"""Daily access-stimulation monitor.

Implements the FCC 47 CFR 61.3(bbb) "access stimulation" detection rule:
when a local-exchange carrier's terminating interstate traffic exceeds
originating interstate traffic by a 3:1 ratio over a rolling 6-month
window, the carrier is deemed an "access-stimulating" LEC and must
either benchmark its terminating switched-access rate to the other LEC's
or refund the differential. For a CLEC reseller, tripping this threshold
is a compliance red-flag: the rate-cap disclosure must appear on the
499-A filing's ``term_switched_access`` revenue line, and an admin
review is required before the Q1 filing goes out.

Flow (for each active ``cdr_ingestion_profiles`` row):

  1. Aggregate 6 months of ``cdr_traffic_studies`` into:
        term_minutes  = SUM(retail_minutes)
        orig_minutes  = SUM(wholesale_minutes)
     (Retail traffic → terminating proxy; wholesale traffic →
     originating proxy. Per the 499-A plan spec: this is a conservative
     proxy until direction-tagged CDRs are mandatory.)
  2. If ``orig_minutes > 0`` and ``term/orig > 3.0`` *and* the profile
     hasn't been flagged in the last 30 days:
       - Stamp ``access_stim_flagged_at=NOW()`` on the profile
       - Persist evidence payload to ``access_stim_evidence_json``
       - Create an admin ToDo via ERPNext for the Accounting Advisor role

Usage:

    python -m scripts.workers.access_stim_monitor
    python -m scripts.workers.access_stim_monitor --dry-run
"""

from __future__ import annotations

import argparse
import json
import logging
import os
import sys
from datetime import datetime, timezone
from typing import Optional

import psycopg2
import psycopg2.extras

log = logging.getLogger("access_stim_monitor")
logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s [%(levelname)s] %(name)s: %(message)s",
    handlers=[logging.StreamHandler(sys.stdout)],
)

DATABASE_URL = os.environ.get("DATABASE_URL", "")

ACCESS_STIM_RATIO_THRESHOLD = 3.0
RE_FLAG_COOLDOWN_DAYS = 30
WINDOW_LABEL = "6m"


# ─── Admin ToDo helper ────────────────────────────────────────────────────

def _create_admin_todo(profile_id: int, description: str) -> None:
    """Create an ERPNext ToDo for the Accounting Advisor role.

    Mirrors the pattern in
    ``scripts.workers.services.cores_frn_registration.CORESFRNRegistrationHandler._create_admin_todo``.
    Failures are swallowed (logged) to avoid blocking the monitor's
    evidence-persistence path.
    """
    try:
        from scripts.workers.erpnext_client import ERPNextClient
        ERPNextClient().create_resource(
            "ToDo",
            {
                "description": f"[access-stim-monitor] profile_id={profile_id}\n\n{description}",
                "priority": "High",
                "role": "Accounting Advisor",
            },
        )
    except Exception as exc:                                # pragma: no cover
        log.error("Could not create admin ToDo for profile %s: %s", profile_id, exc)


# ─── Monitor core ─────────────────────────────────────────────────────────

def evaluate_profile(
    conn,
    profile_id: int,
    *,
    dry_run: bool = False,
) -> dict:
    """Evaluate one profile. Returns a summary dict."""
    with conn.cursor(cursor_factory=psycopg2.extras.RealDictCursor) as cur:
        cur.execute(
            """
            SELECT COALESCE(SUM(COALESCE(retail_minutes, 0) + COALESCE(wholesale_minutes, 0)), 0)
                   AS total_minutes,
                   COALESCE(SUM(COALESCE(retail_minutes, 0)), 0)    AS term_minutes,
                   COALESCE(SUM(COALESCE(wholesale_minutes, 0)), 0) AS orig_minutes
              FROM cdr_traffic_studies
             WHERE profile_id = %s
               AND generated_at >= NOW() - INTERVAL '6 months'
            """,
            (profile_id,),
        )
        agg = cur.fetchone() or {}
    term_minutes = int(agg.get("term_minutes") or 0)
    orig_minutes = int(agg.get("orig_minutes") or 0)

    if orig_minutes <= 0:
        return {
            "profile_id": profile_id,
            "flagged": False,
            "reason": "no_orig_traffic",
            "term_minutes": term_minutes,
            "orig_minutes": orig_minutes,
        }
    ratio = term_minutes / orig_minutes
    if ratio <= ACCESS_STIM_RATIO_THRESHOLD:
        return {
            "profile_id": profile_id,
            "flagged": False,
            "reason": "below_threshold",
            "ratio": round(ratio, 3),
            "term_minutes": term_minutes,
            "orig_minutes": orig_minutes,
        }

    # Threshold exceeded — check cooldown
    with conn.cursor(cursor_factory=psycopg2.extras.RealDictCursor) as cur:
        cur.execute(
            """
            SELECT access_stim_flagged_at
              FROM cdr_ingestion_profiles
             WHERE id = %s
            """,
            (profile_id,),
        )
        row = cur.fetchone() or {}
    last_flagged = row.get("access_stim_flagged_at")
    if last_flagged is not None:
        now = datetime.now(tz=last_flagged.tzinfo) if last_flagged.tzinfo else datetime.utcnow()
        delta = now - last_flagged
        if delta.days < RE_FLAG_COOLDOWN_DAYS:
            return {
                "profile_id": profile_id,
                "flagged": False,
                "reason": "cooldown",
                "ratio": round(ratio, 3),
                "term_minutes": term_minutes,
                "orig_minutes": orig_minutes,
                "last_flagged_at": last_flagged.isoformat(),
            }

    evidence = {
        "ratio": round(ratio, 3),
        "term_minutes": term_minutes,
        "orig_minutes": orig_minutes,
        "threshold": ACCESS_STIM_RATIO_THRESHOLD,
        "window": WINDOW_LABEL,
        "evaluated_at": datetime.now(tz=timezone.utc).isoformat(),
    }

    if dry_run:
        log.info(
            "[dry-run] profile %s would be flagged: ratio=%.2f:1 (term=%d, orig=%d)",
            profile_id, ratio, term_minutes, orig_minutes,
        )
        return {
            "profile_id": profile_id,
            "flagged": True,
            "dry_run": True,
            "evidence": evidence,
        }

    with conn.cursor() as cur:
        cur.execute(
            """
            UPDATE cdr_ingestion_profiles
               SET access_stim_flagged_at = NOW(),
                   access_stim_evidence_json = %s::jsonb
             WHERE id = %s
            """,
            (json.dumps(evidence), profile_id),
        )
    conn.commit()

    description = (
        f"Access stimulation 3:1 threshold exceeded for profile {profile_id} "
        f"(ratio {ratio:.2f}:1). Revenue reported on term_switched_access "
        f"should include 47 CFR 61.3(bbb) rate-cap disclosure.\n\n"
        f"Evidence: term_minutes={term_minutes:,}, orig_minutes={orig_minutes:,}, "
        f"window={WINDOW_LABEL}, evaluated_at={evidence['evaluated_at']}."
    )
    _create_admin_todo(profile_id, description)
    log.warning(
        "profile %s flagged access-stim ratio=%.2f:1 (term=%d, orig=%d)",
        profile_id, ratio, term_minutes, orig_minutes,
    )
    return {
        "profile_id": profile_id,
        "flagged": True,
        "dry_run": False,
        "evidence": evidence,
    }


def run_once(*, dry_run: bool = False) -> dict:
    conn = psycopg2.connect(DATABASE_URL)
    summaries: list[dict] = []
    try:
        with conn.cursor(cursor_factory=psycopg2.extras.RealDictCursor) as cur:
            cur.execute(
                """
                SELECT id
                  FROM cdr_ingestion_profiles
                 WHERE active = TRUE
                 ORDER BY id
                """,
            )
            profiles = cur.fetchall()
        for p in profiles:
            summaries.append(evaluate_profile(conn, p["id"], dry_run=dry_run))
    finally:
        conn.close()
    flagged = sum(1 for s in summaries if s.get("flagged") and not s.get("dry_run"))
    dry_flagged = sum(1 for s in summaries if s.get("flagged") and s.get("dry_run"))
    return {
        "evaluated": len(summaries),
        "flagged": flagged,
        "dry_flagged": dry_flagged,
        "summaries": summaries,
    }


def main() -> None:
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "--dry-run",
        action="store_true",
        help="Evaluate but do not update profiles or create ToDos.",
    )
    args = parser.parse_args()
    result = run_once(dry_run=args.dry_run)
    print(json.dumps(result, default=str, indent=2))


if __name__ == "__main__":
    main()