# Implementation Plan: Queue Collapsible Sections

## Overview

Add collapsible, grouped sections to the IvantiTodoQueuePage. Items are organized into a hybrid layout: an "Inventory" section (CARD, GRANITE, DECOM workflow types) at the top, followed by vendor-grouped sections for FP and Archer items. Each section has a clickable header that toggles visibility. This is a frontend-only change to a single file with property-based tests for the grouping logic.

## Tasks

- [x] 1. Add section header styles and icon imports
  - [x] 1.1 Add ChevronDown and ChevronRight to the lucide-react import statement
    - Add `ChevronDown, ChevronRight` to the existing import from `lucide-react`
    - _Requirements: 5.2_

  - [x] 1.2 Add section header style entries to the STYLES constant
    - Add `sectionHeaderInventory`, `sectionHeaderVendor`, and `sectionCount` style objects to the existing `STYLES` constant
    - Use green accent (`#10B981`) for Inventory header, neutral (`#94A3B8`) for vendor headers
    - Include `cursor: 'pointer'`, `userSelect: 'none'`, monospace font, uppercase text
    - _Requirements: 3.3, 3.4, 3.5, 5.1, 5.3_

- [x] 2. Implement grouping computation and collapse state
  - [x] 2.1 Add the `groupedSections` useMemo hook
    - Add a `useMemo` that transforms `visibleItems` into an array of section objects `{ key, label, type, items }`
    - Items with workflow_type CARD, GRANITE, or DECOM go into the Inventory section
    - Remaining items are grouped by vendor field (null/empty vendor → "Unknown")
    - Inventory section appears first (if non-empty), vendor sections sorted alphabetically
    - Sections with zero items are omitted
    - _Requirements: 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7_

  - [x] 2.2 Add collapse state and toggle handler
    - Add `const [collapsedSections, setCollapsedSections] = useState({})` for collapse tracking
    - Add `toggleSection` callback that flips the boolean for a given section key
    - All sections default to expanded (empty object → falsy lookup)
    - _Requirements: 2.2, 2.7_

- [x] 3. Refactor render to use grouped sections with collapsible headers
  - [x] 3.1 Replace flat `visibleItems.map(...)` with grouped section rendering
    - Map over `groupedSections` instead of `visibleItems` directly
    - For each section, render a clickable Section Header with chevron icon, label, and item count
    - Conditionally render section body (item rows) only when section is not collapsed
    - Preserve existing queue item row rendering logic inside each section body
    - Add `role="button"`, `tabIndex={0}`, `aria-expanded`, `aria-label` to section headers for accessibility
    - _Requirements: 2.1, 2.3, 2.4, 2.5, 2.6, 3.1, 3.2_

  - [x] 3.2 Verify cross-section selection still works correctly
    - Ensure Select All checkbox still toggles all `visibleItems` across all sections regardless of collapse state
    - Ensure selection count reflects total selected items across all sections
    - Ensure floating action bar operates on all selected items regardless of collapse state
    - Ensure collapsing a section does not clear or modify `selectedIds`
    - _Requirements: 4.1, 4.2, 4.3, 4.4, 4.5, 4.6_

  - [x] 3.3 Verify existing functionality is preserved
    - Ticket link badges continue to display on items with associated Jira tickets
    - Consolidation modal continues to function with selected items
    - Floating action bar appears when items are selected
    - Completed items count still displays at the bottom
    - Empty state renders without section headers when no visible items exist
    - _Requirements: 5.4, 5.5, 5.6, 5.7, 5.8_

- [x] 4. Checkpoint - Ensure frontend builds successfully
  - Ensure all tests pass, ask the user if questions arise.

- [x] 5. Write property-based tests for grouping logic
  - [x]* 5.1 Write property test: Grouping Correctness
    - **Property 1: Grouping Correctness**
    - Every item with workflow_type CARD, GRANITE, or DECOM appears in the Inventory section; every FP/Archer item appears in the vendor section matching its vendor field (or "Unknown" if null/empty); no item appears in more than one section
    - Extract the grouping logic into a testable pure function or test it inline
    - **Validates: Requirements 1.1, 1.2, 1.5**

  - [x]* 5.2 Write property test: Section Ordering
    - **Property 2: Section Ordering**
    - Inventory section (if present) is always first; vendor sections are sorted alphabetically by label
    - **Validates: Requirements 1.3, 1.4**

  - [x]* 5.3 Write property test: Empty Section Omission
    - **Property 3: Empty Section Omission**
    - No section in the output has zero items; if no inventory-type items exist, no Inventory section appears
    - **Validates: Requirements 1.6, 1.7**

  - [x]* 5.4 Write property test: Section Header Count Accuracy
    - **Property 4: Section Header Count Accuracy**
    - For every section, the items array length equals the count that would be displayed in the header
    - **Validates: Requirements 3.1, 3.2**

  - [x]* 5.5 Write property test: Selection Independence from Collapse State
    - **Property 5: Selection Independence from Collapse State**
    - Toggling collapse state does not alter the set of selected item IDs; Select All always covers all visible items regardless of collapse
    - **Validates: Requirements 4.2, 4.4, 4.5**

- [x] 6. Final checkpoint - Ensure all tests pass
  - Ensure all tests pass, ask the user if questions arise.

## Notes

- Tasks marked with `*` are optional and can be skipped for faster MVP
- This is a frontend-only change to a single file: `frontend/src/components/pages/IvantiTodoQueuePage.js`
- Property tests should use `fast-check` (already a project dependency) and extract the grouping logic as a pure function for testability
- The selection logic (`selectedIds`, `toggleSelectAll`, `allVisibleSelected`) operates on `visibleItems` which is independent of collapse state — no changes needed to selection logic
- The collapse state is purely visual — it controls rendering, not data

## Task Dependency Graph

```json
{
  "waves": [
    { "id": 0, "tasks": ["1.1", "1.2"] },
    { "id": 1, "tasks": ["2.1", "2.2"] },
    { "id": 2, "tasks": ["3.1"] },
    { "id": 3, "tasks": ["3.2", "3.3"] },
    { "id": 4, "tasks": ["5.1", "5.2", "5.3", "5.4", "5.5"] }
  ]
}
```