# Component Analytics Hook

## Objective

Instrument shared components once instead of hand-writing events on every screen.

Interaction tracking attached to the app's shared components, emitting named events carrying the context of where they were used.

## Before You Begin

This feature is being added to an application that already exists and already
works. Do not scaffold a new project, and do not assume a blank slate.

Inspect the codebase first and establish:

- The existing application structure and where code of this kind already lives.
- The framework and version in use.
- The existing design system — colours, spacing, typography, and component conventions.
- Existing UI components you can reuse instead of writing new ones.
- The existing database structure, if this feature needs to persist anything.
- The existing authentication and authorization system, if this feature is user-scoped.
- Dependencies already installed, so you don't add a library that duplicates one.
- The existing test setup and conventions.

Only start writing code once you understand the above. If the application
already implements part of this feature, extend it rather than replacing it.

## Implementation Instructions

1. Identify the shared components that account for most interaction — buttons, links, menus, dialogs, tabs, table rows, form submits — and attach tracking inside them rather than at each of the hundreds of call sites.
2. Have each component emit its own identity and the context it was rendered in: the screen, the surface, and a stable identifier supplied by the caller. Position on the page and visible label are not identity.
3. Emit exactly one event per user action. A menu item inside a card inside a table row must not produce three overlapping records of the same click.
4. Keep component events separate from business events. A dialog opening is a UI fact; a subscription being upgraded is a product fact recorded where the outcome is confirmed, not where the button was pressed.
5. Names, properties, and versioning are owned by UI Event Naming Schema, and redaction, sampling, and consent are owned by Interaction Telemetry Guardrails. This feature owns where events originate and what context they carry. Do not restate either policy inside the components.

## UI and UX Requirements

Match the application's existing design system exactly. Reuse its components,
spacing, and typography. This feature should look like it was always there.

## Responsive Requirements

Works on mobile, tablet, and desktop. Touch targets are large enough to hit on a
phone, and nothing overflows horizontally at 320px.

## Accessibility Requirements

- Fully keyboard navigable.
- Correct semantic elements and ARIA roles.
- Visible focus states.
- Meets WCAG AA contrast.
- Dynamic changes are announced to screen readers.
- Respects prefers-reduced-motion.

## Edge Cases

- Nested interactive components will each see the same click as it bubbles, producing duplicate events for one action. Decide which level owns the event and stop it from being recorded again as it travels upward.
- A component event and a business event describing the same moment must not be conflated. Tracking an upgrade at the button records intent, including the attempts that failed at payment, which is a different number from upgrades that happened.
- Component properties must never carry the values inside them. A search field emits that a search ran, not the query; a row emits its record identifier, not the customer's name or email.
- Names must survive a visual refactor. An event tied to a component's current label, colour, or place in the layout breaks the moment the page is redesigned, which is exactly when the comparison matters most.
- Rapid repeated interaction — a double click on submit, a held arrow key through a list — must be collapsed rather than emitted once per event.
- Components rendered off-screen, in a hidden tab, or restored from a cached page must not emit view events for things nobody saw.
- Events queued while the browser is offline or during a page unload need a delivery path, or the last action before someone leaves is always the one that is missing.

## Testing

Exercise the feature end to end in the running application. Cover every edge case
above, then run the existing test suite and confirm nothing regressed.

## Acceptance Criteria

- [ ] Shared components emit their own interaction events without per-screen instrumentation.
- [ ] Each event carries a stable component identifier plus its screen and surface context.
- [ ] One user action produces exactly one event, including in nested interactive components.
- [ ] Component events and business events are separate streams with separate names.
- [ ] No event property contains user-entered text or personal data.
- [ ] Event identity is unchanged by a visual redesign of the component.
- [ ] Naming and privacy policy live in their own features rather than being duplicated in component code.
- [ ] The feature matches the existing design system.
- [ ] No existing functionality is broken.

## Adaptation Rules

- Match the existing design system. Do not introduce a new colour palette,
  spacing scale, or component library.
- Reuse existing components and utilities wherever they fit.
- Follow the naming, file layout, and code style already present.
- Do not upgrade, replace, or remove existing dependencies to make this
  feature fit. Adapt the feature to the app, not the app to the feature.
- Do not break existing functionality. If a change is genuinely required in
  existing code, make the smallest one that works and say so.
- If something in these instructions conflicts with how the application is
  built, follow the application and explain the deviation.

## Final Verification

Before you report the work as done:

1. Re-read the acceptance criteria above and check each one against what you
   actually built.
2. Run the application and exercise the feature end to end.
3. Run the existing test suite and confirm you have broken nothing.
4. Check the feature on mobile, tablet, and desktop widths.
5. Check keyboard navigation and focus handling.
6. Summarize what changed: files added, files modified, and anything you
   deliberately did differently because of how this application is built.

If any acceptance criterion is unmet, fix it before reporting completion.