app.js

const express = require("express");
const bodyParser = require("body-parser");
const dotenv = require("dotenv");
const mongoose = require("mongoose");
const path = require("path");
const fs = require("fs");
const multer = require("multer");
const graphqlHttp = require("express-graphql");

const graphqlSchema = require("./graphql/schema");
const graphqlResolver = require("./graphql/resolvers");
const auth = require("./middleware/auth");

dotenv.config();
const app = express();

const fileStorage = multer.diskStorage({
    destination: (req, file, cb) => {
        cb(null, "images");
    },
    filename: (req, file, cb) => {
        cb(null, Date.now()+"-"+file.originalname);
    }
});
const fileFilter = (req,file,cb) => {
    if(file.mimetype == "image/jpg" || file.mimetype == "image/jpeg" || file.mimetype == "image/png") {
        cb(null, true);
    } else { cb(null, false); }
}

app.use(bodyParser.json());
app.use(multer({
    storage: fileStorage,
    fileFilter: fileFilter
}).single("image"));
app.use("/images", express.static(path.join(__dirname,"images")))
app.use((req,res,next) => {
    res.setHeader("Access-Control-Allow-Origin","*");
    res.setHeader("Access-Control-Allow-Methods", "GET,POST,PUT,PATCH,DELETE");
    res.setHeader("Access-Control-Allow-Headers", "Content-Type, Authorization");
    if(req.method === "OPTIONS") {
        res.sendStatus(200);
    }
    next();
});

app.use(auth);

app.put("/post-image", (req, res, next) => {
    if(!req.isAuth) {
        const error = new Error("Not authenticated");
        error.code = 401;
        throw error;
    }
    if(!req.file) {
        return res.status(200).json({message: "No image provided"});
    }
    if(req.body.oldPath) {
        clearImage(req.body.oldPath);
    }
    return res.status(201).json({message: "Image saved.", filePath: req.file.path});
});

app.use("/graphql", graphqlHttp({
    schema: graphqlSchema,
    rootValue: graphqlResolver,
    graphiql: true,
    formatError(err) {
        if(!err.originalError) {
            return err;
        }
        const data = err.originalError.data || [];
        const message = err.message || "An error occurred.";
        const code = err.originalError.code || 500;
        return {message: message, status: code, data: data}
    }
}));

app.use((error, req, res, next) => {
    console.log(error);
    const status = error.statusCode || 500;
    const message = error.message;
    const data = error.data || [];
    res.status(status).json({message:message, data: data});
})

mongoose.connect(process.env.dbConnectionString).then(result => {
    app.listen(8080);
})
.catch(err => console.log(err)); 

const clearImage = imagePath => {
    filePath = path.join(__dirname,"..",imagePath);
    return fs.unlink(filePath, err => console.log(err));
}