From aaf73868db2a090422fd8ce618090526b62dd404 Mon Sep 17 00:00:00 2001
From: loyalsoldier <10487845+Loyalsoldier@users.noreply.github.com>
Date: Fri, 31 Jul 2020 12:56:49 +0800
Subject: [PATCH] Add findRedundantDomain.py script

---
 findRedundantDomain.py | 70 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100644 findRedundantDomain.py

diff --git a/findRedundantDomain.py b/findRedundantDomain.py
new file mode 100644
index 0000000..2e21d24
--- /dev/null
+++ b/findRedundantDomain.py
@@ -0,0 +1,70 @@
+#!/usr/bin/env python3
+
+import sys
+print(sys.argv[1], sys.argv[2])
+
+''' Find redundant items in domain lists.
+    e.g. 'bar.foo.com' is redundant for 'foo.com'.
+'''
+
+
+def load(list):
+    ''' Parse conf file & Prepare data structure
+        Returns: [ ['abc', 'com'],
+                   ['bar', 'foo', 'com'],
+                   ... ]
+    '''
+
+    results = []
+    with open(list, 'r') as f:
+        for line in f.readlines():
+            line = line.strip()
+            if line == '' or line.startswith('#'):
+                continue
+            # A domain name is case-insensitive and
+            # consists of several labels, separated by a full stop
+            domain_labels = line.lower().split('.')
+            results.append(domain_labels)
+
+    # Sort results by domain labels' length
+    results.sort(key=len)
+    return results
+
+
+def find(labelses, removedDomainFile):
+    ''' Find redundant items by a tree of top-level domain label to sub-level.
+        `tree` is like { 'com': { 'foo: { 'bar': LEAF },
+                                  'abc': LEAF },
+                         'org': ... }
+    '''
+
+    tree = {}
+    LEAF = 1
+    for labels in labelses:
+        domain = '.'.join(labels)
+        # Init root node as current node
+        node = tree
+        while len(labels) > 0:
+            label = labels.pop()
+            if label in node:
+                # If child node is a LEAF node,
+                # current domain must be an existed domain or a subdomain of an existed.
+                if node[label] == LEAF:
+                    print(f"Redundant found: {domain} at {'.'.join(labels)}")
+                    with open(removedDomainFile, "a") as f:
+                        f.write(domain)
+                        f.write("\n")
+                    break
+            else:
+                # Create a leaf node if current label is last one
+                if len(labels) == 0:
+                    node[label] = LEAF
+                # Create a branch node
+                else:
+                    node[label] = {}
+            # Iterate to child node
+            node = node[label]
+
+
+if __name__ == '__main__':
+    find(load(sys.argv[1]), sys.argv[2])