"""
ECHO ULTIMATE — OpenEnv-compliant environment.

EchoOpenEnv extends BOTH openenv.core.Environment AND gymnasium.Env (via EchoEnv),
satisfying the full OpenEnv protocol:

    reset(seed, episode_id, **kwargs)  → EchoObservation
    step(action: EchoAction, ...)      → EchoObservation
    state                              → EchoState  (property)
    get_metadata()                     → EnvironmentMetadata

Plus OpenEnv task-listing helpers:
    info()        → environment metadata dict
    list_tasks()  → all TaskSpec dicts
    get_task(id)  → single TaskSpec dict

Gymnasium-style callers (server, training) use the _gym_reset / _gym_step
helpers which still return (obs_dict, info) / (obs, reward, done, …) tuples.
"""

from __future__ import annotations

from dataclasses import dataclass, asdict
from typing import Any, Dict, Optional, List, Tuple

try:
    from openenv.core import Environment
    try:
        from openenv.core.env import EnvironmentMetadata
    except ImportError:
        EnvironmentMetadata = None
except ImportError:
    # Fallback: plain base class when openenv is not available
    class Environment:
        def __init__(self, transform=None, rubric=None, **kwargs):
            pass
    EnvironmentMetadata = None

from env.echo_env import EchoEnv
from env.task_bank import TaskBank
from env.reward import RewardHistory
from models import EchoAction, EchoObservation, EchoState
from core.tasks import TASKS
from config import cfg


# ── OpenEnv task spec ─────────────────────────────────────────────────────────

@dataclass
class TaskSpec:
    id: str
    name: str
    description: str
    pass_threshold: float
    metric: str
    n_episodes: int
    domains: List[str]
    difficulties: List[str]

    def to_dict(self) -> dict:
        return asdict(self)


@dataclass
class EnvInfo:
    name: str
    version: str
    description: str
    observation_format: str
    action_format: str
    reward_range: Tuple[float, float]
    domains: List[str]
    tasks: List[str]

    def to_dict(self) -> dict:
        return asdict(self)


# ── Main environment ──────────────────────────────────────────────────────────

class EchoOpenEnv(Environment[EchoAction, EchoObservation, EchoState], EchoEnv):
    """
    ECHO ULTIMATE: OpenEnv-compliant RL environment for LLM calibration.

    Extends openenv.core.Environment (OpenEnv protocol) AND EchoEnv (gymnasium.Env).

    OpenEnv usage — stateless per-request:
        env = EchoOpenEnv()
        obs = env.reset()                          # EchoObservation
        obs = env.step(EchoAction(response="...")) # EchoObservation
        s   = env.state                            # EchoState

    Gymnasium usage — stateful episodes:
        obs_dict, info = env._gym_reset()
        obs_dict, r, done, _, info = env._gym_step("<confidence>72</confidence><answer>Paris</answer>")

    Training loop:
        env = EchoOpenEnv(phase=1)
        for _ in range(n_steps):
            obs_dict, info = env._gym_reset()
            prompt = info["formatted_prompt"]
            response = model.generate(prompt)
            _, reward, _, _, _ = env._gym_step(response)
    """

    # OpenEnv class attributes
    SUPPORTS_CONCURRENT_SESSIONS: bool = False
    OPENENV_PROTOCOL_VERSION: str = "1.0"
    N_TASKS: int = 3
    OBSERVATION_TYPE: str = "dict"
    ACTION_TYPE: str = "text"

    def __init__(
        self,
        task_id: Optional[str] = None,
        task_bank: Optional[TaskBank] = None,
        reward_history: Optional[RewardHistory] = None,
        phase: int = 1,
        self_consistency: bool = False,
        generate_fn=None,
        render_mode: Optional[str] = None,
    ) -> None:
        # Init gymnasium env (EchoEnv sets up task_bank, reward_history, spaces, etc.)
        EchoEnv.__init__(
            self,
            task_bank=task_bank,
            reward_history=reward_history,
            phase=phase,
            self_consistency=self_consistency,
            generate_fn=generate_fn,
            render_mode=render_mode,
        )
        # Init openenv.core.Environment (sets transform=None, rubric=None)
        Environment.__init__(self, transform=None, rubric=None)
        self._default_task_id = task_id

    # ── OpenEnv abstract method: reset ────────────────────────────────────────

    def reset(
        self,
        seed: Optional[int] = None,
        episode_id: Optional[str] = None,
        **kwargs,
    ) -> EchoObservation:
        """
        OpenEnv reset — returns EchoObservation.

        Accepts kwargs: options={"task_id": "task_hard"}  or  task_id="task_easy".
        """
        options = kwargs.get("options")
        task_id = kwargs.get("task_id") or self._default_task_id
        if options is None and task_id:
            options = {"task_id": task_id}

        obs_dict, _ = EchoEnv.reset(self, seed=seed, options=options)
        return self._obs_from_dict(obs_dict, done=False)

    # ── OpenEnv abstract method: step ─────────────────────────────────────────

    def step(
        self,
        action: EchoAction | str,
        timeout_s: Optional[float] = None,
        **kwargs,
    ) -> EchoObservation:
        """OpenEnv step — accepts EchoAction or raw string, returns EchoObservation."""
        response = action.response if isinstance(action, EchoAction) else str(action)
        obs_dict, reward, terminated, truncated, info = EchoEnv.step(self, response)
        return self._obs_from_step(obs_dict, reward, terminated or truncated, info)

    # ── OpenEnv abstract property: state ──────────────────────────────────────

    @property
    def state(self) -> EchoState:
        """OpenEnv state property — returns full EchoState snapshot."""
        task = self._current_task or {}
        snap = self.reward_history.get_training_snapshot(last_n=100)
        profiles = self.reward_history.get_domain_profiles()
        return EchoState(
            current_question=task.get("question", ""),
            domain=task.get("domain", ""),
            difficulty=task.get("difficulty", ""),
            phase=self.phase,
            step_count=self._episode_step,
            total_reward=self._episode_reward,
            domain_stats={
                d: {"ece": round(p.ece, 3), "accuracy": round(p.accuracy, 3)}
                for d, p in profiles.items()
                if p.n_samples > 0
            },
        )

    # ── OpenEnv metadata ──────────────────────────────────────────────────────

    def get_metadata(self):
        """OpenEnv environment metadata."""
        if EnvironmentMetadata is not None:
            return EnvironmentMetadata(
                name="ECHO-ULTIMATE",
                version="2.0.0",
                description=(
                    "RL environment for LLM metacognitive calibration. "
                    "Trains models to accurately predict their own probability of "
                    "being correct across 7 domains via GRPO with Brier-score rewards."
                ),
            )
        return {
            "name": "ECHO-ULTIMATE",
            "version": "2.0.0",
            "description": "OpenEnv RL environment for LLM metacognitive calibration.",
        }

    # ── Gymnasium-compatible helpers (for server + training) ──────────────────

    def _gym_reset(
        self,
        seed: Optional[int] = None,
        options: Optional[dict] = None,
    ) -> Tuple[dict, dict]:
        """Gymnasium-style reset returning (obs_dict, info) tuple."""
        if options is None and self._default_task_id:
            options = {"task_id": self._default_task_id}
        return EchoEnv.reset(self, seed=seed, options=options)

    def _gym_step(self, response: str) -> Tuple[dict, float, bool, bool, dict]:
        """Gymnasium-style step returning (obs, reward, terminated, truncated, info)."""
        return EchoEnv.step(self, response)

    # ── Task-listing helpers (OpenEnv task bank protocol) ─────────────────────

    def info(self) -> dict:
        """Return environment metadata dict."""
        return EnvInfo(
            name="ECHO-ULTIMATE",
            version="2.0.0",
            description=(
                "RL environment for LLM metacognitive calibration. "
                "Teaches models to accurately predict their own probability of being correct "
                "across 7 domains via GRPO with Brier-score calibration rewards."
            ),
            observation_format=(
                "EchoObservation: {question, domain, difficulty, reward, done, "
                "ece, accuracy, confidence, brier_score, is_correct, feedback}"
            ),
            action_format="EchoAction: {response='<confidence>N</confidence><answer>TEXT</answer>'}",
            reward_range=(cfg.REWARD_CLIP_LOW, cfg.REWARD_CLIP_HIGH),
            domains=cfg.DOMAINS,
            tasks=[t.id for t in TASKS],
        ).to_dict()

    def list_tasks(self) -> List[dict]:
        """Return all task specifications."""
        return [
            TaskSpec(
                id=t.id,
                name=t.name,
                description=t.description,
                pass_threshold=t.pass_threshold,
                metric=t.metric,
                n_episodes=t.n_episodes,
                domains=cfg.DOMAINS,
                difficulties=cfg.DIFFICULTIES,
            ).to_dict()
            for t in TASKS
        ]

    def get_task(self, task_id: str) -> Optional[dict]:
        """Return a single task spec by ID."""
        for t in TASKS:
            if t.id == task_id:
                return TaskSpec(
                    id=t.id,
                    name=t.name,
                    description=t.description,
                    pass_threshold=t.pass_threshold,
                    metric=t.metric,
                    n_episodes=t.n_episodes,
                    domains=cfg.DOMAINS,
                    difficulties=cfg.DIFFICULTIES,
                ).to_dict()
        return None

    # ── Evaluation helper ─────────────────────────────────────────────────────

    def evaluate(
        self,
        n_episodes: int = 30,
        task_id: Optional[str] = None,
    ) -> dict:
        """Run n_episodes and return OpenEnv-style evaluation results."""
        rewards = []
        for _ in range(n_episodes):
            obs_dict, info = self._gym_reset(
                options={"task_id": task_id} if task_id else None
            )
            placeholder = "<confidence>50</confidence><answer>unknown</answer>"
            _, reward, _, _, _ = self._gym_step(placeholder)
            rewards.append(reward)

        metrics = self.get_metrics()
        task_spec = self.get_task(task_id) if task_id else None
        threshold = task_spec["pass_threshold"] if task_spec else 0.5
        score = max(0.0, 1.0 - metrics.ece) * min(1.0, metrics.accuracy / 0.55)

        return {
            "n_episodes":           n_episodes,
            "ece":                  round(metrics.ece, 4),
            "accuracy":             round(metrics.accuracy, 4),
            "brier_score":          round(metrics.brier, 4),
            "overconfidence_rate":  round(metrics.overconfidence_rate, 4),
            "mean_reward":          round(sum(rewards) / len(rewards), 4),
            "score":                round(score, 4),
            "pass_threshold":       threshold,
            "passed":               score >= threshold,
        }

    # ── Internal helpers ──────────────────────────────────────────────────────

    def _obs_from_dict(self, obs_dict: dict, done: bool = False) -> EchoObservation:
        """Convert _build_obs() dict → EchoObservation (after reset)."""
        task = self._current_task or {}
        return EchoObservation(
            question=task.get("question", obs_dict.get("question", "")),
            domain=obs_dict.get("domain", ""),
            difficulty=obs_dict.get("difficulty", ""),
            ece=float(obs_dict.get("running_ece", 0.0)),
            accuracy=float(obs_dict.get("running_accuracy", 0.0)),
            confidence=int(obs_dict.get("running_mean_confidence", 50)),
            done=done,
        )

    def _obs_from_step(
        self,
        obs_dict: dict,
        reward: float,
        done: bool,
        info: dict,
    ) -> EchoObservation:
        """Convert step() outputs → EchoObservation."""
        return EchoObservation(
            question=(self._current_task or {}).get("question", ""),
            domain=info.get("domain", obs_dict.get("domain", "")),
            difficulty=info.get("difficulty", obs_dict.get("difficulty", "")),
            reward=float(reward),
            done=done,
            ece=float(obs_dict.get("running_ece", 0.0)),
            accuracy=float(info.get("accuracy", 0.0)),
            confidence=int(info.get("parsed_confidence", 50)),
            brier_score=float(info.get("brier_reward", 0.0)),
            is_correct=bool(info.get("was_correct", False)),
            feedback=info.get("breakdown", ""),
        )


# ── Convenience factory ───────────────────────────────────────────────────────

def make_echo_env(
    task_id: Optional[str] = None,
    phase: int = 1,
    **kwargs,
) -> EchoOpenEnv:
    """Factory function for creating an ECHO OpenEnv environment."""
    return EchoOpenEnv(task_id=task_id, phase=phase, **kwargs)