"""Data router factory — assembles the router with all available sources."""

from __future__ import annotations

import logging

from .router import DataRouter
from .sources.akshare_source import AKShareSource
from .sources.worldbank_source import WorldBankSource
from .sources.gpt_researcher_source import GPTResearcherSource

logger = logging.getLogger(__name__)


def create_data_router() -> DataRouter:
    """Create a DataRouter with all available data sources.

    Priority order (lower = tried first):
        10  AKShare       — free, fast, covers Chinese macro/industry
        20  World Bank    — free, global macro
        90  GPT Researcher — universal fallback (web research)

    Future additions:
        30  巨潮资讯       — free tier, Chinese public companies
        40  天眼查 API     — paid, company data
        50  Choice API     — paid, financial data
        60  Statista API   — paid, global industry stats
        70  FRED API       — free, US macro
        80  UN Comtrade    — free, global trade
    """
    router = DataRouter()

    # --- Free tier (always available) ---
    router.register(AKShareSource(), priority=10)
    router.register(WorldBankSource(), priority=20)

    # --- Universal fallback ---
    router.register(GPTResearcherSource(), priority=90)

    logger.info(f"[data_factory] created router with {len(router.sources)} sources")
    return router


# Singleton
_router: DataRouter | None = None


def get_data_router() -> DataRouter:
    global _router
    if _router is None:
        _router = create_data_router()
    return _router