"""Generic eSign helper — create signing records and send signing links.

Usage from any service handler:

    from scripts.workers.services.telecom.esign_helper import request_esign

    request_esign(
        conn=conn,
        order_number="CO-ABC12345",
        document_type="rmd",
        document_title="RMD Certification Letter",
        entity_name="Acme Telecom LLC",
        customer_email="john@example.com",
        customer_name="John Smith",
        document_minio_key="compliance/CO-ABC12345/rmd_letter.pdf",
        requires_perjury=True,
        metadata={"frn": "0015341902"},
    )

This will:
  1. INSERT a row into esign_records (status = 'pending')
  2. Generate a JWT portal token
  3. Send a signing email with the portal link
"""
import logging
import os
import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText

logger = logging.getLogger("esign_helper")


def request_esign(
    conn,
    order_number: str,
    document_type: str,
    document_title: str,
    entity_name: str,
    customer_email: str,
    customer_name: str = "",
    document_minio_key: str = "",
    requires_perjury: bool = False,
    metadata: dict | None = None,
    expires_hours: int = 72,
) -> int | None:
    """Create an esign record and email the signing link.

    Returns the esign_records.id on success, None on failure.
    """
    import json
    from datetime import datetime, timedelta, timezone

    try:
        import jwt as pyjwt
    except ImportError:
        try:
            import PyJWT as pyjwt  # type: ignore
        except ImportError:
            logger.error("No JWT library available — cannot create esign link")
            return None

    secret = os.environ.get("CUSTOMER_JWT_SECRET", "changeme")
    domain = os.environ.get("DOMAIN", "performancewest.net")
    expires_at = datetime.now(timezone.utc) + timedelta(hours=expires_hours)

    # 1. Upsert into esign_records (replace any existing pending record)
    try:
        with conn.cursor() as cur:
            cur.execute(
                """INSERT INTO esign_records
                   (order_number, document_type, document_title, entity_name,
                    document_minio_key, document_metadata, requires_perjury,
                    status, expires_at)
                   VALUES (%s, %s, %s, %s, %s, %s, %s, 'pending', %s)
                   ON CONFLICT (order_number, document_type)
                       WHERE status IN ('pending', 'signed')
                   DO UPDATE SET
                       document_title = EXCLUDED.document_title,
                       entity_name = EXCLUDED.entity_name,
                       document_minio_key = EXCLUDED.document_minio_key,
                       document_metadata = EXCLUDED.document_metadata,
                       requires_perjury = EXCLUDED.requires_perjury,
                       expires_at = EXCLUDED.expires_at,
                       updated_at = NOW()
                   RETURNING id""",
                (
                    order_number,
                    document_type,
                    document_title,
                    entity_name,
                    document_minio_key,
                    json.dumps(metadata or {}),
                    requires_perjury,
                    expires_at,
                ),
            )
            row = cur.fetchone()
            esign_id = row[0] if row else None
        conn.commit()
    except Exception as exc:
        logger.error("Failed to insert esign record for %s: %s", order_number, exc)
        conn.rollback()
        return None

    # 2. Generate JWT portal token
    token = pyjwt.encode(
        {
            "order_id": order_number,
            "order_type": document_type,
            "email": customer_email,
        },
        secret,
        algorithm="HS256",
    )
    sign_url = f"https://{domain}/portal/esign/?token={token}"

    # 3. Send signing email
    try:
        _send_signing_email(
            to_email=customer_email,
            to_name=customer_name or entity_name,
            entity_name=entity_name,
            document_title=document_title,
            sign_url=sign_url,
            order_number=order_number,
        )
        logger.info(
            "eSign link sent to %s for %s (%s)",
            customer_email, order_number, document_type,
        )
    except Exception as exc:
        logger.warning("Could not send eSign email for %s: %s", order_number, exc)
        # Non-fatal — record exists, admin can resend

    return esign_id


def _send_signing_email(
    to_email: str,
    to_name: str,
    entity_name: str,
    document_title: str,
    sign_url: str,
    order_number: str,
) -> None:
    """Send the signing invitation email."""
    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_PASS", "")

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

    subject = f"Action Required: Sign Your {document_title}"

    body = f"""\
<div style="font-family:'Inter',system-ui,sans-serif;max-width:600px;margin:0 auto;color:#1f2937">
  <div style="background:#1e3a5f;color:#fff;padding:24px 28px;border-radius:12px 12px 0 0">
    <h1 style="margin:0;font-size:20px;font-weight:700">Document Ready for Signature</h1>
    <p style="margin:6px 0 0;opacity:.8;font-size:14px">{entity_name}</p>
  </div>

  <div style="background:#fff;border:1px solid #e2e8f0;border-top:none;padding:28px;border-radius:0 0 12px 12px">
    <p style="margin:0 0 16px;font-size:15px">Hi {to_name},</p>

    <p style="margin:0 0 16px;font-size:15px">
      Your <strong>{document_title}</strong> is ready for review and signature.
      Please click the button below to review the document and provide your electronic signature.
    </p>

    <div style="text-align:center;margin:28px 0">
      <a href="{sign_url}"
         style="display:inline-block;background:#1e3a5f;color:#fff;padding:14px 36px;
                border-radius:10px;font-weight:700;font-size:16px;text-decoration:none">
        Review &amp; Sign Document
      </a>
    </div>

    <p style="margin:0 0 12px;font-size:13px;color:#64748b">
      This link expires in 72 hours. If it expires, contact us and we'll send a new one.
    </p>

    <hr style="border:none;border-top:1px solid #e2e8f0;margin:20px 0">

    <p style="margin:0;font-size:12px;color:#9ca3af">
      Performance West Inc. &mdash; (888) 411-0383<br>
      Order: {order_number}
    </p>
  </div>
</div>"""

    msg = MIMEMultipart("alternative")
    msg["From"] = "Performance West <noreply@performancewest.net>"
    msg["To"] = f"{to_name} <{to_email}>"
    msg["Subject"] = subject
    msg["Reply-To"] = "info@performancewest.net"
    msg.attach(MIMEText(body, "html"))

    with smtplib.SMTP(smtp_host, smtp_port, timeout=30) as server:
        server.starttls()
        server.login(smtp_user, smtp_pass)
        server.send_message(msg)


def check_esign_status(conn, order_number: str, document_type: str) -> dict | None:
    """Check if a document has been signed. Returns the record dict or None."""
    with conn.cursor() as cur:
        cur.execute(
            """SELECT id, status, signed_at, signer_email, signature_type
               FROM esign_records
               WHERE order_number = %s AND document_type = %s
                 AND status IN ('pending', 'signed')
               ORDER BY created_at DESC LIMIT 1""",
            (order_number, document_type),
        )
        row = cur.fetchone()
        if not row:
            return None
        return {
            "id": row[0],
            "status": row[1],
            "signed_at": row[2],
            "signer_email": row[3],
            "signature_type": row[4],
        }