"""
Config loader (local-only).

This project is fully localized: all sensitive configuration should come from
`backend_api_python/.env` (or OS environment variables).

We keep the return shape compatible with the old PHP `loadConfig`:
flat keys like `openrouter.api_key` become nested dicts like:
{
  "openrouter": {"api_key": "..."}
}
"""

import os
from typing import Any, Dict, List, Optional, Tuple

from app.utils.logger import get_logger

logger = get_logger(__name__)

# Configure cache
_config_cache: Optional[Dict[str, Any]] = None


def load_addon_config() -> Dict[str, Any]:
    """
    Build config from environment variables (.env / OS env).

    NOTE: We intentionally do NOT load secrets from the database.

    Returns:
        Nested config dict (PHP-compatible shape)
    """
    global _config_cache

    # If the cache exists, return directly
    if _config_cache is not None:
        return _config_cache

    config: Dict[str, Any] = {}

    def set_nested(cfg: Dict[str, Any], dotted_key: str, value: Any) -> None:
        keys = dotted_key.split(".")
        ref = cfg
        for i, k in enumerate(keys):
            if i == len(keys) - 1:
                ref[k] = value
            else:
                if k not in ref or not isinstance(ref[k], dict):
                    ref[k] = {}
                ref = ref[k]

    def env_get(name: str) -> Optional[str]:
        val = os.getenv(name)
        if val is None:
            return None
        val = str(val).strip()
        return val if val != "" else None

    # Map env vars to PHP-style dotted keys.
    mappings: List[Tuple[str, str, str]] = [
        # internal
        ("INTERNAL_API_KEY", "internal_api.key", "string"),
        # OpenRouter / LLM
        ("OPENROUTER_API_KEY", "openrouter.api_key", "string"),
        ("OPENROUTER_API_URL", "openrouter.api_url", "string"),
        ("OPENROUTER_MODEL", "openrouter.model", "string"),
        ("OPENROUTER_TEMPERATURE", "openrouter.temperature", "float"),
        ("OPENROUTER_MAX_TOKENS", "openrouter.max_tokens", "int"),
        ("OPENROUTER_TIMEOUT", "openrouter.timeout", "int"),
        ("OPENROUTER_CONNECT_TIMEOUT", "openrouter.connect_timeout", "int"),
        # OpenAI Direct
        ("OPENAI_API_KEY", "openai.api_key", "string"),
        ("OPENAI_BASE_URL", "openai.base_url", "string"),
        ("OPENAI_MODEL", "openai.model", "string"),
        # Google Gemini
        ("GOOGLE_API_KEY", "google.api_key", "string"),
        ("GOOGLE_MODEL", "google.model", "string"),
        # DeepSeek
        ("DEEPSEEK_API_KEY", "deepseek.api_key", "string"),
        ("DEEPSEEK_BASE_URL", "deepseek.base_url", "string"),
        ("DEEPSEEK_MODEL", "deepseek.model", "string"),
        # xAI Grok
        ("GROK_API_KEY", "grok.api_key", "string"),
        ("GROK_BASE_URL", "grok.base_url", "string"),
        ("GROK_MODEL", "grok.model", "string"),
        # LLM Provider Selection
        ("LLM_PROVIDER", "llm.provider", "string"),
        # App
        ("RATE_LIMIT", "app.rate_limit", "int"),
        ("ENABLE_CACHE", "app.enable_cache", "bool"),
        ("ENABLE_REQUEST_LOG", "app.enable_request_log", "bool"),
        # Data source common
        ("DATA_SOURCE_TIMEOUT", "data_source.timeout", "int"),
        ("DATA_SOURCE_RETRY", "data_source.retry_count", "int"),
        ("DATA_SOURCE_RETRY_BACKOFF", "data_source.retry_backoff", "float"),
        # Finnhub
        ("FINNHUB_API_KEY", "finnhub.api_key", "string"),
        ("FINNHUB_TIMEOUT", "finnhub.timeout", "int"),
        ("FINNHUB_RATE_LIMIT", "finnhub.rate_limit", "int"),
        # CCXT
        ("CCXT_DEFAULT_EXCHANGE", "ccxt.default_exchange", "string"),
        ("CCXT_TIMEOUT", "ccxt.timeout", "int"),
        # Other sources
        ("YFINANCE_TIMEOUT", "yfinance.timeout", "int"),
        ("TIINGO_API_KEY", "tiingo.api_key", "string"),
        ("TIINGO_TIMEOUT", "tiingo.timeout", "int"),
        # Search (Google CSE / Bing)
        ("SEARCH_PROVIDER", "search.provider", "string"),
        ("SEARCH_MAX_RESULTS", "search.max_results", "int"),
        ("SEARCH_GOOGLE_API_KEY", "search.google.api_key", "string"),
        ("SEARCH_GOOGLE_CX", "search.google.cx", "string"),
        ("SEARCH_BING_API_KEY", "search.bing.api_key", "string"),
        # Tavily (AI-optimized search)
        ("TAVILY_API_KEYS", "tavily.api_keys", "string"),
        # SerpAPI (Google/Bing scraper)
        ("SERPAPI_KEYS", "serpapi.api_keys", "string"),
    ]

    for env_name, dotted_key, value_type in mappings:
        raw = env_get(env_name)
        if raw is None:
            continue
        try:
            value = _convert_config_value(raw, value_type)
            set_nested(config, dotted_key, value)
        except Exception as e:
            logger.warning(f"Config env parse failed: {env_name} -> {dotted_key}: {e}")

    _config_cache = config
    return config


def _convert_config_value(value: str, value_type: str) -> Any:
    """
    Convert configuration values ​​according to type (consistent with the convertConfigValue method on the PHP side)

    Args:
        value: configuration value string (may be None)
        value_type: configuration type

    Returns:
        Converted configuration value
    """
    # Handling None or null values
    if value is None or value == "":
        if value_type == "int":
            return 0
        elif value_type == "float":
            return 0.0
        elif value_type == "bool":
            return False
        elif value_type == "json":
            return {}
        else:
            return ""

    try:
        if value_type == "int":
            return int(value)
        elif value_type == "float":
            return float(value)
        elif value_type == "bool":
            return bool(value) or value == "1" or value == "true" or value == "True"
        elif value_type == "json":
            import json

            try:
                return json.loads(value) if value else {}
            except (json.JSONDecodeError, TypeError):
                return {}
        else:
            return str(value) if value is not None else ""
    except (ValueError, TypeError) as e:
        logger.warning(f"Config value type conversion failed: value={value}, type={value_type}, error={str(e)}")
        # Returns default value if conversion fails
        if value_type == "int":
            return 0
        elif value_type == "float":
            return 0.0
        elif value_type == "bool":
            return False
        elif value_type == "json":
            return {}
        else:
            return str(value) if value is not None else ""


def get_internal_api_key() -> Optional[str]:
    """
    Get the internal API key (preferably read from environment variables)

    Returns:
        Internal API key, returns None if not configured
    """
    try:
        env_val = os.getenv("INTERNAL_API_KEY", "").strip()
        if env_val:
            return env_val

        config = load_addon_config()
        api_key = config.get("internal_api", {}).get("key")

        if api_key:
            logger.debug(f"Loaded INTERNAL_API_KEY from env-config shape, length: {len(api_key)}")
        else:
            logger.warning("Missing INTERNAL_API_KEY (env).")

        return api_key
    except Exception as e:
        logger.error(f"Failed to load internal API key: {str(e)}")
        return None


def clear_config_cache():
    """
    Clear configuration cache (called after configuration update)
    """
    global _config_cache
    _config_cache = None
    logger.debug("Addon config cache cleared")