#!/usr/bin/env python
__author__ = "Philippe May <phil.dev@philome.mooo.com>"
__license__ = "BSD"
__doc__ = "Listen to messages from the SMS Forwarder app on Android, and send mail."

import os
import textwrap
from datetime import datetime
from socket import gethostname
from email.message import EmailMessage

from fastapi import FastAPI
from aiosmtplib import send
from pydantic import BaseModel, Field, EmailStr
from pydantic_settings import BaseSettings, SettingsConfigDict

USER = os.environ.get("USER", "root")
HOST_NAME = gethostname()


## Definition of settings:
class MailSettings(BaseSettings):
    model_config = SettingsConfigDict(env_prefix="SMS_HANDLER_MAIL_")
    enable: bool = True
    sender: str = f"{USER}@{HOST_NAME}"
    to: str = f"{USER}@{HOST_NAME}"
    server: str = "localhost"
    server_port: int = 25
    server_start_tls: bool = False
    template: str = textwrap.dedent(
        """\
        {text}
        ---
        From: {from} {fromName}
        Sent: {sentStamp:%c}
        Received: {receivedStamp:%c}
        Sim: {sim}
        """
    )


class Settings(BaseSettings):
    model_config = SettingsConfigDict(env_prefix="SMS_HANDLER_")
    mail: MailSettings = MailSettings()


class SmsAlert(BaseModel):
    from_: str = Field(alias="from")  # "from" is reserved word in Python, use an alias
    fromName: str = ""
    text: str
    sentStamp: datetime
    receivedStamp: datetime
    sim: str


settings = Settings()
app = FastAPI()


def send_mail(smsAlert: SmsAlert):
    msg = EmailMessage()
    msg["Subject"] = f"SMS from {smsAlert.from_}"
    msg["From"] = settings.mail.sender
    msg["To"] = settings.mail.to
    fmt = dict(smsAlert)  # Make a dict for sms
    fmt["from"] = fmt.pop("from_")
    msg.set_content(settings.mail.template.format_map(fmt))
    return send(
        msg,
        hostname=settings.mail.server,
        port=settings.mail.server_port,
        start_tls=settings.mail.server_start_tls,
    )


@app.post("/handle-sms")
async def handle_sms(smsAlert: SmsAlert):
    if settings.mail.enable:
        await send_mail(smsAlert)
    return "OK"


def main():
    from uvicorn import run
    from argparse import ArgumentParser

    parser = ArgumentParser(description=__doc__)
    parser.add_argument(
        "-l", "--host", type=str, default="0.0.0.0", help="Addess to listen to"
    )
    parser.add_argument(
        "-p", "--port", type=int, default=8025, help="Port to listen to"
    )
    parser.add_argument(
        "-v", "--version", action="store_true", help="Print version and exit"
    )
    args = parser.parse_args()

    if args.version:
        import sys
        from importlib.metadata import version

        print(version("sms_handler"))
        sys.exit(0)

    run(app, host=args.host, port=args.port)


if __name__ == "__main__":
    main()