# Research: Migration Dashboard Grid

## 1. Superset API Capabilities

**Objective**: Verify how to fetch dashboard metadata (title, last modified, status).

- **Findings**:
  - The `SupersetClient.get_dashboards` method in `superset_tool/client.py` already exists.
  - It fetches the following columns by default: `["slug", "id", "changed_on_utc", "dashboard_title", "published"]`.
  - This covers all requirements:
    - Name -> `dashboard_title`
    - Last Modified -> `changed_on_utc`
    - Status -> `published`
  - Pagination is handled internally by `_fetch_all_pages`, so the client fetches *all* dashboards.

- **Decision**: Use the existing `SupersetClient.get_dashboards` method. No changes needed to the core client.

## 2. Frontend Grid Implementation

**Objective**: Choose a strategy for the grid component (filtering, sorting, pagination).

- **Options**:
  1.  **Server-side pagination**: Fetch page by page. Good for huge datasets (>10k).
  2.  **Client-side pagination**: Fetch all, filter/sort/paginate in browser. Good for typical datasets (<1k) and simplifies "Select All" logic.

- **Findings**:
  - Spec explicitly requests "Client-side (Fetch all, filter locally)".
  - Spec requires "Select All" to select *all filtered results*, which is trivial with client-side state but complex with server-side pagination (requires tracking exclusion list or query parameters).
  - Existing `MappingTable.svelte` is too simple (no sorting/pagination).

- **Decision**:
  - Implement a new `DashboardGrid.svelte` component.
  - **State Management**:
    - `dashboards`: Array of all fetched dashboards.
    - `filterText`: String for name filtering.
    - `sortColumn`: 'title' | 'changed_on' | 'published'.
    - `sortDirection`: 'asc' | 'desc'.
    - `currentPage`: Integer.
    - `pageSize`: Integer (default 20).
    - `selectedIds`: Set/Array of selected dashboard IDs.
  - **Logic**:
    - `filteredDashboards`: Derived store/value based on `dashboards` + `filterText`.
    - `sortedDashboards`: Derived from `filteredDashboards` + `sort` params.
    - `paginatedDashboards`: Slice of `sortedDashboards` for current page.
    - "Select All": Adds all IDs from `sortedDashboards` (not just `paginatedDashboards`) to `selectedIds`.

## 3. API Contract

**Objective**: Define the endpoint to serve dashboard data.

- **Current State**: Need to check if an endpoint exists that returns this data.
- **Requirement**: `GET /api/migration/dashboards` (or similar).
- **Response Structure**:
  ```json
  [
    {
      "id": 123,
      "title": "Sales Dashboard",
      "changed_on": "2023-10-27T10:00:00Z",
      "published": true
    },
    ...
  ]
  ```

- **Decision**: Create or update a route in `backend/src/api/routes/migration.py` (or `mappings.py` if more appropriate, but `migration` seems better for source selection).