index.js

const express = require("express");
const app = express();
const cors = require("cors");
const pool = require("./db");
const path = require("path");
const PORT = process.env.PORT || 5000;

// middleware
app.use(cors());
app.use(express.json());    // allows access to req.body

// process.env.PORT
// process.env.NODE_ENV => production or undefined
if (process.env.NODE_ENV === "production") {
    // server static content
    // go into build folder from npm run build
    app.use(express.static(path.join(__dirname, "client/build")));
}

// other options
// app.use(express.static("./client/build"));

// ROUTES //
// create a todo
app.post('/todos', async(req, res) => {
    try {
        const {description} = req.body;
        const newTodo = await pool.query(
            "INSERT INTO todo (description) VALUES($1) RETURNING *", 
            [description]
        );

        res.json(newTodo.rows[0]);
    } catch (err) {
        console.error(err.message);
    }
});

// get all todos
app.get('/todos', async(req, res) => {
    try {
        const allTodos = await pool.query("SELECT * FROM todo");
        res.json(allTodos.rows);
    } catch (err) {
        console.error(err.message);
    }
});

// get a todo
app.get('/todos/:id', async(req, res) => {
    try {
        const {id} = req.params;
        const todo = await pool.query("SELECT * FROM todo WHERE todo_id = $1", [id]);

        res.json(todo.rows[0]);
    } catch (err) {
        console.error(err.message);
    }
});

// update a todo
app.put('/todos/:id', async(req, res) => {
    try {
        const {id} = req.params;
        const {description} = req.body;
        const updateTodo = await pool.query(
            "UPDATE todo SET description = $1 WHERE todo_id = $2",
            [description, id],
        );

        res.json("Todo was updated");
    } catch (err) {
        console.error(err.message);
    }
});

// delete a todo
app.delete('/todos/:id', async(req, res) => {
    try {
        const {id} = req.params;
        const deleteTodo = await pool.query(
            "DELETE FROM todo WHERE todo_id = $1",
            [id]
        );

        res.json("Todo was deleted");
    } catch (err) {
        console.error(err.message);
    }
})

app.listen(PORT, () => {
    console.log(`server has started on port ${PORT}`);
});