#!/usr/bin/env python3
"""Download Yahoo Finance OHLCV data and persist as Parquet files."""

from __future__ import annotations

import argparse
import logging
import os
import sys
from datetime import datetime, timedelta
from pathlib import Path
from zoneinfo import ZoneInfo

import pandas as pd
import yfinance as yf

from telemetry import capture_exception, init_telemetry

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s %(levelname)s %(message)s",
)
logger = logging.getLogger("sync")

ET = ZoneInfo("America/New_York")


def parquet_dir() -> Path:
    path = Path(os.environ.get("PARQUET_DIR", "/data/parquet"))
    path.mkdir(parents=True, exist_ok=True)
    return path


def core_tickers() -> list[str]:
    raw = os.environ.get(
        "CORE_TICKERS",
        "SPY,QQQ,AAPL,MSFT,GOOGL,AMZN,NVDA,META,IWM,TLT",
    )
    return [t.strip().upper() for t in raw.split(",") if t.strip()]


def seed_years() -> int:
    return int(os.environ.get("SEED_YEARS", "5"))


def parquet_path(ticker: str) -> Path:
    return parquet_dir() / f"{ticker.upper()}.parquet"


def normalize_frame(df: pd.DataFrame) -> pd.DataFrame:
    if isinstance(df.columns, pd.MultiIndex):
        df.columns = [col[0] if isinstance(col, tuple) else col for col in df.columns]

    df = df.reset_index()
    if "Datetime" in df.columns and "Date" not in df.columns:
        df = df.rename(columns={"Datetime": "Date"})
    if "Date" not in df.columns and "index" in df.columns:
        df = df.rename(columns={"index": "Date"})

    keep = [c for c in ["Date", "Open", "High", "Low", "Close", "Volume"] if c in df.columns]
    df = df[keep].copy()
    df["Date"] = pd.to_datetime(df["Date"]).dt.tz_localize(None)
    df = df.drop_duplicates(subset=["Date"], keep="last").sort_values("Date")
    return df


def download_history(ticker: str, start: datetime, end: datetime | None = None) -> pd.DataFrame:
    end = end or datetime.now(tz=ET)
    raw = yf.download(
        ticker,
        start=start.date(),
        end=(end + timedelta(days=1)).date(),
        auto_adjust=True,
        progress=False,
        threads=False,
    )
    if raw.empty:
        raise RuntimeError(f"No data returned for {ticker}")
    return normalize_frame(raw)


def save_ticker(ticker: str, frame: pd.DataFrame) -> None:
    path = parquet_path(ticker)
    frame.to_parquet(path, index=False)
    logger.info("Wrote %s rows to %s", len(frame), path)


def seed_all() -> int:
    tickers = core_tickers()
    start = datetime.now(tz=ET) - timedelta(days=365 * seed_years())
    failures = 0

    for ticker in tickers:
        try:
            frame = download_history(ticker, start=start)
            save_ticker(ticker, frame)
        except Exception as exc:
            failures += 1
            logger.exception("Seed failed for %s", ticker)
            capture_exception(exc)

    return failures


def append_daily(ticker: str) -> None:
    path = parquet_path(ticker)
    if path.exists():
        existing = pd.read_parquet(path)
        existing["Date"] = pd.to_datetime(existing["Date"])
        last_date = existing["Date"].max()
        start = last_date.to_pydatetime()
    else:
        start = datetime.now(tz=ET) - timedelta(days=30)
        existing = pd.DataFrame()

    new_frame = download_history(ticker, start=start - timedelta(days=5))
    if existing.empty:
        merged = new_frame
    else:
        merged = (
            pd.concat([existing, new_frame], ignore_index=True)
            .drop_duplicates(subset=["Date"], keep="last")
            .sort_values("Date")
        )

    save_ticker(ticker, merged)


def sync_daily() -> int:
    failures = 0
    for ticker in core_tickers():
        try:
            append_daily(ticker)
        except Exception as exc:
            failures += 1
            logger.exception("Daily sync failed for %s", ticker)
            capture_exception(exc)
    return failures


def main(argv: list[str] | None = None) -> int:
    init_telemetry("quant-harvester")

    parser = argparse.ArgumentParser(description="Yahoo Finance -> Parquet sync")
    parser.add_argument("--seed", action="store_true", help="Download full history")
    parser.add_argument("--daily", action="store_true", help="Append latest daily bars")
    args = parser.parse_args(argv)

    if not args.seed and not args.daily:
        parser.error("Specify --seed and/or --daily")

    exit_code = 0
    if args.seed:
        logger.info("Starting historical seed for %s", ", ".join(core_tickers()))
        if seed_all() > 0:
            exit_code = 1

    if args.daily:
        logger.info("Starting daily append for %s", ", ".join(core_tickers()))
        if sync_daily() > 0:
            exit_code = 1

    return exit_code


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