# send_mail.py
# @author: Abner Coimbre <abner@handmadecities.com>
# Copyright (c) 2023 Handmade Cities

# ============================    Contributors    =========================
# Bug & warning fixes
#  Jacob Bell (@MysteriousJ)
#  Asaf Gartner
#
# Emotional Support
#  Cucui Ganon Rosario
# =========================================================================

# WARNING: send_mail.py requires a companion app.ini file provided by Abner. Without it the script will crash!

# QUICK NOTES:
#
# 1. This script is for Handmade meetup hosts. You can email a meetup invite to your group like so:
#
# > python3 send_mail.py --subject SUBJECT --body BODY
#
# where SUBJECT is the subject of your email and BODY is the file containing its contents. Plain text or HTML is supported
#
# 2. Your emails automatically include fancy Handmade Cities branding with unsubscribe links
#
# 3. You can dump the mailing list of your meetup group so far:
#
# > python3 send_mail.py --dump
#
# This list grows automatically as more people sign up for your city (at handmadecities.com/meetups)

import argparse
import configparser
import requests
import json

def dump_emails():
    headers = {
        "Content-Type": "application/json",
        "Authorization": HMC_SHARED_SECRET 
    }

    target = {
        "city": HMC_CITY
    }

    # Request mailing list from Handmade Cities
    payload  = json.dumps(target)
    response = requests.post(HMC_API_URL, headers=headers, data=payload)

    emails = []

    # Check if the request was successful (HTTP status code 200)
    if response.status_code == 200:
        # Parse the JSON response
        response_json = response.json()
        # Check if the 'emails' key exists in the response
        if 'emails' in response_json:
            # Extract the 'emails' JSON array
            emails = response_json['emails']

    return emails

def sendPostmarkMessage(subject, body, to):
    headers = {
        "Accept": "application/json",
        "Content-Type": "application/json",
        "X-Postmark-Server-Token": POSTMARK_SERVER_TOKEN
    }

    messages = []
    
    # Postmark supports 500 messages per API call.
    # Split the 'to' list into chunks of 500 or fewer email addresses
    for i in range(0, len(to), 500):
        to_chunk = to[i:i+500]
        
        for email in to_chunk:
            message = {
                "From": POSTMARK_SENDER_EMAIL,
                "To": email,
                "TemplateId": POSTMARK_TEMPLATE_ID,
                "TemplateModel": {
                    "name": SENDER_NAME,
                    "email": POSTMARK_SENDER_EMAIL,
                    "body": body,
                    "subject": subject
                },
                "MessageStream": POSTMARK_MESSAGE_STREAM
            }
            messages.append(message)

        payload = {
            "Messages": messages
        }

        # Debug:
        # print(json.dumps(payload, indent=4))

        result = requests.post(POSTMARK_API_URL, headers=headers, json=payload)
        print(result.text)
        
        # Clear the messages list for the next chunk
        messages.clear()

if __name__ == '__main__':
    # Create a ConfigParser object and read the INI file
    config = configparser.ConfigParser()
    config.read('app.ini')

    # Read the values and store them in Python variables
    LIVE        = config.getboolean('DEFAULT', 'LIVE')
    TEST_EMAIL  = config.get('DEFAULT', 'TEST_EMAIL')
    SENDER_NAME = config.get('DEFAULT', 'SENDER_NAME')

    postmark_section          = config['postmark']
    POSTMARK_SERVER_TOKEN     = postmark_section.get('SERVER_TOKEN')
    POSTMARK_API_URL          = postmark_section.get('API_URL')
    POSTMARK_TEMPLATE_ID      = int(postmark_section.get('TEMPLATE_ID'))
    POSTMARK_SENDER_EMAIL     = postmark_section.get('SENDER_EMAIL')
    POSTMARK_MESSAGE_STREAM   = postmark_section.get('MESSAGE_STREAM')

    hmc_section       = config['hmc']
    HMC_API_URL       = hmc_section.get('API_URL')
    HMC_SHARED_SECRET = hmc_section.get('SHARED_SECRET')
    HMC_CITY          = hmc_section.get('CITY')

    # Parse command-line arguments
    parser = argparse.ArgumentParser(description="Handmade Meetups v0.1 (handmadecities.com/meetups)")
    parser.add_argument("--dump", action="store_true", help="print the emails of your meetup group")
    parser.add_argument("--subject", help="subject of the email you're about to send")
    parser.add_argument("--body", help="path to the email body content file. HTML or plain text is supported")
    args = parser.parse_args()

    # Main:
    meetup_group = []

    if args.dump:
        meetup_group = dump_emails()
        for email in meetup_group:
            print(email)
    elif args.subject and args.body:
        subject = args.subject
        body = ''
        with open(args.body, 'r') as file:
            body = file.read()
        if LIVE:
            meetup_group = dump_emails()
            sendPostmarkMessage(subject, body, meetup_group)
        else:
            meetup_group.append(TEST_EMAIL) # Send a single email to whichever address is in TEST_EMAIL
            sendPostmarkMessage(subject, body, meetup_group)
    else:
        parser.print_help()