"""Chat/session API: start a one-shot session, send messages, finish + debrief."""
from __future__ import annotations

from flask import Blueprint, jsonify, request

from ..llm import LLMError
from ..services.simulator import Simulator
from .helpers import ApiError, current_user, require_auth, require_roles

chat_bp = Blueprint("chat", __name__)


def _stores():
    from flask import current_app

    return {
        "groups": current_app.extensions["group_store"],
        "sessions": current_app.extensions["session_store"],
        "llm": current_app.extensions["llm"],
    }


def _sim(group, persona):
    llm = _stores()["llm"]
    if not llm:
        raise ApiError("LLM not configured", 500)
    return Simulator(llm)


SCENARIOS = {
    "social": {
        "label": "Social Media",
        "init": "customer",
        "system_preamble": "💬 ช่องทาง ข้อความโซเชียล — ลูกค้าทักมาหาคุณก่อน (โทนสั้น ทักๆ ตามสไตล์แชท)",
        "adapt": "You are chatting on a social-messaging app (LINE-style). Keep replies SHORT, casual, and quick — one line to a few lines. The customer opened the chat.",
    },
    "f2f_call": {
        "label": "พบหน้า / โทรศัพท์",
        "init": "seller",
        "system_preamble": "📞 สถานการณ์ พบหน้าหรือโทรศัพท์ — คุณต้องเป็นฝ่ายเปิดการสนทนาเชิงรุกกับลีด (lead)",
        "adapt": "This is a face-to-face or phone sales situation. You must sound natural and conversational like a live talk. The seller will open — you are the lead they are reaching out to.",
    },
    "recontact": {
        "label": "ลูกค้ากลับมาติดต่อ (เคยได้ข้อมูล 1-3 เดือน)",
        "init": "customer",
        "system_preamble": "⏳ 1-3 เดือนผ่านไป... ลูกค้าคนนี้เคยได้รับข้อมูลสินค้าไปแล้ว ตอนนี้กลับมาติดต่อคุณอีกครั้ง (พร้อมตัดสินใจมากขึ้น)",
        "adapt": "This customer researched you 1-3 months ago. They have already read about the product and are now more ready to decide. They re-contacted you on a messaging channel. Keep replies natural and fairly concise.",
    },
}


def _scenario_config(scenario: str, persona: dict):
    cfg = SCENARIOS.get(scenario, SCENARIOS["social"])
    return cfg, cfg["init"]


def _build_abbrev_debrief(outcome: str, persona: dict, internal: dict) -> dict:
    """Build a lightweight debrief from the persona's own decision + per-turn signals
    (no extra LLM judge call needed since the persona chose to buy/walk)."""
    signals = internal.get("signals", [])
    turning_points = [
        f"รอบที่ {sig['turn']}: ลูกค้า{'เริ่มใจขึ้น' if sig['mood'] > 0 else 'เริ่มหงุดหงิด/ลังเล'}"
        for sig in signals if sig.get("type") in ("annoy", "warm")
    ]
    why = (
        "ลูกค้าตัดสินใจซื้อ (แก้ปัญหาและยอมรับข้อเสนอแล้ว)"
        if outcome == "won"
        else "ลูกค้าตัดสินใจไม่ซื้อ — ยังไม่เห็นคุณค่าพอ หรือการตอบไม่ตรงความต้องการ"
    )
    return {
        "outcome": outcome,
        "score": 60 if outcome == "won" else 25,
        "pain": (persona.get("pains") or [{}])[0].get("description", "") if persona.get("pains") else "",
        "why": why,
        "failurePoints": [] if outcome == "won" else ["ปิดการขายไม่สำเร็จ", "ลูกค้าถอยก่อนตัดสินใจซื้อ"],
        "coaching": (
            ["ทำได้ดีมาก — ลูกค้าปิดการขายกับคุณ"]
            if outcome == "won"
            else turning_points + ["ลองถามความต้องการให้ลึกกว่าเดิม", "รับมือข้อโต้แย้งให้ตรงจุด"]
        ),
        "turning_points": turning_points,
        "signals": signals,
        "revealed_persona": {
            "pains": persona.get("pains", []),
            "income": persona.get("income", ""),
            "personality": persona.get("personality", ""),
            "budget": persona.get("budget", ""),
            "negotiation_levers": persona.get("negotiation_levers", []),
            "opener": persona.get("opener", ""),
            "background": persona.get("background", ""),
            "tolerance": persona.get("tolerance", 3),
        },
    }


def _get_ready_group(s, gid: str) -> dict:
    """Org-scoped group access for trainees + require ready status (IDOR defense)."""
    group = s["groups"].get_or_none(gid)
    if not group or group.get("status") != "ready":
        raise ApiError("group not ready", 404)
    actor = current_user()
    # super_admin can access any; otherwise owner (for personal groups) + same org.
    owner = group.get("owner_user_id")
    if actor.get("role") != "super_admin":
        if owner and owner != actor["id"]:
            raise ApiError("permission denied", 403)
        if group.get("org_id") != actor.get("org_id"):
            raise ApiError("permission denied", 403)
    return group


@chat_bp.post("/<gid>/personas/<pid>/chat/start")
@require_auth
@require_roles("user")
def start_session(gid: str, pid: str):
    s = _stores()
    group = _get_ready_group(s, gid)
    persona = s["groups"].get_persona(gid, pid)
    if not persona:
        raise ApiError("persona not found", 404)
    actor = current_user()
    # Scenario chosen by the trainee at chat start (not baked into the persona).
    body = request.get_json(silent=True) or {}
    scenario = (body.get("scenario") or "social").strip().lower()
    if scenario not in ("social", "f2f_call", "recontact"):
        scenario = "social"
    scenario_meta, init_mode = _scenario_config(scenario, persona)
    # One-shot: reject if already finished this persona
    try:
        session = s["sessions"].create(
            user_id=actor["id"], group_id=gid, persona_id=pid,
            persona_name=persona.get("name", "?"),
            persona_meta={
                "tier": persona.get("tier"),
                "initiation_mode": init_mode,
                "channel": persona.get("channel"),
                "scenario": scenario,
            },
        )
    except ValueError as exc:
        raise ApiError(str(exc), 400)

    s["sessions"].update(
        session["id"],
        scenario=scenario,
        internal={**(session.get("internal") or {}), "turns": 0, "score": 50, "signals": []},
    )
    sim = _sim(group, persona)
    # Seed messages: system note(s) then customer opener for customer-first scenarios.
    seeded = list(session.get("messages", []))
    if scenario_meta.get("system_preamble"):
        seeded.append({"role": "system", "text": scenario_meta["system_preamble"]})
    if init_mode == "customer":
        opener = persona.get("opener") or "Hi, I saw your product and had a question."
        seeded.append({"role": "customer", "text": opener})
    s["sessions"].update(session["id"], messages=seeded)
    sess = s["sessions"].get(session["id"])
    return jsonify({
        "session": sess,
        "initiation_mode": init_mode,
        "scenario": scenario,
        "scenario_meta": scenario_meta,
    })


@chat_bp.post("/<gid>/personas/<pid>/chat/send")
@require_auth
@require_roles("user")
def send_message(gid: str, pid: str):
    s = _stores()
    actor = current_user()
    session = s["sessions"].active_for_persona(actor["id"], pid)
    if not session or session.get("group_id") != gid:
        raise ApiError("no active session for this persona", 404)

    data = request.get_json(silent=True) or {}
    text = (data.get("text") or "").strip()
    if not text:
        raise ApiError("message is empty")
    if len(text) > 2000:
        raise ApiError("message too long")

    group = s["groups"].get_or_none(gid)
    persona = s["groups"].get_persona(gid, pid) if group else None
    if not group or not persona:
        raise ApiError("session context missing", 404)
    messages = list(session.get("messages", []))
    messages.append({"role": "seller", "text": text})
    scenario = session.get("scenario", "social") or "social"
    adapt = SCENARIOS.get(scenario, SCENARIOS["social"]).get("adapt", "")

    sim = _sim(group, persona)
    try:
        reply, meta = sim.persona_reply(
            persona=persona,
            sales_kit=group.get("sales_kit") or {},
            messages=messages,
            internal=session.get("internal", {}),
            scenario=scenario,
            scenario_adapt=adapt,
        )
    except LLMError as exc:
        raise ApiError(f"LLM error: {exc}", 500)
    messages.append({"role": "customer", "text": reply})

    # Update internal state: track misses (poor answers) and mood trend.
    internal = session.get("internal", {}) or {}
    internal.setdefault("turns", 0)
    internal["turns"] = internal.get("turns", 0) + 1
    internal["signals"] = internal.get("signals", [])
    try:
        mood = int(meta.get("mood", 0))
    except (TypeError, ValueError):
        mood = 0
    # A clearly annoyed customer is a "miss" against the seller.
    if mood <= -1:
        internal["misses"] = internal.get("misses", 0) + 1
        internal["signals"].append({"turn": internal["turns"], "mood": mood, "type": "annoy"})
    elif mood >= 1:
        internal["signals"].append({"turn": internal["turns"], "mood": mood, "type": "warm"})

    # Decision by the persona ends the session (one-shot lock).
    decision = meta.get("decision")
    if decision in ("buy", "walk"):
        outcome = "won" if decision == "buy" else "lost"
        debrief = _build_abbrev_debrief(outcome, persona, internal)
        s["sessions"].update(
            session["id"],
            status="finished",
            outcome=outcome,
            messages=messages,
            internal=internal,
            debrief=debrief,
        )
        return jsonify({
            "reply": reply,
            "messages": messages,
            "finished": True,
            "outcome": outcome,
            "debrief": debrief,
            "session": s["sessions"].get(session["id"]),
        })

    s["sessions"].update(session["id"], messages=messages, internal=internal)
    return jsonify({"reply": reply, "messages": messages})


@chat_bp.post("/<gid>/personas/<pid>/chat/finish")
@require_auth
@require_roles("user")
def finish_session(gid: str, pid: str):
    """End the chat and produce the debrief via the judge-LLM (reveals latent fields)."""
    s = _stores()
    actor = current_user()
    session = s["sessions"].active_for_persona(actor["id"], pid)
    if not session or session.get("group_id") != gid:
        raise ApiError("no active session for this persona", 404)
    group = s["groups"].get_or_none(gid)
    persona = s["groups"].get_persona(gid, pid)

    sim = _sim(group, persona)
    messages = session.get("messages", [])
    try:
        verdict = sim.judge(
            persona=persona, messages=messages, internal=session.get("internal", {})
        )
    except LLMError as exc:
        raise ApiError(f"LLM error: {exc}", 500)

    outcome = "won" if verdict.get("outcome") == "won" else "lost"
    debrief = {
        **verdict,
        "revealed_persona": {
            "pains": persona.get("pains", []),
            "income": persona.get("income", ""),
            "personality": persona.get("personality", ""),
            "budget": persona.get("budget", ""),
            "negotiation_levers": persona.get("negotiation_levers", []),
            "opener": persona.get("opener", ""),
            "background": persona.get("background", ""),
        },
    }
    s["sessions"].update(
        session["id"],
        status="finished",
        outcome=outcome,
        debrief=debrief,
        internal=session.get("internal", {}),
    )
    return jsonify({"session": s["sessions"].get(session["id"]), "debrief": debrief})


@chat_bp.get("/sessions")
@require_auth
def my_sessions():
    s = _stores()
    uid = current_user()["id"]
    sessions = s["sessions"].list_for_user(uid)
    return jsonify({"sessions": sessions})


@chat_bp.get("/sessions/<sid>")
@require_auth
@require_roles("user")
def get_session(sid: str):
    s = _stores()
    session = s["sessions"].get_or_none(sid)
    if not session or session.get("user_id") != current_user()["id"]:
        raise ApiError("session not found", 404)
    return jsonify({"session": session})


@chat_bp.get("/<gid>/personas/<pid>/chat/resume")
@require_auth
@require_roles("user")
def resume_session(gid: str, pid: str):
    """Resume an active (unfinished) session for this persona so the trainee can continue."""
    s = _stores()
    actor = current_user()
    session = s["sessions"].active_for_persona(actor["id"], pid)
    if not session or session.get("group_id") != gid:
        raise ApiError("no active session for this persona", 404)
    return jsonify({"session": session, "scenario": session.get("scenario", "social")})