[fix] engine tineye: handle 422 response of not supported img format

Closes: https://github.com/searxng/searxng/issues/1449
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

searx/engines/tineye.py

@@ -17,6 +17,7 @@ billion images `[tineye.com] <https://tineye.com/how>`_.
 
 from urllib.parse import urlencode
 from datetime import datetime
+from flask_babel import gettext
 
 about = {
     "website": 'https://tineye.com',
@@ -28,20 +29,41 @@ about = {
 }
 
 engine_type = 'online_url_search'
+""":py:obj:`searx.search.processors.online_url_search`"""
+
 categories = ['general']
 paging = True
 safesearch = False
 base_url = 'https://tineye.com'
 search_string = '/result_json/?page={page}&{query}'
 
+FORMAT_NOT_SUPPORTED = gettext(
+    "Could not read that image url. This may be due to an unsupported file"
+    " format. TinEye only supports images that are JPEG, PNG, GIF, BMP, TIFF or WebP."
+)
+"""TinEye error message"""
+
+NO_SIGNATURE_ERROR = gettext(
+    "The image is too simple to find matches. TinEye requires a basic level of"
+    " visual detail to successfully identify matches."
+)
+"""TinEye error message"""
+
+DOWNLOAD_ERROR = gettext("The image could not be downloaded.")
+"""TinEye error message"""
+
 
 def request(query, params):
+    """Build TinEye HTTP request using ``search_urls`` of a :py:obj:`engine_type`."""
+
+    params['raise_for_httperror'] = False
 
     if params['search_urls']['data:image']:
         query = params['search_urls']['data:image']
     elif params['search_urls']['http']:
         query = params['search_urls']['http']
 
+    logger.debug("query URL: %s", query)
     query = urlencode({'url': query})
 
     # see https://github.com/TinEye/pytineye/blob/main/pytineye/api.py
@@ -59,45 +81,145 @@ def request(query, params):
     return params
 
 
+def parse_tineye_match(match_json):
+    """Takes parsed JSON from the API server and turns it into a :py:obj:`dict`
+    object.
+
+    Attributes `(class Match) <https://github.com/TinEye/pytineye/blob/main/pytineye/api.py>`__
+
+    - `image_url`, link to the result image.
+    - `domain`, domain this result was found on.
+    - `score`, a number (0 to 100) that indicates how closely the images match.
+    - `width`, image width in pixels.
+    - `height`, image height in pixels.
+    - `size`, image area in pixels.
+    - `format`, image format.
+    - `filesize`, image size in bytes.
+    - `overlay`, overlay URL.
+    - `tags`, whether this match belongs to a collection or stock domain.
+
+    - `backlinks`, a list of Backlink objects pointing to the original websites
+      and image URLs. List items are instances of :py:obj:`dict`, (`Backlink
+      <https://github.com/TinEye/pytineye/blob/main/pytineye/api.py>`__):
+
+      - `url`, the image URL to the image.
+      - `backlink`, the original website URL.
+      - `crawl_date`, the date the image was crawled.
+
+    """
+
+    # HINT: there exists an alternative backlink dict in the domains list / e.g.::
+    #
+    #     match_json['domains'][0]['backlinks']
+
+    backlinks = []
+    if "backlinks" in match_json:
+
+        for backlink_json in match_json["backlinks"]:
+            if not isinstance(backlink_json, dict):
+                continue
+
+            crawl_date = backlink_json.get("crawl_date")
+            if crawl_date:
+                crawl_date = datetime.fromisoformat(crawl_date[:-3])
+            else:
+                crawl_date = datetime.min
+
+            backlinks.append(
+                {
+                    'url': backlink_json.get("url"),
+                    'backlink': backlink_json.get("backlink"),
+                    'crawl_date': crawl_date,
+                    'image_name': backlink_json.get("image_name"),
+                }
+            )
+
+    return {
+        'image_url': match_json.get("image_url"),
+        'domain': match_json.get("domain"),
+        'score': match_json.get("score"),
+        'width': match_json.get("width"),
+        'height': match_json.get("height"),
+        'size': match_json.get("size"),
+        'image_format': match_json.get("format"),
+        'filesize': match_json.get("filesize"),
+        'overlay': match_json.get("overlay"),
+        'tags': match_json.get("tags"),
+        'backlinks': backlinks,
+    }
+
+
 def response(resp):
+    """Parse HTTP response from TinEye."""
     results = []
 
-    # Define wanted results
-    json_data = resp.json()
-    number_of_results = json_data['num_matches']
-
-    for i in json_data['matches']:
-        image_format = i['format']
-        width = i['width']
-        height = i['height']
-        thumbnail_src = i['image_url']
-        backlink = i['domains'][0]['backlinks'][0]
-        url = backlink['backlink']
-        source = backlink['url']
-        title = backlink['image_name']
-        img_src = backlink['url']
-
-        # Get and convert published date
-        api_date = backlink['crawl_date'][:-3]
-        publishedDate = datetime.fromisoformat(api_date)
-
-        # Append results
+    try:
+        json_data = resp.json()
+    except Exception as exc:  # pylint: disable=broad-except
+        msg = "can't parse JSON response // %s" % exc
+        logger.error(msg)
+        json_data = {'error': msg}
+
+    # handle error codes from Tineye
+
+    if resp.is_error:
+        if resp.status_code in (400, 422):
+
+            message = 'HTTP status: %s' % resp.status_code
+            error = json_data.get('error')
+            s_key = json_data.get('suggestions', {}).get('key', '')
+
+            if error and s_key:
+                message = "%s (%s)" % (error, s_key)
+            elif error:
+                message = error
+
+            if s_key == "Invalid image URL":
+                # test https://docs.searxng.org/_static/searxng-wordmark.svg
+                message = FORMAT_NOT_SUPPORTED
+            elif s_key == 'NO_SIGNATURE_ERROR':
+                # test https://pngimg.com/uploads/dot/dot_PNG4.png
+                message = NO_SIGNATURE_ERROR
+            elif s_key == 'Download Error':
+                # test https://notexists
+                message = DOWNLOAD_ERROR
+
+            # see https://github.com/searxng/searxng/pull/1456#issuecomment-1193105023
+            # results.append({'answer': message})
+            logger.error(message)
+
+            return results
+
+        resp.raise_for_status()
+
+    # append results from matches
+
+    for match_json in json_data['matches']:
+
+        tineye_match = parse_tineye_match(match_json)
+        if not tineye_match['backlinks']:
+            continue
+
+        backlink = tineye_match['backlinks'][0]
         results.append(
             {
                 'template': 'images.html',
-                'url': url,
-                'thumbnail_src': thumbnail_src,
-                'source': source,
-                'title': title,
-                'img_src': img_src,
-                'format': image_format,
-                'widht': width,
-                'height': height,
-                'publishedDate': publishedDate,
+                'url': backlink['backlink'],
+                'thumbnail_src': tineye_match['image_url'],
+                'source': backlink['url'],
+                'title': backlink['image_name'],
+                'img_src': backlink['url'],
+                'format': tineye_match['image_format'],
+                'widht': tineye_match['width'],
+                'height': tineye_match['height'],
+                'publishedDate': backlink['crawl_date'],
             }
         )
 
-    # Append number of results
-    results.append({'number_of_results': number_of_results})
+    # append number of results
+
+    number_of_results = json_data.get('num_matches')
+    if number_of_results:
+        results.append({'number_of_results': number_of_results})
 
     return results