import type { SampleGroupNode } from '../composables/useSampleGroups'
import type { GroupDragKind, GroupReorderPosition } from './SampleSelector.groups'

/**
 * Handlers and state predicates shared by every level of the group tree.
 * Passed down as a single prop so the recursive row component does not have to
 * re-emit each event at every nesting level.
 */
export interface SampleGroupTreeContext {
  isExpanded: (key: string) => boolean
  toggleExpanded: (key: string) => void
  isSampleSelected: (sample: string) => boolean
  isFullySelected: (samples: string[]) => boolean
  isPartiallySelected: (samples: string[]) => boolean
  toggleSamples: (samples: string[]) => void
  toggleSample: (sample: string) => void
  removeGroups: (groupNames: string[]) => void
  removeSampleFromGroup: (sample: string, groupName: string) => void
  openColorPicker: (groupNames: string[], event: Event) => void
  // Drag state + handlers, mirroring `useSampleSelectorDrag`.
  draggingSample: () => string | null
  dragOverGroup: () => string | null
  draggingGroup: () => string | null
  draggingGroupKind: () => GroupDragKind | null
  reorderTarget: () => string | null
  reorderPosition: () => GroupReorderPosition | null
  onSampleDragStart: (sample: string, groupName: string | null, event: DragEvent) => void
  onSampleDragEnd: () => void
  onSampleDragOver: (groupName: string, event: DragEvent) => void
  onSampleDragLeave: () => void
  onSampleDrop: (groupName: string, event: DragEvent) => void
  onGroupDragStart: (name: string, kind: GroupDragKind, event: DragEvent) => void
  onGroupDragEnd: () => void
  onGroupDragOver: (name: string, kind: GroupDragKind, event: DragEvent) => void
  onGroupDragLeave: (event: DragEvent) => void
  onGroupDrop: (name: string, kind: GroupDragKind, event: DragEvent) => void
  /** Alt+ArrowUp / Alt+ArrowDown reorder a group among its siblings. */
  onGroupReorderKeydown: (name: string, kind: GroupDragKind, event: KeyboardEvent) => void
}

/** Every concrete group name beneath a node, in tree order. */
export function collectLeafGroupNames(node: SampleGroupNode): string[] {
  if (node.group) return [node.group.name]
  return node.children.flatMap(collectLeafGroupNames)
}

/** Expansion keys for a whole tree, used by "expand all". */
export function collectNodeKeys(nodes: SampleGroupNode[]): string[] {
  return nodes.flatMap(node => [node.key, ...collectNodeKeys(node.children)])
}