"""Symbol conversion utilities.

CCXT uses 'BASE/QUOTE' format (e.g. "XAU/USD").
MT5 uses broker-specific names (e.g. "XAUUSD", "XAUUSDc", "XAUUSD.i").

The wrapper supports two strategies:
1. User-provided symbol_map in config (recommended, explicit)
2. Default: strip the "/" and concatenate (works for plain symbols)
"""

# Common quote currencies in forex/metals
COMMON_QUOTES = [
    "USD", "EUR", "GBP", "JPY", "CHF", "CAD", "AUD", "NZD",
    "CNY", "HKD", "SGD", "XAU", "XAG", "XPT", "XPD",
]


def to_mt5_symbol(symbol, default_suffix=""):
    """Convert CCXT symbol (XAU/USD) to MT5 format (XAUUSD).

    Args:
        symbol: CCXT-format symbol (e.g. "XAU/USD" or "XAUUSDc")
        default_suffix: suffix to append when no symbol_map is provided
                        (e.g. "c" for ECN, ".i" for CFD indices)

    Returns:
        str: MT5-format symbol
    """
    # Already in MT5 format (no slash)
    if "/" not in symbol:
        return symbol

    base, quote = symbol.split("/", 1)
    return f"{base}{quote}{default_suffix}"


def to_ccxt_symbol(symbol, quote=None):
    """Best-effort conversion from MT5 symbol to CCXT format.

    Args:
        symbol: MT5 symbol (e.g. "XAUUSDc")
        quote: Optional explicit quote currency to split on

    Returns:
        str: CCXT symbol (e.g. "XAU/USD" or original if cannot split)
    """
    # Strip common suffixes
    cleaned = symbol
    for suffix in ("c", ".i", ".m", ".pro", ".ecn", ".raw", ".std"):
        if cleaned.endswith(suffix):
            cleaned = cleaned[: -len(suffix)]
            break

    # Try explicit quote first
    if quote and cleaned.endswith(quote) and len(cleaned) > len(quote):
        return f"{cleaned[: -len(quote)]}/{quote}"

    # Try common quotes
    for q in COMMON_QUOTES:
        if cleaned.endswith(q) and len(cleaned) > len(q):
            return f"{cleaned[: -len(q)]}/{q}"

    # Cannot split reliably
    return symbol