in0 split album.source.sh into cohesive modules

Refactor the ~1442-line album.source.sh ([SRP] violation) into three
cohesive modules, leaving album.source.sh a thin coordinator. Pure code
move, no behavior change -- whole functions and their doc comments moved
verbatim; the assembled bin/shuriken contains the same function set.

- image-pipeline.source.sh: ImageMagick derivative generation
  (create_photo_derivatives, create_all_photo_derivatives) and photo
  asset prep (prepare_generation_photo_assets).
- album-metadata.source.sh: EXIF identify caching, exif tooltip/details
  helpers, file counts, shuriken.json metadata, EXIF cache clearing and
  the dry-run plan.
- album-render.source.sh: preview/view/details/splash/redirect page
  rendering, the parallel render-job orchestration and the
  ALBUM_VIEW_PAGE_BY_PHOTO global.
- album.source.sh: thin coordinator (generate, refresh_splash,
  generate_stats_pages, site-asset/archive/html-clean helpers).

Add the three modules to LIB_SOURCES (Justfile) and to the
SHURIKEN_LIB_SOURCES markers in src/shuriken.sh, ordered after random
and before album.source.sh / stats.source.sh.

just build, just test, just shellcheck, just check-generated and
git diff --check all pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

1 files changed, 739 insertions, 0 deletions

diff --git a/src/lib/album-render.source.sh b/src/lib/album-render.source.sh
new file mode 100644
index 0000000..ff86727
--- /dev/null
+++ b/src/lib/album-render.source.sh
@@ -0,0 +1,739 @@
+# Maps each album photo filename to its view-page basename ("<page>-<preview>")
+# as assigned during render_album_pages. The stats filter mini-albums read this
+# so each view page can link "Details" to the album's own details page for the
+# photo. Declared globally so it always exists for callers even when no album
+# was rendered.
+declare -gA ALBUM_VIEW_PAGE_BY_PHOTO=()
+
+album_photo_files() {
+    local -r photos_dir="$1"; shift
+
+    find "$DIST_DIR/$photos_dir" -maxdepth 1 -type f -printf '%f\n' \
+        | maybe_shuffle
+}
+
+start_preview_page() {
+    local -r photos_dir="$1"; shift
+    local -r html_dir="$1"; shift
+    local -r blurs_dir="$1"; shift
+    local -r backhref="$1"; shift
+    local -r page_name="$1"; shift
+    local -r header_bar="$1"; shift
+    local background_image
+
+    background_image=$(randomphoto "$photos_dir" "$page_name")
+    template header "$page_name.html" \
+        html_dir "$html_dir" \
+        backhref "$backhref" \
+        blurs_dir "$blurs_dir" \
+        background_image "$background_image" \
+        show_header_bar "$header_bar"
+}
+
+finish_preview_page() {
+    local -r page_name="$1"; shift
+    local -r html_dir="$1"; shift
+    local -r backhref="$1"; shift
+    local -r tarball_name="$1"; shift
+
+    template footer "$page_name.html" \
+        html_dir "$html_dir" \
+        backhref "$backhref" \
+        tarball_name "$tarball_name"
+}
+
+finish_preview_page_with_next() {
+    local -r page_name="$1"; shift
+    local -r html_dir="$1"; shift
+    local -r backhref="$1"; shift
+    local -r tarball_name="$1"; shift
+    local -r next_page="$1"; shift
+    local -r prev_page="$1"; shift
+
+    template next "$page_name.html" \
+        html_dir "$html_dir" \
+        next "$next_page" \
+        prev "$prev_page"
+    finish_preview_page "$page_name" "$html_dir" "$backhref" "$tarball_name"
+}
+
+render_previous_page_link() {
+    local -r page_name="$1"; shift
+    local -r html_dir="$1"; shift
+    local -r prev_page="$1"; shift
+
+    template prev "$page_name.html" \
+        html_dir "$html_dir" \
+        prev "$prev_page"
+}
+
+# Assemble one complete preview page (page-N.html) in a single call: header,
+# optional previous-page link, every thumbnail in order, then the footer (with
+# a next-page link unless this is the last page). The appends to the one page
+# file happen here, in sequence, so the per-page ordering is preserved even when
+# this whole function runs as one backgrounded render job (parallelism is only
+# ACROSS pages, never within a page). The page's photos are the trailing
+# positional arguments; each photo's preview index is its 1-based position.
+render_full_preview_page() {
+    local -r photos_dir="$1"; shift
+    local -r html_dir="$1"; shift
+    local -r thumbs_dir="$1"; shift
+    local -r blurs_dir="$1"; shift
+    local -r backhref="$1"; shift
+    local -r tarball_name="$1"; shift
+    local -r page_name="$1"; shift
+    local -r page_num="$1"; shift
+    local -r header_bar="$1"; shift
+    local -r prev_page="$1"; shift
+    local -r next_page="$1"; shift
+    local -i preview_num=0
+    local photo
+
+    start_preview_page \
+        "$photos_dir" "$html_dir" "$blurs_dir" "$backhref" "$page_name" \
+        "$header_bar"
+    if [ -n "$prev_page" ]; then
+        render_previous_page_link "$page_name" "$html_dir" "$prev_page"
+    fi
+
+    for photo in "$@"; do
+        (( ++preview_num ))
+        render_preview_thumbnail \
+            "$page_name" "$html_dir" "$thumbs_dir" "$backhref" \
+            "$page_num" "$preview_num" "$photo"
+    done
+
+    if [ -n "$next_page" ]; then
+        finish_preview_page_with_next \
+            "$page_name" "$html_dir" "$backhref" "$tarball_name" \
+            "$next_page" "$prev_page"
+    else
+        finish_preview_page "$page_name" "$html_dir" "$backhref" "$tarball_name"
+    fi
+}
+
+# Enqueue one complete preview page as a background render job, throttled to
+# IMAGE_JOBS via the shared template render job pool. Mirrors
+# queue_album_view_render_job: wait for a free slot, background the whole-page
+# assembly, then track its pid/label so a failed job flips render_failed and
+# makes generation fail loudly. The page's photos are passed as trailing
+# positional args; the background subshell forks a private copy of them, so the
+# caller is free to reuse its per-page accumulator for the next page.
+queue_preview_page_render_job() {
+    local -r photos_dir="$1"; shift
+    local -r html_dir="$1"; shift
+    local -r thumbs_dir="$1"; shift
+    local -r blurs_dir="$1"; shift
+    local -r backhref="$1"; shift
+    local -r tarball_name="$1"; shift
+    local -r page_name="$1"; shift
+    local -r page_num="$1"; shift
+    local -r header_bar="$1"; shift
+    local -r prev_page="$1"; shift
+    local -r next_page="$1"; shift
+    # shellcheck disable=SC2178
+    local -n render_job_pids_ref="$1"; shift
+    # Passed by name to wait_for_template_render_job_slot.
+    # shellcheck disable=SC2034,SC2178
+    local -n render_job_statuses_ref="$1"; shift
+    # Passed by name to wait_for_template_render_job_slot and assigned below.
+    # shellcheck disable=SC2034,SC2178
+    local -n render_job_labels_ref="$1"; shift
+    # shellcheck disable=SC2178
+    local -n render_failed_ref="$1"; shift
+    # Remaining positional args ("$@") are this page's photos in order.
+
+    wait_for_template_render_job_slot \
+        render_job_pids_ref \
+        render_job_statuses_ref \
+        render_job_labels_ref \
+        render_failed_ref
+    render_full_preview_page \
+        "$photos_dir" \
+        "$html_dir" \
+        "$thumbs_dir" \
+        "$blurs_dir" \
+        "$backhref" \
+        "$tarball_name" \
+        "$page_name" \
+        "$page_num" \
+        "$header_bar" \
+        "$prev_page" \
+        "$next_page" \
+        "$@" &
+    render_job_pids_ref+=("$!")
+    render_job_labels_ref["$!"]="template render job for preview $page_name"
+}
+
+render_preview_thumbnail() {
+    local -r page_name="$1"; shift
+    local -r html_dir="$1"; shift
+    local -r thumbs_dir="$1"; shift
+    local -r backhref="$1"; shift
+    local -r page_num="$1"; shift
+    local -r preview_num="$1"; shift
+    local -r photo_file="$1"; shift
+    local animation_class
+
+    animation_class=$(random_animation_css_class slow "$photo_file")
+    template preview "$page_name.html" \
+        html_dir "$html_dir" \
+        backhref "$backhref" \
+        thumbs_dir "$thumbs_dir" \
+        page_num "$page_num" \
+        preview_num "$preview_num" \
+        photo "$photo_file" \
+        animation_class "$animation_class"
+}
+
+render_view_page() {
+    local -r html_dir="$1"; shift
+    local -r photos_dir="$1"; shift
+    local -r blurs_dir="$1"; shift
+    local -r backhref="$1"; shift
+    local -r tarball_name="$1"; shift
+    local -r page_num="$1"; shift
+    local -r preview_num="$1"; shift
+    local -r photo_file="$1"; shift
+    local animation_class
+    local exif_tooltip_text
+
+    template header "$page_num-$preview_num.html" \
+        html_dir "$html_dir" \
+        backhref "$backhref" \
+        blurs_dir "$blurs_dir" \
+        background_image "$photo_file" \
+        show_header_bar 'no'
+
+    animation_class=$(random_animation_css_class fast "$photo_file")
+    # Reuse the same EXIF tooltip as the details page so hovering the image in
+    # the normal view shows the camera/exposure summary (reads the shared
+    # identify cache, so no extra ImageMagick work).
+    exif_tooltip_text=$(
+        photo_exif_tooltip_text "$photo_file" "$INCOMING_DIR/$photo_file"
+    )
+    template view "$page_num-$preview_num.html" \
+        html_dir "$html_dir" \
+        backhref "$backhref" \
+        photos_dir "$photos_dir" \
+        page_num "$page_num" \
+        preview_num "$preview_num" \
+        photo "$photo_file" \
+        animation_class "$animation_class" \
+        exif_tooltip "$exif_tooltip_text"
+    template footer "$page_num-$preview_num.html" \
+        html_dir "$html_dir" \
+        backhref "$backhref" \
+        tarball_name "$tarball_name"
+}
+
+render_details_page() {
+    local -r html_dir="$1"; shift
+    local -r photos_dir="$1"; shift
+    local -r blurs_dir="$1"; shift
+    local -r backhref="$1"; shift
+    local -r tarball_name="$1"; shift
+    local -r page_num="$1"; shift
+    local -r preview_num="$1"; shift
+    local -r photo_file="$1"; shift
+    local animation_class
+    local exif_details_html
+    local exif_tooltip_text
+
+    template header "$page_num-$preview_num-details.html" \
+        html_dir "$html_dir" \
+        backhref "$backhref" \
+        blurs_dir "$blurs_dir" \
+        background_image "$photo_file" \
+        show_header_bar 'no'
+
+    animation_class=$(random_animation_css_class fast "$photo_file")
+    exif_details_html=$(
+        photo_exif_details_html "$photo_file" "$INCOMING_DIR/$photo_file"
+    )
+    exif_tooltip_text=$(
+        photo_exif_tooltip_text "$photo_file" "$INCOMING_DIR/$photo_file"
+    )
+    template details "$page_num-$preview_num-details.html" \
+        html_dir "$html_dir" \
+        backhref "$backhref" \
+        photos_dir "$photos_dir" \
+        page_num "$page_num" \
+        preview_num "$preview_num" \
+        photo "$photo_file" \
+        animation_class "$animation_class" \
+        exif_details "$exif_details_html" \
+        exif_tooltip "$exif_tooltip_text"
+    template footer "$page_num-$preview_num-details.html" \
+        html_dir "$html_dir" \
+        backhref "$backhref" \
+        tarball_name "$tarball_name"
+}
+
+render_photo_view_and_details() {
+    local -r photos_dir="$1"; shift
+    local -r blurs_dir="$1"; shift
+    local -r html_dir="$1"; shift
+    local -r backhref="$1"; shift
+    local -r tarball_name="$1"; shift
+    local -r page_num="$1"; shift
+    local -r preview_num="$1"; shift
+    local -r photo="$1"; shift
+
+    render_view_page \
+        "$html_dir" \
+        "$photos_dir" \
+        "$blurs_dir" \
+        "$backhref" \
+        "$tarball_name" \
+        "$page_num" \
+        "$preview_num" \
+        "$photo"
+    render_details_page \
+        "$html_dir" \
+        "$photos_dir" \
+        "$blurs_dir" \
+        "$backhref" \
+        "$tarball_name" \
+        "$page_num" \
+        "$preview_num" \
+        "$photo"
+}
+
+record_rendered_view_page() {
+    # shellcheck disable=SC2178
+    local -n view_pages_ref="$1"; shift
+    # shellcheck disable=SC2178
+    local -n last_views_ref="$1"; shift
+    local -r page="$1"; shift
+    local -r preview="$1"; shift
+
+    if [ -z "${last_views_ref[$page]+set}" ]; then
+        view_pages_ref+=("$page")
+    fi
+    last_views_ref["$page"]="$preview"
+}
+
+# Render every navigation redirect for a single view page (the prev/next
+# wrap-around stubs that bounce N-0 / N-(last+1) to the neighbouring page).
+# Each redirect is its own self-contained file (the template overwrites it), so
+# this whole group is safe to run as one independent background job; only the
+# files for distinct pages are produced here. The wrap-around redirects for the
+# very last page (0-MAXPREVIEWS and the loop-to-1 links) are emitted as part of
+# that page's group.
+render_page_view_redirects() {
+    local -r html_dir="$1"; shift
+    local -ri page="$1"; shift
+    local -ri lastview="$1"; shift
+    local -ri max_page="$1"; shift
+    local -r prevredirect="${page}-0"
+    local -r nextredirect="${page}-$(( lastview + 1 ))"
+
+    template redirect "$prevredirect.html" \
+        html_dir "$html_dir" \
+        redirect_page "$(( page - 1 ))-${MAXPREVIEWS}"
+    template redirect "$prevredirect-details.html" \
+        html_dir "$html_dir" \
+        redirect_page "$(( page - 1 ))-${MAXPREVIEWS}-details"
+
+    if (( page == max_page )); then
+        template redirect "0-$MAXPREVIEWS.html" \
+            html_dir "$html_dir" \
+            redirect_page "${page}-$lastview"
+        template redirect "0-$MAXPREVIEWS-details.html" \
+            html_dir "$html_dir" \
+            redirect_page "${page}-$lastview-details"
+        template redirect "$nextredirect.html" \
+            html_dir "$html_dir" \
+            redirect_page '1-1'
+        template redirect "$nextredirect-details.html" \
+            html_dir "$html_dir" \
+            redirect_page '1-1-details'
+    else
+        template redirect "$nextredirect.html" \
+            html_dir "$html_dir" \
+            redirect_page "$(( page + 1 ))-1"
+        template redirect "$nextredirect-details.html" \
+            html_dir "$html_dir" \
+            redirect_page "$(( page + 1 ))-1-details"
+    fi
+}
+
+# Render all navigation redirects in parallel, one background job per view page,
+# throttled to IMAGE_JOBS via the shared template render job pool. This blocks
+# until every redirect is on disk (and fails loudly if any job failed), so
+# callers can rely on the redirects existing once it returns -- the redirect
+# groups are mutually independent, so only timing changes, not output.
+render_view_redirects() {
+    local -r html_dir="$1"; shift
+    # shellcheck disable=SC2178
+    local -n view_pages_ref="$1"; shift
+    # shellcheck disable=SC2178
+    local -n redirect_last_views_ref="$1"; shift
+    local max_page
+    local page
+    # Render job pool, throttled to IMAGE_JOBS by the job-pool helpers.
+    # shellcheck disable=SC2034
+    local -a render_job_pids=()
+    # shellcheck disable=SC2034
+    local -A render_job_statuses=()
+    # shellcheck disable=SC2034
+    local -A render_job_labels=()
+    local -i render_failed=0
+
+    if (( ${#view_pages_ref[@]} == 0 )); then
+        return
+    fi
+
+    max_page=${view_pages_ref[$(( ${#view_pages_ref[@]} - 1 ))]}
+
+    for page in "${view_pages_ref[@]}"; do
+        wait_for_template_render_job_slot \
+            render_job_pids render_job_statuses render_job_labels render_failed
+        render_page_view_redirects \
+            "$html_dir" "$page" "${redirect_last_views_ref[$page]}" \
+            "$max_page" &
+        render_job_pids+=("$!")
+        # shellcheck disable=SC2034
+        render_job_labels["$!"]="template render job for redirect page $page"
+    done
+
+    wait_for_template_render_jobs \
+        render_job_pids render_job_statuses render_job_labels render_failed
+    if (( render_failed != 0 )); then
+        return 1
+    fi
+}
+
+render_album_index_redirect() {
+    local -r html_dir="$1"; shift
+
+    template 'redirect' 'index.html' \
+        html_dir "$html_dir" \
+        redirect_page 'page-1'
+}
+
+render_album_splash_page() {
+    local -r photos_dir="$1"; shift
+    local -r html_dir="$1"; shift
+    local -r blurs_dir="$1"; shift
+    local -r backhref="$1"; shift
+    local html='index.html'
+    local photo
+
+    if (( $# > 0 )); then
+        html="$1"
+        shift
+    fi
+
+    photo=$(random_splash_photo "$photos_dir" "$blurs_dir")
+    template 'splash' "$html" \
+        html_dir "$html_dir" \
+        backhref "$backhref" \
+        blurs_dir "$blurs_dir" \
+        background_image "$photo" \
+        photos_dir "$photos_dir" \
+        photo "$photo" \
+        enter_page 'page-1'
+}
+
+render_album_index() {
+    local -r photos_dir="$1"; shift
+    local -r html_dir="$1"; shift
+    local -r blurs_dir="$1"; shift
+    local -r backhref="$1"; shift
+
+    if [ "$SPLASH_PAGE" = yes ]; then
+        render_album_splash_page "$photos_dir" "$html_dir" "$blurs_dir" \
+            "$backhref"
+    else
+        render_album_index_redirect "$html_dir"
+    fi
+}
+
+album_page_name() {
+    local -r page_num="$1"; shift
+
+    printf 'page-%s\n' "$page_num"
+}
+
+queue_album_view_render_job() {
+    local -r photos_dir="$1"; shift
+    local -r blurs_dir="$1"; shift
+    local -r html_dir="$1"; shift
+    local -r backhref="$1"; shift
+    local -r tarball_name="$1"; shift
+    local -r page_num="$1"; shift
+    local -r preview_num="$1"; shift
+    local -r photo="$1"; shift
+    # shellcheck disable=SC2178
+    local -n render_job_pids_ref="$1"; shift
+    # Passed by name to wait_for_template_render_job_slot.
+    # shellcheck disable=SC2034,SC2178
+    local -n render_job_statuses_ref="$1"; shift
+    # Passed by name to wait_for_template_render_job_slot and assigned below.
+    # shellcheck disable=SC2034,SC2178
+    local -n render_job_labels_ref="$1"; shift
+    # shellcheck disable=SC2178
+    local -n render_failed_ref="$1"; shift
+
+    wait_for_template_render_job_slot \
+        render_job_pids_ref \
+        render_job_statuses_ref \
+        render_job_labels_ref \
+        render_failed_ref
+    render_photo_view_and_details \
+        "$photos_dir" \
+        "$blurs_dir" \
+        "$html_dir" \
+        "$backhref" \
+        "$tarball_name" \
+        "$page_num" \
+        "$preview_num" \
+        "$photo" &
+    render_job_pids_ref+=("$!")
+    render_job_labels_ref["$!"]="template render job for photo $photo"
+}
+
+wait_for_album_view_render_jobs() {
+    # shellcheck disable=SC2178
+    local -n render_job_pids_ref="$1"; shift
+    # Passed by name to wait_for_template_render_jobs.
+    # shellcheck disable=SC2034,SC2178
+    local -n render_job_statuses_ref="$1"; shift
+    # Passed by name to wait_for_template_render_jobs.
+    # shellcheck disable=SC2034,SC2178
+    local -n render_job_labels_ref="$1"; shift
+    # shellcheck disable=SC2178
+    local -n render_failed_ref="$1"; shift
+
+    wait_for_template_render_jobs \
+        render_job_pids_ref \
+        render_job_statuses_ref \
+        render_job_labels_ref \
+        render_failed_ref
+    if (( render_failed_ref != 0 )); then
+        return 1
+    fi
+}
+
+# Group the album's photos into pages of at most MAXPREVIEWS, in their final
+# (shuffled/sorted) order. The result is emitted one line per page as a
+# tab-separated record "<page_num>\t<photo>\t<photo>..." so the caller can walk
+# pages without keeping every page in memory at once. Order is fully
+# deterministic (album_photo_files already applies the seeded shuffle), so the
+# downstream parallelism only changes timing, never which photo lands where.
+album_page_records() {
+    local -r photos_dir="$1"; shift
+    local photo
+    local -i num=1
+    local -i count=0
+    local line=''
+
+    while IFS= read -r photo; do
+        if (( count == MAXPREVIEWS )); then
+            printf '%d\t%s\n' "$num" "$line"
+            (( ++num ))
+            count=0
+            line=''
+        fi
+        if (( count == 0 )); then
+            line="$photo"
+        else
+            line="$line"$'\t'"$photo"
+        fi
+        (( ++count ))
+    done < <(album_photo_files "$photos_dir")
+
+    if (( count > 0 )); then
+        printf '%d\t%s\n' "$num" "$line"
+    fi
+}
+
+# Per-photo bookkeeping shared by the album loop: queue the view+details render
+# job, record the page/preview as a rendered view page (for redirect generation)
+# and remember the photo -> view-page mapping for the stats mini-albums. Kept
+# separate from the preview-page assembly so each concern stays small.
+_album_record_view_photo() {
+    local -r photos_dir="$1"; shift
+    local -r blurs_dir="$1"; shift
+    local -r html_dir="$1"; shift
+    local -r backhref="$1"; shift
+    local -r tarball_name="$1"; shift
+    local -ri page_num="$1"; shift
+    local -ri preview_num="$1"; shift
+    local -r photo="$1"; shift
+    local -r pids_name="$1"; shift
+    local -r statuses_name="$1"; shift
+    local -r labels_name="$1"; shift
+    local -r failed_name="$1"; shift
+    local -r view_pages_name="$1"; shift
+    local -r last_views_name="$1"; shift
+
+    queue_album_view_render_job \
+        "$photos_dir" "$blurs_dir" "$html_dir" "$backhref" "$tarball_name" \
+        "$page_num" "$preview_num" "$photo" \
+        "$pids_name" "$statuses_name" "$labels_name" "$failed_name"
+    record_rendered_view_page "$view_pages_name" "$last_views_name" \
+        "$page_num" "$preview_num"
+    # Read later by the stats filter mini-albums (render_filter_pages) for
+    # their Details links; shellcheck cannot see that cross-function use.
+    # shellcheck disable=SC2034
+    ALBUM_VIEW_PAGE_BY_PHOTO["$photo"]="$page_num-$preview_num"
+}
+
+render_album_pages() {
+    local -r photos_dir="$1"; shift
+    local -r html_dir="$1"; shift
+    local -r thumbs_dir="$1"; shift
+    local -r blurs_dir="$1"; shift
+    local -r backhref="$1"; shift
+    local -r tarball_name="$1"; shift
+
+    local header_bar
+    local name
+    local next_name
+    local page_num
+    local photo
+    local prev_name=''
+    local record
+    local -i preview_num
+    # Passed by name to the render-pool helpers below.
+    # shellcheck disable=SC2034
+    local -i render_failed=0
+    # shellcheck disable=SC2034
+    local -a render_job_pids=()
+    # shellcheck disable=SC2034
+    local -A render_job_labels=()
+    # shellcheck disable=SC2034
+    local -A render_job_statuses=()
+    # Passed by name to record_rendered_view_page and render_view_redirects.
+    # shellcheck disable=SC2034
+    local -A rendered_last_views=()
+    # shellcheck disable=SC2034
+    local -a rendered_view_pages=()
+    local -a page_photos=()
+    local -a page_records=()
+
+    # Rebuild the photo -> view-page map for this album from scratch so a
+    # re-generate (or a smaller incoming set) does not keep stale entries. The
+    # per-photo entries are written in _album_record_view_photo, which shellcheck
+    # cannot see from here.
+    # shellcheck disable=SC2034
+    ALBUM_VIEW_PAGE_BY_PHOTO=()
+
+    # Materialise the full deterministic page layout first so each preview page
+    # knows up front whether it has a following page (and thus a "next" link).
+    mapfile -t page_records < <(album_page_records "$photos_dir")
+
+    for record in "${page_records[@]}"; do
+        page_num=${record%%$'\t'*}
+        name=$(album_page_name "$page_num")
+        # The first page shows the header bar; later pages do not (matches the
+        # previous start_preview_page calls).
+        if [ -z "$prev_name" ]; then
+            header_bar='yes'
+        else
+            header_bar='no'
+        fi
+
+        # Split the tab-separated photo list for this page into an array.
+        IFS=$'\t' read -r -a page_photos <<< "${record#*$'\t'}"
+
+        preview_num=0
+        for photo in "${page_photos[@]}"; do
+            (( ++preview_num ))
+            _album_record_view_photo \
+                "$photos_dir" "$blurs_dir" "$html_dir" "$backhref" \
+                "$tarball_name" "$page_num" "$preview_num" "$photo" \
+                render_job_pids render_job_statuses render_job_labels \
+                render_failed rendered_view_pages rendered_last_views
+        done
+
+        # A page has a "next" link unless it is the last record.
+        next_name=''
+        if (( page_num < ${#page_records[@]} )); then
+            next_name=$(album_page_name "$(( page_num + 1 ))")
+        fi
+        queue_preview_page_render_job \
+            "$photos_dir" "$html_dir" "$thumbs_dir" "$blurs_dir" "$backhref" \
+            "$tarball_name" "$name" "$page_num" "$header_bar" \
+            "$prev_name" "$next_name" \
+            render_job_pids render_job_statuses render_job_labels \
+            render_failed \
+            "${page_photos[@]}"
+
+        prev_name="$name"
+    done
+
+    if ! wait_for_album_view_render_jobs \
+        render_job_pids \
+        render_job_statuses \
+        render_job_labels \
+        render_failed; then
+        return 1
+    fi
+    render_view_redirects "$html_dir" rendered_view_pages rendered_last_views
+    render_album_index "$photos_dir" "$html_dir" "$blurs_dir" "$backhref"
+}
+
+splash_photo_files() {
+    local -r photos_dir="$1"; shift
+    local -r blurs_dir="$1"; shift
+    local photo
+
+    while IFS= read -r photo; do
+        if [ -f "$DIST_DIR/$blurs_dir/$photo" ]; then
+            printf '%s\n' "$photo"
+        fi
+    done < <(
+        find "$DIST_DIR/$photos_dir" -maxdepth 1 -type f -printf '%f\n' \
+            | sort
+    )
+}
+
+random_splash_photo() {
+    local -r photos_dir="$1"; shift
+    local -r blurs_dir="$1"; shift
+    local -i index
+    local photo
+    local -a photos=()
+
+    while IFS= read -r photo; do
+        photos+=("$photo")
+    done < <(splash_photo_files "$photos_dir" "$blurs_dir")
+
+    if (( ${#photos[@]} == 0 )); then
+        printf 'ERROR: No splash photos found in %s with matching blurs in %s\n' \
+            "$(_display_path "$DIST_DIR/$photos_dir")" \
+            "$(_display_path "$DIST_DIR/$blurs_dir")" >&2
+        return 1
+    fi
+
+    index=$(random_index "photo:$photos_dir:splash" "${#photos[@]}")
+    printf '%s\n' "${photos[index]}"
+}
+
+randomphoto() {
+    local -r photos_dir="$1"; shift
+    local -r context="${1:-$photos_dir}"
+    local -i index
+    local photo
+    local -a photos=()
+
+    while IFS= read -r photo; do
+        photos+=("$photo")
+    done < <(
+        find "$DIST_DIR/$photos_dir" -maxdepth 1 -type f -printf '%f\n' \
+            | sort
+    )
+
+    if (( ${#photos[@]} == 0 )); then
+        printf 'ERROR: No photos found in %s\n' \
+            "$(_display_path "$DIST_DIR/$photos_dir")" >&2
+        return 1
+    fi
+
+    index=$(random_index "photo:$photos_dir:$context" "${#photos[@]}")
+    printf '%s\n' "${photos[index]}"
+}