1 files changed, 77 insertions, 0 deletions
diff --git a/searx/external_urls.py b/searx/external_urls.py
new file mode 100644
index 000000000..da58b8f54
--- /dev/null
+++ b/searx/external_urls.py
@@ -0,0 +1,77 @@
+import math
+
+from searx.data import EXTERNAL_URLS
+
+
+IMDB_PREFIX_TO_URL_ID = {
+    'tt': 'imdb_title',
+    'mn': 'imdb_name',
+    'ch': 'imdb_character',
+    'co': 'imdb_company',
+    'ev': 'imdb_event'
+}
+
+
+def get_imdb_url_id(imdb_item_id):
+    id_prefix = imdb_item_id[:2]
+    return IMDB_PREFIX_TO_URL_ID.get(id_prefix)
+
+
+def get_external_url(url_id, item_id, alternative="default"):
+    """Return an external URL or None if url_id is not found.
+
+    url_id can take value from data/external_urls.json
+    The "imdb_id" value is automaticaly converted according to the item_id value.
+
+    If item_id is None, the raw URL with the $1 is returned.
+    """
+    if url_id == 'imdb_id' and item_id is not None:
+        url_id = get_imdb_url_id(item_id)
+
+    url_description = EXTERNAL_URLS.get(url_id)
+    if url_description:
+        url_template = url_description["urls"].get(alternative)
+        if url_template is not None:
+            if item_id is not None:
+                return url_template.replace('$1', item_id)
+            else:
+                return url_template
+    return None
+
+
+def get_earth_coordinates_url(latitude, longitude, osm_zoom, alternative='default'):
+    url = get_external_url('map', None, alternative)\
+        .replace('${latitude}', str(latitude))\
+        .replace('${longitude}', str(longitude))\
+        .replace('${zoom}', str(osm_zoom))
+    return url
+
+
+def area_to_osm_zoom(area):
+    """Convert an area in km² into an OSM zoom. Less reliable if the shape is not round.
+
+    logarithm regression using these data:
+     * 9596961 -> 4 (China)
+     * 3287263 -> 5 (India)
+     * 643801 -> 6 (France)
+     * 6028 -> 9
+     * 1214 -> 10
+     * 891 -> 12
+     * 12 -> 13
+
+    In WolframAlpha:
+        >>> log fit {9596961,15},{3287263, 14},{643801,13},{6028,10},{1214,9},{891,7},{12,6}
+
+    with 15 = 19-4 (China); 14 = 19-5 (India) and so on
+
+    Args:
+        area (int,float,str): area in km²
+
+    Returns:
+        int: OSM zoom or 19 in area is not a number
+    """
+    try:
+        amount = float(area)
+        return max(0, min(19, round(19 - 0.688297 * math.log(226.878 * amount))))
+    except ValueError:
+        return 19