"""Global auto-filing toggle + admin-review workflow.

Gates the Playwright submission step of every FCC/USAC/BDC filing handler
so that — by default — no filing is submitted to the FCC without a
Performance West admin reviewing the generated packet first.

Design
------

* Settings live in ERPNext ``Compliance Settings`` (single DocType) under
  the ``auto_filing_enabled`` Check field. Default = False (safer).
* A per-order override field (``custom_auto_filing_override`` on the Sales
  Order) lets the admin approve a specific filing one-shot after review
  without flipping the global toggle.
* When auto-filing is OFF and there's no per-order override, the handler:
    1. Produces and uploads the packet as normal.
    2. Creates an ERPNext ToDo assigned to ``admin_email`` (default
       ``ops@performancewest.net``) with a summary + "Approve & File"
       CTA link.
    3. Sends the admin a short HTML email with the same summary + link.
    4. Leaves the order in "Awaiting Admin Review" state — the workflow
       picks it back up when the admin clicks Approve.

The Approve-and-File link hits the Express API endpoint
``POST /api/v1/compliance-orders/:order_number/approve-and-file`` which
sets ``custom_auto_filing_override = 1`` on the Sales Order and
re-dispatches the handler. Handler reads the override flag and runs
the Playwright submission even if the global toggle is still off.

Env fallback
------------

If ERPNext is unreachable (e.g. during local development), the module
reads the env var ``AUTO_FILING_ENABLED`` as a truthy override. Admin
email falls back to ``ADMIN_EMAIL`` env var, then
``ops@performancewest.net``.
"""

from __future__ import annotations

import logging
import os
import smtplib
from dataclasses import dataclass
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from typing import Optional

logger = logging.getLogger(__name__)


DEFAULT_ADMIN_EMAIL = "ops@performancewest.net"


# ─── Settings lookup ──────────────────────────────────────────────────────


@dataclass
class AutoFilingDecision:
    """Result of ``check_auto_filing`` — caller branches on ``may_submit``."""

    may_submit: bool
    reason: str
    admin_email: str
    global_enabled: bool
    order_override: bool


def _env_truthy(value: str | None) -> bool:
    if not value:
        return False
    return value.strip().lower() in ("1", "true", "yes", "on")


def _settings_from_erpnext() -> tuple[bool, str]:
    """Read ``Compliance Settings`` from ERPNext — returns (enabled, admin_email)."""
    try:
        from scripts.workers.erpnext_client import ERPNextClient

        erp = ERPNextClient()
        settings = erp.get_resource("Compliance Settings", "Compliance Settings")
        if isinstance(settings, list):
            settings = settings[0] if settings else {}
        enabled = bool(settings.get("auto_filing_enabled", 0))
        admin = (
            settings.get("admin_email")
            or os.environ.get("ADMIN_EMAIL")
            or DEFAULT_ADMIN_EMAIL
        )
        return enabled, admin
    except Exception as exc:
        logger.debug("auto_filing: ERPNext settings read failed: %s", exc)
        return _env_truthy(os.environ.get("AUTO_FILING_ENABLED")), (
            os.environ.get("ADMIN_EMAIL") or DEFAULT_ADMIN_EMAIL
        )


def check_auto_filing(order_data: dict) -> AutoFilingDecision:
    """Resolve whether the calling handler may submit to the FCC/USAC.

    The handler passes the current ``order_data`` (as received from
    ``job_server.py``). We inspect the per-order override first, then
    fall back to the global setting.
    """
    order_override = bool(order_data.get("custom_auto_filing_override", 0))
    global_enabled, admin_email = _settings_from_erpnext()

    if order_override:
        return AutoFilingDecision(
            may_submit=True,
            reason="per-order admin override",
            admin_email=admin_email,
            global_enabled=global_enabled,
            order_override=True,
        )
    if global_enabled:
        return AutoFilingDecision(
            may_submit=True,
            reason="global auto_filing_enabled",
            admin_email=admin_email,
            global_enabled=True,
            order_override=False,
        )
    return AutoFilingDecision(
        may_submit=False,
        reason="auto-filing disabled; admin review required",
        admin_email=admin_email,
        global_enabled=False,
        order_override=False,
    )


# ─── Admin review hand-off ────────────────────────────────────────────────


def request_admin_review(
    *,
    order_number: str,
    service_slug: str,
    service_name: str,
    entity_name: str,
    frn: str,
    packet_minio_paths: list[str],
    admin_email: str,
    summary: str = "",
) -> None:
    """Create an ERPNext ToDo + send a short email to the admin.

    The email and the ToDo both include a one-click "Approve & File" URL
    that re-dispatches the handler for this order with the auto-filing
    override set.
    """
    api_base = os.environ.get("API_URL", "http://api:3001").rstrip("/")
    approve_url = (
        f"{api_base}/api/v1/compliance-orders/{order_number}/approve-and-file"
    )

    todo_description = (
        f"[{service_slug}] Admin review required for {order_number}\n\n"
        f"Carrier: {entity_name}\n"
        f"FRN:     {frn or 'N/A'}\n"
        f"Service: {service_name}\n\n"
        f"Auto-filing is disabled. The generated packet is staged in MinIO — "
        f"review it, then POST to the approve-and-file URL (or click the "
        f"button in the admin email) to submit the filing to the FCC.\n\n"
        f"Files in MinIO:\n"
        + "\n".join(f"  • {p}" for p in packet_minio_paths)
        + f"\n\nApprove & File:\n  {approve_url}\n"
    )
    if summary:
        todo_description += f"\nHandler notes:\n{summary}\n"

    _create_todo(todo_description, admin_email)
    _send_admin_email(
        to_email=admin_email,
        order_number=order_number,
        service_name=service_name,
        entity_name=entity_name,
        frn=frn,
        packet_minio_paths=packet_minio_paths,
        approve_url=approve_url,
        summary=summary,
    )


def _create_todo(description: str, admin_email: str) -> None:
    try:
        from scripts.workers.erpnext_client import ERPNextClient

        ERPNextClient().create_resource(
            "ToDo",
            {
                "description": description,
                "priority": "High",
                "allocated_to": admin_email,
                "status": "Open",
            },
        )
    except Exception as exc:
        logger.warning("auto_filing: could not create admin ToDo: %s", exc)


_EMAIL_TMPL = """\
<html>
<body style="font-family:Arial,Helvetica,sans-serif;color:#1f2937;">
  <h2 style="color:#1a2744;margin:0 0 12px;">Filing ready for review</h2>
  <p><strong>Order:</strong> {order_number}<br>
     <strong>Carrier:</strong> {entity_name}<br>
     <strong>FRN:</strong> {frn}<br>
     <strong>Service:</strong> {service_name}</p>
  <p>Auto-filing is <em>disabled</em>. The generated packet is staged in MinIO.
     Review the documents, then click below to submit the filing to the FCC.</p>
  <p><a href="{approve_url}"
        style="display:inline-block;padding:12px 22px;background:#059669;
               color:#fff;border-radius:4px;font-weight:600;text-decoration:none;">
     Approve &amp; File →
  </a></p>
  <h3 style="margin:22px 0 6px;color:#1a2744;">Packet files</h3>
  <ul style="margin:0 0 12px 18px;padding:0;">
    {files}
  </ul>
  {summary_block}
  <p style="color:#64748b;font-size:12px;margin-top:24px;">
    To enable auto-filing globally, set <code>auto_filing_enabled = 1</code>
    in the ERPNext Compliance Settings doctype (or set
    <code>AUTO_FILING_ENABLED=1</code> in the worker environment).
  </p>
</body>
</html>
"""


def _send_admin_email(
    *,
    to_email: str,
    order_number: str,
    service_name: str,
    entity_name: str,
    frn: str,
    packet_minio_paths: list[str],
    approve_url: str,
    summary: str,
) -> None:
    smtp_host = os.environ.get("SMTP_HOST", "co.carrierone.com")
    smtp_port = int(os.environ.get("SMTP_PORT", "587"))
    smtp_user = os.environ.get("SMTP_USER", "")
    smtp_pass = os.environ.get("SMTP_PASSWORD", "")
    smtp_from = os.environ.get("SMTP_FROM", "orders@performancewest.net")

    if not smtp_user or not smtp_pass:
        logger.warning("auto_filing: SMTP not configured — skipping admin email")
        return

    files_html = "\n    ".join(
        f"<li style=\"margin:3px 0;\"><code>{p}</code></li>"
        for p in packet_minio_paths
    ) or "<li><em>(none)</em></li>"
    summary_block = (
        f"<h3 style=\"margin:22px 0 6px;color:#1a2744;\">Handler notes</h3>"
        f"<pre style=\"background:#f8fafc;padding:10px;border-radius:4px;"
        f"white-space:pre-wrap;font-size:12px;\">{summary}</pre>"
        if summary else ""
    )
    html = _EMAIL_TMPL.format(
        order_number=order_number,
        entity_name=entity_name,
        frn=frn or "N/A",
        service_name=service_name,
        approve_url=approve_url,
        files=files_html,
        summary_block=summary_block,
    )

    msg = MIMEMultipart("alternative")
    msg["Subject"] = f"[Review & File] {order_number} — {service_name}"
    msg["From"] = smtp_from
    msg["To"] = to_email
    msg.attach(MIMEText(html, "html"))

    try:
        with smtplib.SMTP(smtp_host, smtp_port) as server:
            if smtp_port != 25:
                server.starttls()
            server.login(smtp_user, smtp_pass)
            server.sendmail(smtp_from, [to_email], msg.as_string())
        logger.info("auto_filing: admin review email sent to %s", to_email)
    except Exception as exc:
        logger.warning("auto_filing: could not send admin email: %s", exc)


# ─── Per-order override writer (used by the API approve-and-file endpoint) ─

def set_order_override(sales_order_name: str) -> bool:
    """Flip ``custom_auto_filing_override`` to 1 on the Sales Order."""
    try:
        from scripts.workers.erpnext_client import ERPNextClient

        ERPNextClient().set_value(
            "Sales Order",
            sales_order_name,
            "custom_auto_filing_override",
            1,
        )
        return True
    except Exception as exc:
        logger.warning("auto_filing: could not set override: %s", exc)
        return False