"""
Commission eligibility worker.

Daily cron job that transitions pending commissions to eligible
once the linked order has been delivered for at least 14 days.

Usage:
    python -m scripts.workers.commission_worker        # one-shot run
    CRON: 0 6 * * * python -m scripts.workers.commission_worker

Environment variables:
    DATABASE_URL   – PostgreSQL connection string
    SMTP_HOST      – outbound mail server
    SMTP_PORT      – mail port (default 587)
    SMTP_USER      – SMTP login
    SMTP_PASS      – SMTP password
"""

from __future__ import annotations

import logging
import os
import smtplib
import sys
from collections import defaultdict
from datetime import datetime, timedelta, timezone
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from typing import Any

import psycopg2
import psycopg2.extras

# ---------------------------------------------------------------------------
# Config
# ---------------------------------------------------------------------------

DATABASE_URL = os.environ.get("DATABASE_URL", "")
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", "")
ADMIN_EMAIL = "ops@performancewest.net"
FROM_EMAIL = os.environ.get("FROM_EMAIL", "commissions@performancewest.net")

HOLD_DAYS = 14  # days after delivery before commission becomes eligible

log = logging.getLogger("commission_worker")
logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s [%(name)s] %(levelname)s %(message)s",
    stream=sys.stdout,
)

# ---------------------------------------------------------------------------
# Order-type → table / query mapping
# ---------------------------------------------------------------------------

ORDER_QUERIES: dict[str, str] = {
    "canada_crtc": """
        SELECT order_number, status, delivered_at
        FROM canada_crtc_orders
        WHERE order_number = %s AND status = 'delivered'
    """,
    "formation": """
        SELECT order_number, status, delivered_at
        FROM formation_orders
        WHERE order_number = %s AND status = 'delivered'
    """,
    "service": """
        SELECT order_number, status, delivered_at
        FROM orders
        WHERE order_number = %s AND status = 'delivered'
    """,
    "bundle": """
        SELECT order_number, status, delivered_at
        FROM orders
        WHERE order_number = %s AND status = 'delivered'
    """,
}


# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------


def _check_order_delivered(
    cur: Any,
    order_type: str,
    order_number: str,
) -> datetime | None:
    """Return delivered_at timestamp if order is delivered, else None."""
    query = ORDER_QUERIES.get(order_type)
    if query is None:
        log.warning("Unknown order_type=%s for order=%s", order_type, order_number)
        return None

    cur.execute(query, (order_number,))
    row = cur.fetchone()
    if row is None:
        return None

    return row.get("delivered_at") or row.get("delivered_date")


def _send_email(to: str, subject: str, body_html: str) -> None:
    """Send a single email via SMTP."""
    if not SMTP_USER or not SMTP_PASS:
        log.warning("SMTP credentials not configured – skipping email to %s", to)
        return

    msg = MIMEMultipart("alternative")
    msg["From"] = FROM_EMAIL
    msg["To"] = to
    msg["Subject"] = subject
    msg.attach(MIMEText(body_html, "html"))

    try:
        with smtplib.SMTP(SMTP_HOST, SMTP_PORT, timeout=30) as server:
            server.ehlo()
            server.starttls()
            server.ehlo()
            server.login(SMTP_USER, SMTP_PASS)
            server.sendmail(FROM_EMAIL, [to], msg.as_string())
        log.info("Email sent to %s: %s", to, subject)
    except Exception:
        log.exception("Failed to send email to %s", to)


def _cents_to_dollars(cents: int) -> str:
    """Format cents as $X,XXX.XX."""
    return f"${cents / 100:,.2f}"


# ---------------------------------------------------------------------------
# Core logic
# ---------------------------------------------------------------------------


def process_pending_commissions() -> dict[str, Any]:
    """
    Scan all pending commissions and promote to eligible where the linked
    order has been delivered for at least HOLD_DAYS.

    Returns summary dict.
    """
    if not DATABASE_URL:
        log.error("DATABASE_URL is not set – aborting")
        return {"error": "DATABASE_URL not set"}

    now = datetime.now(timezone.utc)
    cutoff = now - timedelta(days=HOLD_DAYS)

    conn = psycopg2.connect(DATABASE_URL)
    conn.autocommit = False
    cur = conn.cursor(cursor_factory=psycopg2.extras.RealDictCursor)

    newly_eligible: list[dict[str, Any]] = []
    skipped = 0
    errors = 0

    try:
        # ----- Fetch all pending commissions -----
        cur.execute("""
            SELECT
                cl.id,
                cl.agent_code,
                cl.order_type,
                cl.order_number,
                cl.commission_cents,
                cl.customer_name,
                sa.email AS agent_email,
                sa.name  AS agent_name
            FROM commission_ledger cl
            JOIN sales_agents sa ON sa.agent_code = cl.agent_code
            WHERE cl.status = 'pending'
            ORDER BY cl.created_at
        """)
        pending_rows = cur.fetchall()
        log.info("Found %d pending commission(s) to evaluate", len(pending_rows))

        for row in pending_rows:
            try:
                delivered_at = _check_order_delivered(
                    cur, row["order_type"], row["order_number"]
                )

                if delivered_at is None:
                    skipped += 1
                    continue

                # Ensure delivered_at is tz-aware
                if delivered_at.tzinfo is None:
                    delivered_at = delivered_at.replace(tzinfo=timezone.utc)

                if delivered_at > cutoff:
                    # Not yet past the hold period
                    skipped += 1
                    continue

                # ----- Promote to eligible -----
                cur.execute(
                    """
                    UPDATE commission_ledger
                    SET status = 'eligible',
                        eligible_at = %s,
                        order_delivered_at = %s,
                        updated_at = %s
                    WHERE id = %s
                    """,
                    (now, delivered_at, now, row["id"]),
                )

                newly_eligible.append(
                    {
                        "id": row["id"],
                        "agent_code": row["agent_code"],
                        "agent_name": row["agent_name"],
                        "agent_email": row["agent_email"],
                        "order_type": row["order_type"],
                        "order_number": row["order_number"],
                        "commission_cents": row["commission_cents"],
                        "customer_name": row["customer_name"],
                        "delivered_at": delivered_at,
                    }
                )
                log.info(
                    "Commission %s (order %s) → eligible  [delivered %s]",
                    row["id"],
                    row["order_number"],
                    delivered_at.isoformat(),
                )

            except Exception:
                errors += 1
                log.exception(
                    "Error processing commission id=%s order=%s",
                    row["id"],
                    row["order_number"],
                )

        conn.commit()
    except Exception:
        conn.rollback()
        log.exception("Fatal error during commission processing")
        raise
    finally:
        cur.close()
        conn.close()

    # ----- Notifications -----
    if newly_eligible:
        _notify_admin(newly_eligible)
        _notify_agents(newly_eligible)

    summary = {
        "pending_evaluated": len(pending_rows) if "pending_rows" in dir() else 0,
        "newly_eligible": len(newly_eligible),
        "skipped": skipped,
        "errors": errors,
        "total_eligible_cents": sum(e["commission_cents"] for e in newly_eligible),
    }
    log.info("Run complete: %s", summary)
    return summary


# ---------------------------------------------------------------------------
# Notification helpers
# ---------------------------------------------------------------------------


def _notify_admin(eligible: list[dict[str, Any]]) -> None:
    """Send a summary email to the admin."""
    count = len(eligible)
    total_cents = sum(e["commission_cents"] for e in eligible)

    rows_html = ""
    for e in eligible:
        rows_html += (
            f"<tr>"
            f"<td>{e['order_number']}</td>"
            f"<td>{e['agent_code']}</td>"
            f"<td>{e['agent_name']}</td>"
            f"<td>{_cents_to_dollars(e['commission_cents'])}</td>"
            f"<td>{e['delivered_at'].strftime('%Y-%m-%d')}</td>"
            f"</tr>"
        )

    body = f"""
    <h2>Commission Eligibility Report</h2>
    <p><strong>{count}</strong> commission(s) totalling
       <strong>{_cents_to_dollars(total_cents)}</strong>
       are now eligible for payout.</p>
    <table border="1" cellpadding="6" cellspacing="0"
           style="border-collapse:collapse; font-family:monospace;">
        <tr>
            <th>Order</th><th>Agent</th><th>Name</th>
            <th>Commission</th><th>Delivered</th>
        </tr>
        {rows_html}
    </table>
    <p style="color:#888; font-size:12px;">
        Approve these in ERPNext → Commission Ledger, or reply to this email.
    </p>
    """
    _send_email(
        ADMIN_EMAIL,
        f"{count} commissions ({_cents_to_dollars(total_cents)}) now eligible for payout",
        body,
    )


def _notify_agents(eligible: list[dict[str, Any]]) -> None:
    """Send per-agent emails for each newly-eligible commission."""
    by_agent: dict[str, list[dict[str, Any]]] = defaultdict(list)
    for e in eligible:
        by_agent[e["agent_email"]].append(e)

    for agent_email, commissions in by_agent.items():
        for c in commissions:
            body = f"""
            <p>Hi {c['agent_name']},</p>
            <p>Your <strong>{_cents_to_dollars(c['commission_cents'])}</strong>
               commission for order <strong>{c['order_number']}</strong>
               is now eligible.</p>
            <p>We'll process your payout shortly.</p>
            <p style="color:#888; font-size:12px;">
                — Performance West Commissions
            </p>
            """
            _send_email(
                agent_email,
                f"Your {_cents_to_dollars(c['commission_cents'])} commission "
                f"for order {c['order_number']} is now eligible",
                body,
            )


# ---------------------------------------------------------------------------
# Entrypoint
# ---------------------------------------------------------------------------

if __name__ == "__main__":
    log.info("Commission worker starting (manual run)")
    result = process_pending_commissions()
    log.info("Done. Summary: %s", result)