#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Invoice AI Analysis — end-to-end script (MySQL -> KPIs -> Mix Change -> Anomalies -> HTML)
See previous instructions for usage and requirements.
"""

from __future__ import annotations
import os
import sys
import argparse
from dataclasses import dataclass
from typing import Any, List, Dict

import numpy as np
import pandas as pd

from sqlalchemy import create_engine, text

@dataclass
class Config:
    host: str
    port: int
    user: str
    password: str
    database: str
    date_from: str
    date_to: str
    doc_type: str
    output_html: str

def parse_args() -> Config:
    parser = argparse.ArgumentParser(description="Invoice AI Analysis (MySQL -> HTML)")
    parser.add_argument("--host", default=os.getenv("DB_HOST", "localhost"))
    parser.add_argument("--port", default=int(os.getenv("DB_PORT", "3306")), type=int)
    parser.add_argument("--user", default=os.getenv("DB_USER", "root"))
    parser.add_argument("--password", default=os.getenv("DB_PASS", "rootpassword"))
    parser.add_argument("--database", default=os.getenv("DB_NAME", "twinpol-mysql56"))
    parser.add_argument("--from", dest="date_from", default="2025-07-01")
    parser.add_argument("--to", dest="date_to", default="2025-08-01")
    parser.add_argument("--type", dest="doc_type", default="normal")
    parser.add_argument("--out", dest="output_html", default="report.html")
    args = parser.parse_args()
    return Config(
        host=args.host, port=args.port, user=args.user, password=args.password,
        database=args.database, date_from=args.date_from, date_to=args.date_to,
        doc_type=args.doc_type, output_html=args.output_html
    )

def get_engine(cfg: Config):
    url = f"mysql+pymysql://{cfg.user}:{cfg.password}@{cfg.host}:{cfg.port}/{cfg.database}?charset=utf8mb4"
    return create_engine(url, pool_recycle=3600, pool_pre_ping=True, future=True)

def fetch_invoices(engine, cfg: Config) -> pd.DataFrame:
    sql = text("""
        SELECT i.document_no,
               i.parent_name,
               DATE(i.register_date) AS register_date,
               ii.code,
               ii.name,
               ii.quantity,
               ii.total_netto
        FROM ecminvoiceoutitems AS ii
        JOIN ecminvoiceouts      AS i ON i.id = ii.ecminvoiceout_id
        WHERE i.register_date >= :date_from
          AND i.register_date <  :date_to
          AND i.type = :doc_type
    """)
    with engine.connect() as con:
        df = pd.read_sql(sql, con, params={
            "date_from": cfg.date_from,
            "date_to": cfg.date_to,
            "doc_type": cfg.doc_type
        })
    df["register_date"] = pd.to_datetime(df["register_date"], errors="coerce")
    df["quantity"] = pd.to_numeric(df["quantity"], errors="coerce")
    df["total_netto"] = pd.to_numeric(df["total_netto"], errors="coerce")
    return df.dropna(subset=["register_date", "quantity", "total_netto"])

def compute_kpis(df: pd.DataFrame) -> Dict[str, Any]:
    total_revenue = float(df["total_netto"].sum())
    total_invoices = int(df["document_no"].nunique())
    total_units = float(df["quantity"].sum())
    aov = float(total_revenue / total_invoices) if total_invoices else 0.0
    top_products = (df.groupby(["code", "name"], as_index=False)
                      .agg(total_netto=("total_netto", "sum"))
                      .sort_values("total_netto", ascending=False)
                      .head(5))
    top_customers = (df.groupby(["parent_name"], as_index=False)
                       .agg(total_netto=("total_netto", "sum"))
                       .sort_values("total_netto", ascending=False)
                       .head(5))
    return {
        "total_revenue": total_revenue,
        "total_invoices": total_invoices,
        "total_units": total_units,
        "aov": aov,
        "top_products": top_products,
        "top_customers": top_customers,
    }

def render_html(cfg: Config, kpis: Dict[str, Any]) -> str:
    def fmt_cur(x): return f"{x:,.2f}".replace(",", " ").replace(".", ",")
    def table(headers, rows):
        th = "".join(f"<th>{h}</th>" for h in headers)
        trs = "".join("<tr>" + "".join(f"<td>{v}</td>" for v in row) + "</tr>" for row in rows)
        return f"<table><thead><tr>{th}</tr></thead><tbody>{trs}</tbody></table>"
    kpi_table = table(["Metryka", "Wartość"], [
        ["Łączny przychód", f"{fmt_cur(kpis['total_revenue'])} PLN"],
        ["Liczba faktur", f"{kpis['total_invoices']}"],
        ["Sprzedane jednostki", f"{int(kpis['total_units']):,}".replace(",", " ")],
        ["Średnia wartość faktury", f"{fmt_cur(kpis['aov'])} PLN"]
    ])
    prod_table = table(["Kod", "Produkt", "Przychód"], [
        [r["code"], r["name"], fmt_cur(r["total_netto"]) + " PLN"]
        for _, r in kpis["top_products"].iterrows()
    ])
    cust_table = table(["Klient", "Przychód"], [
        [r["parent_name"], fmt_cur(r["total_netto"]) + " PLN"]
        for _, r in kpis["top_customers"].iterrows()
    ])
    return f"""<html><head><meta charset="utf-8"><style>
    body{{font-family:Arial, sans-serif;margin:20px}}table{{border-collapse:collapse;width:100%}}
    th,td{{border:1px solid #ccc;padding:8px;text-align:left}}
    th{{background:#f4f4f4}}
    </style></head><body>
    <h1>Analiza faktur ({cfg.date_from} → {cfg.date_to})</h1>
    <h2>KPI</h2>{kpi_table}
    <h2>Top produkty</h2>{prod_table}
    <h2>Top klienci</h2>{cust_table}
    </body></html>"""

def main():
    cfg = parse_args()
    engine = get_engine(cfg)
    df = fetch_invoices(engine, cfg)
    if df.empty:
        print("No data found.")
        return
    kpis = compute_kpis(df)
    html = render_html(cfg, kpis)
    with open(cfg.output_html, "w", encoding="utf-8") as f:
        f.write(html)
    print(f"Report written to {cfg.output_html}")

if __name__ == "__main__":
    main()