first commit

searx/plugins/oa_doi_rewrite.py

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+# SPDX-License-Identifier: AGPL-3.0-or-later
+# pylint: disable=missing-module-docstring
+from __future__ import annotations
+import typing
+
+import re
+from urllib.parse import parse_qsl
+
+from flask_babel import gettext
+from searx import get_setting
+from searx.plugins import Plugin, PluginInfo
+from searx.extended_types import sxng_request
+
+from ._core import log
+
+if typing.TYPE_CHECKING:
+    from searx.search import SearchWithPlugins
+    from searx.extended_types import SXNG_Request
+    from searx.result_types import Result, LegacyResult
+    from searx.plugins import PluginCfg
+
+
+ahmia_blacklist: list = []
+
+
+def filter_url_field(result: "Result|LegacyResult", field_name: str, url_src: str) -> bool | str:
+    """Returns bool ``True`` to use URL unchanged (``False`` to ignore URL).
+    If URL should be modified, the returned string is the new URL to use."""
+
+    if field_name != "url":
+        return True  # use it unchanged
+
+    doi = extract_doi(result.parsed_url)
+    if doi and len(doi) < 50:
+        for suffix in ("/", ".pdf", ".xml", "/full", "/meta", "/abstract"):
+            doi = doi.removesuffix(suffix)
+        new_url = get_doi_resolver() + doi
+        if "doi" not in result:
+            result["doi"] = doi
+        log.debug("oa_doi_rewrite: [URL field: %s] %s -> %s", field_name, url_src, new_url)
+        return new_url  # use new url
+
+    return True  # use it unchanged
+
+
+class SXNGPlugin(Plugin):
+    """Avoid paywalls by redirecting to open-access."""
+
+    id = "oa_doi_rewrite"
+
+    def __init__(self, plg_cfg: "PluginCfg") -> None:
+        super().__init__(plg_cfg)
+        self.info = PluginInfo(
+            id=self.id,
+            name=gettext("Open Access DOI rewrite"),
+            description=gettext("Avoid paywalls by redirecting to open-access versions of publications when available"),
+            preference_section="general",
+        )
+
+    def on_result(
+        self,
+        request: "SXNG_Request",
+        search: "SearchWithPlugins",
+        result: "Result",
+    ) -> bool:  # pylint: disable=unused-argument
+        if result.parsed_url:
+            result.filter_urls(filter_url_field)
+        return True
+
+
+regex = re.compile(r'10\.\d{4,9}/[^\s]+')
+
+
+def extract_doi(url):
+    m = regex.search(url.path)
+    if m:
+        return m.group(0)
+    for _, v in parse_qsl(url.query):
+        m = regex.search(v)
+        if m:
+            return m.group(0)
+    return None
+
+
+def get_doi_resolver() -> str:
+    doi_resolvers = get_setting("doi_resolvers")
+    selected_resolver = sxng_request.preferences.get_value('doi_resolver')[0]
+    if selected_resolver not in doi_resolvers:
+        selected_resolver = get_setting("default_doi_resolver")
+    return doi_resolvers[selected_resolver]