from collections import namedtuple
import hashlib
from pandas import read_csv

class _ReadOnlyProperty(object):
    def __init__(self, value):
        self.__value = value
    
    def __get__(self, obj, objtype):
        return self.__value

    def __set__(self, obj, value):
        return NotImplementedError("Cannot change a constant.")

def __make_read_only(cls):
    for k, v in cls.__dict__.items():
        if not callable(getattr(cls, k)) and '__' not in k:
            setattr(cls, k, _ReadOnlyProperty(v))
    # def raise_err(self, attr, value):
    #     raise NotImplementedError("Cannot add an attribute.")
    # setattr(cls, '__setattr__', raise_err)
    return cls

@__make_read_only
class __Constants(object):
    DB_LOCATION        = 'https://aresvalley.com/Storage/Artemis/Database/data.zip'
    REF_LOC            = 'https://aresvalley.com/Storage/Artemis/Database/data.zip.log'
    DATA_FOLDER        = 'Data'
    SPECTRA_FOLDER     = 'Spectra'
    AUDIO_FOLDER       = 'Audio'
    ICONS_FOLDER       = 'icons_imgs'
    __Band             = namedtuple("Band", ["lower", "upper"])
    __ELF              = __Band(0, 30) # Formally it is (3, 30) Hz.
    __SLF              = __Band(30, 300)
    __ULF              = __Band(300, 3000)
    __VLF              = __Band(3000, 30000)
    __LF               = __Band(30 * 10**3, 300 * 10**3)
    __MF               = __Band(300 * 10 ** 3, 3000 * 10**3)
    __HF               = __Band(3 * 10**6, 30 * 10**6)
    __VHF              = __Band(30 * 10**6, 300 * 10**6)
    __UHF              = __Band(300 * 10**6, 3000 * 10**6)
    __SHF              = __Band(3 * 10**9, 30 * 10**9)
    __EHF              = __Band(30 * 10**9, 300 * 10**9)
    BANDS              = (__ELF, __SLF, __ULF, __VLF, __LF, __MF, __HF, __VHF, __UHF, __SHF, __EHF)
    ACTIVE_COLOR       = "#39eaff"
    INACTIVE_COLOR     = "#9f9f9f"
    CONVERSION_FACTORS = {"Hz":1, "kHz":1000, "MHz":1000000, "GHz":1000000000}
    MODES              = {"FM": ["NFM", "WFM"],
                          "AM": [],
                          "CW": [],
                          "SK": ["FSK", "PSK", "MSK"],
                          "SB": ["LSB", "USB", "DSB"],
                          "Chirp Spread Spectrum": [],
                          "FHSS-TDM": [],
                          "RAW": [],
                          "SC-FDMA": [],}
    APPLY              = "Apply"
    REMOVE             = "Remove"
    UNKNOWN            = "N/A"
    MODULATIONS        = ["8VSB",
                          "AFSK",
                          "AM",
                          "BFSK",
                          "C4FM",
                          "CDMA",
                          "COFDM",
                          "CW",
                          "FFSK",
                          "FM",
                          "FMCW",
                          "FMOP",
                          "FSK",
                          "GFSK",
                          "GMSK",
                          "IFK",
                          "MFSK",
                          "MSK",
                          "OFDM",
                          "OOK",
                          "PAM",
                          "PPM",
                          "PSK",
                          "QAM",
                          "TDMA",]

Constants = __Constants()

def reset_apply_remove_btn(button):
    if button.isChecked():
        button.setChecked(False)
        button.clicked.emit()

def checksum_ok(data, what):
    code = hashlib.sha256()
    code.update(data)
    if what == "folder":
        n = 0
    elif what == "db":
        n = 1
    else:
        raise ValueError("Wrong entry name.")
    try:
        reference = read_csv(Constants.REF_LOC, delimiter = '*').iat[-1, n]
    except HTTPError:
        return False
    return code.hexdigest() == reference