from __future__ import annotations

from typing import Any, Dict, Optional, Tuple

from .factory import ManufacturingFactoryEnv
from .models import (
    ManufacturingAction,
    ManufacturingEnvState,
    ManufacturingObservation,
    ManufacturingReward,
)
from .tasks import TASK_REGISTRY, Task


class ManufacturingTaskEnv:
    """Canonical user-facing API for the Space Manufacturing RL environment."""

    def __init__(
        self,
        task_name: str = "easy",
        num_platforms: Optional[int] = None,
        max_steps: Optional[int] = None,
    ) -> None:
        self._task_name = task_name
        self._num_platforms_override = num_platforms
        self._max_steps_override = max_steps
        self._factory: Optional[ManufacturingFactoryEnv] = None
        self._task: Optional[Task] = None
        self.set_task(task_name)

    # ── Class methods ──────────────────────────────────────────────────────────

    @staticmethod
    def list_tasks() -> Dict[str, str]:
        return {name: task.description for name, task in TASK_REGISTRY.items()}

    # ── Setup ──────────────────────────────────────────────────────────────────

    def set_task(self, task_name: str) -> None:
        if task_name not in TASK_REGISTRY:
            raise ValueError(
                f"Unknown task '{task_name}'. Available: {list(TASK_REGISTRY.keys())}"
            )
        self._task_name = task_name
        self._task = TASK_REGISTRY[task_name]
        self._factory = ManufacturingFactoryEnv(
            num_platforms=self._num_platforms_override or self._task.num_platforms,
            max_steps=self._max_steps_override or self._task.max_steps,
            seed=self._task.seed,
            pending_orders=list(self._task.pending_orders),
            delivery_windows=list(self._task.delivery_windows),
            solar_zones=dict(self._task.solar_zones),
        )

    # ── Core API ───────────────────────────────────────────────────────────────

    def reset(self) -> ManufacturingObservation:
        assert self._factory is not None
        return self._factory.reset()

    def step(
        self, action: ManufacturingAction
    ) -> Tuple[ManufacturingObservation, ManufacturingReward, bool, Dict[str, Any]]:
        assert self._factory is not None
        return self._factory.step(action)

    def state(self) -> ManufacturingEnvState:
        assert self._factory is not None
        f = self._factory
        return ManufacturingEnvState(
            episode_id=f.episode_id,
            task_name=self._task_name,
            step_count=f.step_count,
            max_steps=f.max_steps,
            seed=f.seed,
            done=f.done,
            total_reward=f.total_reward,
            metrics=dict(f.metrics),
            platforms=list(f.platforms),
            delivery_windows=list(f.delivery_windows),
            solar_conditions=dict(f._solar_zones),
            pending_orders=list(f.pending_orders),
        )

    # ── Internal helper (for server compatibility) ─────────────────────────────

    def _observation_from_dict(self, d: Dict[str, Any]) -> ManufacturingObservation:
        return ManufacturingObservation.model_validate(d)