Source code for promptpay.qrcode

import re
import libscrc
import qrcode
from PIL import Image

ID_PAYLOAD_FORMAT = "00"
ID_POI_METHOD = "01"
ID_MERCHANT_INFORMATION_BOT = "29"
ID_TRANSACTION_CURRENCY = "53"
ID_TRANSACTION_AMOUNT = "54"
ID_COUNTRY_CODE = "58"
ID_CRC = "63"

PAYLOAD_FORMAT_EMV_QRCPS_MERCHANT_PRESENTED_MODE = "01"
POI_METHOD_STATIC = "11"
POI_METHOD_DYNAMIC = "12"
MERCHANT_INFORMATION_TEMPLATE_ID_GUID = "00"
BOT_ID_MERCHANT_PHONE_NUMBER = "01"
BOT_ID_MERCHANT_TAX_ID = "02"
BOT_ID_MERCHANT_EWALLET_ID = "03"
GUID_PROMPTPAY = "A000000677010111"
TRANSACTION_CURRENCY_THB = "764"
COUNTRY_CODE_TH = "TH"



[docs]def sanitize_target(target: str = "") -> str:
    """
    Format target, allow only numeric character e.g.

    | - "012345678901234" => "012345678901234"
    | - "080-123-4567" => "0801234567"
    | - "1-1111-11111-11-1" => "1111111111111"
    | - "+66-89-123-4567" => "66891234567"

    :param target:
    :return:
    """
    result = re.sub(r"\D", "", target)

    return result




[docs]def format_target(target: str = "") -> str:
    """
    todo complete docblockr

    :param target:
    :return:
    """
    result = sanitize_target(target)

    if len(result) < 13:
        result = re.sub("^0", "66", result)
        result = ("0000000000000" + result)[-13:]  # last 13 digits

    return result




[docs]def format_amount(amount: float = 0.00) -> str:
    """
    Convert to number with 2 decimal (string type) e.g.

    | - 10.23 => "10.23"
    | - 10 => "10.00"
    | - 1337.1337 => "1337.13"
    | - 1337.1387 => "1337.14"

    :param amount:
    :return:
    """
    result = "{0:.2f}".format(amount)

    return result




[docs]def checksum(target: str = "") -> str:
    """
    todo complete docblockr

    :param target:
    :return:
    """
    byte_str = target.encode("ascii")  # convert to bytes
    hex_str = hex(libscrc.xmodem(byte_str, 0xFFFF))
    code = hex_str.replace("0x", "").upper()
    result = ("0000" + code)[-4:]  # only last 4 digits

    return result




[docs]def format(id: str = "", value: str = "") -> str:
    """
    todo complete docblockr

    :param id:
    :param value:
    :return:
    """
    last2digits = ("00" + str(len(value)))[-2:]
    result = id + last2digits + value

    return result




[docs]def generate_payload(id: str = "", amount: float = 0.00) -> str:
    """
    Generate payload for generate PromptPay QR code

    :param id: PromptPay id e.g. national ID, phone number, eWallet, etc.
    :param amount: number
    :return:
    """
    # sanitize id
    target = sanitize_target(id)

    # id type
    n_target_chars = len(target)
    target_type = BOT_ID_MERCHANT_PHONE_NUMBER
    if n_target_chars >= 15:
        target_type = BOT_ID_MERCHANT_EWALLET_ID
    elif n_target_chars >= 13:
        target_type = BOT_ID_MERCHANT_TAX_ID

    data = [
        format(ID_PAYLOAD_FORMAT, PAYLOAD_FORMAT_EMV_QRCPS_MERCHANT_PRESENTED_MODE),
        format(ID_POI_METHOD, POI_METHOD_DYNAMIC if amount else POI_METHOD_STATIC),
        format(
            ID_MERCHANT_INFORMATION_BOT,
            "".join(
                [
                    format(MERCHANT_INFORMATION_TEMPLATE_ID_GUID, GUID_PROMPTPAY),
                    format(target_type, format_target(target)),
                ]
            ),
        ),
        format(ID_COUNTRY_CODE, COUNTRY_CODE_TH),
        format(ID_TRANSACTION_CURRENCY, TRANSACTION_CURRENCY_THB),
    ]
    if amount:
        data.append(format(ID_TRANSACTION_AMOUNT, format_amount(amount)))

    data2crc = "".join(data) + ID_CRC + "04"
    data.append(format(ID_CRC, checksum(data2crc)))

    return "".join(data)




[docs]def to_image(payload: str = "") -> Image:
    """
    todo complete docblockr

    :param payload: PromptPay Payload
    :return:
    """
    img = qrcode.make(payload)

    return img




[docs]def to_file(payload: str = "", filepath: str = "") -> None:
    """

    :param payload: PromptPay Payload
    :param filepath: Target destination file path
    :return:
    """
    imgfile = open(filepath, "wb")
    img = to_image(payload)
    img.save(imgfile, "PNG")
    imgfile.close()