const HomebrewModel = require('./homebrew.model.js').model;
const router = require('express').Router();
const Moment = require('moment');
const templateFn = require('../client/template.js');
const zlib = require('zlib');
const rateLimit = require('express-rate-limit');

// Define rate limiter options
const loginLimiter = rateLimit({
	timeWindow : 24 * 60 * 60 * 1000, // 24 hours window
	max        : 10, // limit each IP to 10 requests per timeWindow
	handler    : ()=>{throw { HBErrorCode: '470', code: 470, message: 'Too many failed login attempts, try again later' }; }
});

//Local version username and password
process.env.ADMIN_USER = process.env.ADMIN_USER || 'admin';
process.env.ADMIN_PASS = process.env.ADMIN_PASS || 'password3';

const mw = {
    adminOnly: [
        loginLimiter,
        (req, res, next) => {
            if (!req.get('authorization')) {
                return res
                    .set('WWW-Authenticate', 'Basic realm="Authorization Required"')
                    .status(401)
                    .send('Authorization Required');
            }
            const [username, password] = Buffer.from(req.get('authorization').split(' ').pop(), 'base64')
                .toString('ascii')
                .split(':');
            if (process.env.ADMIN_USER === username && process.env.ADMIN_PASS === password) {
                return next();
            }
            throw { HBErrorCode: '403', code: 403, message: 'Access denied' };
        }
    ]
};

const junkBrewPipeline = [
	{	$match : {
		updatedAt  : { $lt: Moment().subtract(30, 'days').toDate() },
		lastViewed : { $lt: Moment().subtract(30, 'days').toDate() }
	} },
	{ $project: { textBinSize: { $binarySize: '$textBin' } } },
	{ $match: { textBinSize: { $lt: 140 } } },
	{ $limit: 100 }
];

/* Search for brews that aren't compressed (missing the compressed text field) */
const uncompressedBrewQuery = HomebrewModel.find({
	'text' : { '$exists': true }
}).lean().limit(10000).select('_id');

// Search for up to 100 brews that have not been viewed or updated in 30 days and are shorter than 140 bytes
router.get('/admin/cleanup', mw.adminOnly, (req, res)=>{
	HomebrewModel.aggregate(junkBrewPipeline).option({ maxTimeMS: 60000 })
		.then((objs)=>res.json({ count: objs.length }))
		.catch((error)=>{
			console.error(error);
			res.status(500).json({ error: 'Internal Server Error' });
		});
});

// Delete up to 100 brews that have not been viewed or updated in 30 days and are shorter than 140 bytes
router.post('/admin/cleanup', mw.adminOnly, (req, res)=>{
	HomebrewModel.aggregate(junkBrewPipeline).option({ maxTimeMS: 60000 })
		.then((docs)=>{
			const ids = docs.map((doc)=>doc._id);
			return HomebrewModel.deleteMany({ _id: { $in: ids } });
		}).then((result)=>{
			res.json({ count: result.deletedCount });
		}).catch((error)=>{
			console.error(error);
			res.status(500).json({ error: 'Internal Server Error' });
		});
});

/* Searches for matching edit or share id, also attempts to partial match */
router.get('/admin/lookup/:id', mw.adminOnly, async (req, res, next)=>{
	HomebrewModel.findOne({
		$or : [
			{ editId: { $regex: req.params.id, $options: 'i' } },
			{ shareId: { $regex: req.params.id, $options: 'i' } },
		]
	}).exec()
	.then((brew)=>{
		if(!brew)	// No document found
			return res.status(404).json({ error: 'Document not found' });
		else
			return res.json(brew);
	})
	.catch((err)=>{
		console.error(err);
		return res.status(500).json({ error: 'Internal Server Error' });
	});
});

/* Find 50 brews that aren't compressed yet */
router.get('/admin/finduncompressed', mw.adminOnly, (req, res)=>{
	const query = uncompressedBrewQuery.clone();

	query.exec()
		.then((objs)=>{
			const ids = objs.map((obj)=>obj._id);
			res.json({ count: ids.length, ids });
		})
		.catch((err)=>{
			console.error(err);
			res.status(500).send(err.message || 'Internal Server Error');
		});
});


/* Compresses the "text" field of a brew to binary */
router.put('/admin/compress/:id', (req, res)=>{
	HomebrewModel.findOne({ _id: req.params.id })
		.then((brew)=>{
			if(!brew)
				return res.status(404).send('Brew not found');

			if(brew.text) {
				brew.textBin = brew.textBin || zlib.deflateRawSync(brew.text);	//Don't overwrite textBin if exists
				brew.text = undefined;
			}

			return brew.save();
		})
		.then((obj)=>res.status(200).send(obj))
		.catch((err)=>{
			console.error(err);
			res.status(500).send('Error while saving');
		});
});


router.get('/admin/stats', mw.adminOnly, async (req, res)=>{
	try {
		const totalBrewsCount = await HomebrewModel.countDocuments({});
		const publishedBrewsCount = await HomebrewModel.countDocuments({ published: true });

		return res.json({
			totalBrews          : totalBrewsCount,
			totalPublishedBrews : publishedBrewsCount
		});
	} catch (error) {
		console.error(error);
		return res.status(500).json({ error: 'Internal Server Error' });
	}
});

router.get('/admin', mw.adminOnly, (req, res)=>{
	templateFn('admin', {
		url : req.originalUrl
	})
	.then((page)=>res.send(page))
	.catch((err)=>res.sendStatus(500));
});

module.exports = router;