searxng/searx/webadapter.py

from typing import Dict, List, Optional, Tuple
from searx.exceptions import SearxParameterException
from searx.query import RawTextQuery, VALID_LANGUAGE_CODE
from searx.engines import categories, engines
from searx.search import SearchQuery, EngineRef
from searx.preferences import Preferences


# remove duplicate queries.
# FIXME: does not fix "!music !soundcloud", because the categories are 'none' and 'music'
def deduplicate_engineref_list(engineref_list: List[EngineRef]) -> List[EngineRef]:
    engineref_dict = {q.category + '|' + q.name: q for q in engineref_list}
    return engineref_dict.values()


def validate_engineref_list(engineref_list: List[EngineRef], preferences: Preferences)\
        -> Tuple[List[EngineRef], List[EngineRef], List[EngineRef]]:
    """Validate query_engines according to the preferences

    Returns:
        List[EngineRef]: list of existing engines with a validated token
        List[EngineRef]: list of unknown engine
        List[EngineRef]: list of engine with invalid token according to the preferences
    """
    valid = []
    unknown = []
    no_token = []
    for engineref in engineref_list:
        if engineref.name not in engines:
            unknown.append(engineref)
            continue

        engine = engines[engineref.name]
        if not preferences.validate_token(engine):
            no_token.append(engineref)
            continue

        valid.append(engineref)
    return valid, unknown, no_token


def parse_pageno(form: Dict[str, str]) -> int:
    pageno_param = form.get('pageno', '1')
    if not pageno_param.isdigit() or int(pageno_param) < 1:
        raise SearxParameterException('pageno', pageno_param)
    return int(pageno_param)


def parse_lang(preferences: Preferences, form: Dict[str, str], raw_text_query: RawTextQuery) -> str:
    # get language
    # set specific language if set on request, query or preferences
    # TODO support search with multible languages
    if len(raw_text_query.languages):
        query_lang = raw_text_query.languages[-1]
    elif 'language' in form:
        query_lang = form.get('language')
    else:
        query_lang = preferences.get_value('language')

    # check language
    if not VALID_LANGUAGE_CODE.match(query_lang):
        raise SearxParameterException('language', query_lang)

    return query_lang


def parse_safesearch(preferences: Preferences, form: Dict[str, str]) -> int:
    if 'safesearch' in form:
        query_safesearch = form.get('safesearch')
        # first check safesearch
        if not query_safesearch.isdigit():
            raise SearxParameterException('safesearch', query_safesearch)
        query_safesearch = int(query_safesearch)
    else:
        query_safesearch = preferences.get_value('safesearch')

    # safesearch : second check
    if query_safesearch < 0 or query_safesearch > 2:
        raise SearxParameterException('safesearch', query_safesearch)

    return query_safesearch


def parse_time_range(form: Dict[str, str]) -> str:
    query_time_range = form.get('time_range')
    # check time_range
    query_time_range = None if query_time_range in ('', 'None') else query_time_range
    if query_time_range not in (None, 'day', 'week', 'month', 'year'):
        raise SearxParameterException('time_range', query_time_range)
    return query_time_range


def parse_timeout(form: Dict[str, str], raw_text_query: RawTextQuery) -> Optional[float]:
    query_timeout = raw_text_query.timeout_limit
    if query_timeout is None and 'timeout_limit' in form:
        raw_time_limit = form.get('timeout_limit')
        if raw_time_limit in ['None', '']:
            return None
        else:
            try:
                return float(raw_time_limit)
            except ValueError:
                raise SearxParameterException('timeout_limit', raw_time_limit)


def parse_specific(raw_text_query: RawTextQuery) -> Tuple[List[EngineRef], List[str]]:
    query_engineref_list = raw_text_query.enginerefs
    additional_categories = set()
    for engineref in raw_text_query.enginerefs:
        if engineref.from_bang:
            additional_categories.add('none')
        else:
            additional_categories.add(engineref.category)
    query_categories = list(additional_categories)
    return query_engineref_list, query_categories


def parse_category_form(query_categories: List[str], name: str, value: str) -> None:
    if name == 'categories':
        query_categories.extend(categ for categ in map(str.strip, value.split(',')) if categ in categories)
    elif name.startswith('category_'):
        category = name[9:]

        # if category is not found in list, skip
        if category not in categories:
            return

        if value != 'off':
            # add category to list
            query_categories.append(category)
        elif category in query_categories:
            # remove category from list if property is set to 'off'
            query_categories.remove(category)


def get_selected_categories(preferences: Preferences, form: Dict[str, str]) -> List[str]:
    selected_categories = []

    if form is not None:
        for name, value in form.items():
            parse_category_form(selected_categories, name, value)

    # if no category is specified for this search,
    # using user-defined default-configuration which
    # (is stored in cookie)
    if not selected_categories:
        cookie_categories = preferences.get_value('categories')
        for ccateg in cookie_categories:
            selected_categories.append(ccateg)

    # if still no category is specified, using general
    # as default-category
    if not selected_categories:
        selected_categories = ['general']

    return selected_categories


def parse_generic(preferences: Preferences, form: Dict[str, str], disabled_engines: List[str])\
        -> Tuple[List[EngineRef], List[str]]:
    query_engineref_list = []
    query_categories = []

    # set categories/engines
    load_default_categories = True
    for pd_name, pd in form.items():
        if pd_name == 'engines':
            pd_engines = [EngineRef(engine_name, engines[engine_name].categories[0])
                          for engine_name in map(str.strip, pd.split(',')) if engine_name in engines]
            if pd_engines:
                query_engineref_list.extend(pd_engines)
                load_default_categories = False
        else:
            parse_category_form(query_categories, pd_name, pd)

    if not load_default_categories:
        if not query_categories:
            query_categories = list(set(engine['category']
                                        for engine in query_engineref_list))
    else:
        if not query_categories:
            query_categories = get_selected_categories(preferences, None)

        # using all engines for that search, which are
        # declared under the specific categories
        for categ in query_categories:
            query_engineref_list.extend(EngineRef(engine.name, categ)
                                        for engine in categories[categ]
                                        if (engine.name, categ) not in disabled_engines)

    return query_engineref_list, query_categories


def get_search_query_from_webapp(preferences: Preferences, form: Dict[str, str])\
        -> Tuple[SearchQuery, RawTextQuery, List[EngineRef], List[EngineRef]]:
    # no text for the query ?
    if not form.get('q'):
        raise SearxParameterException('q', '')

    # set blocked engines
    disabled_engines = preferences.engines.get_disabled()

    # parse query, if tags are set, which change
    # the serch engine or search-language
    raw_text_query = RawTextQuery(form['q'], disabled_engines)

    # set query
    query = raw_text_query.getQuery()
    query_pageno = parse_pageno(form)
    query_lang = parse_lang(preferences, form, raw_text_query)
    query_safesearch = parse_safesearch(preferences, form)
    query_time_range = parse_time_range(form)
    query_timeout = parse_timeout(form, raw_text_query)
    external_bang = raw_text_query.external_bang

    if raw_text_query.enginerefs and raw_text_query.specific:
        # if engines are calculated from query,
        # set categories by using that informations
        query_engineref_list, query_categories = parse_specific(raw_text_query)
    else:
        # otherwise, using defined categories to
        # calculate which engines should be used
        query_engineref_list, query_categories = parse_generic(preferences, form, disabled_engines)

    query_engineref_list = deduplicate_engineref_list(query_engineref_list)
    query_engineref_list, query_engineref_list_unknown, query_engineref_list_notoken =\
        validate_engineref_list(query_engineref_list, preferences)

    return (SearchQuery(query, query_engineref_list, query_categories,
                        query_lang, query_safesearch, query_pageno,
                        query_time_range, query_timeout,
                        external_bang=external_bang),
            raw_text_query,
            query_engineref_list_unknown,
            query_engineref_list_notoken)