        list.save();
        res.redirect("/" + customListName);
      } else {
        // Show an existing list
        res.render("list", { listTitle: foundList.name, newListItems: foundList.items });
      }
    }
  });
});

app.get("/about", function (req, res) {
  res.render("about");
});

app.listen(3000, function () {
  console.log("Server started on port 3000");
});