import requests

class PyGQ:
    SURAH_LAST = 114
    SURAH_FIRST = 1
    def __init__(self, url="http://api.globalquran.com/ayah/", token="",
    lg_codes={}, cache_size=0):
        """url and token are API url and token. lg_codes is a dict which maps 
           2 letter language codes to their fullname. like:
           {"en": "en.sahih", "ar": "quran-simple"}
        """

        self.url = url
        self.token = token
        self.lg_codes = lg_codes
        self.cache_size = cache_size
        self.cache = list()

    def __update_cache(self):
        if not self.cache_size: return
        if len(self.cache) > self.cache_size:
            while len(self.cache) > self.cache_size:
                self.cache.pop()

    def getAyah(self, surah, ayah, lang):
        """Returns a dict containing the verse itself, ayah and surah number
        and id. example:
            {
            "surah": 1,
            "ayah": 1,
            "id": 1,
            "verse": "In the name of Allah, the Entirely Merciful, the Especially Merciful."
            }
        """
        if len(lang) == 2:
            if lang in self.lg_codes:
                lang = self.lg_codes[lang]
            else:
                raise ValueError(lang+ " is not supported using 2letter codes")
        if (not self.SURAH_FIRST <= surah <= self.SURAH_LAST):
            raise ValueError("surah(chapter) must be between "
                             + str(self.SURAH_FIRST) + " and " +
                             str(self.SURAH_LAST))

        # TODO: check if it's in cache, if so use cache, if not get and add to
        # cache
        if self.cache_size:
            for key, json_ in self.cache: # FIXME: better name than json_
                if (surah,ayah,lang) == key:
                    self.cache.remove((key,json_))
                    self.cache.insert(0, (key,json_))
                    return json_
                    

        req_url = self.url + str(surah) + ":" + str(ayah) + "/" + lang
        ayah_json = requests.get(req_url, params = {'key': self.token}).json()
        while len(ayah_json) == 1:
            ayah_json = ayah_json[next(iter(ayah_json))]

        if ayah_json["surah"] != surah:
            raise ValueError("Invalid ayah number for this surah")
        
        self.cache.insert(0, ((surah, ayah, lang), ayah_json))
        self.__update_cache()
        return ayah_json

if __name__ == "__main__":
    import sys
    if len(sys.argv) < 2:
        print("Usage:", sys.argv[0], "surah:ayah [lang]")
        sys.exit(0)
    
    surah, ayah = sys.argv[1].split(":")
    surah = int(surah)
    ayah = int(ayah)
    lang = "en.sahih" if len(sys.argv) < 3 else sys.argv[2]

    Q = PyGQ()
    print(Q.getAyah(surah, ayah, lang)["verse"])