import {
  type AnyNodeId,
  type FloorplanMoveTarget,
  type FloorplanMoveTargetSession,
  useScene,
  type WallNode,
  type WindowNode,
} from '@pascal-app/core'
import { snapToHalf } from '@pascal-app/editor'
import { createFloorplanCursorResolver } from '../shared/floorplan-cursor'
import {
  findClosestWallInPlan,
  projectWallLocalPointToPlan,
  snapLocalXToNeighbors,
} from '../shared/wall-attach-target'
import { clampToWall, hasWallChildOverlap } from './window-math'

/**
 * 2D floor-plan move handler for window. Same shape as door (see
 * `nodes/src/door/floorplan-move.ts`) — pointer in plan space → snap
 * to nearest wall → project onto wall axis → snap local-X to 0.5m →
 * clamp inside wall bounds → commit.
 *
 * Window-specific: local Y (vertical position on the wall) is preserved
 * from the source node — we don't try to reposition the sill from a 2D
 * pointer (there's no Y signal in plan view). The 3D move tool handles
 * vertical motion; the 2D move is a horizontal-only re-anchor.
 */

export const windowFloorplanMoveTarget: FloorplanMoveTarget<WindowNode> = ({ node }) => {
  const startLevelId = (() => {
    const wall = useScene.getState().nodes[node.parentId as AnyNodeId]
    return wall ? (wall.parentId as AnyNodeId | null) : null
  })()
  const originalWall = node.parentId
    ? (useScene.getState().nodes[node.parentId as AnyNodeId] as WallNode | undefined)
    : undefined
  const resolveCursor = createFloorplanCursorResolver({
    original:
      originalWall?.type === 'wall'
        ? projectWallLocalPointToPlan(originalWall, node.position[0])
        : [node.position[0], 0],
    metadata: node.metadata,
  })

  // Preserve the source window's local Y — 2D move doesn't have a way
  // to express vertical motion, so we keep whatever vertical position
  // the window had when the move started.
  const startLocalY = node.position[1]

  // Track the last successful placement so `commit()` can write it
  // atomically — same deterministic-commit fix as `doorFloorplanMoveTarget`.
  let lastValid: {
    position: [number, number, number]
    rotation: [number, number, number]
    side: WindowNode['side']
    parentId: string
    wallId: string
  } | null = null

  const session: FloorplanMoveTargetSession = {
    affectedIds: [node.id as AnyNodeId],
    apply({ planPoint, modifiers }) {
      const nodes = useScene.getState().nodes
      const resolvedPlanPoint = resolveCursor(planPoint)
      const hit = findClosestWallInPlan(resolvedPlanPoint, nodes, startLevelId)
      if (!hit) return

      // Figma-style along-wall alignment first (edge-to-edge with other
      // openings / wall ends), winning over the 0.5m grid snap; falls back
      // to grid when nothing aligns. Alt bypasses; Shift drops the grid snap.
      const neighborX = modifiers.altKey
        ? null
        : snapLocalXToNeighbors({
            wall: hit.wall,
            localX: hit.localX,
            width: node.width,
            selfId: node.id as AnyNodeId,
            nodes,
          })
      const snappedLocalX = neighborX ?? (modifiers.shiftKey ? hit.localX : snapToHalf(hit.localX))
      const { clampedX, clampedY } = clampToWall(
        hit.wall,
        snappedLocalX,
        startLocalY,
        node.width,
        node.height,
      )

      lastValid = {
        position: [clampedX, clampedY, 0],
        rotation: [0, hit.itemRotation, 0],
        side: hit.side,
        parentId: hit.wall.id,
        wallId: hit.wall.id,
      }

      useScene.getState().updateNodes([
        {
          id: node.id as AnyNodeId,
          data: lastValid,
        },
      ])
    },
    canCommit() {
      const live = useScene.getState().nodes[node.id as AnyNodeId] as WindowNode | undefined
      if (!live || live.type !== 'window') return false
      const overlapping = hasWallChildOverlap(
        live.parentId as string,
        live.position[0],
        live.position[1],
        live.width,
        live.height,
        live.id,
      )
      return !overlapping
    },
    commit() {
      // Own the atomic write so the overlay takes the deterministic
      // commit-path (revert → resume → session.commit()). The dispatcher's
      // diff path would otherwise re-derive the final state by comparing
      // the post-apply scene to the snapshot — that works most of the
      // time but produces an empty diff (and silent revert) when the
      // committed move lands on the same `parentId` with identical data.
      // See `doorFloorplanMoveTarget.commit` for the original fix.
      if (!lastValid) return
      useScene.getState().updateNodes([
        {
          id: node.id as AnyNodeId,
          data: lastValid,
        },
      ])
    },
  }

  return session
}