# app/orchestrator.py
from __future__ import annotations
import re
from typing import Dict, Any, Callable, Optional

from utils.config import get_settings
from utils.phone import extract_phone, looks_valid
from app.tools import dispatch_tool

# -----------------------------
# Resolve router/NLG per BACKEND
# -----------------------------
_s = get_settings()

_route_fn: Optional[Callable[[str], Dict[str, Any]]] = None
_nlg_fn:   Optional[Callable[[str, Dict[str, Any], str], str]] = None

def _load_router():
    global _route_fn, _nlg_fn
    backend = (_s.BACKEND_LLM or "").lower()

    try:
        if backend == "llamacpp":
            from models.llm_router import respond as route, nlg as nlg_impl
            _route_fn, _nlg_fn = route, nlg_impl
        elif backend == "openai":
            from models.openai_router import respond as route, nlg as nlg_impl
            _route_fn, _nlg_fn = route, nlg_impl
        elif backend == "groq":
            from models.groq_router import respond as route, nlg as nlg_impl
            _route_fn, _nlg_fn = route, nlg_impl
        else:
            # Unknown backend → safe fallbacks
            _route_fn = lambda _: {"tool": None, "args": {}}
            _nlg_fn = _fallback_nlg
    except Exception:
        # If import fails, still keep app running with safe fallbacks
        _route_fn = lambda _: {"tool": None, "args": {}}
        _nlg_fn   = _fallback_nlg

def _fallback_nlg(tool: str, tool_result: Dict[str, Any] | None, user_text: str) -> str:
    """Minimal reply if no NLG provided by the chosen backend."""
    tr = tool_result or {}
    if tool in (None, "", "smalltalk"):
        return "Hello! How can I help with FutureCafe—menu, hours, reservations, or orders?"
    if tool == "get_hours":
        hours = tr.get("hours") or "11:00–22:00 daily"
        address = tr.get("address") or "123 Main St"
        return f"We’re open {hours} at {address}. What else can I do for you?"
    if tool == "menu_lookup":
        items = tr.get("items") or []
        if items:
            names = ", ".join(i.get("name", "item") for i in items[:6])
            return f"Here are some popular items: {names}. Would you like to order any of these?"
        return "I can look up menu items—any dietary needs or a specific dish?"
    if tool == "create_reservation":
        when = tr.get("when") or tr.get("datetime") or "your requested time"
        code = tr.get("reservation_id") or tr.get("code") or "a confirmation code"
        return f"Reservation confirmed for {when}. Code {code}. Anything else I can help with?"
    if tool == "create_order":
        items = tr.get("items") or []
        if items:
            summary = ", ".join(f"{i.get('qty','1')}× {i.get('name','item')}" for i in items)
            total = tr.get("total")
            return f"Order placed: {summary}" + (f". Total ${total:.2f}" if isinstance(total, (int,float)) else "") + "."
        return "Your order is noted. Anything to add?"
    # Generic fallback
    return "Done. Anything else I can help you with?"

# Load router once at import
_load_router()

# -----------------------------
# Public API
# -----------------------------
def llm_route_and_execute(user_text: str) -> Dict[str, Any]:
    """
    1) Route the user_text to a tool (model-dependent)
    2) Enrich args (e.g., reservation phone/name)
    3) Execute tool (dispatch_tool)
    4) Generate reply (NLG if available, else fallback)
    Returns a single dict suitable for the UI diagnostics panel.
    """
    text = (user_text or "").strip()
    if not text:
        return {
            "intent": "smalltalk",
            "slots": {},
            "tool_selected": None,
            "tool_result": None,
            "response": "Hello! How can I help with FutureCafe today?",
        }

    # --- 1) Route ---
    try:
        route = _route_fn(text) if _route_fn else {"tool": None, "args": {}}
        if not isinstance(route, dict):
            route = {"tool": None, "args": {}}
    except Exception:
        route = {"tool": None, "args": {}}

    tool = route.get("tool")
    args = dict(route.get("args") or {})

    # --- 2) Enrich args for reservation ---
    if tool == "create_reservation":
        phone = extract_phone(text)
        if looks_valid(phone) and not args.get("phone"):
            args["phone"] = phone
        # lightweight name inference: “my name is X”, “I am X”, “I’m X”
        if not args.get("name"):
            m = re.search(r"(?:my name is|i am|i'm)\s+([A-Z][a-z]+)", text, re.I)
            if m:
                args["name"] = m.group(1)

    # --- 3) Execute tool (optional) ---
    tool_result = None
    if tool:
        try:
            tool_result = dispatch_tool(tool, args)
        except Exception as e:
            tool_result = {"ok": False, "error": f"tool_error: {e!s}"}

    # --- 4) NLG (or fallback) ---
    try:
        reply = _nlg_fn(tool or "", tool_result or {}, text) if _nlg_fn else _fallback_nlg(tool or "", tool_result or {}, text)
    except Exception:
        reply = _fallback_nlg(tool or "", tool_result or {}, text)

    return {
        "intent": tool or "smalltalk",
        "slots": args,
        "tool_selected": tool,
        "tool_result": tool_result,
        "response": reply,
    }