"""FCC Form 499-A Discontinuance Filing Handler.

For carriers who no longer provide telecommunications services and need
to close out their USAC 499-A filing obligations. Files a final 499-A
with zero revenue and requests discontinuance status from USAC.

This is typically for:
- Pure broadband resale ISPs who were incorrectly filing 499-A
- Carriers who have ceased operations
- Companies that were acquired and the FRN is being retired
"""
from __future__ import annotations

import logging
import os
from datetime import datetime

from .base_handler import BaseComplianceHandler

logger = logging.getLogger("workers.services.form_499a_discontinuance")


class Form499ADiscontinuanceHandler(BaseComplianceHandler):
    SERVICE_SLUG = "fcc-499a-discontinuance"
    SERVICE_NAME = "Form 499-A Discontinuance Filing"

    async def process(self, order_data: dict) -> dict | None:
        order_number = order_data.get("order_number", "")
        entity = order_data.get("entity", {})
        intake_data = order_data.get("intake_data", {})

        filer_id = intake_data.get("filer_id_499") or entity.get("filer_id_499", "")
        frn = intake_data.get("frn") or entity.get("frn", "")
        legal_name = entity.get("legal_name") or intake_data.get("entity_name", "")

        logger.info(
            "Form499ADiscontinuanceHandler: %s for %s (FRN: %s, Filer ID: %s)",
            order_number, legal_name, frn, filer_id,
        )

        discontinuance_reason = intake_data.get("discontinuance_reason", "Ceased providing telecommunications services")
        last_service_date = intake_data.get("last_service_date", "")

        # Per FCC 499-A Instructions: discontinuance requires TWO steps:
        # 1. File the final 499-A (may have actual revenue from the portion
        #    of the year the company operated — NOT required to be zero)
        # 2. Submit a deactivation letter to USAC within 30 days of ceasing service
        #
        # Line 603: check TRS/LNP/NANPA exemption boxes, write
        # "Not in business as of filing date" on the explanation line
        self._create_admin_todo(
            order_number,
            f"FILE 499-A DISCONTINUANCE for {legal_name}\n\n"
            f"FRN: {frn}\n"
            f"Filer ID: {filer_id}\n"
            f"Reason: {discontinuance_reason}\n"
            f"Last service date: {last_service_date or 'Not specified'}\n\n"
            f"STEP 1 — File Final 499-A:\n"
            f"  Log in to USAC E-File (https://forms.universalservice.org/)\n"
            f"  File the final 499-A reporting actual revenue for the period\n"
            f"  the company was in service (may be $0 if no revenue, or\n"
            f"  actual revenue for partial year). On Line 603, check all\n"
            f"  exemption boxes (TRS, LNP, NANPA) and write 'Not in business\n"
            f"  as of {last_service_date or 'filing date'}' on the explanation line.\n\n"
            f"STEP 2 — Submit USAC Deactivation Letter:\n"
            f"  Send letter to USAC (Form499@usac.org) with:\n"
            f"  - Company name: {legal_name}\n"
            f"  - Filer ID: {filer_id}\n"
            f"  - FRN: {frn}\n"
            f"  - Termination date: {last_service_date or 'TBD'}\n"
            f"  - Reason: {discontinuance_reason}\n"
            f"  - Successor entity: {intake_data.get('successor_entity', 'None')}\n"
            f"  Must be submitted within 30 days of ceasing service.\n"
            f"  Processing takes up to 60-90 days.\n\n"
            f"STEP 3 — Update CORES:\n"
            f"  Update FCC CORES registration to reflect inactive status.\n\n"
            f"STEP 4 — Related Filings:\n"
            f"  Confirm CPNI, RMD, and BDC filings are also discontinued.\n\n"
            f"Client email: {entity.get('contact_email') or order_data.get('customer_email', '')}",
        )

        # Send confirmation to client
        self._send_confirmation(
            to=entity.get("contact_email") or order_data.get("customer_email", ""),
            entity_name=legal_name,
            order_number=order_number,
            filer_id=filer_id,
        )

        return {"status": "submitted_for_processing"}

    def _send_confirmation(
        self, to: str, entity_name: str, order_number: str, filer_id: str,
    ) -> None:
        if not to:
            return
        try:
            import smtplib
            from email.mime.multipart import MIMEMultipart
            from email.mime.text import MIMEText

            subject = f"Form 499-A Discontinuance Filed — {entity_name}"
            html = f"""
            <div style="font-family:Inter,sans-serif;max-width:600px;margin:0 auto;color:#1f2937">
              <div style="background:#1e3a5f;padding:16px 24px;border-radius:8px 8px 0 0">
                <h2 style="color:#fff;margin:0;font-size:16px">Form 499-A Discontinuance</h2>
              </div>
              <div style="padding:24px;border:1px solid #e5e7eb;border-top:none;border-radius:0 0 8px 8px">
                <p>We've received your request to discontinue the FCC Form 499-A filing
                obligation for <strong>{entity_name}</strong> (Filer ID: {filer_id}).</p>

                <p>We will:</p>
                <ol style="font-size:14px;color:#374151;padding-left:1.25rem">
                  <li>File your final Form 499-A reporting revenue for the period you were in service (this may be zero or actual revenue for a partial year)</li>
                  <li>Submit a deactivation letter to USAC requesting closure of your filer account</li>
                  <li>Update your FCC CORES registration to reflect inactive status</li>
                  <li>Confirm discontinuance of related obligations (CPNI, RMD, BDC)</li>
                </ol>

                <p>USAC processing takes 60-90 days. You'll receive a confirmation
                email at each step. During this period, you won't receive new
                invoices for USF contributions.</p>

                <p style="font-size:13px;color:#6b7280;margin-top:1rem">
                  Order: {order_number}<br>
                  Questions? Reply to this email or contact
                  <a href="mailto:ops@performancewest.net">ops@performancewest.net</a>.
                </p>
              </div>
            </div>
            """
            msg = MIMEMultipart("alternative")
            msg["From"] = os.environ.get("SMTP_FROM", "Performance West <noreply@performancewest.net>")
            msg["To"] = to
            msg["Subject"] = subject
            msg.attach(MIMEText(html, "html"))

            with smtplib.SMTP(
                os.environ.get("SMTP_HOST", "co.carrierone.com"),
                int(os.environ.get("SMTP_PORT", "587")),
                timeout=30,
            ) as s:
                s.starttls()
                s.login(os.environ.get("SMTP_USER", ""), os.environ.get("SMTP_PASS", ""))
                s.send_message(msg)
        except Exception as exc:
            logger.warning("Discontinuance confirmation email failed: %s", exc)