#!/usr/bin/env python3
"""One-off: import Capi Autopartes inventory from CSV into tenant_capi_autopartes.

Replicates the semantics of pos/blueprints/inventory_bp.py::bulk_import_items:
  - creates missing categories
  - INSERT new items (with generated barcode) or UPDATE existing by part_number
  - records initial stock on the main branch via inventory_engine.record_initial
  - registers sku_secundario aliases

Usage (as postgres):
  MASTER_DB_URL=postgresql://postgres@/nexus_autoparts \
  TENANT_DB_URL_TEMPLATE='postgresql://postgres@/{db_name}' \
  POS_JWT_SECRET=... REDIS_ENABLED=false \
  python3 scripts/import_capi_inventory.py
"""

import csv
import io
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.barcode_generator import generate_barcode  # noqa: E402
from services.inventory_engine import record_initial  # noqa: E402

CSV_PATH = '/home/Autopartes/data/Inventario capi.csv'
TENANT_DB = 'tenant_capi_autopartes'
BRANCH_ID = 1
COMMIT_EVERY = 500


def parse_rows(path):
    raw = open(path, 'rb').read()
    text = None
    for enc in ('utf-8-sig', 'cp1252', 'latin-1'):
        try:
            text = raw.decode(enc)
            break
        except UnicodeDecodeError:
            continue
    if text is None:
        raise RuntimeError('Could not decode CSV')
    return list(csv.DictReader(io.StringIO(text)))


def to_decimal(val, default=0.0):
    try:
        v = float(str(val).replace(',', '').strip())
        return v
    except (ValueError, TypeError):
        return default


def main():
    rows = parse_rows(CSV_PATH)
    print(f'Filas en CSV: {len(rows)}')

    conn = psycopg2.connect(dbname=TENANT_DB)
    cur = conn.cursor()

    # 1. Create categories
    cat_names = sorted({r['categoria'].strip() for r in rows if r['categoria'].strip()})
    for name in cat_names:
        cur.execute("INSERT INTO categories (name) VALUES (%s) ON CONFLICT DO NOTHING", (name,))
    conn.commit()
    cur.execute("SELECT id, name FROM categories")
    category_map = {r[1].strip().lower(): r[0] for r in cur.fetchall()}
    print(f'Categorías creadas/existentes: {len(category_map)}')

    # 2. Import items
    created = updated = skipped = 0
    warnings = []

    for i, row in enumerate(rows, start=1):
        part_number = row['numero_de_parte'].strip()
        name = row['nombre'].strip()
        if not part_number or not name:
            skipped += 1
            warnings.append(f'Fila {i}: sin numero_de_parte o nombre')
            continue

        brand = row['marca'].strip()
        price_1 = to_decimal(row['precio'])
        stock = int(to_decimal(row['cantidad']))
        cost = to_decimal(row['costo'])
        description = (row.get('descripcion') or '').strip()
        category_name = row['categoria'].strip()
        category_id = category_map.get(category_name.lower()) if category_name else None

        cur.execute("SELECT id FROM inventory WHERE part_number = %s", (part_number,))
        existing = cur.fetchone()

        if existing:
            item_id = existing[0]
            cur.execute("""
                UPDATE inventory SET
                    name = %s,
                    brand = COALESCE(NULLIF(%s,''), brand),
                    cost = CASE WHEN %s > 0 THEN %s ELSE cost END,
                    price_1 = CASE WHEN %s > 0 THEN %s ELSE price_1 END,
                    description = COALESCE(NULLIF(%s,''), description),
                    category_id = COALESCE(%s, category_id)
                WHERE id = %s
            """, (name, brand, cost, cost, price_1, price_1, description, category_id, item_id))
            updated += 1
            if stock > 0:
                record_initial(conn, item_id, BRANCH_ID, stock, cost if cost > 0 else None)
        else:
            barcode = generate_barcode(conn, TENANT_DB)
            cur.execute("""
                INSERT INTO inventory
                (part_number, barcode, name, brand, cost, price_1, location, description, category_id, unit)
                VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s)
                RETURNING id
            """, (part_number, barcode, name, brand, cost, price_1, '', description, category_id, 'PZA'))
            item_id = cur.fetchone()[0]
            created += 1
            if stock > 0:
                record_initial(conn, item_id, BRANCH_ID, stock, cost if cost > 0 else None)

        sku_secondary = (row.get('sku_secundario') or '').strip()
        if sku_secondary:
            cur.execute("""
                INSERT INTO inventory_sku_aliases (inventory_id, sku, label)
                VALUES (%s, %s, %s) ON CONFLICT DO NOTHING
            """, (item_id, sku_secondary, 'Secundario'))

        if i % COMMIT_EVERY == 0:
            conn.commit()
            print(f'  {i}/{len(rows)} procesadas (nuevos={created}, act={updated})', flush=True)

    conn.commit()

    cur.execute("SELECT count(*) FROM inventory")
    total_inv = cur.fetchone()[0]
    cur.execute("SELECT COALESCE(SUM(stock),0) FROM inventory_stock WHERE branch_id = %s", (BRANCH_ID,))
    total_stock = cur.fetchone()[0]
    cur.execute("SELECT count(*) FROM inventory_sku_aliases")
    total_alias = cur.fetchone()[0]

    print('\n=== RESUMEN ===')
    print(f'Nuevos: {created} | Actualizados: {updated} | Saltados: {skipped}')
    print(f'Total inventario: {total_inv} | Stock total sucursal {BRANCH_ID}: {total_stock} | Alias: {total_alias}')
    if warnings:
        print(f'Advertencias ({len(warnings)}):')
        for w in warnings[:20]:
            print('  -', w)

    cur.close()
    conn.close()


if __name__ == '__main__':
    main()