[YouTube] Fix extraction of n param deobfuscation function name

This commit adds two new regular expressions to parse the n parameter function.

It also improves existing regular expressions by using the constant representing
multiple characters instead of adding the one or multiple characters
token manually in each regex for everything and not only function names.

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/YoutubeThrottlingParameterUtils.java

@@ -22,7 +22,7 @@ final class YoutubeThrottlingParameterUtils {
 
     private static final String SINGLE_CHAR_VARIABLE_REGEX = "[a-zA-Z0-9$_]";
 
-    private static final String FUNCTION_NAME_REGEX = SINGLE_CHAR_VARIABLE_REGEX + "+";
+    private static final String MULTIPLE_CHARS_REGEX = SINGLE_CHAR_VARIABLE_REGEX + "+";
 
     private static final String ARRAY_ACCESS_REGEX = "\\[(\\d+)]";
 
@@ -30,31 +30,54 @@ final class YoutubeThrottlingParameterUtils {
     private static final Pattern[] DEOBFUSCATION_FUNCTION_NAME_REGEXES = {
 
             /*
-             * The first regex matches the following text, where we want rDa and the array index
+             * The first regex matches the following text, where we want Wma and the array index
+             * accessed:
+             *
+             * a.D&&(b="nn"[+a.D],WL(a),c=a.j[b]||null)&&(c=SDa[0](c),a.set(b,c),SDa.length||Wma("")
+             */
+            Pattern.compile(SINGLE_CHAR_VARIABLE_REGEX + "=\"nn\"\\[\\+" + MULTIPLE_CHARS_REGEX
+                    + "\\." + MULTIPLE_CHARS_REGEX + "]," + MULTIPLE_CHARS_REGEX + "\\("
+                    + MULTIPLE_CHARS_REGEX + "\\)," + MULTIPLE_CHARS_REGEX + "="
+                    + MULTIPLE_CHARS_REGEX + "\\." + MULTIPLE_CHARS_REGEX + "\\["
+                    + MULTIPLE_CHARS_REGEX + "]\\|\\|null\\).+\\|\\|(" + MULTIPLE_CHARS_REGEX
+                    + ")\\(\"\"\\)"),
+
+            /*
+             * The second regex matches the following text, where we want SDa and the array index
+             * accessed:
+             *
+             * a.D&&(b="nn"[+a.D],WL(a),c=a.j[b]||null)&&(c=SDa[0](c),a.set(b,c),SDa.length||Wma("")
+             */
+            Pattern.compile(SINGLE_CHAR_VARIABLE_REGEX + "=\"nn\"\\[\\+" + MULTIPLE_CHARS_REGEX
+                    + "\\." + MULTIPLE_CHARS_REGEX + "]," + MULTIPLE_CHARS_REGEX + "\\("
+                    + MULTIPLE_CHARS_REGEX + "\\)," + MULTIPLE_CHARS_REGEX + "="
+                    + MULTIPLE_CHARS_REGEX + "\\." + MULTIPLE_CHARS_REGEX + "\\["
+                    + MULTIPLE_CHARS_REGEX + "]\\|\\|null\\)&&\\(" + MULTIPLE_CHARS_REGEX + "=("
+                    + MULTIPLE_CHARS_REGEX + ")" + ARRAY_ACCESS_REGEX),
+
+            /*
+             * The third regex matches the following text, where we want rma:
+             *
+             * a.D&&(b="nn"[+a.D],c=a.get(b))&&(c=rDa[0](c),a.set(b,c),rDa.length||rma("")
+             */
+            Pattern.compile(SINGLE_CHAR_VARIABLE_REGEX + "=\"nn\"\\[\\+" + MULTIPLE_CHARS_REGEX
+                    + "\\." + MULTIPLE_CHARS_REGEX + "]," + MULTIPLE_CHARS_REGEX + "="
+                    + MULTIPLE_CHARS_REGEX + "\\.get\\(" + MULTIPLE_CHARS_REGEX + "\\)\\).+\\|\\|("
+                    + MULTIPLE_CHARS_REGEX + ")\\(\"\"\\)"),
+
+            /*
+             * The fourth regex matches the following text, where we want rDa and the array index
              * accessed:
              *
              * a.D&&(b="nn"[+a.D],c=a.get(b))&&(c=rDa[0](c),a.set(b,c),rDa.length||rma("")
              */
-            Pattern.compile(SINGLE_CHAR_VARIABLE_REGEX + "+=\"nn\"\\[\\+"
+            Pattern.compile(SINGLE_CHAR_VARIABLE_REGEX + "=\"nn\"\\[\\+" + MULTIPLE_CHARS_REGEX
-                    + SINGLE_CHAR_VARIABLE_REGEX + "+\\." + SINGLE_CHAR_VARIABLE_REGEX + "+],"
+                    + "\\." + MULTIPLE_CHARS_REGEX + "]," + MULTIPLE_CHARS_REGEX + "="
-                    + SINGLE_CHAR_VARIABLE_REGEX + "+=" + SINGLE_CHAR_VARIABLE_REGEX
+                    + MULTIPLE_CHARS_REGEX + "\\.get\\(" + MULTIPLE_CHARS_REGEX + "\\)\\)&&\\("
-                    + "+\\.get\\(" + SINGLE_CHAR_VARIABLE_REGEX + "+\\)\\)&&\\("
+                    + MULTIPLE_CHARS_REGEX + "=(" + MULTIPLE_CHARS_REGEX + ")\\[(\\d+)]"),
-                    + SINGLE_CHAR_VARIABLE_REGEX + "+=(" + SINGLE_CHAR_VARIABLE_REGEX
-                    + "+)\\[(\\d+)]"),
 
             /*
-             * The second regex matches the following text, where we want rma:
+             * The fifth regex matches the following text, where we want BDa and the array index
-             *
-             * a.D&&(b="nn"[+a.D],c=a.get(b))&&(c=rDa[0](c),a.set(b,c),rDa.length||rma("")
-             */
-            Pattern.compile(SINGLE_CHAR_VARIABLE_REGEX + "+=\"nn\"\\[\\+"
-                    + SINGLE_CHAR_VARIABLE_REGEX + "+\\." + SINGLE_CHAR_VARIABLE_REGEX + "+],"
-                    + SINGLE_CHAR_VARIABLE_REGEX + "+=" + SINGLE_CHAR_VARIABLE_REGEX + "+\\.get\\("
-                    + SINGLE_CHAR_VARIABLE_REGEX + "+\\)\\).+\\|\\|(" + SINGLE_CHAR_VARIABLE_REGEX
-                    + "+)\\(\"\"\\)"),
-
-            /*
-             * The third regex matches the following text, where we want BDa and the array index
              * accessed:
              *
              * (b=String.fromCharCode(110),c=a.get(b))&&(c=BDa[0](c)
@@ -62,17 +85,17 @@ final class YoutubeThrottlingParameterUtils {
             Pattern.compile("\\(" + SINGLE_CHAR_VARIABLE_REGEX + "=String\\.fromCharCode\\(110\\),"
                     + SINGLE_CHAR_VARIABLE_REGEX + "=" + SINGLE_CHAR_VARIABLE_REGEX + "\\.get\\("
                     + SINGLE_CHAR_VARIABLE_REGEX + "\\)\\)" + "&&\\(" + SINGLE_CHAR_VARIABLE_REGEX
-                    + "=(" + FUNCTION_NAME_REGEX + ")" + "(?:" + ARRAY_ACCESS_REGEX + ")?\\("
+                    + "=(" + MULTIPLE_CHARS_REGEX + ")" + "(?:" + ARRAY_ACCESS_REGEX + ")?\\("
                     + SINGLE_CHAR_VARIABLE_REGEX + "\\)"),
 
             /*
-             * The fourth regex matches the following text, where we want Yva and the array index
+             * The sixth regex matches the following text, where we want Yva and the array index
              * accessed:
              *
              * .get("n"))&&(b=Yva[0](b)
              */
             Pattern.compile("\\.get\\(\"n\"\\)\\)&&\\(" + SINGLE_CHAR_VARIABLE_REGEX
-                    + "=(" + FUNCTION_NAME_REGEX + ")(?:" + ARRAY_ACCESS_REGEX + ")?\\("
+                    + "=(" + MULTIPLE_CHARS_REGEX + ")(?:" + ARRAY_ACCESS_REGEX + ")?\\("
                     + SINGLE_CHAR_VARIABLE_REGEX + "\\)")
     };
     // CHECKSTYLE:ON