Code to get cached URLs from wayback machine

src/calibre/ebooks/metadata/sources/search_engines.py

@@ -4,6 +4,7 @@
 
 from __future__ import absolute_import, division, print_function, unicode_literals
 
+import json
 import time
 from collections import defaultdict, namedtuple
 from future_builtins import map
@@ -13,15 +14,27 @@ from urlparse import parse_qs
 from lxml import etree
 
 import html5lib
-from calibre import browser, prints
+from calibre import browser as _browser, prints
 from calibre.utils.monotonic import monotonic
+from calibre.utils.random_ua import random_user_agent, accept_header_for_ua
 
 current_version = (1, 0, 0)
 minimum_calibre_version = (2, 80, 0)
 
 
 last_visited = defaultdict(lambda: 0)
-Result = namedtuple('Result', 'url text cached_url')
+Result = namedtuple('Result', 'url title cached_url')
+
+
+def browser():
+    ua = random_user_agent()
+    br = _browser(user_agent=ua)
+    br.set_handle_gzip(True)
+    br.addheaders += [
+        ('Accept', accept_header_for_ua(ua)),
+        ('Upgrade-insecure-requests', '1'),
+    ]
+    return br
 
 
 def encode_query(**query):
@@ -29,13 +42,13 @@ def encode_query(**query):
     return urlencode(q).decode('utf-8')
 
 
-def parse(raw):
+def parse_html(raw):
     return html5lib.parse(raw, treebuilder='lxml', namespaceHTMLElements=False)
 
 
-def query(br, url, key, dump_raw=None):
+def query(br, url, key, dump_raw=None, limit=1, parser=parse_html):
     delta = monotonic() - last_visited[key]
-    if delta < 1 and delta > 0:
+    if delta < limit and delta > 0:
         time.sleep(delta)
     try:
         raw = br.open_novisit(url).read()
@@ -44,7 +57,7 @@ def query(br, url, key, dump_raw=None):
     if dump_raw is not None:
         with open(dump_raw, 'wb') as f:
             f.write(raw)
-    return parse(raw)
+    return parser(raw)
 
 
 def quote_term(x):
@@ -67,6 +80,19 @@ def ddg_href(url):
     return url
 
 
+def wayback_machine_cached_url(url, br=None):
+    q = quote_term(url)
+    br = br or browser()
+    data = query(br, 'https://archive.org/wayback/available?url=' +
+                 q, 'wayback', parser=json.loads)
+    try:
+        closest = data['archived_snapshots']['closest']
+    except KeyError:
+        return
+    if closest['available']:
+        return closest['url']
+
+
 def ddg_search(terms, site=None, br=None, log=prints, safe_search=False, dump_raw=None):
     # https://duck.co/help/results/syntax
     terms = map(ddg_term, terms)
@@ -74,16 +100,23 @@ def ddg_search(terms, site=None, br=None, log=prints, safe_search=False, dump_ra
     if site is not None:
         terms.append(quote_term(('site:' + site)))
     q = '+'.join(terms)
-    url = 'https://duckduckgo.com/html/?q={q}&kp={kp}'.format(q=q, kp=1 if safe_search else -1)
+    url = 'https://duckduckgo.com/html/?q={q}&kp={kp}'.format(
+        q=q, kp=1 if safe_search else -1)
     log('Making ddg query: ' + url)
     br = br or browser()
     root = query(br, url, 'ddg', dump_raw)
     ans = []
     for a in root.xpath('//*[@class="results"]//*[@class="result__title"]/a[@href and @class="result__a"]'):
-        ans.append(Result(ddg_href(a.get('href')), etree.tostring(a, encoding=unicode, method='text', with_tail=False), None))
+        ans.append(Result(ddg_href(a.get('href')), etree.tostring(
+            a, encoding=unicode, method='text', with_tail=False), None))
     return ans
 
 
 def ddg_develop():
-    from pprint import pprint
-    pprint(ddg_search('heroes abercrombie'.split(), 'amazon.com', dump_raw='/t/raw.html'))
+    br = browser()
+    for result in ddg_search('heroes abercrombie'.split(), 'amazon.com', dump_raw='/t/raw.html', br=br):
+        if '/dp/' in result.url:
+            print(result.title)
+            print(' ', result.url)
+            print(' ', wayback_machine_cached_url(result.url, br))
+            print()