#!/usr/bin/env python3
"""
Import Atlas data into Nexus POS tenant_refaccionaria_atlas.

Sources (expected in /home/):
  - Articulos Atlas.xlsx  -> inventory catalog (stock = 0)
  - Clientes.xlsx         -> customers
  - Historico V.xlsx      -> historical_sales (read-only reference)
"""

import os
import sys
import re
from datetime import datetime
from decimal import Decimal

import psycopg2
import pandas as pd

BASE_DIR = "/home"
TENANT_DB = "tenant_refaccionaria_atlas"


def get_tenant_conn():
    dsn = os.environ.get("TENANT_DB_URL", f"postgresql://postgres@localhost/{TENANT_DB}")
    return psycopg2.connect(dsn)


def normalize_text(val, max_len=None):
    if pd.isna(val):
        return None
    s = str(val).strip()
    if s in ("", "nan", "None"):
        return None
    if max_len:
        s = s[:max_len]
    return s


def normalize_price(val):
    if pd.isna(val):
        return Decimal("0")
    try:
        return Decimal(str(float(val))).quantize(Decimal("0.01"))
    except (ValueError, TypeError):
        return Decimal("0")


def clean_part_number(val):
    s = normalize_text(val, max_len=100)
    if not s:
        return None
    # Remove problematic chars but keep basic alphanumeric + dash/underscore
    s = re.sub(r"[^\w\-./]", "", s)
    return s[:100] or None


def import_inventory(conn):
    path = os.path.join(BASE_DIR, "Articulos Atlas.xlsx")
    df = pd.read_excel(path)
    print(f"[inventory] Read {len(df)} rows from {path}")

    cur = conn.cursor()
    inserted = 0
    skipped_dup = 0
    seen = set()

    for _, row in df.iterrows():
        part_number = clean_part_number(row.get("Clave"))
        if not part_number:
            continue
        if part_number in seen:
            skipped_dup += 1
            continue
        seen.add(part_number)

        name = normalize_text(row.get("Producto"), max_len=300) or part_number
        description = normalize_text(row.get("Nombre Alterno"), max_len=500)
        category = normalize_text(row.get("Categoría 1"), max_len=100)
        subcategory = normalize_text(row.get("Categoría 2"), max_len=100)
        unit = normalize_text(row.get("Unidad"), max_len=20)
        barcode = clean_part_number(row.get("Código de barras"))
        price = normalize_price(row.get("Precio lista"))

        # Concatenate category info into description if present
        extra_info = " | ".join(filter(None, [category, subcategory, unit]))
        if extra_info:
            description = f"{description or ''} [{extra_info}]".strip() if description else f"[{extra_info}]"

        cur.execute(
            """
            INSERT INTO inventory
                (part_number, name, description, cost, price_1, tax_rate,
                 unit, barcode, brand, is_active)
            VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s)
            ON CONFLICT (part_number) DO NOTHING
            RETURNING id
            """,
            (
                part_number,
                name,
                description,
                Decimal("0"),
                price,
                Decimal("0.16"),
                unit,
                barcode,
                category,
                True,
            ),
        )
        if cur.fetchone():
            inserted += 1

    conn.commit()
    cur.close()
    print(f"[inventory] Inserted: {inserted}, Duplicates skipped: {skipped_dup}")


def import_customers(conn):
    path = os.path.join(BASE_DIR, "Clientes.xlsx")
    df = pd.read_excel(path)
    print(f"[customers] Read {len(df)} rows from {path}")

    cur = conn.cursor()
    inserted = 0
    skipped = 0

    for _, row in df.iterrows():
        name = normalize_text(row.get("Empresa"), max_len=200)
        if not name:
            skipped += 1
            continue

        # Skip generic "Publico" row if it has no real name
        if name.lower() in ("publico", "publico en general", "público", "público en general"):
            skipped += 1
            continue

        credit_limit = normalize_price(row.get("Límite de crédito"))
        customer_type = normalize_text(row.get("Tipo de cliente"), max_len=50)
        segment = normalize_text(row.get("Segmento"), max_len=50)
        payment_terms = normalize_text(row.get("Condiciones de Pago"), max_len=100)
        notes = " | ".join(filter(None, [customer_type, segment, payment_terms]))

        # Avoid duplicates by name
        cur.execute("SELECT 1 FROM customers WHERE name = %s LIMIT 1", (name,))
        if cur.fetchone():
            skipped += 1
            continue

        cur.execute(
            """
            INSERT INTO customers
                (name, razon_social, credit_limit, price_tier, is_active)
            VALUES (%s, %s, %s, %s, %s)
            RETURNING id
            """,
            (
                name,
                name,
                credit_limit,
                1,
                True,
            ),
        )
        if cur.fetchone():
            inserted += 1

    conn.commit()
    cur.close()
    print(f"[customers] Inserted: {inserted}, Skipped: {skipped}")


def create_historical_sales_table(conn):
    cur = conn.cursor()
    cur.execute(
        """
        CREATE TABLE IF NOT EXISTS historical_sales (
            id SERIAL PRIMARY KEY,
            external_document_id VARCHAR(50),
            document_no VARCHAR(50),
            sale_date DATE,
            customer_name VARCHAR(200),
            total NUMERIC(12,2),
            subtotal NUMERIC(12,2),
            amount_paid NUMERIC(12,2),
            payment_method VARCHAR(50),
            discount NUMERIC(12,2) DEFAULT 0,
            balance NUMERIC(12,2) DEFAULT 0,
            raw_payment_code VARCHAR(20),
            created_at TIMESTAMPTZ DEFAULT NOW()
        );

        CREATE INDEX IF NOT EXISTS idx_historical_sales_date
            ON historical_sales(sale_date);
        CREATE INDEX IF NOT EXISTS idx_historical_sales_customer
            ON historical_sales(customer_name);
        CREATE INDEX IF NOT EXISTS idx_historical_sales_document
            ON historical_sales(document_no);
        """
    )
    conn.commit()
    cur.close()


def payment_label(code):
    mapping = {
        "1": "Efectivo",
        "3": "Tarjeta",
        "4": "Transferencia",
        "6": "Cheque",
        "28": "Crédito",
        "99": "Por definir",
    }
    return mapping.get(str(code).strip(), f"Código {code}")


def import_historical_sales(conn):
    path = os.path.join(BASE_DIR, "Historico V.xlsx")
    df = pd.read_excel(path)
    print(f"[historical_sales] Read {len(df)} rows from {path}")

    create_historical_sales_table(conn)

    cur = conn.cursor()
    inserted = 0

    for _, row in df.iterrows():
        doc_id = normalize_text(row.get("ID Documento"), max_len=50)
        doc_no = normalize_text(row.get("Documento No."), max_len=50)

        fecha = row.get("Fecha")
        if pd.isna(fecha):
            sale_date = None
        else:
            try:
                sale_date = pd.to_datetime(fecha).date()
            except Exception:
                sale_date = None

        customer = normalize_text(row.get("Cliente"), max_len=200)
        total = normalize_price(row.get("Total"))
        subtotal = normalize_price(row.get("SubTotal"))
        paid = normalize_price(row.get("Total Pagado"))
        discount = normalize_price(row.get("Descuento"))
        balance = normalize_price(row.get("Saldo"))
        raw_payment = normalize_text(row.get("Forma de Pago"), max_len=20)
        payment_label_str = payment_label(raw_payment) if raw_payment else None

        cur.execute(
            """
            INSERT INTO historical_sales
                (external_document_id, document_no, sale_date, customer_name,
                 total, subtotal, amount_paid, payment_method, discount, balance,
                 raw_payment_code)
            VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)
            ON CONFLICT DO NOTHING
            """,
            (
                doc_id,
                doc_no,
                sale_date,
                customer,
                total,
                subtotal,
                paid,
                payment_label_str,
                discount,
                balance,
                raw_payment,
            ),
    )
        inserted += cur.rowcount

    conn.commit()
    cur.close()
    print(f"[historical_sales] Inserted: {inserted}")


def main():
    print(f"Connecting to tenant {TENANT_DB}...")
    conn = get_tenant_conn()

    try:
        import_inventory(conn)
        import_customers(conn)
        import_historical_sales(conn)
        print("\nImport completed successfully.")
    except Exception as e:
        print(f"ERROR: {e}")
        conn.rollback()
        raise
    finally:
        conn.close()


if __name__ == "__main__":
    main()