isleward/src/server/config/loginRewards.js

let config = {
	0: [{
		name: 'Common Essence',
		sprite: [0, 2]
	}, {
		name: 'Iron Bar',
		sprite: [0, 0]
	}, {
		name: 'Cloth Scrap',
		sprite: [0, 1]
	}, {
		name: 'Leather Scrap',
		sprite: [0, 7]
	}],
	1: [{
		name: 'Magic Essence',
		sprite: [0, 3]
	}],
	2: [{
		name: 'Rare Essence',
		sprite: [0, 4]
	}], 
	3: [{
		name: 'Cerulean Pearl',
		sprite: [11, 9]
	}, {
		name: 'Epic Essence',
		sprite: [0, 5]
	}],
	4: [{
		name: 'Legendary Essence',
		sprite: [0, 6]
	}]
};
	
module.exports = {
	generate: function (streak) {
		let items = [];

		let qualityTotals = {
			0: 1 + Math.min(streak * 3, 15),
			1: ~~(streak / 3),
			2: ~~(streak / 5),
			3: ~~(streak / 10),
			4: ~~(streak / 21)
		};

		for (let p in qualityTotals) {
			let total = qualityTotals[p];
			let picks = config[p];

			while (total > 0) {
				let pick = picks[~~(Math.random() * picks.length)];
				let amount = 1 + ~~(Math.random() * (total - 1));
				total -= amount;

				let item = items.find(f => (f.name === pick.name));
				if (!item) {
					item = extend(true, {
						material: true,
						quality: p
					}, pick);
					item.quantity = 0;

					items.push(item);
				}

				item.quantity += amount;
			}
		}

		if (items.length > 0)
			items[0].msg = `Daily login reward for ${streak} days:`;

		return items;
	}
};