#!/usr/bin/env python3

import math
import time
import numpy as np
from scipy.stats import levy, uniform
from time import sleep
from enum import Enum

from control.uav_controller import Controller
from vision.object_detector import ObjectDetector
from utils.helpers import distance_2d
from safety.geofence import clip_to_geofence
from navigation.patterns.spiral import plan_spiral
from navigation.patterns.lawnmower import plan_lawnmower
from navigation.patterns.levy import plan_levy

class SearchMode(Enum):
    SPIRAL = "spiral"
    LAWNMOWER = "lawnmower"
    LEVY = "levy"
class Search:
    POSITION_TOLERANCE = 0.05
    CHECK_INTERVAL = 0.5
    MAX_TRAVEL_TIME = 300.0

    def __init__(self, ctrl: Controller, detector: ObjectDetector,
                 camera=None, mode: str = "spiral", altitude: float = 5.0,
                 actions: dict = None):
        self.ctrl = ctrl
        self.detector = detector
        self.camera = camera
        self.mode = SearchMode(mode.lower())
        self.altitude = altitude
        self.found_markers = {}
        self.running = True
        self.landed = False
        self._landing = False
        self.landing_enabled = False

        self.actions = actions or {}
        self.land_ids = set(self.actions.get("land", []))
        self.target_ids = set(self.actions.get("target", []))
        self.on_target_found = None
        self._dispatched_targets = set()

        hfov = 1.3962634
        self.cam_fov_meters = 2.0 * self.altitude * math.tan(hfov / 2.0)

        self.spiral_max_legs = 40
        overlap_spacing = self.cam_fov_meters * 0.8
        self.spiral_initial_leg = overlap_spacing
        self.spiral_leg_increment = overlap_spacing

        self.lawn_width = 30.0
        self.lawn_height = 30.0
        self.lawn_lane_spacing = self.cam_fov_meters * 0.8
        self.lawn_lanes = int(self.lawn_width / max(self.lawn_lane_spacing, 0.1)) + 1

        self.levy_max_steps = 20
        self.levy_field_size = 50.0
        self.levy_angle_dist = uniform(loc=-180, scale=360)

        self.waypoints = []
        self.current_wp = 0
        self._on_waypoint_change = None

    def configure(self, **kwargs):
        for key, value in kwargs.items():
            if hasattr(self, key):
                setattr(self, key, value)

    def plan(self, start_pos=(0.0, 0.0), geofence_points=None):
        if geofence_points:
            warn_dist = getattr(self, 'geofence_warn_dist', 3.0)
            xs = [p[0] for p in geofence_points]
            ys = [p[1] for p in geofence_points]
            safe_w = (max(xs) - min(xs)) - 2 * warn_dist
            safe_h = (max(ys) - min(ys)) - 2 * warn_dist
            if safe_w > 0 and safe_h > 0:
                self.lawn_width = safe_w
                self.lawn_height = safe_h
                self.levy_field_size = min(safe_w, safe_h)

        hfov = 1.3962634
        self.cam_fov_meters = 2.0 * self.altitude * math.tan(hfov / 2.0)
        overlap_spacing = self.cam_fov_meters * 0.8
        self.spiral_initial_leg = overlap_spacing
        self.spiral_leg_increment = overlap_spacing
        self.lawn_lane_spacing = overlap_spacing
        self.lawn_lanes = int(self.lawn_width / max(self.lawn_lane_spacing, 0.1)) + 1

        if self.mode == SearchMode.SPIRAL:
            waypoints = plan_spiral(start_pos, self.spiral_initial_leg, self.spiral_leg_increment, self.spiral_max_legs)
        elif self.mode == SearchMode.LAWNMOWER:
            waypoints = plan_lawnmower(start_pos, self.lawn_width, self.lawn_height, self.lawn_lane_spacing)
        elif self.mode == SearchMode.LEVY:
            waypoints = plan_levy(start_pos, self.levy_max_steps, self.levy_field_size, overlap_spacing, self.levy_angle_dist)
        else:
            waypoints = [start_pos]

        if geofence_points:
            warn_dist = getattr(self, 'geofence_warn_dist', 3.0)
            stop_on_leave = (self.mode == SearchMode.SPIRAL)
            waypoints = clip_to_geofence(waypoints, geofence_points, warn_dist, stop_on_leave)

        self.waypoints = waypoints
        self.current_wp = 0

        print(f"\n[PLAN] {self.mode.value.upper()} flight plan: "
              f"{len(waypoints)} waypoints")
        for i, (wx, wy) in enumerate(waypoints):
            print(f"  WP{i:02d}: ({wx:+.1f}, {wy:+.1f})")
        if geofence_points:
            print(f"[PLAN] Clipped to geofence ({len(geofence_points)} vertices)")

        return waypoints

    def run(self):
        if not self.waypoints:
            self.plan()

        n = len(self.waypoints)
        print(f"\n{'=' * 50}")
        print(f"  SEARCH: {self.mode.value.upper()} at {self.altitude}m")
        print(f"  Waypoints: {n}")
        if self.land_ids:
            print(f"  Landing targets: {self.land_ids}")
        print(f"{'=' * 50}\n")

        for i, (wx, wy) in enumerate(self.waypoints):
            if not self.running:
                break

            self.current_wp = i
            if self._on_waypoint_change:
                self._on_waypoint_change(i)

            self.ctrl.update_state()
            pos = self.ctrl.get_local_position()
            dist = distance_2d((pos['x'], pos['y']), (wx, wy))

            dir_label = ""
            if i > 0:
                prev = self.waypoints[i - 1]
                dx = wx - prev[0]
                dy = wy - prev[1]
                if abs(dx) > abs(dy):
                    dir_label = "N" if dx > 0 else "S"
                else:
                    dir_label = "E" if dy > 0 else "W"

            print(f"[SEARCH] WP {i + 1}/{n}  "
                  f"→ ({wx:+.1f}, {wy:+.1f})  "
                  f"dist:{dist:.1f}m  {dir_label}  "
                  f"markers:{len(self.found_markers)}")

            self.move_to_local(wx, wy)

        if not self._landing:
            print(f"\n[SEARCH] Search complete. "
                  f"Found {len(self.found_markers)} markers.")

        return self.found_markers

    def get_camera_frame(self):
        if self.camera is None:
            return None
        frame = self.camera.raw_frames.get("downward")
        if frame is None:
            frame = self.camera.raw_frames.get("gimbal")
        return frame

    def check_for_markers(self):
        frame = self.get_camera_frame()
        if frame is None:
            return []

        detections = self.detector.detect(frame)
        new_markers = []
        for d in detections:
            marker_id = d.get("id")
            if marker_id is None:
                continue

            if marker_id not in self.found_markers:
                self.ctrl.update_state()
                pos = self.ctrl.get_local_position()
                self.found_markers[marker_id] = {
                    "id": marker_id,
                    "uav_position": pos.copy(),
                    "distance": d.get("distance", 0),
                    "timestamp": time.time(),
                }
                new_markers.append(d)
                print(f"\n[SEARCH] ArUco ID:{marker_id} detected! "
                      f"distance:{d['distance']:.2f}m  "
                      f"UAV at ({pos['x']:.1f}, {pos['y']:.1f})")

            if marker_id in self.target_ids and marker_id not in self._dispatched_targets:
                self._dispatched_targets.add(marker_id)
                self.running = False

                final_pos = self.center_over_target(marker_id)

                print(f"\n[SEARCH] Target ID:{marker_id} centered! "
                      f"Dispatching UGV to ({final_pos['x']:.1f}, {final_pos['y']:.1f})")
                if self.on_target_found:
                    self.on_target_found(marker_id, final_pos['x'], final_pos['y'])

            if marker_id in self.land_ids and not self._landing and self.landing_enabled:
                print(f"\n[SEARCH] Landing target ID:{marker_id} found! "
                      f"Starting approach.")
                self._landing = True
                self.execute_landing(detections)
                return new_markers

        return new_markers

    def execute_landing(self, initial_detections):
        target_det = None
        for d in initial_detections:
            if d.get("id") in self.land_ids:
                target_det = d
                break

        if target_det is None:
            print("[SEARCH] Lost landing target, resuming search")
            return

        print(f"\n[SEARCH] ===== LANDING SEQUENCE =====")
        print(f"[SEARCH] Target marker ID:{target_det['id']}  "
              f"distance:{target_det['distance']:.2f}m")

        IMG_W, IMG_H = 640, 480
        IMG_CX, IMG_CY = IMG_W / 2, IMG_H / 2
        HFOV = 1.3962634

        self.ctrl.update_state()
        current_alt = self.ctrl.altitude

        DESCENT_STEP = max(0.5, current_alt * 0.25)
        LAND_ALT = min(1.0, current_alt - 0.2)
        CENTER_PX = 50
        MAX_CORRECTIONS = 200
        MAX_LOST = 30
        GAIN = 0.35

        self.ctrl.update_state()
        current_alt = self.ctrl.altitude

        print(f"[SEARCH] Visual servoing descent from {current_alt:.1f}m")

        while current_alt > LAND_ALT and self.running:
            centered = self._center_over_marker(
                current_alt, IMG_W, IMG_H, IMG_CX, IMG_CY, HFOV,
                CENTER_PX, MAX_CORRECTIONS, MAX_LOST, GAIN)

            if centered is None:
                print(f"\n[SEARCH] Marker lost, aborting landing")
                self._landing = False
                return

            current_alt = max(current_alt - DESCENT_STEP, LAND_ALT)
            print(f"\n[SEARCH] Descending to {current_alt:.1f}m")
            self.ctrl.update_state()
            cur = self.ctrl.get_local_position()
            self.ctrl.move_local_ned(cur['x'], cur['y'], -current_alt)
            sleep(2.0)

        print(f"[SEARCH] Final centering at {LAND_ALT:.1f}m")
        self._center_over_marker(
            LAND_ALT, IMG_W, IMG_H, IMG_CX, IMG_CY, HFOV,
            35, MAX_CORRECTIONS, MAX_LOST, 0.25)

        print(f"\n[SEARCH] ===== LANDING =====")
        self.ctrl.land()
        self.landed = True
        self.running = False

    def center_over_target(self, target_id):
        print(f"\n[SEARCH] ===== CENTERING OVER TARGET {target_id} =====")
        if hasattr(self, 'uav_min_cms'):
            print(f"[SEARCH] Reducing speed to minimum ({self.uav_min_cms} cm/s) for centering.")
            self.ctrl.configure_speed_limits(wpnav_speed=self.uav_min_cms, loit_speed=self.uav_min_cms)

        IMG_W, IMG_H = 640, 480
        IMG_CX, IMG_CY = IMG_W / 2, IMG_H / 2
        HFOV = 1.3962634

        CENTER_PX = 30
        MAX_CORRECTIONS = 200
        MAX_LOST = 30
        GAIN = 0.35

        self.ctrl.update_state()
        current_alt = self.ctrl.altitude

        centered = self._center_over_marker(
            current_alt, IMG_W, IMG_H, IMG_CX, IMG_CY, HFOV,
            CENTER_PX, MAX_CORRECTIONS, MAX_LOST, GAIN, allowed_ids=[target_id])

        if not centered:
            print(f"\n[SEARCH] Failed to fully center, using best estimate.")
        else:
            print(f"\n[SEARCH] Successfully centered over target {target_id}.")

        self.ctrl.update_state()
        pos = self.ctrl.get_local_position()
        return pos

    def _center_over_marker(self, target_alt, img_w, img_h, img_cx, img_cy,
                            hfov, center_px, max_corrections, max_lost, gain, allowed_ids=None):
        if allowed_ids is None:
            allowed_ids = self.land_ids

        lost_count = 0
        centered = False

        for attempt in range(max_corrections):
            frame = self.get_camera_frame()
            if frame is None:
                sleep(0.3)
                continue

            detections = self.detector.detect(frame)
            target = None
            for d in detections:
                if d.get("id") in allowed_ids:
                    target = d
                    break

            if target is None:
                lost_count += 1
                print(f"\r[SEARCH] Alt:{target_alt:.1f}m  "
                      f"MARKER LOST ({lost_count}/{max_lost})       ",
                      end='', flush=True)
                if lost_count >= max_lost:
                    return None
                sleep(0.3)
                continue

            lost_count = 0

            cx, cy = target["center_px"]
            err_x = cx - img_cx
            err_y = cy - img_cy

            print(f"\r[SEARCH] Alt:{target_alt:.1f}m  "
                  f"err=({err_x:+.0f},{err_y:+.0f})px  "
                  f"dist:{target['distance']:.2f}m  "
                  f"({attempt+1}/{max_corrections})       ",
                  end='', flush=True)

            if abs(err_x) < center_px and abs(err_y) < center_px:
                centered = True
                print(f"\n[SEARCH] Centered at {target_alt:.1f}m!")
                break

            self.ctrl.update_state()
            alt = max(self.ctrl.altitude, 0.5)
            ground_w = 2.0 * alt * math.tan(hfov / 2.0)
            m_per_px = ground_w / img_w

            correction_forward = -err_y * m_per_px * gain
            correction_right = err_x * m_per_px * gain

            self.ctrl.update_state()
            yaw = self.ctrl.current_yaw

            correction_n = correction_forward * math.cos(yaw) - correction_right * math.sin(yaw)
            correction_e = correction_forward * math.sin(yaw) + correction_right * math.cos(yaw)

            cur = self.ctrl.get_local_position()
            self.ctrl.move_local_ned(
                cur['x'] + correction_n,
                cur['y'] + correction_e,
                -target_alt)
            sleep(0.5)

        if not centered:
            print(f"\n[SEARCH] Partially centered at {target_alt:.1f}m, continuing")

        return centered

    def wait_for_position(self, target_x, target_y, timeout=None):
        self.ctrl.update_state()
        pos = self.ctrl.get_local_position()
        dist_total = distance_2d((pos['x'], pos['y']), (target_x, target_y))

        if timeout is None:

            timeout = 30.0 + (dist_total * 3.0)

        t0 = time.time()
        while time.time() - t0 < timeout and self.running:
            self.ctrl.update_state()
            self.check_for_markers()
            if not self.running:
                return False
            pos = self.ctrl.get_local_position()
            dist = distance_2d(
                (pos['x'], pos['y']),
                (target_x, target_y)
            )
            elapsed = int(time.time() - t0)
            print(f"\r[SEARCH] Moving: {dist:.1f}m to target  ({elapsed}s)  "
                  f"markers found: {len(self.found_markers)}  ",
                  end='', flush=True)
            if dist < self.POSITION_TOLERANCE:
                print()
                return True
            sleep(self.CHECK_INTERVAL)
        print()
        return False

        return False

    def move_to_local(self, x, y):
        z = -self.altitude
        self.ctrl.move_local_ned(x, y, z)
        return self.wait_for_position(x, y)

    def stop(self):
        self.running = False

    def get_results(self):
        return {
            "mode": self.mode.value,
            "markers_found": len(self.found_markers),
            "markers": self.found_markers,
            "landed": self.landed,
        }