#
# This file is part of pyasn1-modules software.
#
# Copyright (c) 2005-2020, Ilya Etingof <etingof@gmail.com>
# License: https://www.pysnmp.com/pyasn1/license.html
#
import base64
import sys

stSpam, stHam, stDump = 0, 1, 2


# The markers parameters is in form ('start1', 'stop1'), ('start2', 'stop2')...
# Return is (marker-index, substrate)
def readPemBlocksFromFile(fileObj, *markers):
    startMarkers = dict(
        map(lambda x: (x[1], x[0]), enumerate(map(lambda y: y[0], markers)))
    )
    stopMarkers = dict(
        map(lambda x: (x[1], x[0]), enumerate(map(lambda y: y[1], markers)))
    )
    idx = -1
    substrate = ""
    certLines = []
    state = stSpam
    while True:
        certLine = fileObj.readline()
        if not certLine:
            break
        certLine = certLine.strip()
        if state == stSpam:
            if certLine in startMarkers:
                certLines = []
                idx = startMarkers[certLine]
                state = stHam
                continue
        if state == stHam:
            if certLine in stopMarkers and stopMarkers[certLine] == idx:
                state = stDump
            else:
                certLines.append(certLine)
        if state == stDump:
            if sys.version_info[0] <= 2:
                substrate = "".join([base64.b64decode(x) for x in certLines])
            else:
                substrate = b"".join([base64.b64decode(x.encode()) for x in certLines])
            break
    return idx, substrate


# Backward compatibility routine
def readPemFromFile(
    fileObj,
    startMarker="-----BEGIN CERTIFICATE-----",
    endMarker="-----END CERTIFICATE-----",
):
    idx, substrate = readPemBlocksFromFile(fileObj, (startMarker, endMarker))
    return substrate


def readBase64fromText(text):
    if sys.version_info[0] <= 2:
        return base64.b64decode(text)
    else:
        return base64.b64decode(text.encode())


def readBase64FromFile(fileObj):
    return readBase64fromText(fileObj.read())