[feat] engines: add tiger.ch engine

Add support for https://tiger.ch (general, news)

It is disabled and inactive by default because it's just a metasearch engine
like SearXNG is, so it's mostly useful for bypassing rate-limits on other
engines: (it has its own German index, but it's not that great) in theory it
supports different locales, but I was too lazy to implement that (I only need
German and English results anyways, which are returned by default...)

searx/engines/tiger.py

@@ -0,0 +1,167 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+"""Tiger_ is a Swiss meta search engine.
+
+.. _Tiger: https://tiger.ch
+"""
+
+from json import loads
+import random
+from urllib.parse import urlencode
+
+import typing as t
+
+from dateutil import parser
+from lxml import html
+
+from searx.exceptions import SearxEngineAPIException
+from searx.extended_types import SXNG_Response
+from searx.network import get, post
+from searx.result_types import EngineResults
+from searx.utils import extr, eval_xpath_list, eval_xpath, extract_text
+from searx.enginelib import EngineCache
+
+if t.TYPE_CHECKING:
+    from searx.search.processors import OnlineParams
+
+about = {
+    "website": "https://tiger.ch",
+    "official_api_documentation": None,
+    "use_official_api": False,
+    "require_api_key": False,
+    "results": "HTML",
+}
+
+paging = True
+
+base_url = "https://tiger.ch"
+categories = []
+tiger_category = "Websuche"
+"""
+Possible values: "Websuche", "News".
+"""
+
+
+CACHE: EngineCache
+"""Cache to store session codes (result of solved CAPTCHA)."""
+
+
+def init(_):
+    if tiger_category not in ("Websuche", "News"):
+        raise ValueError("invalid search category: %s" % tiger_category)
+
+
+def setup(engine_settings: dict[str, t.Any]) -> bool:
+    global CACHE  # pylint: disable=global-statement
+    CACHE = EngineCache(engine_settings["name"])
+    return True
+
+
+def _obtain_session_code() -> str:
+    """The challenge works like this:
+
+    - We first generate 3 random numbers.
+    - Then we send them to /Human.svc/Make to get the operands (+, -) for the
+      math challenge (i.e. a simple calculation)
+    - Based on the operands, we calculate a result (usually done by the user by
+      hand)
+    - We send the result of the math calculation to the server to obtain a
+      session "code" that has to be sent as cookie parameter for all searches
+
+    E.g., challenges look like ``19-3+5``.
+    """
+    cached_session = CACHE.get("session")
+    if cached_session:
+        return cached_session
+
+    results_page = get(f"{base_url}/_internCode.aspx")
+    doc = html.fromstring(results_page.text)
+
+    extra_data: dict[str, str] = {}
+    for extra_param in ("__VIEWSTATE", "__VIEWSTATEGENERATOR", "__EVENTVALIDATION"):
+        extra_data[extra_param] = doc.xpath(f"//input[@name='{extra_param}']/@value")[0]
+
+    # var z1 = Math.floor((Math.random() * 8) + 11);
+    # var z2 = Math.floor((Math.random() * 8) + 1);
+    # var z3 = Math.floor((Math.random() * 8) + 1);
+    num1 = random.randint(11, 19)
+    num2 = random.randint(1, 9)
+    num3 = random.randint(1, 9)
+
+    challenge = get(f"{base_url}/Services/Human.svc/Make?M1={num1}&M2={num2}&M3={num3}", cookies=results_page.cookies)
+    signs = loads(challenge.json()["d"])[0]
+    sign1 = signs["Z1"]
+    sign2 = signs["Z2"]
+
+    result = num1
+    for num, sign in [(num2, sign1), (num3, sign2)]:
+        if sign == "+":
+            result += num
+        else:
+            result -= num
+
+    logger.debug(f"got challenge: {num1} {sign1} {num2} {sign2} {num3} = {result}")
+    data = {
+        **extra_data,
+        "txtM": str(result),
+        "btnHuman": "OK",
+    }
+
+    challenge_response = post(
+        f"{base_url}/_internCode.aspx",
+        cookies=results_page.cookies,
+        data=data,
+    )
+
+    cookie = challenge_response.cookies["Tiger.ch"]
+    code = extr(cookie, "Code=", "&")
+    if not code:
+        raise SearxEngineAPIException("failed to obtain session code")
+
+    CACHE.set("session", code, expire=60 * 24 * 60)  # cookie is valid for two months
+    return code
+
+
+def request(query: str, params: "OnlineParams"):
+    code = _obtain_session_code()
+    args = {"w": query, "page": params["pageno"]}
+    params["url"] = f"{base_url}/{tiger_category}?{urlencode(args)}"
+    params["cookies"]["Tiger.ch"] = f"Code={code}"
+
+
+def response(resp: "SXNG_Response") -> EngineResults:
+    res = EngineResults()
+    doc = html.fromstring(resp.text)
+
+    if tiger_category == "Websuche":
+        for result in eval_xpath_list(doc, "//div[@id='mainContainer']//table/tr"):
+            res.add(
+                res.types.MainResult(
+                    url=extract_text(eval_xpath(result, ".//a[contains(@class, 'weblink')]/@href")),
+                    title=extract_text(eval_xpath(result, ".//a[contains(@class, 'weblink')]")) or "",
+                    content=extract_text(eval_xpath(result, ".//*[contains(@class, 'webbodynopic')]")) or "",
+                )
+            )
+    elif tiger_category == "News":
+        for result in eval_xpath_list(doc, "//div[@id='panNews']/div"):
+            publishedDate = None
+            try:
+                date_str = extract_text(eval_xpath(result, ".//span[contains(@class, 'help')]/span")) or ""
+                date_str = date_str.strip().removeprefix("-").strip()
+                publishedDate = parser.parse(date_str)
+            except parser.ParserError:
+                pass
+
+            thumbnail = extract_text(eval_xpath(result, "./img/@src"))
+            if thumbnail:
+                thumbnail = base_url + thumbnail
+
+            res.add(
+                res.types.MainResult(
+                    url=extract_text(eval_xpath(result, ".//a[contains(@class, 'webLink')]/@href")),
+                    title=extract_text(eval_xpath(result, ".//a[contains(@class, 'webLink')]")) or "",
+                    thumbnail=thumbnail or "",
+                    publishedDate=publishedDate,
+                )
+            )
+
+    return res

searx/settings.yml

@@ -2078,6 +2078,22 @@ engines:
     shortcut: ts
     disabled: true
 
+  - name: tiger
+    engine: tiger
+    categories: general
+    tiger_category: Websuche
+    shortcut: tig
+    disabled: true
+    inactive: true
+
+  - name: tiger news
+    engine: tiger
+    categories: news
+    tiger_category: News
+    shortcut: tign
+    disabled: true
+    inactive: true
+
   - name: tmdb
     engine: xpath
     paging: true