#!/usr/bin/env python3
"""Credit risk score report (A9).

Prints rule-based credit scores for a tenant's customers using
``services.credit_scoring.score_customer``. Read-only: never writes to the DB.

Usage (as root/postgres, from /home/Autopartes):
    python3 scripts/credit_score_report.py --tenant 31
    python3 scripts/credit_score_report.py --tenant 45 --only-credit
    python3 scripts/credit_score_report.py --all --tier risk
    python3 scripts/credit_score_report.py --tenant 31 --json
"""

import argparse
import json
import os
import sys

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

from tenant_db import get_tenant_conn, get_master_conn  # noqa: E402
from services.credit_scoring import score_customer  # noqa: E402


def list_tenants(only_id=None):
    conn = get_master_conn()
    try:
        cur = conn.cursor()
        if only_id:
            cur.execute(
                "SELECT id, name, db_name FROM tenants "
                "WHERE is_active = true AND id = %s",
                (only_id,),
            )
        else:
            cur.execute(
                "SELECT id, name, db_name FROM tenants WHERE is_active = true ORDER BY id"
            )
        rows = cur.fetchall()
        cur.close()
        return rows
    finally:
        conn.close()


def customer_ids(conn, only_credit=False, limit=None):
    cur = conn.cursor()
    where = "WHERE c.is_active = true"
    if only_credit:
        where += " AND (c.credit_limit > 0 OR c.credit_balance > 0)"
    sql = f"SELECT c.id FROM customers c {where} ORDER BY c.id"
    if limit:
        sql += " LIMIT %s"
        cur.execute(sql, (limit,))
    else:
        cur.execute(sql)
    ids = [r[0] for r in cur.fetchall()]
    cur.close()
    return ids


def report_tenant(tenant_id, tenant_name, only_credit, limit, tier_filter, as_json):
    conn = get_tenant_conn(tenant_id)
    try:
        ids = customer_ids(conn, only_credit=only_credit, limit=limit)
        rows = []
        for cid in ids:
            try:
                rows.append(score_customer(conn, cid))
            except Exception as exc:
                rows.append({'customer_id': cid, 'error': str(exc)})
    finally:
        conn.close()

    if tier_filter:
        rows = [r for r in rows if r.get('tier') == tier_filter]

    if as_json:
        print(json.dumps({'tenant_id': tenant_id, 'tenant': tenant_name, 'scores': rows},
                         ensure_ascii=False, indent=2, default=str))
        return

    print(f"\n=== Tenant {tenant_id} — {tenant_name} ({len(rows)} clientes) ===")
    print(f"{'ID':>6}  {'score':>5}  {'tier':<6}  {'lim_sug':>12}  {'datos':>5}  señal principal")
    for r in sorted(rows, key=lambda x: x.get('score', 0)):
        if 'error' in r:
            print(f"{r['customer_id']:>6}  ERROR: {r['error']}")
            continue
        reasons = r.get('reasons') or []
        headline = next(
            (x for x in reasons if 'Mora' in x or 'atraso' in x or 'excedido' in x),
            reasons[-1] if reasons else '',
        )
        print(f"{r['customer_id']:>6}  {r['score']:>5}  {r['tier']:<6}  "
              f"{r['recommended_limit']:>12,.2f}  {r['data_points']:>5}  {headline}")


def main():
    parser = argparse.ArgumentParser(description="Credit risk score report (A9)")
    group = parser.add_mutually_exclusive_group(required=True)
    group.add_argument('--tenant', type=int, help='Tenant id')
    group.add_argument('--all', action='store_true', help='All active tenants')
    parser.add_argument('--only-credit', action='store_true',
                        help='Only customers with a credit line or balance')
    parser.add_argument('--tier', choices=['good', 'medium', 'risk'],
                        help='Only show customers in this tier')
    parser.add_argument('--limit', type=int, help='Max customers per tenant')
    parser.add_argument('--json', action='store_true', help='Emit JSON')
    args = parser.parse_args()

    tenants = list_tenants(None if args.all else args.tenant)
    if not tenants:
        print("No tenants found", file=sys.stderr)
        return 1

    for tenant_id, name, _db_name in tenants:
        report_tenant(tenant_id, name, args.only_credit, args.limit,
                      args.tier, args.json)
    return 0


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