"""
scenarios/obstacle.py
---------------------
Static Obstacle Scenario.

A traffic cone (or configurable static prop) is placed on the ego lane
ahead of the vehicle. The ego autopilot must detect and react to the
obstruction. No per-frame logic is needed — this is a purely static scene.
"""

import sys
import os

sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

from scenarios.base import ScenarioBase


class ObstacleScenario(ScenarioBase):
    """
    Scenario: Static obstacle on the ego lane.

    A prop is spawned on the road ahead. The ego continues under
    autopilot and must navigate around or brake for the obstacle.
    """

    OBSTACLE_DISTANCE_M = 30  # metres ahead of ego for static prop
    # CARLA blueprint name for the static prop
    PROP_BLUEPRINT      = "static.prop.trafficcone01"

    def __init__(self):
        super().__init__()
        self._obstacle = None

    # ------------------------------------------------------------------
    # ScenarioBase interface
    # ------------------------------------------------------------------

    @property
    def name(self) -> str:
        return "obstacle"

    @property
    def ego_spawn_point(self):
        # Working Town10 intersection point (Southbound)
        import carla
        return carla.Transform(carla.Location(x=107.412, y=45.309, z=0.5), carla.Rotation(yaw=-87.7))

    def setup(self, world, ego_vehicle, traffic_manager) -> None:
        self._world = world
        self._ego   = ego_vehicle
        self._tm    = traffic_manager

        bp_lib = world.get_blueprint_library()

        # Locate prop blueprint
        prop_bps = bp_lib.filter(self.PROP_BLUEPRINT)
        if not prop_bps:
            # Fallback to any traffic cone available
            prop_bps = bp_lib.filter("static.prop.trafficcone*")
        if not prop_bps:
            raise RuntimeError(
                f"[ObstacleScenario] Blueprint '{self.PROP_BLUEPRINT}' not found. "
                "Check CARLA content pack."
            )
        prop_bp = prop_bps[0]

        # Place obstacle on the ego lane ahead
        spawn_wp = self._get_waypoint_ahead(self.OBSTACLE_DISTANCE_M, lane_offset=0)
        if spawn_wp is None:
            raise RuntimeError(
                "[ObstacleScenario] Could not find waypoint ahead — "
                "ensure ego is on a driveable road."
            )

        # Offset slightly to lane centre to avoid collision with road mesh
        obstacle_transform = spawn_wp.transform
        obstacle_transform.location.z += 0.1   # tiny Z lift avoids clipping

        self._obstacle = world.try_spawn_actor(prop_bp, obstacle_transform)
        if self._obstacle is None:
            raise RuntimeError(
                "[ObstacleScenario] Failed to spawn obstacle at "
                f"{obstacle_transform.location}."
            )

        self._actors.append(self._obstacle)

        print(
            f"[{self.name}] '{self.PROP_BLUEPRINT}' placed "
            f"{self.OBSTACLE_DISTANCE_M} m ahead of ego."
        )

    def step(self, frame_count: int, ego_vehicle, pbar=None) -> None:
        # Static scenario — no per-frame logic required
        pass

    def cleanup(self) -> None:
        self._destroy_actors()
        print(f"[{self.name}] Cleanup complete.")

    # ------------------------------------------------------------------
    # Optional overrides
    # ------------------------------------------------------------------

    def get_scenario_metadata(self) -> dict:
        return {
            "scenario":           self.name,
            "obstacle_prop":      self.PROP_BLUEPRINT,
            "obstacle_distance_m": self.OBSTACLE_DISTANCE_M,
        }