"""FRED API client for macroeconomic data."""

from __future__ import annotations

import pandas as pd
from fredapi import Fred

from src.config import DATA_RAW_FRED, FRED_API_KEY
from src.utils import setup_logging

logger = setup_logging("fred")


def get_fred_client() -> Fred:
    """Return an authenticated FRED client."""
    return Fred(api_key=FRED_API_KEY)


def _fetch_series(
    series_id: str,
    start: str = "2024-01-01",
    end: str = "2026-06-01",
) -> pd.DataFrame:
    """Generic helper: fetch a FRED series and return as DataFrame."""
    client = get_fred_client()
    data = client.get_series(series_id, observation_start=start, observation_end=end)
    df = data.to_frame(name=series_id)
    df.index.name = "date"
    return df


def fetch_fed_funds_rate(
    start: str = "2024-01-01",
    end: str = "2026-06-01",
) -> pd.DataFrame:
    """Fetch DFF series (daily federal funds rate)."""
    df = _fetch_series("DFF", start, end)
    path = DATA_RAW_FRED / "fed_funds_rate.csv"
    df.to_csv(path)
    logger.info("Saved DFF (%d obs) to %s", len(df), path)
    return df


def fetch_cpi(
    start: str = "2024-01-01",
    end: str = "2026-06-01",
) -> pd.DataFrame:
    """Fetch CPIAUCSL series (Consumer Price Index)."""
    df = _fetch_series("CPIAUCSL", start, end)
    path = DATA_RAW_FRED / "cpi.csv"
    df.to_csv(path)
    logger.info("Saved CPIAUCSL (%d obs) to %s", len(df), path)
    return df


def fetch_unemployment(
    start: str = "2024-01-01",
    end: str = "2026-06-01",
) -> pd.DataFrame:
    """Fetch UNRATE series (unemployment rate)."""
    df = _fetch_series("UNRATE", start, end)
    path = DATA_RAW_FRED / "unemployment.csv"
    df.to_csv(path)
    logger.info("Saved UNRATE (%d obs) to %s", len(df), path)
    return df


def fetch_all_fred_data() -> None:
    """Fetch all FRED series and save to data/raw/fred/."""
    DATA_RAW_FRED.mkdir(parents=True, exist_ok=True)
    logger.info("=== Starting FRED data acquisition ===")

    try:
        fetch_fed_funds_rate()
    except Exception as exc:
        logger.error("Failed to fetch DFF: %s", exc)

    try:
        fetch_cpi()
    except Exception as exc:
        logger.error("Failed to fetch CPIAUCSL: %s", exc)

    try:
        fetch_unemployment()
    except Exception as exc:
        logger.error("Failed to fetch UNRATE: %s", exc)

    logger.info("=== FRED data acquisition complete ===")