#!/usr/bin/env python3
"""Run the A5 business anomaly scan for one or all tenants.

Reports, per tenant, the anomalies detected by services.anomaly_detector:
atypical discounts (per cajero / per SKU), sales below cost, repeated
cancellations and off-hours tickets.

Usage (as postgres):
  MASTER_DB_NAME=nexus_autopartes python3 scripts/run_anomaly_scan.py [db_name|all] [days]
  python3 scripts/run_anomaly_scan.py tenant_refaccionaria_atlas 30
  python3 scripts/run_anomaly_scan.py all 90 --json

Exit code is 1 when at least one critical/high finding is reported, so it can
be wired into cron/Alertmanager; 0 otherwise.
"""

import json
import os
import sys

sys.path.insert(0, os.path.join(os.path.dirname(os.path.abspath(__file__)), '..', 'pos'))

import psycopg2  # noqa: E402
from services.anomaly_detector import detect_anomalies  # noqa: E402

MASTER_DB = os.environ.get('MASTER_DB_NAME', 'nexus_autoparts')

SEVERITY_ORDER = {'critical': 0, 'high': 1, 'medium': 2, 'low': 3}


def _tenant_dbs():
    conn = psycopg2.connect(dbname=MASTER_DB)
    try:
        cur = conn.cursor()
        cur.execute("SELECT db_name FROM tenants WHERE is_active = true ORDER BY db_name")
        dbs = [r[0] for r in cur.fetchall()]
        cur.close()
    finally:
        conn.close()
    return dbs


def _print_report(db_name, report):
    sample = report['sample']
    cold = ' (COLD START: poca historia)' if report['cold_start'] else ''
    print(f"\n=== {db_name}{cold} ===")
    print(f"  ventana: {report['window_days']}d | sale_items={sample['sale_items']} "
          f"sales={sample['sales']} empleados={sample['employees']}")
    if not report['employees'] and not report['skus']:
        print("  sin anomalías")
        return

    for entry in report['employees']:
        print(f"  [empleado {entry['employee_id']} {entry['employee_name']}] "
              f"score={entry['score']}")
        for a in sorted(entry['anomalies'], key=lambda x: SEVERITY_ORDER.get(x['severity'], 9)):
            print(f"     - {a['severity']:8s} {a['type']:20s} {a['detail']}")
    for entry in report['skus']:
        types = ', '.join(sorted({a['type'] for a in entry['anomalies']}))
        print(f"  [sku {entry['inventory_id']} {entry['name']}] score={entry['score']} -> {types}")


def main():
    args = [a for a in sys.argv[1:] if not a.startswith('--')]
    as_json = '--json' in sys.argv
    target = args[0] if args else 'all'
    days = int(args[1]) if len(args) > 1 else 90

    dbs = _tenant_dbs() if target == 'all' else [target]
    reports = {}
    exit_code = 0

    for db in dbs:
        try:
            conn = psycopg2.connect(dbname=db)
        except Exception as e:
            print(f"[{db}] ERROR de conexión: {e}", file=sys.stderr)
            exit_code = 2
            continue
        try:
            report = detect_anomalies(conn, days=days)
        except Exception as e:
            print(f"[{db}] ERROR: {e}", file=sys.stderr)
            exit_code = 2
            continue
        finally:
            conn.close()

        reports[db] = report
        if not as_json:
            _print_report(db, report)
        if report['summary']['by_type'] and any(
                e['anomalies'] and min(
                    SEVERITY_ORDER.get(a['severity'], 9) for a in e['anomalies']) <= 1
                for e in report['employees'] + report['skus']):
            exit_code = max(exit_code, 1)

    if as_json:
        print(json.dumps(reports, indent=2, default=str))

    return exit_code


if __name__ == '__main__':
    sys.exit(main())