import type { WallNode } from '@pascal-app/core'

/**
 * Default sill height (metres from the floor to the BOTTOM of a window) for a
 * fresh window that has no wall-face height yet — the off-wall ghost and the
 * floor-cursor placement use it so a new window floats slightly above the
 * ground rather than sitting on it. The committed Y is the window's CENTRE, so
 * callers add `height / 2`. An existing window keeps its own sill.
 */
export const DEFAULT_WINDOW_SILL_M = 0.5

/**
 * Converts wall-local (X along wall, Y = height above wall base) to world XYZ.
 * Wall XZ uses level-local coordinates (levels only offset in Y, not XZ).
 * Pass levelYOffset (the level group's current world Y) and slabElevation (the
 * wall mesh's Y within the level group) so the cursor lands at the correct world
 * height — matching how WallSystem positions the wall mesh at slabElevation.
 */
export function wallLocalToWorld(
  wallNode: WallNode,
  localX: number,
  localY: number,
  levelYOffset = 0,
  slabElevation = 0,
): [number, number, number] {
  const wallAngle = Math.atan2(
    wallNode.end[1] - wallNode.start[1],
    wallNode.end[0] - wallNode.start[0],
  )
  return [
    wallNode.start[0] + localX * Math.cos(wallAngle),
    slabElevation + localY + levelYOffset,
    wallNode.start[1] + localX * Math.sin(wallAngle),
  ]
}

/**
 * Clamps window center position so it stays fully within wall bounds.
 */
export function clampToWall(
  wallNode: WallNode,
  localX: number,
  localY: number,
  width: number,
  height: number,
): { clampedX: number; clampedY: number } {
  const dx = wallNode.end[0] - wallNode.start[0]
  const dz = wallNode.end[1] - wallNode.start[1]
  const wallLength = Math.sqrt(dx * dx + dz * dz)
  const wallHeight = wallNode.height ?? 2.5

  const clampedX = Math.max(width / 2, Math.min(wallLength - width / 2, localX))
  const clampedY = Math.max(height / 2, Math.min(wallHeight - height / 2, localY))
  return { clampedX, clampedY }
}

/**
 * Wall-child overlap is shared by door + window placement (one source of
 * truth in `shared/wall-attach-target.ts`). Re-exported here so existing
 * `./window-math` importers don't change.
 */
export { hasWallChildOverlap } from '../shared/wall-attach-target'