Drop: Select quality of cards based on drop rates

commands/drop.js

@@ -2,6 +2,7 @@ const { SlashCommandBuilder, ActionRowBuilder, ButtonBuilder, ButtonStyle, Compo
 const { Card, User, Character, DropHistory, sequelize } = require("../models");
 const { customAlphabet } = require("nanoid");
 const { CardUtils, UserUtils, ReplyUtils, GeneralUtils, Rendering } = require("../util");
+const { QUALITY } = require("../config/constants");
 const card = require("../models/card");
 
 module.exports = {
@@ -33,6 +34,28 @@ module.exports = {
         });
 
         for (let i = 0; i < 3; i++) {
+            //generate quality based on drop rate
+            let quality = undefined;
+            let roll = Math.random() * 100;
+            if (roll <= 45.0) {
+                quality = QUALITY.BAD; //45%
+            }
+            if (roll > 45.0) {
+                quality = QUALITY.OK; //25%
+            }
+            if (roll > 70.0) {
+                quality = QUALITY.GOOD; //15%
+            }
+            if (roll > 85.0) {
+                quality = QUALITY.GREAT; //10%
+            }
+            if (roll > 95.0) {
+            quality = QUALITY.EXCELLENT; //5%
+            }
+            if (roll > 99.9) {
+                quality = QUALITY.SHINY; //0.1%
+            }
+
             //get number of characters in database
             const characterId = characters[i].id
             console.log(`characterId: ${characterId}`);
@@ -40,7 +63,7 @@ module.exports = {
             let newCard = await Card.create({
                 characterId: characterId,
                 identifier: CardUtils.generateIdentifier(),
-                quality: Math.floor(Math.random() * 6) + 1,
+                quality: quality,
                 printNr: await CardUtils.getNextPrintNumber(characterId),
                 
             });

config/constants.js

@@ -0,0 +1,20 @@
+const QUALITY = {
+    BAD : 1,
+    OK : 2,
+    GOOD : 3,
+    GREAT : 4,
+    EXCELLENT : 5,
+    SHINY : 6
+}
+
+const QUALITY_NAMES = {
+    1 : "Bad",
+    2 : "Ok",
+    3 : "Good",
+    4 : "Great",
+    5 : "Excellent",
+    6 : "Shiny"
+}
+
+exports.QUALITY = QUALITY;
+exports.QUALITY_NAMES = QUALITY_NAMES;

dropRateTest.js

@@ -0,0 +1,45 @@
+const { QUALITY, QUALITY_NAMES } = require('./config/constants');
+let results = [];
+let drops = 1000;
+let header = `⫭=== Quality distribution for ${drops.toLocaleString()} drops: ===⫬`;
+console.log(header);
+console.log(`|${' '.repeat(header.length-2)}|`);
+for ( let  i =  0 ; i <  drops ; i++) {
+    //generate rarity based on drop rate
+    let quality = undefined;
+    let roll = Math.random() * 100;
+    if (roll <= 45.0) {
+        quality = QUALITY.BAD;
+    }
+    if (roll > 45.0) {
+        quality = QUALITY.OK;
+    }
+    if (roll > 70.0) {
+        quality = QUALITY.GOOD;
+    }
+    if (roll > 85.0) {
+        quality = QUALITY.GREAT;
+    }
+    if (roll > 95.0) {
+     quality = QUALITY.EXCELLENT;
+    }
+    if (roll > 99.9) {
+        quality = QUALITY.SHINY;
+    }
+    results.push(quality);
+}
+
+//count the number of times each quality appears
+let counts = {};
+results.forEach(function(x) { counts[x] = (counts[x] || 0)+1; });
+//print results with percentages
+let p_total = 0;
+for (let key in counts) {
+    let p = counts[key]/results.length * 100;
+    p_total += p;
+    let cpStr = `${counts[key].toLocaleString()} (${p}%)`;
+    let fStr = `| ${key}/${QUALITY_NAMES[key]}${' '.repeat(10-QUALITY_NAMES[key].length)}: ${cpStr}`;
+    console.log(`${fStr}${' '.repeat(header.length-fStr.length-1)}|`);
+}
+console.log(`⌊${'_'.repeat(header.length-2)}⌋`);
+