dashboard/api.py

"""
Dashboard API router for Parlay.
Provides REST endpoints for the frontend game interface.
Mounted at /api in main.py.
"""
import asyncio
import json
import logging
import os
import uuid
from pathlib import Path
from typing import Any, Optional

import numpy as np
from fastapi import APIRouter, HTTPException
from fastapi.responses import StreamingResponse
from pydantic import BaseModel

from agent.gemini_client import MODEL_ID_DEMO, call_gemini
from agent.gemini_client import validate_ai_offer_direction
from agent.personas import PERSONAS, build_system_prompt
from agent.tom_tracker import ToMTracker
from game.leaderboard import Leaderboard
from game.scenarios import SCENARIOS, get_scenario
from game.tactical_cards import TACTICAL_CARDS, get_card
from parlay_env.exceptions import InvalidPersonaError, InvalidScenarioError
from parlay_env.game_theory import compute_nash_bargaining_solution, compute_zopa
from parlay_env.grader import detect_bluff_challenge, grade_episode
from parlay_env.models import BeliefState, HiddenState, ParlayAction, ParlayState, PersonaType, TacticalMove
from parlay_env.reward import (
    PSI,
    ZOPA_EROSION_CONSECUTIVE_TURNS,
    ZOPA_EROSION_RATE,
    ZOPA_EROSION_TENSION_THRESHOLD,
)

logger = logging.getLogger(__name__)
router = APIRouter(prefix="/api", tags=["Dashboard"])

_leaderboard = Leaderboard()

CP_START = 100
CP_REGEN = 5
MAX_TURNS = 20

_sessions: dict[str, dict[str, Any]] = {}

# Opponent backend for /api/game/move: "gemini" (default) or "trained" (HF_MODEL_REPO + Qwen)
OPPONENT_MODE: str = "gemini"
_RESULTS_DIR = Path("results")
_IMAGES_DIR = Path("images")
_CP_COSTS: dict[TacticalMove, int] = {
    TacticalMove.ANCHOR_HIGH: 0,
    TacticalMove.BATNA_REVEAL: 20,
    TacticalMove.SILENCE: 5,
}


class StartRequest(BaseModel):
    scenario_id: str
    persona: str
    player_name: str = "Player"


class MoveRequest(BaseModel):
    session_id: str
    amount: Optional[float] = None
    message: str = ""
    tactical_move: Optional[str] = None


class AcceptRequest(BaseModel):
    session_id: str


class WalkAwayRequest(BaseModel):
    session_id: str


class GameStepRequest(BaseModel):
    session_id: str
    move: str = "counter"
    offer_amount: Optional[float] = None
    card_id: Optional[str] = None
    message: str = ""


class SessionStartRequest(BaseModel):
    scenario_id: str = "saas_enterprise"
    persona: str = "shark"
    player_name: str = "Player"


class SessionStepRequest(BaseModel):
    amount: float = 145_000.0
    message: str = "I propose this amount."
    tactical_move: Optional[str] = None


class SetOpponentRequest(BaseModel):
    model: str  # "trained" | "gemini"


class ModelChatMessage(BaseModel):
    role: str  # "user" | "assistant"
    text: str


class ModelChatRequest(BaseModel):
    message: str
    scenario_id: str = "saas_enterprise"
    persona: str = "shark"
    history: list[ModelChatMessage] = []
    temperature: float = 0.7
    max_tokens: int = 300


def _get_tension(state: ParlayState, player_move: Optional[TacticalMove], opponent_move: Optional[TacticalMove]) -> float:
    base = 20.0 + ((state.step_count + 1) / MAX_TURNS) * 55.0
    if player_move == TacticalMove.ANCHOR_HIGH or opponent_move == TacticalMove.ANCHOR_HIGH:
        base += 15.0
    if player_move == TacticalMove.BATNA_REVEAL or opponent_move == TacticalMove.BATNA_REVEAL:
        base += 10.0
    if player_move == TacticalMove.SILENCE or opponent_move == TacticalMove.SILENCE:
        base += 5.0
    return float(max(0.0, min(100.0, base)))


def _serialise_cards() -> list[dict[str, Any]]:
    return [
        {
            "id": card.id,
            "move": card.id,
            "name": card.name,
            "cp_cost": card.cp_cost,
            "description": card.description,
            "theory": card.theory,
            "game_theory_ref": card.game_theory_ref,
        }
        for card in TACTICAL_CARDS.values()
    ]


def _build_observation(
    state: ParlayState,
    opponent_offer: Optional[float] = None,
    last_utterance: str = "",
    reward: float = 0.0,
    drift_event: Optional[str] = None,
) -> dict[str, Any]:
    zopa = compute_zopa(state.hidden_state.budget_ceiling, state.hidden_state.walk_away_price)
    zopa_lower = zopa[0] if zopa else state.hidden_state.walk_away_price
    zopa_upper = zopa[1] if zopa else state.hidden_state.budget_ceiling
    nash = compute_nash_bargaining_solution(state.hidden_state.budget_ceiling, state.hidden_state.walk_away_price)
    belief = state.belief_history[-1]
    current_offer = state.offer_history[-1] if state.offer_history else 0.0
    return {
        "step_count": state.step_count,
        "episode_done": state.episode_done,
        "current_offer": current_offer,
        "opponent_offer": opponent_offer,
        "zopa_lower": zopa_lower,
        "zopa_upper": zopa_upper,
        "nash_point": nash,
        "tension_score": state.tension_score,
        "belief_state": belief.model_dump(),
        "last_utterance": last_utterance,
        "available_moves": [move.value for move in TacticalMove],
        "credibility_points": state.credibility_points,
        "reward": reward,
        "cumulative_reward": state.cumulative_reward,
        "drift_event": drift_event,
        "zopa_erosion_ticks": state.zopa_erosion_ticks,
        "zopa_width_pct_remaining": state.zopa_width_pct_remaining,
        "session_id": state.session_id,
    }


def _build_session(scenario_id: str, persona_str: str, player_name: str) -> tuple[str, dict[str, Any]]:
    scenario = get_scenario(scenario_id)
    try:
        persona_type = PersonaType(persona_str)
    except ValueError as exc:
        raise InvalidPersonaError(
            f"Invalid persona: {persona_str!r}. Valid: {[p.value for p in PersonaType]}"
        ) from exc

    session_id = str(uuid.uuid4())
    rng = np.random.default_rng(hash(session_id) % 10000)
    noise = float(rng.uniform(0.95, 1.05))
    hidden = HiddenState(
        budget_ceiling=round(scenario.batna_buyer * noise, 2),
        walk_away_price=round(scenario.batna_seller * noise, 2),
        urgency_score=float(np.clip(0.5 + rng.uniform(-0.15, 0.15), 0.0, 1.0)),
        has_alternative=scenario.id in ("saas_enterprise", "acquisition_term_sheet"),
        persona_drifted=False,
    )
    initial_belief = BeliefState(
        est_budget=hidden.budget_ceiling * 0.80,
        est_walk_away=hidden.walk_away_price * 1.15,
        est_urgency=0.50,
        est_has_alternative=False,
        confidence=0.30,
    )
    tom = ToMTracker(initial_belief, persona_type)
    state = ParlayState(
        session_id=session_id,
        scenario_id=scenario_id,
        persona=persona_type,
        step_count=0,
        cumulative_reward=0.0,
        hidden_state=hidden,
        belief_history=[initial_belief],
        offer_history=[],
        drift_events_fired=0,
        episode_done=False,
        credibility_points=CP_START,
        original_zopa_width=scenario.batna_buyer - scenario.batna_seller,
        zopa_width_pct_remaining=1.0,
    )
    system_prompt = build_system_prompt(
        persona=persona_type,
        scenario_id=scenario_id,
        scenario_title=scenario.title,
        scenario_description=scenario.description,
        batna=hidden.walk_away_price,
        budget=hidden.budget_ceiling,
        urgency=hidden.urgency_score,
    )
    return session_id, {
        "session_id": session_id,
        "player_name": player_name,
        "scenario": scenario,
        "state": state,
        "tom_tracker": tom,
        "system_prompt": system_prompt,
        "conversation": [],
        "drift_turn": None,
        "drift_adapted": False,
        "last_opponent_offer": None,
        "last_opponent_move": None,
    }


def get_session(session_id: str) -> dict[str, Any] | None:
    return _sessions.get(session_id)


def _apply_zopa_erosion(state: ParlayState) -> None:
    if state.tension_score >= ZOPA_EROSION_TENSION_THRESHOLD:
        state.high_tension_streak += 1
    else:
        state.high_tension_streak = 0

    if state.high_tension_streak >= ZOPA_EROSION_CONSECUTIVE_TURNS:
        zopa_width = state.hidden_state.budget_ceiling - state.hidden_state.walk_away_price
        base_width = state.original_zopa_width or zopa_width
        shift = base_width * ZOPA_EROSION_RATE
        state.hidden_state.budget_ceiling -= shift
        state.hidden_state.walk_away_price += shift
        state.zopa_erosion_ticks += 1
        state.high_tension_streak = 0

        if state.hidden_state.budget_ceiling <= state.hidden_state.walk_away_price:
            state.walk_away = True
            state.termination_reason = "zopa_collapsed"

    current_zopa = max(0.0, state.hidden_state.budget_ceiling - state.hidden_state.walk_away_price)
    state.zopa_width_pct_remaining = (
        current_zopa / state.original_zopa_width if state.original_zopa_width > 0 else 0.0
    )


def _apply_drift(session: dict[str, Any]) -> Optional[str]:
    state: ParlayState = session["state"]
    scenario = session["scenario"]
    for event in scenario.drift_events:
        if event.trigger_turn == state.step_count:
            session["drift_turn"] = state.step_count
            state.drift_events_fired += 1
            session["tom_tracker"].drift_event(
                event.effect_on_urgency,
                event.effect_on_has_alternative,
                event_description=event.event,
            )
            state.belief_history = list(session["tom_tracker"].history)
            logger.info(
                "Drift event fired: scenario=%s turn=%d event=%r urgency_delta=%+.2f",
                state.scenario_id, state.step_count, event.event, event.effect_on_urgency,
            )
            return event.event
    return None


@router.get("/scenarios")
async def list_scenarios() -> dict:
    """List all available negotiation scenarios."""
    return {
        "scenarios": [
            {
                "id": s.id,
                "title": s.title,
                "description": s.description,
                "currency": s.currency,
                "unit": s.unit,
                "zopa_lower": s.zopa[0],
                "zopa_upper": s.zopa[1],
                "anchor_seller": s.anchor_seller,
                "anchor_buyer": s.anchor_buyer,
                "difficulty": s.difficulty,
                "drift_count": len(s.drift_events),
            }
            for s in SCENARIOS.values()
        ]
    }


@router.get("/personas")
async def list_personas() -> dict:
    """List all available negotiator personas."""
    return {
        "personas": [
            {
                "id": pt.value,
                "name": cfg.name,
                "symbol": cfg.symbol,
                "emoji": cfg.emoji,
                "aggression": cfg.aggression,
                "patience": cfg.patience,
                "bluff_rate": cfg.bluff_rate,
                "tom_depth": cfg.tom_depth,
                "color_var": cfg.color_var,
                "opening_line": cfg.opening_line,
            }
            for pt, cfg in PERSONAS.items()
        ]
    }


def _training_status_payload() -> dict[str, Any]:
    """Build JSON for GET /api/training-status."""
    eval_path = _RESULTS_DIR / "eval_results.json"
    grpo: float | None = None
    base: float | None = None
    sft: float | None = None
    rnd: float | None = None
    has_results = False
    if eval_path.is_file():
        try:
            raw = json.loads(eval_path.read_text(encoding="utf-8"))
            has_results = True
            grpo = raw.get("grpo_mean_reward")
            base = raw.get("base_mean_reward")
            sft = raw.get("sft_mean_reward")
            rnd = raw.get("random_mean_reward")
            if grpo is not None:
                grpo = float(grpo)
            if base is not None:
                base = float(base)
            if sft is not None:
                sft = float(sft)
            if rnd is not None:
                rnd = float(rnd)
        except Exception:  # noqa: BLE001
            has_results = False
    if rnd is None and eval_path.is_file():
        for baseline_path in (
            _RESULTS_DIR / "random_baseline.json",
            _RESULTS_DIR / "baseline.json",
        ):
            if not baseline_path.is_file():
                continue
            try:
                blob = json.loads(baseline_path.read_text(encoding="utf-8"))
                v = blob.get("mean_reward")
                if v is None:
                    v = blob.get("avg_reward")
                if v is not None:
                    rnd = float(v)
                    break
            except Exception:  # noqa: BLE001
                continue
    repo = (os.environ.get("HF_MODEL_REPO") or "").strip() or None

    sft_loss_path: str | None = None
    if (_IMAGES_DIR / "sft_loss_curve.png").is_file():
        sft_loss_path = "/images/sft_loss_curve.png"
    elif (_RESULTS_DIR / "sft_loss_curve.png").is_file():
        sft_loss_path = "/results/sft_loss_curve.png"

    grpo_reward_url: str | None = None
    if (_IMAGES_DIR / "grpo_reward_curve.png").is_file():
        grpo_reward_url = "/images/grpo_reward_curve.png"
    elif (_RESULTS_DIR / "grpo_reward_curve.png").is_file():
        grpo_reward_url = "/results/grpo_reward_curve.png"

    grpo_loss_url: str | None = None
    if (_IMAGES_DIR / "grpo_loss_curve.png").is_file():
        grpo_loss_url = "/images/grpo_loss_curve.png"
    elif (_RESULTS_DIR / "grpo_loss_curve.png").is_file():
        grpo_loss_url = "/results/grpo_loss_curve.png"

    comparison_url: str | None = None
    if (_RESULTS_DIR / "training_curves.png").is_file():
        comparison_url = "/results/training_curves.png"
    elif (_IMAGES_DIR / "training_curves.png").is_file():
        comparison_url = "/images/training_curves.png"
    elif (_IMAGES_DIR / "comparison.png").is_file():
        comparison_url = "/images/comparison.png"

    return {
        "has_results": has_results,
        "grpo_mean_reward": grpo,
        "sft_mean_reward": sft,
        "base_mean_reward": base,
        "random_mean_reward": rnd,
        "model_on_hub": bool(repo),
        "model_repo": repo,
        "sft_loss_url": sft_loss_path,
        "grpo_reward_url": grpo_reward_url,
        "grpo_loss_url": grpo_loss_url,
        "comparison_url": comparison_url,
        "plots_available": {
            "reward_curve": grpo_reward_url is not None,
            "grpo_loss": grpo_loss_url is not None,
            "comparison": comparison_url is not None,
            "transcript": (_RESULTS_DIR / "before_after_transcript.html").is_file(),
            "sft_loss": sft_loss_path is not None,
        },
    }


@router.get("/training-status")
async def get_training_status() -> dict:
    """Live stats and plot availability for the Training Results page."""
    return _training_status_payload()


# Default model ID for docs / judge UI (see openenv.yaml grpo_model)
GRPO_MODEL_REPO_DEFAULT = "sh4shv4t/parlay-grpo-1-5b"


@router.get("/judge-config")
async def get_judge_config() -> dict:
    """
    Status for the /judge page: whether Hub weights are configured and current opponent mode.
    """
    repo = (os.environ.get("HF_MODEL_REPO") or "").strip() or None
    return {
        "hf_model_configured": bool(repo),
        "model_repo": repo,
        "suggested_grpo_repo": GRPO_MODEL_REPO_DEFAULT,
        "opponent_mode": OPPONENT_MODE,
    }


@router.get("/model/info")
async def model_info() -> dict:
    """
    Status + metadata for the /interact page.
    Reports whether the GRPO Hub model is reachable and what repo is configured.
    """
    repo = (os.environ.get("HF_MODEL_REPO") or "").strip() or None
    fallback_repo = GRPO_MODEL_REPO_DEFAULT
    hub_url = f"https://huggingface.co/{repo or fallback_repo}"
    return {
        "configured": bool(repo),
        "model_repo": repo or fallback_repo,
        "hub_url": hub_url,
        "base_model": "Qwen/Qwen2.5-1.5B-Instruct",
        "training": "GRPO (TRL) on Parlay negotiation self-play episodes",
        "note": (
            "Model outputs structured JSON: utterance, optional offer_amount, optional tactical_move."
            if repo
            else (
                "HF_MODEL_REPO is not set — using the public fallback repo. "
                "Set HF_MODEL_REPO in Space secrets to enable local GPU inference."
            )
        ),
    }


def _build_interact_system_prompt(scenario_id: str, persona: str) -> str:
    """Lightweight system prompt for the /interact page (no live game state)."""
    from agent.personas import PERSONAS
    from parlay_env.models import PersonaType

    try:
        pt = PersonaType(persona)
    except ValueError:
        pt = PersonaType.SHARK
    cfg = PERSONAS[pt]

    sc = get_scenario(scenario_id)
    mid = (sc.batna_seller + sc.batna_buyer) / 2

    return (
        f"You are {cfg.name} ({cfg.emoji}), an experienced negotiator.\n\n"
        f"SCENARIO: {sc.title}\n"
        f"{sc.description}\n"
        f"The deal range is roughly {sc.batna_seller:,.0f}–{sc.batna_buyer:,.0f} {sc.currency}.\n"
        f"You are negotiating from the opposing side, targeting around {mid:,.0f}.\n\n"
        f"YOUR STYLE:\n{cfg.style}\n\n"
        "RULES:\n"
        "- Stay in character at all times.\n"
        '- Respond ONLY with valid JSON: {"utterance": "...", "offer_amount": <number or null>, "tactical_move": <string or null>}\n'
        "- Keep utterances under 100 words.\n"
    )


async def _run_hf_inference(
    system_prompt: str,
    history: list[ModelChatMessage],
    message: str,
    temperature: float,
    max_tokens: int,
) -> dict[str, Any]:
    """Load the Hub model (via hf_opponent._sync_generate) and run inference."""
    from agent.hf_opponent import _sync_generate, _get_lock, _build_prompt, _parse_json_block  # noqa: PLC0415

    messages = []
    for h in history:
        role = "user" if h.role == "user" else "model"
        messages.append({"role": role, "parts": [h.text]})
    messages.append({"role": "user", "parts": [message]})

    loop = asyncio.get_event_loop()

    repo = (os.environ.get("HF_MODEL_REPO") or "").strip() or GRPO_MODEL_REPO_DEFAULT
    os.environ.setdefault("HF_MODEL_REPO", repo)

    result = await loop.run_in_executor(
        None,
        lambda: _sync_generate(system_prompt, messages, min(max_tokens, 512)),
    )
    return result


async def _run_hf_api_inference(
    system_prompt: str,
    history: list[ModelChatMessage],
    message: str,
    temperature: float,
    max_tokens: int,
    repo: str,
) -> dict[str, Any]:
    """
    Call the HF Inference API for the given repo.
    Tries the new /v1/chat/completions endpoint first, then falls back to the
    legacy text-generation endpoint.
    """
    import httpx  # noqa: PLC0415
    from agent.hf_opponent import _parse_json_block  # noqa: PLC0415

    token = os.environ.get("HF_TOKEN", "")
    headers = {"Authorization": f"Bearer {token}"} if token else {}

    # Build chat messages for /v1/chat/completions
    chat_msgs = [{"role": "system", "content": system_prompt}]
    for h in history:
        chat_msgs.append({"role": h.role, "content": h.text})
    chat_msgs.append({"role": "user", "content": message})

    url = f"https://api-inference.huggingface.co/models/{repo}/v1/chat/completions"
    payload = {
        "model": repo,
        "messages": chat_msgs,
        "max_tokens": min(max_tokens, 512),
        "temperature": temperature,
    }

    async with httpx.AsyncClient(timeout=120.0) as client:
        resp = await client.post(url, json=payload, headers=headers)
        if resp.status_code == 200:
            data = resp.json()
            raw = data["choices"][0]["message"]["content"]
            return _parse_json_block(raw)
        # Legacy text-generation endpoint
        legacy_url = f"https://api-inference.huggingface.co/models/{repo}"
        # Format as ChatML for Qwen
        eot = "<|im_end|>"
        prompt_parts = [f"<|im_start|>system\n{system_prompt}\n{eot}\n"]
        for h in history:
            r = "user" if h.role == "user" else "assistant"
            prompt_parts.append(f"<|im_start|>{r}\n{h.text}\n{eot}\n")
        prompt_parts.append(f"<|im_start|>user\n{message}\n{eot}\n")
        prompt_parts.append(
            "<|im_start|>assistant\n"
            'Respond ONLY with valid JSON: {"utterance": "...", "offer_amount": <number or null>, "tactical_move": <string or null>}\n'
        )
        legacy_payload = {
            "inputs": "".join(prompt_parts),
            "parameters": {"max_new_tokens": min(max_tokens, 256), "temperature": temperature, "return_full_text": False},
        }
        resp2 = await client.post(legacy_url, json=legacy_payload, headers=headers)
        resp2.raise_for_status()
        data2 = resp2.json()
        raw2 = data2[0]["generated_text"] if isinstance(data2, list) else str(data2)
        return _parse_json_block(raw2)


@router.post("/model/chat")
async def model_chat(req: ModelChatRequest) -> dict:
    """
    Direct inference against the GRPO-finetuned negotiation model.
    Used by the /interact page for free-form chat with the model.
    Strategy:
      1. If torch + model weights are loadable locally (GPU Space), load and run.
      2. Otherwise hit the HF Inference API (works on CPU Spaces, may have cold-start).
    """
    try:
        scenario = get_scenario(req.scenario_id)
    except InvalidScenarioError:
        raise HTTPException(status_code=400, detail=f"Unknown scenario: {req.scenario_id!r}")

    valid_personas = {"shark", "diplomat", "veteran"}
    if req.persona not in valid_personas:
        raise HTTPException(status_code=400, detail=f"Unknown persona: {req.persona!r}")

    system_prompt = _build_interact_system_prompt(req.scenario_id, req.persona)
    repo = (os.environ.get("HF_MODEL_REPO") or "").strip() or GRPO_MODEL_REPO_DEFAULT

    # Attempt 1 — local model (fast on GPU Spaces, slow on CPU)
    try:
        import torch  # noqa: PLC0415
        result = await _run_hf_inference(
            system_prompt, req.history, req.message, req.temperature, req.max_tokens
        )
        return {
            "utterance": result.get("utterance", ""),
            "offer_amount": result.get("offer_amount"),
            "tactical_move": result.get("tactical_move"),
            "backend": "local",
            "model_repo": repo,
        }
    except Exception as local_exc:
        logger.info("Local inference unavailable, trying HF API: %s", local_exc)

    # Attempt 2 — HF Inference API (no GPU needed)
    try:
        result = await _run_hf_api_inference(
            system_prompt, req.history, req.message, req.temperature, req.max_tokens, repo
        )
        return {
            "utterance": result.get("utterance", ""),
            "offer_amount": result.get("offer_amount"),
            "tactical_move": result.get("tactical_move"),
            "backend": "hf_api",
            "model_repo": repo,
        }
    except Exception as api_exc:
        logger.warning("HF API inference failed: %s", api_exc)
        raise HTTPException(
            status_code=503,
            detail=(
                f"Model inference failed on both local and HF API backends. "
                f"Model: {repo}. Error: {api_exc}"
            ),
        )


@router.post("/set-opponent")
async def set_opponent(req: SetOpponentRequest) -> dict:
    """
    Switch dashboard game opponent between Gemini and the HF causal model
    (requires HF_MODEL_REPO when model is \"trained\").
    """
    global OPPONENT_MODE
    m = (req.model or "").strip().lower()
    if m not in ("trained", "gemini"):
        raise HTTPException(
            status_code=400,
            detail='model must be "trained" or "gemini"',
        )
    if m == "trained" and not (os.environ.get("HF_MODEL_REPO") or "").strip():
        raise HTTPException(
            status_code=400,
            detail="HF_MODEL_REPO is not set — cannot use trained opponent",
        )
    OPPONENT_MODE = m
    logger.info("Opponent mode set to: %s", OPPONENT_MODE)
    return {"ok": True, "mode": OPPONENT_MODE}


@router.post("/game/start")
async def start_game(req: StartRequest) -> dict:
    """Start a new negotiation session."""
    try:
        session_id, session = _build_session(req.scenario_id, req.persona, req.player_name)
    except (InvalidScenarioError, InvalidPersonaError) as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc

    _sessions[session_id] = session
    scenario = session["scenario"]
    state: ParlayState = session["state"]
    persona_cfg = PERSONAS[state.persona]

    return {
        "session_id": session_id,
        "scenario": {
            "id": scenario.id,
            "title": scenario.title,
            "description": scenario.description,
            "currency": scenario.currency,
            "unit": scenario.unit,
            "anchor_seller": scenario.anchor_seller,
            "anchor_buyer": scenario.anchor_buyer,
        },
        "observation": _build_observation(state),
        "persona": {
            "id": req.persona,
            "name": persona_cfg.name,
            "symbol": persona_cfg.symbol,
            "emoji": persona_cfg.emoji,
            "color_var": persona_cfg.color_var,
            "opening_line": persona_cfg.opening_line,
        },
        "hand": _serialise_cards(),
        "opening_message": persona_cfg.opening_line,
    }


@router.post("/game/move")
async def make_move(req: MoveRequest) -> dict:
    """Submit a negotiation move and get the opponent's response."""
    session = get_session(req.session_id)
    if session is None:
        raise HTTPException(status_code=404, detail="Session not found")

    state: ParlayState = session["state"]
    if state.episode_done:
        raise HTTPException(status_code=400, detail="Episode already concluded")

    if req.amount is None and not (req.message or "").strip() and not req.tactical_move:
        raise HTTPException(
            status_code=400,
            detail="Provide a message, a numeric offer, or a tactical move.",
        )

    move: Optional[TacticalMove] = None
    if req.tactical_move:
        try:
            move = TacticalMove(req.tactical_move)
        except ValueError as exc:
            raise HTTPException(
                status_code=400,
                detail=f"Invalid tactical_move: {req.tactical_move!r}. Valid: {[m.value for m in TacticalMove]}",
            ) from exc

    cost = _CP_COSTS.get(move, 0)
    if state.credibility_points < cost:
        raise HTTPException(
            status_code=400,
            detail=f"Insufficient CP: need {cost}, have {state.credibility_points}",
        )

    drift_event_desc = _apply_drift(session)
    turn = state.step_count
    gemini_messages = []
    for msg in session["conversation"][-8:]:
        role = "user" if msg["role"] == "player" else "model"
        gemini_messages.append({"role": role, "parts": [msg["text"]]})

    if req.amount is not None:
        player_text = f"Player offer: {req.amount:,.0f}. Message: {req.message}"
    else:
        player_text = f"Player message (no new numeric offer on this turn): {req.message or '(tactical or silence)'}"
    if req.tactical_move:
        player_text += f" [Playing card: {req.tactical_move}]"
    gemini_messages.append({"role": "user", "parts": [player_text]})

    player_offer_for_validation = (
        req.amount
        if req.amount is not None
        else (state.offer_history[-1] if state.offer_history else None)
    )

    use_trained = OPPONENT_MODE == "trained" and (os.environ.get("HF_MODEL_REPO") or "").strip()
    if use_trained:
        try:
            from agent.hf_opponent import call_hf_opponent

            opponent_resp = await call_hf_opponent(
                session["system_prompt"],
                gemini_messages,
                max_tokens=500,
                persona=state.persona.value,
                scenario_id=state.scenario_id,
            )
        except Exception as exc:  # noqa: BLE001
            logger.warning("HF opponent failed, falling back to Gemini: %s", exc)
            opponent_resp = await call_gemini(
                session["system_prompt"],
                gemini_messages,
                persona=state.persona.value,
                model=MODEL_ID_DEMO,
                scenario_id=state.scenario_id,
            )
    else:
        opponent_resp = await call_gemini(
            session["system_prompt"],
            gemini_messages,
            persona=state.persona.value,
            model=MODEL_ID_DEMO,
            scenario_id=state.scenario_id,
        )
    opponent_utterance = opponent_resp.get("utterance", "Let me think about that...")
    raw_opp = opponent_resp.get("offer_amount")
    opponent_offer: Optional[float] = None
    if raw_opp is not None:
        try:
            opponent_offer = float(raw_opp)
        except (TypeError, ValueError):
            opponent_offer = None
    if opponent_offer is not None:
        opponent_offer = validate_ai_offer_direction(
            opponent_offer, player_offer_for_validation, state.scenario_id
        )
    opponent_move: Optional[TacticalMove] = None
    try:
        if opponent_resp.get("tactical_move"):
            opponent_move = TacticalMove(opponent_resp["tactical_move"])
    except ValueError:
        opponent_move = None

    session["conversation"].append(
        {"role": "player", "text": req.message, "offer": req.amount, "move": req.tactical_move, "turn": turn + 1}
    )
    session["conversation"].append(
        {"role": "opponent", "text": opponent_utterance, "offer": opponent_offer, "move": opponent_resp.get("tactical_move"), "turn": turn + 1}
    )

    if opponent_move == TacticalMove.BATNA_REVEAL:
        state.hidden_state.last_stated_batna = (
            float(opponent_offer) if opponent_offer is not None else state.hidden_state.walk_away_price * 1.2
        )

    updated_belief = session["tom_tracker"].update(
        observed_offer=opponent_offer,
        observed_move=opponent_move,
        utterance=opponent_utterance,
        turn=turn,
    )

    if session["drift_turn"] is not None and not session["drift_adapted"]:
        adaptation_signals = ["understand", "noted", "given", "considering", "account"]
        matched_signal = next(
            (s for s in adaptation_signals if s in req.message.lower()), None
        )
        if turn <= session["drift_turn"] + 2 and matched_signal:
            session["drift_adapted"] = True
            logger.info(
                "drift_adapted=True session=%s turn=%d matched_phrase=%r snippet=%r",
                req.session_id, turn + 1, matched_signal, req.message[:80],
            )

    new_history = list(state.offer_history)
    if req.amount is not None:
        new_history.append(req.amount)

    next_state = ParlayState(
        **{
            **state.model_dump(),
            "step_count": state.step_count + 1,
            "offer_history": new_history,
            "belief_history": list(session["tom_tracker"].history),
            "credibility_points": min(CP_START, state.credibility_points + CP_REGEN - cost),
        }
    )
    next_state.tension_score = _get_tension(state, move, opponent_move)
    _apply_zopa_erosion(next_state)

    pe = player_offer_for_validation
    if opponent_offer is not None and pe is not None:
        if abs(pe - opponent_offer) / max(abs(pe), 1.0) < 0.03:
            next_state.deal_reached = True
            next_state.termination_reason = "deal_reached"

    utterance = req.message or (f"[Tactical: {req.tactical_move}]" if req.tactical_move else "…")
    action = ParlayAction(utterance=utterance, offer_amount=req.amount, tactical_move=move)
    step_reward = (
        next_state.credibility_points - state.credibility_points
    ) * 0.0  # placeholder to keep local scope explicit
    from parlay_env.grader import compute_step_reward  # noqa: PLC0415

    step_reward = compute_step_reward(state, action, next_state)
    if (
        state.hidden_state.last_stated_batna is not None
        and move is None
        and detect_bluff_challenge(req.message, state.hidden_state.last_stated_batna, state.hidden_state.budget_ceiling)
    ):
        next_state.bluffs_caught = state.bluffs_caught + 1
        step_reward = max(step_reward, PSI)

    next_state.cumulative_reward = state.cumulative_reward + step_reward
    next_state.episode_done = (
        next_state.step_count >= MAX_TURNS
        or step_reward < -100.0
        or next_state.deal_reached
        or next_state.walk_away
    )
    if next_state.episode_done and next_state.termination_reason is None:
        if next_state.walk_away:
            next_state.termination_reason = "zopa_collapsed"
        elif step_reward < -100.0:
            next_state.termination_reason = "reward_floor"
        else:
            next_state.termination_reason = "max_turns"

    session["state"] = next_state
    session["last_opponent_offer"] = opponent_offer
    session["last_opponent_move"] = opponent_move.value if opponent_move else None
    _sessions[req.session_id] = session

    return {
        "opponent": {
            "utterance": opponent_utterance,
            "offer": opponent_offer,
            "tactical_move": opponent_move.value if opponent_move else None,
        },
        "opponent_message": opponent_utterance,
        "opponent_move": opponent_move.value if opponent_move else None,
        "observation": _build_observation(
            next_state,
            opponent_offer=opponent_offer,
            last_utterance=opponent_utterance,
            reward=step_reward,
            drift_event=drift_event_desc,
        ),
        "drift_event": drift_event_desc,
        "done": next_state.episode_done,
        "turns_remaining": MAX_TURNS - next_state.step_count,
        "hand": _serialise_cards(),
    }


@router.post("/game/accept")
async def accept_deal(req: AcceptRequest) -> dict:
    """Accept the current offer and close the deal."""
    session = get_session(req.session_id)
    if session is None:
        raise HTTPException(status_code=404, detail="Session not found")

    state: ParlayState = session["state"]
    if state.episode_done:
        raise HTTPException(status_code=400, detail="Episode already concluded")
    if not state.offer_history and session["last_opponent_offer"] is None:
        raise HTTPException(status_code=400, detail="No offer to accept. Make an offer first.")

    final_price = session["last_opponent_offer"] or state.offer_history[-1]
    state.deal_reached = True
    state.episode_done = True
    state.termination_reason = "deal_accepted"
    grade = grade_episode(
        state,
        final_price=final_price,
        t_close=state.step_count,
        t_max=MAX_TURNS,
        drift_adapted=session["drift_adapted"],
        bluffs_caught=state.bluffs_caught,
    )

    await _leaderboard.record_result(
        player_name=session["player_name"],
        scenario_id=state.scenario_id,
        persona=state.persona.value,
        total_reward=grade.total_reward,
        deal_efficiency=grade.deal_efficiency,
        acts_completed=1,
        deal_closed=True,
    )

    session["state"] = state
    _sessions[req.session_id] = session
    nash = compute_nash_bargaining_solution(state.hidden_state.budget_ceiling, state.hidden_state.walk_away_price)
    zopa = compute_zopa(state.hidden_state.budget_ceiling, state.hidden_state.walk_away_price)
    zopa_width = (zopa[1] - zopa[0]) if zopa else 1.0

    return {
        "final_price": final_price,
        "total_reward": grade.total_reward,
        "deal_efficiency": grade.deal_efficiency,
        "tom_accuracy_avg": grade.tom_accuracy_avg,
        "nash_comparison": {
            "nash_point": nash,
            "your_deal": final_price,
            "delta_pct": round((final_price - nash) / max(zopa_width, 1) * 100, 1),
        },
        "grade": {
            "total_reward": grade.total_reward,
            "deal_efficiency": grade.deal_efficiency,
            "tom_accuracy_avg": grade.tom_accuracy_avg,
            "bluffs_caught": grade.bluffs_caught,
            "drift_adapted": grade.drift_adapted,
        },
    }


@router.post("/game/walkaway")
async def walk_away(req: WalkAwayRequest) -> dict:
    """Walk away from the negotiation without a deal."""
    session = get_session(req.session_id)
    if session is None:
        raise HTTPException(status_code=404, detail="Session not found")

    state: ParlayState = session["state"]
    if state.episode_done:
        raise HTTPException(status_code=400, detail="Episode already concluded")

    state.walk_away = True
    state.episode_done = True
    state.termination_reason = "walk_away"
    session["state"] = state
    _sessions[req.session_id] = session

    nash = compute_nash_bargaining_solution(state.hidden_state.budget_ceiling, state.hidden_state.walk_away_price)
    zopa = compute_zopa(state.hidden_state.budget_ceiling, state.hidden_state.walk_away_price)
    return {
        "result": "walk_away",
        "message": "You walked away. No deal recorded.",
        "counterfactual_optimal": nash,
        "zopa": {"lower": zopa[0] if zopa else 0, "upper": zopa[1] if zopa else 0},
        "termination_reason": state.termination_reason,
    }


@router.get("/leaderboard")
async def get_leaderboard(scenario_id: Optional[str] = None, limit: int = 10) -> dict:
    """Get the global or per-scenario leaderboard."""
    valid_scenarios = list(SCENARIOS.keys())
    if scenario_id and scenario_id not in valid_scenarios:
        raise HTTPException(status_code=400, detail=f"Invalid scenario_id. Valid: {valid_scenarios}")
    entries = await _leaderboard.get_top(scenario_id=scenario_id, limit=min(limit, 50))
    return {"entries": entries, "scenario_id": scenario_id or "global"}


@router.get("/health")
async def health() -> dict:
    """Health check endpoint."""
    return {"status": "ok", "service": "parlay-dashboard"}


@router.post("/game/step")
async def game_step(req: GameStepRequest) -> dict:
    """Unified step endpoint for the browser UI."""
    if req.move == "accept":
        return await accept_deal(AcceptRequest(session_id=req.session_id))
    if req.move == "walk_away":
        return await walk_away(WalkAwayRequest(session_id=req.session_id))

    has_text = bool((req.message or "").strip())
    if req.offer_amount is None and not has_text and not req.card_id:
        raise HTTPException(
            status_code=400,
            detail="Send a message, an offer amount, or a tactical card.",
        )

    tactical_move = req.card_id
    if req.move == "anchor":
        tactical_move = TacticalMove.ANCHOR_HIGH.value

    msg = (req.message or "").strip() or (req.move if req.move not in ("counter", "chat") else "")
    if not msg and tactical_move:
        msg = f"(tactical: {tactical_move})"

    return await make_move(
        MoveRequest(
            session_id=req.session_id,
            amount=req.offer_amount,
            message=msg,
            tactical_move=tactical_move,
        )
    )


@router.post("/session/start")
async def session_start(req: SessionStartRequest) -> dict:
    """Start a simplified session API flow."""
    try:
        session_id, session = _build_session(req.scenario_id, req.persona, req.player_name)
    except (InvalidScenarioError, InvalidPersonaError) as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc

    _sessions[session_id] = session
    return {"session_id": session_id, "status": "ok"}


@router.post("/session/{session_id}/step")
async def session_step(session_id: str, req: SessionStepRequest) -> dict:
    """Execute one negotiation step in a simplified session."""
    return await make_move(
        MoveRequest(
            session_id=session_id,
            amount=req.amount,
            message=req.message,
            tactical_move=req.tactical_move,
        )
    )


@router.get("/session/{session_id}/spectate-stream")
async def spectate_stream(session_id: str):
    """
    Server-Sent Events stream of full session state including hidden fields.
    Used by spectate.html for live demo projection.
    """

    async def event_generator():
        while True:
            session = get_session(session_id)
            if session is None:
                yield f"data: {json.dumps({'error': 'session not found'})}\n\n"
                break

            state: ParlayState = session["state"]
            payload = {
                "turn": state.step_count,
                "tension": state.tension_score,
                "zopa_lower": state.hidden_state.walk_away_price,
                "zopa_upper": state.hidden_state.budget_ceiling,
                "true_urgency": state.hidden_state.urgency_score,
                "true_walkaway": state.hidden_state.budget_ceiling,
                "last_stated_batna": state.hidden_state.last_stated_batna,
                "bluffs_caught": state.bluffs_caught,
                "zopa_erosion_ticks": state.zopa_erosion_ticks,
                "zopa_width_pct": state.zopa_width_pct_remaining,
                "tom_accuracy": session["tom_tracker"].accuracy_against(state.hidden_state),
                "active_market_event": None,
                "true_mev_impact": state.hidden_state.event_impacts,
                "cumulative_reward": state.cumulative_reward,
                "conversation_tail": session["conversation"][-3:],
                "is_terminal": state.deal_reached or state.walk_away or state.episode_done,
                "termination_reason": state.termination_reason,
            }
            yield f"data: {json.dumps(payload)}\n\n"
            if payload["is_terminal"]:
                break
            await asyncio.sleep(2)

    return StreamingResponse(event_generator(), media_type="text/event-stream")