# Location Map Block

## Objective

Put an interactive map on a page showing one location or a whole list of them.

A reusable map block rendering one or many pinned locations, with a static fallback and a text address alternative.

## 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. The app already has Mapbox Geocoding and Google Places Address Lookup. Turn addresses into coordinates through the existing integration and store the result on the record; do not add a second geocoding path for this block.
2. Make the block take either a single location or a collection, and render the same component for both. A one-pin map is a collection of one, not a separate feature.
3. Reserve the block's height before the map initialises so the surrounding page does not jump when tiles arrive. The placeholder should occupy exactly the space the map will fill.
4. Render the address as real text next to or beneath the map, with a link that opens the location in the viewer's own maps application. The map is the decoration; the address is the information.
5. Do not load map tiles or scripts until the block is close to the viewport. A map at the foot of a long page should not cost every visitor a download and a paid tile request they never look at.

## 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

- The map provider can be blocked by a network, an extension, or an outage. Detect that initialisation did not complete and swap in a static image or a plain styled address card, rather than leaving a grey rectangle that never resolves.
- Pins that sit close together merge into an unreadable clump at low zoom. Cluster them into a labelled group that expands as the viewer zooms in, and make sure the count on the cluster is accurate.
- A full-width map on a phone captures the page scroll and traps the visitor. Require a deliberate gesture or a tap to activate panning and zooming, and restore normal page scrolling when the map loses focus.
- Geocoding the same address on every render burns quota and adds latency. Cache the resolved coordinates against the address and only re-resolve when the address text actually changes.
- A map conveys nothing to a screen reader. Provide the address, and for a collection the list of locations, as readable text in the document rather than relying on the map canvas or on alt text alone.
- An address that cannot be geocoded must still render something useful. Show the address text and omit the pin instead of dropping the block or centring the map on the middle of the ocean.
- Interactive maps are heavy and animate on load. Respect the app's Reduced Motion Support by skipping fly-to animations and rendering the map already at its final position.
- Precise pins on private residences expose more than intended. Where a location is a person's home, offer an approximate radius rather than an exact point.

## 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

- [ ] The block renders a single location and a list of locations through one component.
- [ ] Coordinates come from the app's existing geocoding integration and are cached against the address.
- [ ] A blocked or failed map provider degrades to a static image or address card, never a blank area.
- [ ] The page does not shift when the map loads, and the map does not load until near the viewport.
- [ ] Overlapping pins cluster with accurate counts at low zoom.
- [ ] Page scrolling is not hijacked on touch devices.
- [ ] Every location is available as readable text with a link to an external maps application.
- [ ] 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.