"""

    AUTHOR:

        Khushal P Soonderji

    DATE:

        Tuesday, 10th Dec., 2024

    OBJECTIVE:

        To parse raw mail bodies and give a structure that is suitable for storing in No-SQL databases like MongoDB. The
        raw mail's text is expected to be compliant with standard defined in RFC 5322, RFC 2045, and maybe a few more.

    REFERENCES:

        1. GitHub: https://github.com/SpamScope/mail-parser
        2. RFC 5322: https://datatracker.ietf.org/doc/html/rfc5322
        3. RFC 2045: https://datatracker.ietf.org/doc/html/rfc2045
        4. StackOverflow: https://stackoverflow.com/questions/17874360/python-how-to-parse-the-body-from-a-raw-email-given-that-raw-email-does-not

    DOWNLOADS:

        N/A

"""


#   *****************************************************************************************************************
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# ***                                                   IMPORT                                                      ***
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# To make sibling directories accessible for imports:
import sys
sys.path.append(".")
sys.path.append("..")

# System-level activities:
import io

# My utils:
from utils_v2.string import json
from utils_v2.string import regex
from utils_v2.date_time import date_time

# To work with mails:
import email

# To parse the HTML content in the mail:
from bs4 import BeautifulSoup

# To work with datatypes:
from typing import Any, Dict

# To work with various encodings:
import base64
import quopri

import time


#   *****************************************************************************************************************
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# ***                                           MACROS / ONE-TIME INIT                                              ***
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# --- Nothing Yet


#   *****************************************************************************************************************
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# ***                                                VARIABLES                                                      ***
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# --- Nothing Yet


#   *****************************************************************************************************************
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# ***                                                  FUNCTIONS                                                    ***
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def parse_part(
        # part: email.message.Message
        part
) -> Dict[str, Any]:

    part_json = {
        "contentType": part.get_content_type(),
        "contentMainType": part.get_content_maintype(),
        "contentSubType": part.get_content_subtype(),
        "contentCharset": part.get_content_charset(),
        "contentDisposition": part.get_content_disposition(),
        "filename": part.get_filename(),
        "payload": part.get_payload(decode = True)
    }
    if part_json["contentCharset"] is not None:
        part_json["payload"] = part_json["payload"].decode(part_json["contentCharset"])

    print("PARSED PART:", json.to_string(part_json, default = str))

    return part_json


# ---------------------------------------------------------------------------------------------------------------------


def parse(raw_mail: str | bytes) -> Dict[str, Any]:

    """
    To parse the raw mail text to a usable JSON that can even be stored on a No-SQL database like MongoDB.
    DOCUMENTATION:
        1. GitHub: https://github.com/SpamScope/mail-parser
        2. RFC 5322: https://datatracker.ietf.org/doc/html/rfc5322
        3. RFC 2045: https://datatracker.ietf.org/doc/html/rfc2045
    :param raw_mail: The raw mail body that adheres to RFC 5322 and RFC 2045 (among others).
    :return: The parsed JSON format (dict) of the mail.
    """

    # Parse the raw format:
    if isinstance(raw_mail, str): parsed_mail = email.message_from_string(raw_mail)
    else: parsed_mail = email.message_from_bytes(raw_mail)

    # Make variables:
    parts = []
    attachments = []

    # Iterate through each part of the mail for multipart mails:
    if parsed_mail.is_multipart():
        for part in parsed_mail.walk():
            parse_part(part)

            # # Start by extracting basic details about the part:
            # part_json = {
            #     "contentType": part.get("Content-Type"),
            #     "contentDisposition": part.get("Content-Disposition"),
            #     "contentTransferEncoding": part.get("Content-Transfer-Encoding"),
            #     "contentId": part.get("Content-ID"),
            #     # "part": part.get_payload(decode=True)
            # }
            #
            # # Now check if this part is either plain or HTML text:
            # content_type = part_json["contentType"].lower()
            # if (
            #         content_type.find("text/html") >= 0 or
            #         content_type.find("text/plain") >= 0
            # ): parts.append(parse_part(part))
            #
            # # print("MULTIPART PART:", json.to_string(part_json, default = str))
            # # if (
            # #         isinstance(part_json["part"], bytes) and
            # #         part_json[""].find()
            # # ):
            # #     time.sleep(1.0)
            # #     try: part_json["part"] = part_json["part"].decode()
            # #     except: pass
            # # print("MULTIPART PART:", json.to_string(part_json))
            # print("\n\n---\n\n")
            # # if part_json[]

    # When the mails are not multipart, just plaintext:
    else: print("PLAINTEXT PART:", parsed_mail.get_payload())


#   *****************************************************************************************************************
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# ***                                               MAIN PROGRAM                                                    ***
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#   *****************************************************************************************************************


if __name__ == "__main__":

    from utils_v2.system import files

    mail_string_raw = files.read_file(r"/home/developer/Downloads/raw_mail_test.txt")
    parse_results = parse(mail_string_raw)

    # print(json.to_string(parse_results, default = str))