import 'dart:math' as math;

import 'package:wolf_dart/classes/coordinate_2d.dart';
import 'package:wolf_dart/features/entities/entity.dart';

abstract class Enemy extends Entity {
  Enemy({
    required super.x,
    required super.y,
    required super.spriteIndex,
    super.angle,
    super.state,
    super.mapId,
    super.lastActionTime,
  });

  // Standard guard health
  int health = 25;
  bool isDying = false;

  void takeDamage(int amount, int currentTime) {
    if (state == EntityState.dead) return;

    health -= amount;
    // Mark the start of the death/pain
    lastActionTime = currentTime;

    if (health <= 0) {
      state = EntityState.dead;
      // This triggers the dying animation
      isDying = true;
    } else if (math.Random().nextDouble() < 0.5) {
      state = EntityState.pain;
    } else {
      state = EntityState.patrolling;
    }
  }

  // Decodes the Map ID to figure out which way the enemy is facing
  static double getInitialAngle(int objId) {
    int normalizedId = (objId - 108) % 36;
    // 0=East, 1=North, 2=West, 3=South
    int direction = normalizedId % 4;

    switch (direction) {
      case 0:
        return 0.0;
      case 1:
        return 3 * math.pi / 2;
      case 2:
        return math.pi;
      case 3:
        return math.pi / 2;
      default:
        return 0.0;
    }
  }

  // The enemy can now check its own line of sight!
  bool hasLineOfSight(
    Coordinate2D playerPosition,
    bool Function(int x, int y) isWalkable,
  ) {
    double distance = position.distanceTo(playerPosition);

    // 1. FOV Check
    double angleToPlayer = position.angleTo(playerPosition);
    double diff = angle - angleToPlayer;

    while (diff <= -math.pi) {
      diff += 2 * math.pi;
    }
    while (diff > math.pi) {
      diff -= 2 * math.pi;
    }

    if (diff.abs() > math.pi / 2) return false;

    // 2. Map Check
    Coordinate2D dir = (playerPosition - position).normalized;
    double stepSize = 0.2;

    for (double i = 0; i < distance; i += stepSize) {
      Coordinate2D checkPos = position + (dir * i);
      if (!isWalkable(checkPos.x.toInt(), checkPos.y.toInt())) return false;
    }

    return true;
  }

  // The weapon asks the enemy if it is unobstructed from the shooter
  bool hasLineOfSightFrom(
    Coordinate2D source,
    double sourceAngle,
    double distance,
    bool Function(int x, int y) isWalkable,
  ) {
    double dirX = math.cos(sourceAngle);
    double dirY = math.sin(sourceAngle);

    for (double i = 0.5; i < distance; i += 0.2) {
      int checkX = (source.x + dirX * i).toInt();
      int checkY = (source.y + dirY * i).toInt();
      if (!isWalkable(checkX, checkY)) return false;
    }
    return true;
  }

  void update({
    required int elapsedMs,
    required Coordinate2D playerPosition,
    required bool Function(int x, int y) isWalkable,
    required void Function(int damage) onDamagePlayer,
  });
}