"""
fetchers/base.py — Abstract base class for all macro data fetchers.

Provides retry logic, rate limiting, and a common interface.
"""

from abc import ABC, abstractmethod
from datetime import date as Date
from typing import Optional
import logging
import time
import requests


class BaseFetcher(ABC):
    """Abstract base for all macro data fetchers."""

    def __init__(self, timeout: int = 30, max_retries: int = 3):
        self.timeout = timeout
        self.max_retries = max_retries
        self.logger = logging.getLogger(self.__class__.__name__)

    def _get(self, url: str, params: Optional[dict] = None,
             headers: Optional[dict] = None) -> dict:
        """GET with retry and exponential backoff."""
        for attempt in range(self.max_retries):
            try:
                resp = requests.get(
                    url, params=params, headers=headers, timeout=self.timeout
                )
                resp.raise_for_status()
                return resp.json()
            except requests.RequestException as e:
                wait = 2 ** attempt
                self.logger.warning(
                    f"Request failed (attempt {attempt+1}/{self.max_retries}): {e}. "
                    f"Retrying in {wait}s"
                )
                if attempt < self.max_retries - 1:
                    time.sleep(wait)
                else:
                    raise

    def _get_raw(self, url: str, params: Optional[dict] = None,
                 headers: Optional[dict] = None) -> bytes:
        """GET raw bytes with retry (for non-JSON endpoints)."""
        for attempt in range(self.max_retries):
            try:
                resp = requests.get(
                    url, params=params, headers=headers, timeout=self.timeout
                )
                resp.raise_for_status()
                return resp.content
            except requests.RequestException as e:
                wait = 2 ** attempt
                if attempt < self.max_retries - 1:
                    time.sleep(wait)
                else:
                    raise

    @abstractmethod
    def fetch(self, target_date: Optional[Date] = None) -> list[dict]:
        """Fetch raw data. Returns list of record dicts."""
        ...

    @abstractmethod
    def store(self, db_path: str, records: list[dict]) -> int:
        """Store raw records into SQLite. Returns count of new rows."""
        ...