'use strict';

const express = require('express');
const bodyParser = require('body-parser');
const morgan = require('morgan');
const ObjectID = require('mongodb').ObjectID;

const HttpCat = require('./http-cat.js')
const Dao = require('./dao.js');
const config = require('./config.json');

const dao = new Dao();
const app = express();

app.use(HttpCat());
app.use(morgan('dev'));
app.set('etag', false);
app.use(bodyParser.json()); // before request handlers
app.use(express.static('./'));


app.get('/api/contacts', getContacts);
app.get('/api/contacts/:id', getContact);
app.post('/api/contacts', addContact);
app.put('/api/contacts/:id', changeContact);
app.post('/api/contacts/delete', deleteMultibleContacts);
app.delete('/api/contacts/:id', deleteContact);

app.use(errorHandler); // after request handlers

dao.connect(config.mongoUrl)
.then(() => {
    app.listen(3000, () => console.log('Server is running on port 3000'));
}).catch(err => {
    console.log("MongoDB connection failed: ");
    console.log(err)
    process.exit(1);
})


function errorHandler(error, request, response, next) { // there must be 4 arguments
    console.log(error)
    response.status(500).send('error: ' + error.toString());
}

function getContacts(req, resp) {
    dao.findAll().then(data => resp.json(data));
}

function getContact(req, resp) {
    var id = req.params.id;

    if (!ObjectID.isValid(id)) {
        resp.status(400).json("Invalid id");
        return;
    }

    dao.findById(id).then(data => {
        resp.json(data);
    }).catch(err => {
        console.log(err);
        resp.status(404).json(err.toString());
    });
}

function addContact(req, resp, next) {
    var contact = req.body;
    if (contact.name == null ) {
        resp.status(400).json("Can't add a contact without a name");
        return;
    }

    var sanitizedContact = {
        "name": contact.name,
        "phone": contact.phone
    }

    dao.insert(sanitizedContact).then((data) => {
        resp.status(201);
        resp.location("/api/contacts/"+data.insertedId);
        dao.findById(data.insertedId).then(insertedContact => {
            resp.json(insertedContact);
        });
    }).catch(err => {
        console.log(err);
        next(err);
    })
}

function changeContact(req, resp) {
    var id = req.params.id;
    var contact = req.body;

    if (!ObjectID.isValid(id)) {
        resp.status(400).json("Invalid id");
        return;
    }

    if (contact.name == null) {
        resp.status(400).json("Contact must have a name");
        return;
    }

    var sanitizedContact = {
        "name": contact.name,
        "phone": contact.phone
    }

    dao.update(id, sanitizedContact).then(data => {
       resp.status(200).end("Changed");
    }).catch(err => {
        console.log(err);
        resp.status(404).end("Contact Not Found");
    });

}

function deleteContact(req, resp) {
    var id = req.params.id;
    if (!ObjectID.isValid(id)) {
        resp.status(400).json("Invalid id");
        return;
    }

    dao.remove(id).then(data => {
        resp.status(200).json("Deleted");
    }).catch(err => {
        console.log(err);
        resp.status(404).end("Contact Not Found");
    })
}

function deleteMultibleContacts(req, resp) {
    var contactIds = req.body;

    for (let id of contactIds) {
        if (!ObjectID.isValid(id)) {
            resp.status(400).json("Invalid ID in the list");
            return;
        }
    }

    dao.removeMany(contactIds).then(data => {
        resp.status(200).json("Deleted");
    }).catch(err => {
        console.log(err);
        resp.status(400).json("Failed to delete some or all of the contacts" + err.toString());
    })

}