music_library/backlog/completed/ml-145 - Restructure-scrobble-routes-reuse-Release-component-on-scrobble-page.md

id, title, status, assignee, created_date, updated_date, labels, dependencies, references, documentation, priority

id	title	status	assignee	created_date	updated_date	labels	dependencies	references	documentation	priority
ML-145	Restructure /scrobble routes; reuse Release component on scrobble page	Done		2026-04-23 06:11	2026-04-23 14:15	ui scrobble refactor liveview		lib/music_library_web/components/release.ex lib/music_library_web/live/scrobble_live/index.ex lib/music_library_web/live/scrobble_live/show.ex lib/music_library/records/tracklist_pdf.ex backlog/ml-142/plan.md backlog/tasks/ml-142.1 - Port-Finished-at-picker-and-selection-bar-to-ScrobbleLive.Show.md	.claude/plans/scrobble-route-restructure/design.md	medium

Description

Why

/scrobble/:release_id (MusicLibraryWeb.ScrobbleLive.Show) re-implements scrobbling UI that already exists as a LiveComponent used by collection/wishlist show pages (MusicLibraryWeb.Components.Release). Today the scrobble page imports medium/1 and scrobble_button_label/1 from that component but reimplements scrobble_release / scrobble_medium / scrobble_selected_tracks with hard-coded DateTime.utc_now/0, no Finished at picker, and no selection bar. ML-142.1 proposed porting those affordances into ScrobbleLive.Show in parallel — which would leave two drifting implementations.

This task takes the opposite approach: make the Release LiveComponent reusable outside the sheet (currently tightly coupled to %Records.Record{} and wrapped in <.sheet>), restructure the scrobble routes into a bookmarkable hierarchy, and delete the custom scrobble UI in favour of reuse.

Supersedes ML-142.1 — the ML-142.1 ACs become free once the component is reused on the new scrobble page. ML-142.1 can be archived as superseded.

What

Three routes:

• /scrobble — search only. Release-group clicks <.link navigate> to /scrobble/:rg_id (no more inline release-loading state).
• /scrobble/:rg_id (new) — release-group header (cover, title, primary artist, type badge, first-release date, release count) + full list of releases; each release links to /scrobble/:rg_id/releases/:release_id.
• /scrobble/:rg_id/releases/:release_id (new, replaces /scrobble/:release_id) — the scrobble page itself, rendered by the same LiveComponent that powers the collection/wishlist show sheet.

Old /scrobble/:release_id → 404 (personal app; bookmark churn is acceptable, not worth 301-redirect plumbing).

Key refactor decisions (working design doc: .claude/plans/scrobble-route-restructure/design.md, local-only)

1. Release LiveComponent input contract — takes release_id (string) instead of record; adds show_print?: boolean. Header title/artists derive from the loaded %MusicBrainz.Release{}.
2. <.sheet> moves to callsites — single render path for the component. Collection/wishlist show pages wrap in their own <.sheet>; the scrobble release page renders it directly under <Layouts.app>.
3. Selection bar stickiness — switches to position: sticky so it works both inside a sheet (pins to sheet bottom) and on a page (pins to viewport bottom) with single markup, no mode flag.
4. TracklistPdf signatures — generate/1 and generate_medium/2 take a %MusicBrainz.Release{}; no %Records.Record{} required (both fields used by the PDF — title and artists — already exist on the release struct).
5. Module names — new MusicLibraryWeb.ScrobbleLive.ReleaseGroupShow at /scrobble/:rg_id; rename MusicLibraryWeb.ScrobbleLive.Show → MusicLibraryWeb.ScrobbleLive.ReleaseShow at /scrobble/:rg_id/releases/:release_id, removing its custom scrobble UI in favour of embedding the LiveComponent.
6. Unused after refactor — MusicLibraryWeb.Components.Release.scrobble_button_label/1 (delete).

Non-goals

• Scrobble-rule picker on the scrobble page (fresh MB releases have no misrecognised tracks yet).
• Cross-link to /collection/:id when the release is already collected.
• 301-redirecting old /scrobble/:release_id URLs.
• Breadcrumbs on the scrobble page.
• Preserving ?query=X across nested URLs (browser back button already works).
• Splitting the Release LiveComponent into separate Content / Sheet modules.
• Changes to MusicLibrary.ScrobbleActivity.

Acceptance Criteria

• #1 /scrobble/:rg_id renders a release-group header (cover, release-group title, primary artist, type badge, first-release date, release count) and the full list of releases returned by MusicBrainz for that group.
• #2 Each release in the /scrobble/:rg_id list is a navigate link to /scrobble/:rg_id/releases/:release_id.
• #3 /scrobble/:rg_id shows an error toast and redirects to /scrobble if fetching the release group or its releases fails.
• #4 /scrobble/:rg_id/releases/:release_id renders a scrobble page with picker-driven Finished at, release-level scrobble, per-medium scrobble, track-selection + selection-bar scrobble, and Print tracklist — behaviour identical to the collection/wishlist show sheet.
• #5 /scrobble/:rg_id/releases/:release_id has a Back to releases link that navigates to /scrobble/:rg_id.
• #6 Old /scrobble/:release_id returns 404 (not redirected, not aliased).
• #7 /scrobble no longer renders releases inline; release-group list items are navigate links to /scrobble/:rg_id. The ?query=X search param still works as before.
• #8 The Release LiveComponent on the scrobble page and on the collection/wishlist sheet share a single implementation — there is no parallel reimplementation of scrobble handlers, picker, or selection bar.
• #9 The selection bar stays visible at the bottom of the visible scroll region in both contexts (scrobble page viewport, collection/wishlist sheet inner scroll) while tracks scroll, using a single markup path.
• #10 MusicLibrary.Records.TracklistPdf generates tracklist PDFs from a MusicBrainz release struct alone (no Records.Record required). Output for collection/wishlist records is visually unchanged.
• #11 The Release LiveComponent supports suppressing both the release-level and per-medium Print tracklist dropdown entries via a single input (both hidden together); the suppression state is covered by a component test.
• #12 MusicLibraryWeb.ScrobbleLive.Show's custom scrobble UI and handlers (scrobble_release, scrobble_medium, scrobble_selected_tracks, validate, recover_form) are deleted. MusicLibraryWeb.Components.Release.scrobble_button_label/1 is deleted as unused.
• #13 All new user-facing strings are wrapped in gettext; .pot/.po files regenerated via mix gettext.extract --merge.
• #14 Tests updated: test/music_library_web/components/release_test.exs covers the new release_id input contract and both states of the print-suppression input; test/music_library/records/tracklist_pdf_test.exs covers the new generate/1 and generate_medium/2 signatures.
• #15 Tests added: test/music_library_web/live/scrobble_live/release_group_show_test.exs covers happy path (header fields + releases list + link targets) and fetch failure (toast + redirect); test/music_library_web/live/scrobble_live/release_show_test.exs (replacing show_test.exs) smoke-tests mount, component render, and back-link target.
• #16 Tests updated: test/music_library_web/live/scrobble_live/index_test.exs asserts release-group clicks navigate (no inline state); collection/wishlist show tests updated for the new component input shape and callsite sheet markup.
• #17 Manual UI verification via iex -S mix phx.server: sheet selection-bar still pins correctly on collection/wishlist show pages; page selection-bar pins to viewport bottom on scrobble page while tracks list scrolls; navigation loop /scrobble → /scrobble/:rg_id → /scrobble/:rg_id/releases/:release_id → back → back works, and ?query=X survives the browser back button.

Final Summary

Summary

Restructured /scrobble into a three-level URL hierarchy (/scrobble → /scrobble/:rg_id → /scrobble/:rg_id/releases/:release_id) and eliminated the duplicated scrobble UI by making the Release LiveComponent reusable on a standalone page.

Supersedes ML-142.1 — picker and selection bar now live on the scrobble page via reuse, not via a parallel port.

Implementation

Ten commits on branch ml-145-scrobble-route-restructure:

• 8631b97b Add joinphrase to Release.Artist; parse from MB
• 0d1f5803 Refactor TracklistPdf to take release alone
• 4c48bda7 Refactor Release component to take release_id
• d8041dc0 Add /scrobble/:rg_id release-group page
• 0dcd6eab Replace /scrobble/:release_id with nested route
• c7c7e1fe Navigate from scrobble search to release-group page
• 72818bfa Validate release-group shape before parsing
• 779708e6 Hide print tracklist on scrobble release page
• ca9cc768 Hide release-actions dropdown when empty
• 62586c9a Restore flex context for sheet selection bar

Key changes:

• MusicBrainz.Release.Artist gains :joinphrase so TracklistPdf can work from a release struct alone.
• MusicLibraryWeb.Components.Release takes release_id + show_print? (instead of record); header title/artists derive from the loaded release; <.sheet> wrapper moved to callsites; release-actions dropdown auto-hides when both print + connect-last-fm are disabled.
• CollectionLive.Show wraps the component in its own <.sheet> with show_print?={true}.
• New ScrobbleLive.ReleaseGroupShow at /scrobble/:rg_id — async-fetches the release group + its releases, renders header (cover, title, primary artist, type badge, first-release date, release count) + list of releases.
• New ScrobbleLive.ReleaseShow at /scrobble/:rg_id/releases/:release_id — thin LiveView embedding the Release LiveComponent directly (no sheet), passes show_print?={false}.
• ScrobbleLive.Index loses inline release-loading state; release-group clicks navigate to /scrobble/:rg_id.
• Old ScrobbleLive.Show module and test, plus Components.Release.scrobble_button_label/1, deleted.

Verification findings + fixes

Two bugs surfaced during Phase 8 verification:

1. Error-path crash in ReleaseGroupShow.load/1. When MusicBrainz.get_release_group/1 returned an unexpected response shape, ReleaseGroupSearchResult.from_api_response/1 crashed on Enum.map_join(nil, …). The test passed because handle_async({:exit, …}, …) caught it, but the stack trace appeared in logs. Fixed with an explicit parse_release_group/1 helper that pattern-guards the shape and returns {:error, :invalid_release_group_response} for bad input, routing cleanly through the graceful {:error, reason} handler.

2. Sheet layout regression. The Phase-3 root-<div> replacement for <.sheet> did not establish a flex context, so the form's flex-1 no longer expanded inside the sheet, which pushed the selection bar away from the bottom. Fixed by giving the root <div> classes flex h-full min-h-0 flex-1 flex-col — single markup that works in both sheet (flex-pinned last child) and page (sticky-pinned to viewport) contexts.

Tests

• Full suite: 815 passed (43 doctests, 772 tests), 0 skipped.
• mix compile --warnings-as-errors: clean.
• mise run dev:precommit: clean (shellcheck, credo, sobelow, translations, formatting, unused deps, full test run).

New coverage:

• test/music_library_web/live/scrobble_live/release_group_show_test.exs — happy path (header + release links) and fetch failure (toast + redirect to /scrobble).
• test/music_library_web/live/scrobble_live/release_show_test.exs — smoke (mount + component render + back link target).
• show_print?={true|false} verified via Phoenix.LiveViewTest.live_isolated/3 in release_test.exs.

Deleted: test/music_library_web/live/scrobble_live/show_test.exs (replaced by the smoke test above).

Manual UI verification (Phase 8 AC#17)

Confirmed by user in dev server:

• Navigation loop /scrobble → /scrobble/:rg_id → /scrobble/:rg_id/releases/:release_id works; ?query=X survives browser back.
• Scrobble release page: picker, per-release/medium/track scrobble, and selection bar sticky at viewport bottom.
• Collection show sheet: selection bar pins to sheet bottom while tracks scroll.
• Print tracklist works on collection show; correctly hidden on scrobble page.
• Release-actions dropdown button hides entirely on scrobble page (empty dropdown) when Last.fm is connected.

Follow-ups

• ML-142.1 is now fully superseded and can be archived (not done here — archive is a user decision).