Add string decode script

patches/src/main/kotlin/app/revanced/patches/reddit/customclients/redditisfun/api/ImgurAlbumsPatch.kt

@@ -59,3 +59,115 @@ val imgurAlbumsPatch = bytecodePatch(
         """.trimIndent())
     }
 }
+
+/*
+The original contents of the method decodes an obfuscated string, you can use the following script
+to decode the value:
+
+import kotlin.math.pow
+object StringDecryptor {
+    /**
+     * Decrypts a string using a position-dependent Caesar-like cipher.
+     * Handles lowercase, uppercase, and other characters differently.
+     * Replaces '>' with '_' at the end.
+     */
+    fun w(input: String): String {
+        val builder = StringBuilder()
+        val length = input.length
+
+        // Note: Smali loop starts from 1, accesses charAt(i-1), uses 'i' for shift
+        for (i in 1..length) {
+            val charIndex = i - 1 // Index of the character to process
+            var charCode = input[charIndex].code // Get character's Unicode code point
+            var base: Int
+            val mod: Int
+
+            when (input[charIndex]) {
+                in 'a'..'z' -> {
+                    base = 'a'.code
+                    mod = 26
+                    charCode -= base // Normalize to 0-25
+                }
+                in 'A'..'Z' -> {
+                    base = 'A'.code
+                    mod = 26
+                    charCode -= base // Normalize to 0-25
+                }
+                else -> {
+                    // Handles other characters based on space ' '
+                    // Corresponds to the Smali block L3
+                    base = ' '.code
+                    mod = 33
+                    charCode -= base // Normalize relative to space
+                }
+            }
+
+            // Apply the position-dependent shift (subtracting loop counter 'i')
+            // The formula (val - shift + mod) % mod handles potential negative results correctly
+            val shiftedCode = (charCode - i + mod) % mod
+
+            // Add the base back to get the final character code
+            val finalCode = shiftedCode + base
+
+            builder.append(finalCode.toChar())
+        }
+
+        // Final replacement as seen in the Smali code
+        return builder.toString().replace('>', '_')
+    }
+
+    /**
+     * Unscrambles a string based on an index mapping array.
+     * If input is "cba" and map is [2, 0, 1], output is "abc".
+     */
+    fun z(scrambledString: String, indexMap: IntArray): String {
+        val length = indexMap.size
+        // Create an inverse map: targetIndices[original_index] = current_index
+        val targetIndices = IntArray(length)
+        for (i in 0 until length) {
+            targetIndices[indexMap[i]] = i
+        }
+
+        val builder = StringBuilder(length)
+        // Build the unscrambled string using the inverse map
+        for (i in 0 until length) {
+            builder.append(scrambledString[targetIndices[i]])
+        }
+        return builder.toString()
+    }
+
+    fun decode(s: String, offsets: IntArray): String {
+        // Values produced by decompiler are offset
+        val decompilerMult = 2.0.pow(24).toInt()
+        // If you extract the values from the smali directly no offset is needed:
+        //val decompilerMult = 1
+
+        // 1. Unscramble the string using z()
+        val unscrambledString = z(s, offsets.map { it / decompilerMult }.toIntArray())
+        // 2. Decrypt the unscrambled string using w()
+        return w(unscrambledString)
+    }
+}
+
+StringDecryptor.decode("krltdwtl2eikrcbfsg>", intArrayOf(
+    100663296,
+    16777216,
+    117440512,
+    167772160,
+    150994944,
+    67108864,
+    268435456,
+    33554432,
+    50331648,
+    184549376,
+    218103808,
+    83886080,
+    134217728,
+    234881024,
+    0,
+    301989888,
+    201326592,
+    285212672,
+    251658240,
+)) // Output: api.redditisfun.com
+ */