skill: "implementing-drag-drop"
version: "1.0"
domain: "frontend"

base_outputs:
  - path: "src/components/**/*{Sortable,Draggable,Droppable,DragDrop,Kanban}*.{tsx,ts,jsx,js}"
    must_contain:
      - "@dnd-kit/core"
      - "DndContext"
      - "useSensor"
    description: "Drag-and-drop components using dnd-kit library with proper sensor configuration"

  - path: "src/hooks/**/*{Drag,Drop,Sortable}*.{ts,tsx}"
    must_contain:
      - "useSortable"
      - "setNodeRef"
    description: "Custom hooks for drag-and-drop functionality with proper refs and transforms"

  - path: "src/**/*.{tsx,ts,jsx,js}"
    must_contain:
      - "aria-label"
      - "role="
    description: "Accessibility attributes for drag-and-drop interactions (ARIA labels and roles)"

conditional_outputs:
  maturity:
    starter:
      - path: "src/components/**/Sortable*.{tsx,jsx}"
        must_contain:
          - "verticalListSortingStrategy"
          - "arrayMove"
          - "onDragEnd"
        description: "Basic sortable list component with vertical sorting"

      - path: "src/**/*.{tsx,ts,jsx,js}"
        must_contain:
          - "PointerSensor"
          - "KeyboardSensor"
        description: "Basic pointer and keyboard sensor configuration for accessibility"

    intermediate:
      - path: "src/components/**/{Kanban,Board}*.{tsx,jsx}"
        must_contain:
          - "DragOverlay"
          - "onDragOver"
          - "onDragStart"
        description: "Multi-container drag-drop with kanban board pattern and drag overlay"

      - path: "src/components/**/{Dropzone,FileUpload}*.{tsx,jsx}"
        must_contain:
          - "accept"
          - "FileWithMeta"
          - "progress"
        description: "File dropzone component with upload progress and file validation"

      - path: "src/**/*.{tsx,ts,jsx,js}"
        must_contain:
          - "aria-live"
          - "aria-describedby"
        description: "Advanced accessibility with live regions for screen reader announcements"

    advanced:
      - path: "src/components/**/Grid*.{tsx,jsx}"
        must_contain:
          - "rectSortingStrategy"
          - "grid"
        description: "2D grid layout with rect sorting strategy for dashboard widgets"

      - path: "src/hooks/**/use{DragDrop,Sortable}*.{ts,tsx}"
        must_contain:
          - "useMemo"
          - "useCallback"
        description: "Optimized custom hooks with memoization for performance"

      - path: "src/**/*.{tsx,ts,jsx,js}"
        must_contain:
          - "virtualScroll"
          - "throttle"
        description: "Performance optimizations with virtualization and throttling for large lists"

      - path: "src/utils/**/drag*.{ts,js}"
        must_contain:
          - "calculateDropPosition"
          - "collision"
        description: "Custom collision detection and drop position calculation utilities"

  frontend_framework:
    react:
      - path: "src/**/*.{tsx,jsx}"
        must_contain:
          - "useState"
          - "useEffect"
          - "@dnd-kit"
        description: "React components with dnd-kit hooks and state management"

      - path: "src/**/*.{tsx,jsx}"
        must_contain:
          - "useSortable"
          - "CSS.Transform.toString"
        description: "dnd-kit sortable hooks with CSS transform utilities"

    vue:
      - path: "src/**/*.vue"
        must_contain:
          - "ref"
          - "computed"
        description: "Vue components with reactive drag-drop state (if Vue-compatible library used)"

  styling:
    css:
      - path: "src/**/*.css"
        must_contain:
          - ".drag-handle"
          - "cursor: grab"
          - "opacity"
        description: "CSS for drag handles, cursor states, and dragging visual feedback"

      - path: "src/**/*.css"
        must_contain:
          - "transform"
          - "transition"
        description: "CSS transforms and transitions for smooth drag animations"

    styled_components:
      - path: "src/**/*.{tsx,jsx,ts,js}"
        must_contain:
          - "styled"
          - "css`"
          - "isDragging"
        description: "Styled-components with dynamic styling based on drag state"

    tailwind:
      - path: "src/**/*.{tsx,jsx}"
        must_contain:
          - "className="
          - "cursor-grab"
          - "opacity-50"
        description: "Tailwind classes for drag states (grab cursor, opacity, hover effects)"

    design_tokens:
      - path: "src/**/*.{css,tsx,jsx}"
        must_contain:
          - "var(--color-"
          - "var(--shadow-"
          - "var(--radius-"
        description: "Design token variables for consistent theming (colors, shadows, borders)"

scaffolding:
  - path: "src/types/drag-drop.ts"
    reason: "TypeScript type definitions for drag state, events, and configuration"

  - path: "src/utils/drag-calculations.ts"
    reason: "Utility functions for drop position calculation and collision detection"

  - path: "src/hooks/useDragDrop.ts"
    reason: "Custom hook abstracting common drag-and-drop logic and state management"

  - path: "src/components/DragHandle/index.tsx"
    reason: "Reusable drag handle component with proper accessibility and visual affordance"

  - path: "src/config/dnd-config.ts"
    reason: "Centralized dnd-kit configuration (sensors, modifiers, animations)"

metadata:
  primary_blueprints: ["dashboard", "frontend"]
  contributes_to:
    - "Drag-and-drop interactions"
    - "Sortable lists and tables"
    - "Kanban boards"
    - "File upload zones"
    - "Reorderable grids"
    - "Dashboard widget management"
    - "Interactive spatial organization"
    - "Touch-friendly UI manipulation"

  validation_notes:
    - "All drag-drop components MUST include keyboard navigation support"
    - "Screen reader announcements required via aria-live regions"
    - "Touch support required for mobile (long press activation)"
    - "Drag handles should use ⋮⋮ or similar visual indicator"
    - "Alternative non-drag UI must be provided for accessibility"
    - "CSS transforms preferred over position changes for performance"
    - "Virtualization required for lists with >100 items"
    - "All sensor configurations must include both pointer and keyboard"

  key_patterns:
    sortable_list:
      files: ["SortableList.tsx", "useSortable.ts"]
      must_include: ["verticalListSortingStrategy", "arrayMove", "drag-handle"]

    kanban_board:
      files: ["KanbanBoard.tsx", "TaskCard.tsx", "BoardColumn.tsx"]
      must_include: ["DragOverlay", "onDragOver", "closestCorners", "wipLimit"]

    file_dropzone:
      files: ["FileDropzone.tsx", "useFileUpload.ts"]
      must_include: ["accept", "maxSize", "FileWithMeta", "progress"]

    grid_reorder:
      files: ["GridLayout.tsx", "GridItem.tsx"]
      must_include: ["rectSortingStrategy", "display: grid", "responsive"]

  dependencies:
    required:
      - "@dnd-kit/core"
      - "@dnd-kit/sortable"
      - "@dnd-kit/utilities"

    optional:
      - "@dnd-kit/modifiers"
      - "react-virtual"
      - "framer-motion"

  accessibility_requirements:
    critical:
      - "Keyboard navigation (Space/Enter to grab, Arrow keys to move)"
      - "Screen reader announcements for all drag events"
      - "Focus management during drag operations"
      - "Alternative UI (move up/down buttons) for non-drag interaction"
      - "ARIA attributes (aria-grabbed, aria-dropeffect, role)"

    recommended:
      - "Visual focus indicators with high contrast"
      - "Drag instructions in sr-only element"
      - "Live region with aria-live='assertive'"
      - "Clear visual feedback for valid/invalid drop zones"

  performance_thresholds:
    small_list: "<50 items - standard implementation"
    medium_list: "50-100 items - add memoization and throttling"
    large_list: ">100 items - implement virtual scrolling"

  mobile_considerations:
    - "Long press (250-300ms) to initiate drag"
    - "Touch target minimum 44px for handles"
    - "Prevent scroll during drag operation"
    - "Handle gesture conflicts with native scrolling"
    - "Test on actual mobile devices, not just browser emulation"