"""
Stateful SAMHSA Treatment Locator chatbot.

Business logic: criteria extraction, search, response generation. No hallucination:
only real facility data is passed to the model. Conversation design matches
samhsa_chatbot_conversation_example.txt (greet/clarify → first results → follow-up → closing).
"""

import re
from typing import Any

from huggingface_hub import InferenceClient

from config import BASE_MODEL, HF_TOKEN, MY_MODEL
from src.facilities import get_facility_by_name, load_facilities, search

# --- Conversation state (criteria + last results for context) ---
DEFAULT_STATE = {
    "criteria": {},
    "last_results": [],
    "last_facility_detail": None,
    "selected_facility_name": None,
}

SYSTEM_PROMPT = """You are a supportive, non-judgmental assistant that helps people find substance use and mental health treatment facilities in the United States. You use ONLY the facility information provided to you in this conversation—never invent facility names, addresses, phone numbers, or details.

**Your Core Responsibilities:**
1. Help users articulate their treatment needs.
2. Search for matching facilities using their criteria.
3. Present results clearly with complete contact information.
4. Answer follow-up questions using ONLY the provided facility data.

**Conversation Flow:**

**Phase 1 - Greet & Clarify** (when no location given):
- Greet warmly and normalize the user's situation.
- Ask for: location (state/city), treatment type, payment option.
- Optionally ask about: substances (alcohol, opioids, etc.), special needs (veterans, LGBTQ+, pregnant women), therapies (MAT, CBT, 12-step), languages.
- **DO NOT SEARCH** until you have at least a location.

**Phase 2 - Present Results** (when you have location ± treatment type ± payment):
- Present 2-3 facilities numbered (1. 2. 3.) with FORMAT: **Facility Name** — Brief description. This ensures the user can reference them later.
- For EACH facility, include:
  - Phone number (so they can call immediately) and address (so they know where to go).
  - Key relevant details ONLY: payment accepted, languages spoken, specialties (MAT, CBT, etc.), populations served.
- Example: "1. **Boston Medical Center COPE** — Intensive outpatient for alcohol use. Phone: (617) 414-xxxx. Address: 1 BMC Place, Boston, MA. Payment: MassHealth/insurance. Languages: English, Spanish. MAT available."
- Ask: "Would you like more details on any of these, or different options?"

**Phase 3 - Follow-up** (answering questions about specific facilities):
- Answer questions ONLY from the facility data provided.
- If asked "Do they offer [service]?" or "Do they take [insurance]?" — check the Services/Payment fields and answer directly.
- Always provide phone and address for next steps.
- Example: "Yes, Boston Medical Center accepts MassHealth. You can call (617) 414-xxxx to schedule."

**Phase 4 - Closing** (when user is satisfied):
- Acknowledge their step toward treatment.
- Reinforce that calling is the next step.
- Encourage them to reach out anytime they need help.

**Critical Rules:**
- ⛔ NEVER invent facility names, phones, addresses, or services. If the data doesn't have it, don't say it.
- ⛔ Use phone numbers and addresses from the data ALWAYS when presenting facilities.
- ⛔ Do NOT give medical or clinical advice; stick to matching and logistics.
- ⛔ When no location is given, ask for it. Do NOT search without location.
- ✓ Keep responses brief, kind, and action-oriented.
- ✓ Use "Available facilities" or "Here are options:" to frame results clearly.
- ✓ When describing treatment type/payment/languages, pull directly from the Services field.

**Tone:**
Compassionate, clear, non-judgmental, and practical. Normalize substance use and mental health treatment.
"""


def _extract_criteria(text: str) -> dict[str, Any]:
    """Extract location, treatment_type, payment, mat, populations, languages, substances, therapies from user message."""
    text_lower = (text or "").lower().strip()
    criteria = {}

    # State / city patterns with explicit city mapping
    city_to_state_map = {
        "boston": ("Boston", "ma"),
        "austin": ("Austin", "tx"),
        "san antonio": ("San Antonio", "tx"),
        "chicago": ("Chicago", "il"),
        "san francisco": ("San Francisco", "ca"),
        "los angeles": ("Los Angeles", "ca"),
        "belmont": ("Belmont", "ma"),
        "roxbury": ("Roxbury", "ma"),
        "allston": ("Allston", "ma"),
    }
    
    # Check for explicit cities first
    for city_key, (city_name, state) in city_to_state_map.items():
        if city_key in text_lower:
            criteria["location"] = city_name
            criteria["state"] = state
            break
    
    # If no city matched, check for state patterns
    if "state" not in criteria:
        state_abbr = re.findall(r"\b(ma|mass|massachusetts|tx|texas|ca|california|il|illinois)\b", text_lower)
        if state_abbr:
            m = {"ma": "ma", "mass": "ma", "massachusetts": "ma", "tx": "tx", "texas": "tx", "ca": "ca", "california": "ca", "il": "il", "illinois": "il"}
            criteria["state"] = m.get(state_abbr[0], state_abbr[0])
    if not criteria.get("state") and not criteria.get("location"):
        # Generic "location" for short state abbrev
        two_letter = re.search(r"\b([a-z]{2})\b", text_lower)
        if two_letter and two_letter.group(1) in ("ma", "tx", "ca", "il"):
            criteria["state"] = two_letter.group(1)

    # Treatment type
    if any(w in text_lower for w in ["inpatient", "residential"]):
        criteria["treatment_type"] = "inpatient" if "inpatient" in text_lower else "residential"
    elif "outpatient" in text_lower:
        criteria["treatment_type"] = "outpatient"
    elif "telehealth" in text_lower:
        criteria["treatment_type"] = "telehealth"

    # Payment
    if "medicaid" in text_lower or "masshealth" in text_lower:
        criteria["payment"] = "Medicaid"
    if "insurance" in text_lower and "payment" not in criteria:
        criteria["payment"] = "insurance"
    if "sliding scale" in text_lower:
        criteria["payment"] = "sliding scale"
    if "free" in text_lower and "payment" not in criteria:
        criteria["payment"] = "free"
    if "veteran" in text_lower or "va " in text_lower:
        criteria["payment"] = "veterans"
        criteria["populations"] = "veterans"

    # MAT
    if "mat" in text_lower or "medication-assisted" in text_lower or "medication assisted" in text_lower:
        criteria["mat"] = True

    # Populations: veterans, adolescents, LGBTQ+, pregnant women
    if "veteran" in text_lower and "populations" not in criteria:
        criteria["populations"] = "veterans"
    if "adolescent" in text_lower or "youth" in text_lower:
        criteria["populations"] = "adolescents"
    if "lgbtq" in text_lower or "lgbt" in text_lower or "queer" in text_lower:
        criteria["populations"] = "LGBTQ+"
    if "pregnant" in text_lower or "pregnancy" in text_lower:
        criteria["populations"] = "pregnant women"

    # Languages
    if "spanish" in text_lower or "spanish-speaking" in text_lower or "spanish speaking" in text_lower:
        criteria["languages"] = "Spanish"
    if "vietnamese" in text_lower:
        criteria["languages"] = "Vietnamese"
    if "mandarin" in text_lower or "chinese" in text_lower:
        criteria["languages"] = "Mandarin"
    if "bilingual" in text_lower and "languages" not in criteria:
        criteria["languages"] = "Spanish"  # common with "bilingual" in this context

    # Substances
    if "alcohol" in text_lower:
        criteria["substances"] = "alcohol"
    if "opioid" in text_lower or "opioids" in text_lower:
        criteria["substances"] = "opioids"
    if "substance use" in text_lower or "substance abuse" in text_lower and "substances" not in criteria:
        criteria["substances"] = "substance use"

    # Therapies: CBT, 12-step (MAT handled above)
    if "cbt" in text_lower or "cognitive behavioral" in text_lower:
        criteria["therapies"] = "CBT"
    if "12-step" in text_lower or "12 step" in text_lower or "twelve step" in text_lower:
        criteria["therapies"] = "12-step"

    return criteria


def _merge_criteria(existing: dict, new: dict) -> dict:
    """Merge new criteria into existing; new values override."""
    out = dict(existing)
    for k, v in new.items():
        if v is not None and v != "":
            out[k] = v
    return out


def _format_facilities_for_prompt(facilities: list[dict]) -> str:
    """Format facility list for inclusion in system context (model must only use this)."""
    if not facilities:
        return "(No facilities in context. Do not name or describe any facility not listed here.)"
    lines = []
    for i, f in enumerate(facilities, 1):
        name = f.get("facility_name", "Unknown")
        desc = f.get("description", "") or f.get("services", "")
        addr = f.get("address", "")
        city = f.get("city", "")
        state = f.get("state", "")
        phone = (f.get("phone") or "").strip() or (f.get("phone_number") or "").strip()
        mat = f.get("mat", "")
        services = f.get("services", "")
        contact = f"Phone: {phone}. " if phone else "(No phone in data). "
        contact += f"Address: {addr}, {city}, {state}." if (addr or city or state) else ""
        parts = [f"{i}. {name} — {desc} Contact: {contact} MAT: {mat}. Services: {services}."]
        for key, label in (("payment_options", "Payment"), ("substances_addressed", "Substances"), ("languages", "Languages"), ("populations", "Populations")):
            val = f.get(key, "")
            if val and str(val).strip():
                parts.append(f" {label}: {val}.")
        lines.append("".join(parts))
    return "\n".join(lines)


def _detect_numeric_facility_selection(text: str, last_results: list[dict]) -> int | None:
    """If user is selecting by number (1, 2, 3, '1.', 'option 1', 'the first one'), return 1-based index or None."""
    if not last_results or not text or not text.strip():
        return None
    text_lower = text.strip().lower()
    # "1", "1.", "option 1", "the first one", "number 1"
    for i in range(1, min(len(last_results) + 1, 10)):
        if text_lower in (str(i), f"{i}.", f"option {i}", f"number {i}"):
            return i
        if i == 1 and text_lower in ("first", "the first", "the first one"):
            return 1
        if i == 2 and text_lower in ("second", "the second one"):
            return 2
        if i == 3 and text_lower in ("third", "the third one"):
            return 3
    return None


def _detect_facility_mention(text: str, last_results: list[dict]) -> str | None:
    """If user is asking about a specific facility, return a name fragment to look up."""
    if not last_results or not text or not text.strip():
        return None
    text_lower = text.lower()
    for f in last_results:
        name = (f.get("facility_name") or "").lower()
        if name and (name in text_lower or any(word in text_lower for word in name.split() if len(word) > 3)):
            return f.get("facility_name")
    # Common patterns: "the one at X", "Boston Medical Center", "AdCare"
    if "boston medical" in text_lower or "bmc" in text_lower or "cope" in text_lower:
        return "Boston Medical Center"
    if "adcare" in text_lower:
        return "AdCare"
    if "bay cove" in text_lower:
        return "Bay Cove"
    return None


class Chatbot:
    """
    Stateful chatbot: criteria extraction, search when location present, only real data to model.
    """

    def __init__(self):
        model_id = MY_MODEL if MY_MODEL else BASE_MODEL
        self.client = InferenceClient(model=model_id, token=HF_TOKEN)
        self._df = None  # cache for facilities

    def _get_df(self):
        if self._df is None:
            self._df = load_facilities()
        return self._df

    def get_response(
        self,
        message: str,
        history: list[list[str]] | None = None,
        state: dict | None = None,
    ) -> tuple[str, dict]:
        """
        Generate response and updated state. Use only this entrypoint from Gradio (or a future API).
        """
        state = state if state is not None else dict(DEFAULT_STATE)
        history = history or []
        criteria = state.get("criteria", {})
        last_results = state.get("last_results", [])
        last_facility_detail = state.get("last_facility_detail")
        selected_facility_name = state.get("selected_facility_name")

        # Extract criteria from current message and merge
        new_criteria = _extract_criteria(message)
        criteria = _merge_criteria(criteria, new_criteria)

        # Check if user is selecting by number (e.g. "1.", "2") — use existing last_results, don't re-run search
        num_sel = _detect_numeric_facility_selection(message, last_results)
        if num_sel is not None and 1 <= num_sel <= len(last_results):
            chosen = last_results[num_sel - 1]
            last_facility_detail = chosen
            selected_facility_name = chosen.get("facility_name") or chosen.get("name")
            context_data = "Current facility data (use ONLY this for your answer):\n" + _format_facilities_for_prompt([chosen])
        else:
            # Check if user is asking about a specific facility by name
            facility_mention = _detect_facility_mention(message, last_results)
            if facility_mention:
                single = get_facility_by_name(facility_mention, self._get_df())
                if single:
                    last_facility_detail = single
                    selected_facility_name = single.get("facility_name") or single.get("name")
                    context_data = "Current facility data (use ONLY this for your answer):\n" + _format_facilities_for_prompt([single])
                else:
                    context_data = "No matching facility found in data. Say you don't have details for that facility and offer to search again or clarify."
                    last_facility_detail = None
            else:
                last_facility_detail = None
                selected_facility_name = None
                # Run search when we have at least location
                has_location = bool(criteria.get("state") or criteria.get("location"))
                if has_location:
                    results = search(criteria, df=self._get_df(), limit=5)
                    last_results = results
                    context_data = "Current facility data (suggest ONLY these; do not invent any other facility):\n" + _format_facilities_for_prompt(results)
                else:
                    context_data = "No search has been run yet (user has not provided a location). Ask for state or city, and optionally treatment type, payment, substances, populations, therapies, and languages, before suggesting facilities."
                    selected_facility_name = state.get("selected_facility_name")  # preserve when no search

        # Build messages for API: system (with context) + history + current user
        system_content = SYSTEM_PROMPT + "\n\n" + context_data

        messages = [{"role": "system", "content": system_content}]
        for pair in history:
            if len(pair) >= 2:
                messages.append({"role": "user", "content": pair[0]})
                messages.append({"role": "assistant", "content": pair[1]})
        messages.append({"role": "user", "content": message})

        response = self.client.chat.completions.create(
            model=self.client.model,
            messages=messages,
            max_tokens=800,
            temperature=0.5,
        )
        raw = response.choices[0].message.content
        if isinstance(raw, list):
            reply = "".join(
                (b.get("text", "") if isinstance(b, dict) else str(b))
                for b in raw
            ).strip()
        else:
            reply = (raw or "").strip()

        # Return a copy of last_results so Gradio state updates reliably (map re-renders)
        results_for_state = list(last_results) if last_results else []
        detail_for_state = dict(last_facility_detail) if isinstance(last_facility_detail, dict) else last_facility_detail

        new_state = {
            "criteria": dict(criteria),
            "last_results": results_for_state,
            "last_facility_detail": detail_for_state,
            "selected_facility_name": selected_facility_name,
        }
        return reply, new_state