#VERSION: 1.44

# Author:
#  Fabien Devaux <fab AT gnux DOT info>
# Contributors:
#  Christophe Dumez <chris@qbittorrent.org> (qbittorrent integration)
#  Thanks to gab #gcu @ irc.freenode.net (multipage support on PirateBay)
#  Thanks to Elias <gekko04@users.sourceforge.net> (torrentreactor and isohunt search engines)
#
# Licence: BSD

# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
#    * Redistributions of source code must retain the above copyright notice,
#      this list of conditions and the following disclaimer.
#    * Redistributions in binary form must reproduce the above copyright
#      notice, this list of conditions and the following disclaimer in the
#      documentation and/or other materials provided with the distribution.
#    * Neither the name of the author nor the names of its contributors may be
#      used to endorse or promote products derived from this software without
#      specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.

import importlib
import pathlib
import sys
import urllib.parse
from glob import glob
from multiprocessing import Pool, cpu_count
from os import path

THREADED = True
try:
    MAX_THREADS = cpu_count()
except NotImplementedError:
    MAX_THREADS = 1

CATEGORIES = {'all', 'movies', 'tv', 'music', 'games', 'anime', 'software', 'pictures', 'books'}

################################################################################
# Every engine should have a "search" method taking
# a space-free string as parameter (ex. "family+guy")
# it should call prettyPrinter() with a dict as parameter.
# The keys in the dict must be: link,name,size,seeds,leech,engine_url
# As a convention, try to list results by decreasing number of seeds or similar
################################################################################


def initialize_engines():
    """ Import available engines

        Return list of available engines
    """
    supported_engines = []

    engines = glob(path.join(path.dirname(__file__), 'engines', '*.py'))
    for engine in engines:
        engi = path.basename(engine).split('.')[0].strip()
        if len(engi) == 0 or engi.startswith('_'):
            continue
        try:
            # import engines.[engine]
            engine_module = importlib.import_module("engines." + engi)
            # bind class name
            globals()[engi] = getattr(engine_module, engi)
            supported_engines.append(engi)
        except Exception:
            pass

    return supported_engines


def engines_to_xml(supported_engines):
    """ Generates xml for supported engines """
    tab = " " * 4

    for short_name in supported_engines:
        search_engine = globals()[short_name]()

        supported_categories = ""
        if hasattr(search_engine, "supported_categories"):
            supported_categories = " ".join((key
                                             for key in search_engine.supported_categories.keys()
                                             if key != "all"))

        yield "".join((tab, "<", short_name, ">\n",
                       tab, tab, "<name>", search_engine.name, "</name>\n",
                       tab, tab, "<url>", search_engine.url, "</url>\n",
                       tab, tab, "<categories>", supported_categories, "</categories>\n",
                       tab, "</", short_name, ">\n"))


def displayCapabilities(supported_engines):
    """
    Display capabilities in XML format
    <capabilities>
      <engine_short_name>
        <name>long name</name>
        <url>http://example.com</url>
        <categories>movies music games</categories>
      </engine_short_name>
    </capabilities>
    """
    xml = "".join(("<capabilities>\n",
                   "".join(engines_to_xml(supported_engines)),
                   "</capabilities>"))
    print(xml)


def run_search(engine_list):
    """ Run search in engine

        @param engine_list List with engine, query and category

        @retval False if any exceptions occurred
        @retval True  otherwise
    """
    engine, what, cat = engine_list
    try:
        engine = engine()
        # avoid exceptions due to invalid category
        if hasattr(engine, 'supported_categories'):
            if cat in engine.supported_categories:
                engine.search(what, cat)
        else:
            engine.search(what)

        return True
    except Exception:
        return False


def main(args):
    # qbt tend to run this script in 'isolate mode' so append the current path manually
    current_path = str(pathlib.Path(__file__).parent.resolve())
    if current_path not in sys.path:
        sys.path.append(current_path)

    supported_engines = initialize_engines()

    if not args:
        raise SystemExit("./nova2.py [all|engine1[,engine2]*] <category> <keywords>\n"
                         "available engines: %s" % (','.join(supported_engines)))

    elif args[0] == "--capabilities":
        displayCapabilities(supported_engines)
        return

    elif len(args) < 3:
        raise SystemExit("./nova2.py [all|engine1[,engine2]*] <category> <keywords>\n"
                         "available engines: %s" % (','.join(supported_engines)))

    # get only unique engines with set
    engines_list = set(e.lower() for e in args[0].strip().split(','))

    if 'all' in engines_list:
        engines_list = supported_engines
    else:
        # discard un-supported engines
        engines_list = [engine for engine in engines_list
                        if engine in supported_engines]

    if not engines_list:
        # engine list is empty. Nothing to do here
        return

    cat = args[1].lower()

    if cat not in CATEGORIES:
        raise SystemExit(" - ".join(('Invalid category', cat)))

    what = urllib.parse.quote(' '.join(args[2:]))
    if THREADED:
        # child process spawning is controlled min(number of searches, number of cpu)
        with Pool(min(len(engines_list), MAX_THREADS)) as pool:
            pool.map(run_search, ([globals()[engine], what, cat] for engine in engines_list))
    else:
        # py3 note: map is needed to be evaluated for content to be executed
        all(map(run_search, ([globals()[engine], what, cat] for engine in engines_list)))


if __name__ == "__main__":
    main(sys.argv[1:])
