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+srv://[username]:[password]@cluster0.1even.mongodb.net/todolistDB",{useNewUrlParser: true});
 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.get("/:customListName",function(req,res){
  const customListName = _.capitalize(req.params.customListName);

  List.findOne({name: customListName},function(err,foundList){
    if(!err)
    {
      if(!foundList)
      {


      const list = new List({
        name: customListName,
        items:defaultItems
      });
      list.save();
      res.redirect("/"+customListName);
    }

    else
    {
        res.render("list", {listTitle: foundList.name, newListItems: foundList.items});
    }
  }
  });

});






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 iten.");
        res.redirect("/");
      }

    });

  }
  else
  {
    List.findOneAndUpdate({name: listName},{$pull: {items: {_id: checkedItemId}}}, function(err, foundList)
    {
    if(!err)
    {
      res.redirect("/"+listName);
    }

  });
}

});

app.get("/work", function(req,res){
  res.render("list", {listTitle: "Work List", newListItems: workItems});
});

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

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