Initial commit of integrated agent system

backend/config/data_config.py

@@ -0,0 +1,128 @@
+# -*- coding: utf-8 -*-
+"""Centralized data source configuration and fallback ordering."""
+
+import os
+from dataclasses import dataclass
+from typing import Literal, Optional
+
+DataSource = Literal["finnhub", "financial_datasets", "yfinance", "local_csv"]
+_KNOWN_SOURCES: tuple[DataSource, ...] = (
+    "finnhub",
+    "financial_datasets",
+    "yfinance",
+    "local_csv",
+)
+
+
+@dataclass
+class DataSourceConfig:
+    """Resolved data source configuration."""
+
+    source: DataSource
+    api_key: str
+    sources: list[DataSource]
+
+
+# Module-level cache for the resolved configuration
+_config_cache: Optional[DataSourceConfig] = None
+
+
+def _parse_enabled_sources() -> list[DataSource]:
+    """Parse optional enabled source allowlist from the environment."""
+    raw_value = os.getenv("ENABLED_DATA_SOURCES", "").strip().lower()
+    if not raw_value:
+        return []
+
+    enabled: list[DataSource] = []
+    for item in raw_value.split(","):
+        candidate = item.strip()
+        if not candidate or candidate not in _KNOWN_SOURCES:
+            continue
+        if candidate not in enabled:
+            enabled.append(candidate)
+    return enabled
+
+
+def _ordered_sources() -> list[DataSource]:
+    """Resolve source preference and available fallbacks."""
+    preferred = os.getenv("FIN_DATA_SOURCE", "").strip().lower()
+    finnhub_key = os.getenv("FINNHUB_API_KEY", "").strip()
+    fd_key = os.getenv("FINANCIAL_DATASETS_API_KEY", "").strip()
+    enabled_sources = _parse_enabled_sources()
+    wants_yfinance = preferred == "yfinance" or "yfinance" in enabled_sources
+
+    available: list[DataSource] = []
+    if finnhub_key:
+        available.append("finnhub")
+    if fd_key:
+        available.append("financial_datasets")
+    if wants_yfinance:
+        available.append("yfinance")
+    available.append("local_csv")
+
+    if enabled_sources:
+        filtered = [source for source in enabled_sources if source in available]
+        if filtered:
+            available = filtered
+
+    if preferred in available:
+        ordered = [preferred]
+        ordered.extend(source for source in available if source != preferred)
+        return ordered
+    return available
+
+
+def _resolve_config() -> DataSourceConfig:
+    """
+    Resolve data source configuration based on available API keys.
+
+    The effective source should always match the first item in the resolved
+    ordered source list.
+    """
+    sources = _ordered_sources()
+    source = sources[0] if sources else "local_csv"
+
+    api_key = ""
+    if source == "finnhub":
+        api_key = os.getenv("FINNHUB_API_KEY", "").strip()
+    elif source == "financial_datasets":
+        api_key = os.getenv("FINANCIAL_DATASETS_API_KEY", "").strip()
+
+    return DataSourceConfig(source=source, api_key=api_key, sources=sources)
+
+
+def get_config() -> DataSourceConfig:
+    """
+    Get the resolved data source configuration (cached).
+
+    Returns:
+        DataSourceConfig with source and api_key
+
+    Raises:
+        ValueError: If no API key is configured
+    """
+    global _config_cache
+    if _config_cache is None:
+        _config_cache = _resolve_config()
+    return _config_cache
+
+
+def get_data_source() -> DataSource:
+    """Get the configured data source name."""
+    return get_config().source
+
+
+def get_data_sources() -> list[DataSource]:
+    """Get preferred source ordering including fallbacks."""
+    return get_config().sources
+
+
+def get_api_key() -> str:
+    """Get the API key for the configured data source."""
+    return get_config().api_key
+
+
+def reset_config() -> None:
+    """Reset the cached configuration (useful for testing)."""
+    global _config_cache
+    _config_cache = None