From 03ea59286baea102af4a27b6416cb069e69e0c37 Mon Sep 17 00:00:00 2001
From: Lauchmelder <robert.altner11@gmail.com>
Date: Sun, 20 Mar 2022 01:23:01 +0100
Subject: [PATCH] fixed level caching

---
 background.js | 44 +++++++++++++++++++++++++++++++++++---------
 1 file changed, 35 insertions(+), 9 deletions(-)

diff --git a/background.js b/background.js
index caa3d3e..a395c3e 100644
--- a/background.js
+++ b/background.js
@@ -22,33 +22,46 @@ const query = (token, url) =>
     })
 
 const updateCache = async (token, oldLevel, newLevel) => {
+    // If oldLevel is undefined, then a sync has never been performed (first time user)
     if(oldLevel === undefined)
         oldLevel = 1
 
+    // Create a list of levels that need to be synced
+    // If the new level is bigger than the old level (user leveled up)
+    // --> Just fetch the new level(s)
+    // If the new level is smaller than the old level (user reset)
+    // --> Fetch everything up until the new level
     var levelArray = []
-    for(var i = oldLevel; i < newLevel; i++)
+    var startLevel = newLevel > oldLevel ? oldLevel : 1
+    for(var i = startLevel; i < newLevel; i++)
         levelArray.push(i)
 
+    // Turn the array of levels into a comma separated list
     var levelURLString = levelArray.join(",")
 
+    // API endpoint + response data buffers
     var url = "https://api.wanikani.com/v2/subjects?types=vocabulary&levels=" + levelURLString
     var vocabulary = []
-
+    
+    // WaniKani only sends 1000 elements in one response and then provides us with a link to the
+    // next "page" of the data. We need to loop until the next page is null
     do
     {
+        // Query API, extract all the important info and then update the URL to the next page
         var response = await query(token, url).catch(reason => console.error("WaniKani API request failed: " + reason))
         if(response === undefined)
             break
-
+            
         for(let i in response.data)
             vocabulary.push(response.data[i].data.characters)
 
         url = response.pages.next_url
     } while(url !== null)
 
+    // Extract Kanji as well
     var url = "https://api.wanikani.com/v2/subjects?types=kanji&levels=" + levelURLString
     var kanji = []
-
+    
     do
     {
         var response = await query(token, url).catch(reason => console.error("WaniKani API request failed: " + reason))
@@ -61,6 +74,7 @@ const updateCache = async (token, oldLevel, newLevel) => {
         url = response.pages.next_url
     } while(url !== null)
 
+    // If the old level is less than the new level add the old data to the new data
     if(oldLevel < newLevel)
     {
         await chrome.storage.local.get(["vocabulary", "kanji"], (data) => {
@@ -69,40 +83,51 @@ const updateCache = async (token, oldLevel, newLevel) => {
         })
     }
     
+    // Cache the data
     chrome.storage.local.set({
         "vocabulary": vocabulary,
-        "kanji": kanji
+        "kanji": kanji,
+        "level": newLevel
     })
-
-    chrome.storage.local.set({"level": newLevel});
 }
 
+// Synchronizes local data with wanikanis data
 const sync = () => 
     new Promise((resolve, reject) => {
         chrome.storage.local.get(["level", "token"], async (data) => {
+            // See if wanikani token is well formed
             const apiTokenPattern = /[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}/
             if(!apiTokenPattern.test(data.token))
                 return reject("Please set a valid WaniKani API Token")
 
+            // Get user info
             var user = await query(data.token, "https://api.wanikani.com/v2/user").catch(reason => reject("WaniKani API request failed: " + reason))
-
             if(user === undefined)
                 return
             
+            // Get user level
             level = user.data.level
 
-            chrome.storage.local.set({"validUserLevel": level <= user.data.subscription.max_level_granted})
+            // If the users level is somehow larger than their max allowed level, set the flag
+            
 
+            // if users level is larger than max allowed level, abort
             if(level > user.data.subscription.max_level_granted)
+            {
+                chrome.storage.local.set({"validUserLevel": false})
                 return reject("User account level exceeds account level limit")
+            }
 
+            // If the wanikani level differs from the local leve, update the cache
             if(level !== data.level)
                 updateCache(data.token, data.level, level)
 
+            chrome.storage.local.set({"validUserLevel": true})
             resolve("Successfully synchronized data!")
         })
     })
 
+// Message listener for the Sync button
 chrome.runtime.onMessage.addListener((data, sender, sendResponse) => {
     if(data.type === "sync")
         sync()
@@ -116,4 +141,5 @@ chrome.runtime.onMessage.addListener((data, sender, sendResponse) => {
     return true;
 })
 
+// At browser start, sync with wanikani
 sync().then(value => console.log(value)).catch(reason => console.error(reason))
\ No newline at end of file