import type { EnemyAttackTelegraph } from "./enemyAttacks";
import type { CombatPosition } from "./mobRuntimeRegistry";

export interface EnemyTelegraphPlacement {
  readonly sourcePosition: CombatPosition;
  readonly targetPosition: CombatPosition;
  readonly sourceYaw: number;
}

export function enemyTelegraphYaw(placement: EnemyTelegraphPlacement): number {
  const dx = placement.targetPosition[0] - placement.sourcePosition[0];
  const dz = placement.targetPosition[2] - placement.sourcePosition[2];
  return dx * dx + dz * dz > 0.0001 ? Math.atan2(dx, dz) : placement.sourceYaw;
}

export function enemyTelegraphOrigin(
  telegraph: EnemyAttackTelegraph,
  placement: EnemyTelegraphPlacement,
): CombatPosition {
  return telegraph.anchor === "target"
    ? placement.targetPosition
    : placement.sourcePosition;
}

/** Matches the visible warning mesh in the X/Z combat plane. */
export function enemyTelegraphContainsPosition(
  telegraph: EnemyAttackTelegraph,
  placement: EnemyTelegraphPlacement,
  candidate: CombatPosition,
): boolean {
  const origin = enemyTelegraphOrigin(telegraph, placement);
  const dx = candidate[0] - origin[0];
  const dz = candidate[2] - origin[2];
  if (telegraph.shape === "circle") {
    const radius = telegraph.radius ?? 0;
    return dx * dx + dz * dz <= radius * radius;
  }

  const yaw = enemyTelegraphYaw(placement);
  const forwardX = Math.sin(yaw);
  const forwardZ = Math.cos(yaw);
  const forward = dx * forwardX + dz * forwardZ;
  const side = Math.abs(dx * forwardZ - dz * forwardX);
  const length = telegraph.length ?? 0;
  if (forward < 0 || forward > length) return false;
  if (telegraph.shape === "line") return side <= (telegraph.width ?? 0) / 2;
  const distance = Math.hypot(dx, dz);
  if (distance <= 0.0001) return true;
  const halfAngle = ((telegraph.angleDegrees ?? 0) * Math.PI) / 360;
  return Math.acos(Math.min(1, Math.max(-1, forward / distance))) <= halfAngle;
}