Split photoalbum source into lib modules

10 files changed, 2951 insertions, 2845 deletions

diff --git a/Justfile b/Justfile
index 1f8f690..e89c783 100644
--- a/Justfile
+++ b/Justfile
@@ -7,6 +7,7 @@ PREFIX := env_var_or_default("PREFIX", "/usr")
 BINDIR := env_var_or_default("BINDIR", PREFIX + "/bin")
 DATADIR := env_var_or_default("DATADIR", PREFIX + "/share")
 SYSCONFDIR := env_var_or_default("SYSCONFDIR", "/etc/default")
+LIB_SOURCES := "src/lib/bootstrap.source.sh src/lib/system.source.sh src/lib/template.source.sh src/lib/image.source.sh src/lib/album.source.sh src/lib/config.source.sh src/lib/action.source.sh"
 
 default: build
 
@@ -20,8 +21,46 @@ build:
     mkdir -p ./bin
     generated=$(mktemp "./bin/.{{NAME}}.XXXXXX")
     trap 'rm -f "$generated"' EXIT
-    sed "s/PHOTOALBUMVERSION/{{VERSION}}/" \
-        "src/{{NAME}}.sh" > "$generated"
+
+    render_lib_sources() {
+        local lib_source
+        local line
+
+        for lib_source in {{LIB_SOURCES}}; do
+            printf '\n# Inlined from %s\n' "$lib_source"
+            while IFS= read -r line; do
+                line=${line//PHOTOALBUMVERSION/{{VERSION}}}
+                printf '%s\n' "$line"
+            done < "$lib_source"
+        done
+    }
+
+    render_photoalbum() {
+        local in_lib_sources=no
+        local line
+
+        while IFS= read -r line; do
+            case "$line" in
+                '# PHOTOALBUM_LIB_SOURCES_BEGIN')
+                    printf '%s\n' "$line"
+                    render_lib_sources
+                    in_lib_sources=yes
+                    ;;
+                '# PHOTOALBUM_LIB_SOURCES_END')
+                    in_lib_sources=no
+                    printf '\n%s\n' "$line"
+                    ;;
+                *)
+                    if [ "$in_lib_sources" = no ]; then
+                        line=${line//PHOTOALBUMVERSION/{{VERSION}}}
+                        printf '%s\n' "$line"
+                    fi
+                    ;;
+            esac
+        done < "src/{{NAME}}.sh"
+    }
+
+    render_photoalbum > "$generated"
     chmod 0755 "$generated"
     if [ -f "./bin/{{NAME}}" ] && cmp -s "$generated" "./bin/{{NAME}}"; then
         chmod 0755 "./bin/{{NAME}}"
@@ -34,8 +73,46 @@ build:
 check-generated:
     generated=$(mktemp)
     trap 'rm -f "$generated"' EXIT
-    sed "s/PHOTOALBUMVERSION/{{VERSION}}/" \
-        "src/{{NAME}}.sh" > "$generated"
+
+    render_lib_sources() {
+        local lib_source
+        local line
+
+        for lib_source in {{LIB_SOURCES}}; do
+            printf '\n# Inlined from %s\n' "$lib_source"
+            while IFS= read -r line; do
+                line=${line//PHOTOALBUMVERSION/{{VERSION}}}
+                printf '%s\n' "$line"
+            done < "$lib_source"
+        done
+    }
+
+    render_photoalbum() {
+        local in_lib_sources=no
+        local line
+
+        while IFS= read -r line; do
+            case "$line" in
+                '# PHOTOALBUM_LIB_SOURCES_BEGIN')
+                    printf '%s\n' "$line"
+                    render_lib_sources
+                    in_lib_sources=yes
+                    ;;
+                '# PHOTOALBUM_LIB_SOURCES_END')
+                    in_lib_sources=no
+                    printf '\n%s\n' "$line"
+                    ;;
+                *)
+                    if [ "$in_lib_sources" = no ]; then
+                        line=${line//PHOTOALBUMVERSION/{{VERSION}}}
+                        printf '%s\n' "$line"
+                    fi
+                    ;;
+            esac
+        done < "src/{{NAME}}.sh"
+    }
+
+    render_photoalbum > "$generated"
     chmod 0755 "$generated"
     if [ ! -f "./bin/{{NAME}}" ]; then
         printf '%s\n' \
@@ -81,6 +158,8 @@ clean:
 
 shellcheck:
     shellcheck \
+        --external-sources \
+        --check-sourced \
         ./src/photoalbum.sh \
         ./tests/cli.sh \
         ./tests/helpers.sh
diff --git a/bin/photoalbum b/bin/photoalbum
index aae3364..6b686a1 100755
--- a/bin/photoalbum
+++ b/bin/photoalbum
@@ -104,6 +104,12 @@ declare -Ar CLI_OPTION_ARGUMENT=(
     [--sync-destination]=destination
 )
 
+PHOTOALBUM_SOURCE_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+declare -r PHOTOALBUM_SOURCE_DIR
+
+# PHOTOALBUM_LIB_SOURCES_BEGIN
+
+# Inlined from src/lib/bootstrap.source.sh
 usage() {
     cat - <<USAGE >&2
     Usage:
@@ -188,7 +194,7 @@ resolve_source_root() {
     local script_dir
     local source_root
 
-    script_dir=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+    script_dir="$PHOTOALBUM_SOURCE_DIR"
     source_root=$(cd "$script_dir/.." && pwd)
 
     if [[ -f "$source_root/src/photoalbum.default.conf" \
@@ -278,6 +284,7 @@ init_config() {
     log_info "Created ./$rc_file"
 }
 
+# Inlined from src/lib/system.source.sh
 # shellcheck disable=SC2034
 resolve_imagemagick_command() {
     local -r operation="$1"; shift
@@ -451,6 +458,7 @@ resolve_sync_destinations() {
     esac
 }
 
+# Inlined from src/lib/template.source.sh
 _html_escape() {
     local text="$1"; shift
 
@@ -954,6 +962,7 @@ template() {
     render_template "$template_name" "$html" render_context
 }
 
+# Inlined from src/lib/image.source.sh
 cleanphotos() {
     local basename
     local photo
@@ -1246,6 +1255,7 @@ maybe_shuffle() {
     fi
 }
 
+# Inlined from src/lib/album.source.sh
 album_photo_files() {
     local -r photos_dir="$1"; shift
 
@@ -2147,6 +2157,7 @@ dry_run() {
     fi
 }
 
+# Inlined from src/lib/config.source.sh
 print_shell_assignment() {
     local -r name="$1"; shift
     local -r value="$1"; shift
@@ -2827,6 +2838,7 @@ parse_cli_arguments() {
     done
 }
 
+# Inlined from src/lib/action.source.sh
 run_simple_action() {
     case "$action" in
         --version)
@@ -2945,6 +2957,8 @@ run_action() {
     esac
 }
 
+# PHOTOALBUM_LIB_SOURCES_END
+
 main() {
     local action=''
     local config_file=''
diff --git a/src/lib/action.source.sh b/src/lib/action.source.sh
new file mode 100644
index 0000000..01dc245
--- /dev/null
+++ b/src/lib/action.source.sh
@@ -0,0 +1,117 @@
+run_simple_action() {
+    case "$action" in
+        --version)
+            if [[ -n "$config_file" || "$has_config_overrides" = 'yes' \
+                || "$PHOTOALBUM_FORCE_GENERATE" = yes ]]; then
+                usage
+                exit 1
+            fi
+
+            printf 'This is Photoalbum Version %s\n' "$VERSION"
+            ;;
+        --init)
+            if [[ -n "$config_file" || "$has_config_overrides" = 'yes' \
+                || "$PHOTOALBUM_FORCE_GENERATE" = yes ]]; then
+                usage
+                exit 1
+            fi
+
+            init_config
+            ;;
+    esac
+}
+
+load_configured_action() {
+    local -r rc_file="$1"; shift
+
+    if [ ! -f "$rc_file" ]; then
+        missing_config "$rc_file"
+    fi
+
+    # shellcheck source=/dev/null
+    source "$rc_file"
+    apply_config_defaults
+    apply_template_dir_default
+    apply_cli_overrides
+    PHOTOALBUM_CONFIG_SOURCE="$rc_file"
+    export PHOTOALBUM_CONFIG_SOURCE
+}
+
+log_configured_action() {
+    local -r rc_file="$1"; shift
+
+    if [ "$action" = --print-config ]; then
+        return
+    fi
+
+    log_verbose "Selected config file: $rc_file"
+    log_verbose "Effective incoming directory: ${INCOMING_DIR:-}"
+    log_verbose "Effective output directory: ${DIST_DIR:-}"
+    log_verbose "Effective template directory: ${TEMPLATE_DIR:-}"
+    log_verbose "Effective image jobs: ${IMAGE_JOBS:-3}"
+    log_verbose "Effective ImageMagick timeout: ${IMAGEMAGICK_TIMEOUT:-60}s"
+    log_verbose "Effective tar timeout: ${TAR_TIMEOUT:-120}s"
+    log_verbose "Effective splash page setting: ${SPLASH_PAGE:-yes}"
+    log_verbose "Effective tarball setting: ${TARBALL_INCLUDE:-no}"
+    log_verbose "Effective sync delete setting: ${SYNC_DELETE:-yes}"
+    log_verbose "Effective force generation setting: $PHOTOALBUM_FORCE_GENERATE"
+}
+
+run_configured_action() {
+    local rc_file
+
+    if [[ "$PHOTOALBUM_FORCE_GENERATE" = yes && "$action" != --generate ]]; then
+        usage
+        exit 1
+    fi
+
+    rc_file="$(resolve_config_file "$config_file")"
+    load_configured_action "$rc_file"
+    log_configured_action "$rc_file"
+
+    case "$action" in
+        --clean)
+            if [ -d "$DIST_DIR" ]; then
+                log_info "Cleaning $DIST_DIR"
+                rm -rf "$DIST_DIR"
+            else
+                log_verbose "Output directory does not exist: $DIST_DIR"
+            fi
+            ;;
+        --generate)
+            validate_generation_config
+            generate_staged
+            ;;
+        --refresh-splash)
+            validate_refresh_splash_config
+            refresh_splash
+            ;;
+        --sync)
+            validate_sync_config
+            sync_dist
+            ;;
+        --dry-run)
+            validate_generation_config no
+            dry_run
+            ;;
+        --print-config)
+            validate_print_config
+            print_config
+            ;;
+    esac
+}
+
+run_action() {
+    case "$action" in
+        --version|--init)
+            run_simple_action
+            ;;
+        --clean|--generate|--refresh-splash|--sync|--dry-run|--print-config)
+            run_configured_action
+            ;;
+        *)
+            usage
+            exit 1
+            ;;
+    esac
+}
diff --git a/src/lib/album.source.sh b/src/lib/album.source.sh
new file mode 100644
index 0000000..886bd81
--- /dev/null
+++ b/src/lib/album.source.sh
@@ -0,0 +1,900 @@
+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"
+}
+
+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="$1"; shift
+    local animation_class
+
+    template header "$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 "$photo_file")
+    template view "$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"
+    template footer "$page_num-$preview_num.html" \
+        html_dir "$html_dir" \
+        backhref "$backhref" \
+        tarball_name "$tarball_name"
+}
+
+photo_cache_signature() {
+    local -r photo="$1"; shift
+    local -r photo_path="$1"; shift
+    local stat_output
+
+    stat_output=$(stat -c '%s:%Y' "$photo_path")
+    printf '%s:%s\n' "$photo" "$stat_output"
+}
+
+print_cached_photo_identify_output() {
+    local -r cache_file="$1"; shift
+    local line
+    local skipped_signature=no
+
+    while IFS= read -r line || [ -n "$line" ]; do
+        if [ "$skipped_signature" = no ]; then
+            skipped_signature=yes
+            continue
+        fi
+        printf '%s\n' "$line"
+    done < "$cache_file"
+}
+
+cached_photo_identify_output() {
+    local -r photo="$1"; shift
+    local -r photo_path="$1"; shift
+    local cache_dir
+    local cache_file
+    local cached_signature=''
+    local current_signature
+
+    cache_dir="$DIST_DIR/.photoalbum-cache/exif"
+    cache_file="$cache_dir/$photo.txt"
+    current_signature=$(photo_cache_signature "$photo" "$photo_path")
+
+    if [ -f "$cache_file" ]; then
+        IFS= read -r cached_signature < "$cache_file" || true
+        if [ "$cached_signature" = "$current_signature" ]; then
+            print_cached_photo_identify_output "$cache_file"
+            return
+        fi
+    fi
+
+    mkdir -p "$cache_dir"
+    printf '%s\n' "$current_signature" > "$cache_file"
+    imagemagick_identify -verbose "$photo_path" >> "$cache_file" 2>/dev/null \
+        || true
+    print_cached_photo_identify_output "$cache_file"
+}
+
+photo_exif_details_html() {
+    local -r photo="$1"; shift
+    local -r photo_path="$1"; shift
+    local key
+    local key_html
+    local line
+    local value
+    local value_html
+    local -i exif_count=0
+
+    while IFS= read -r line; do
+        if [[ "$line" =~ ^[[:space:]]*exif:([^:]+):[[:space:]]*(.*)$ ]]; then
+            key="exif:${BASH_REMATCH[1]}"
+            value="${BASH_REMATCH[2]}"
+            key_html=$(_html_escape "$key")
+            value_html=$(_html_escape "$value")
+
+            if (( exif_count == 0 )); then
+                printf '<table class="details">\n'
+                printf '<tbody>\n'
+            fi
+
+            printf '<tr><th>%s</th><td>%s</td></tr>\n' \
+                "$key_html" \
+                "$value_html"
+            (( ++exif_count ))
+        fi
+    done < <(cached_photo_identify_output "$photo" "$photo_path")
+
+    if (( exif_count == 0 )); then
+        printf '<p class="details-empty">No EXIF details available.</p>\n'
+        return
+    fi
+
+    printf '</tbody>\n'
+    printf '</table>\n'
+}
+
+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="$1"; shift
+    local animation_class
+    local exif_details_html
+
+    template header "$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/$photo_file"
+    )
+    template details "$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 "$exif_details_html"
+    template footer "$page_num-$preview_num-details.html" \
+        html_dir "$html_dir" \
+        backhref "$backhref" \
+        tarball_name "$tarball_name"
+}
+
+create_photo_derivatives() {
+    local -r photos_dir="$1"; shift
+    local -r thumbs_dir="$1"; shift
+    local -r blurs_dir="$1"; shift
+    local -r photo="$1"; shift
+    local dirname
+    local height
+
+    if [[ -f "$DIST_DIR/$thumbs_dir/$photo" \
+        && -f "$DIST_DIR/$blurs_dir/$photo" ]]; then
+        log_verbose "Skipped existing thumb and blur" \
+            "$(_display_path "$DIST_DIR/$thumbs_dir/$photo") and" \
+            "$(_display_path "$DIST_DIR/$blurs_dir/$photo")"
+        return
+    fi
+
+    dirname="$DIST_DIR/$thumbs_dir"
+    mkdir -p "$dirname"
+    log_info "Creating thumb $(_display_path "$DIST_DIR/$thumbs_dir/$photo")"
+    # Double the height, as CSS scales images based on boxing too.
+    height=$(( THUMBHEIGHT * 2 ))
+    imagemagick \
+        "$DIST_DIR/$photos_dir/$photo" \
+        -geometry "x$height" \
+        "$DIST_DIR/$thumbs_dir/$photo"
+
+    dirname="$DIST_DIR/$blurs_dir"
+    mkdir -p "$dirname"
+    log_info "Creating blur $(_display_path "$DIST_DIR/$blurs_dir/$photo")"
+    imagemagick \
+        "$DIST_DIR/$thumbs_dir/$photo" \
+        -flip \
+        -blur 0x8 \
+        "$DIST_DIR/$blurs_dir/$photo"
+}
+
+create_all_photo_derivatives() {
+    local -r photos_dir="$1"; shift
+    local -r thumbs_dir="$1"; shift
+    local -r blurs_dir="$1"; shift
+    local -i failed=0
+    local -a image_job_pids=()
+    local photo
+
+    while IFS= read -r photo; do
+        wait_for_image_job_slot image_job_pids failed
+        create_photo_derivatives "$photos_dir" "$thumbs_dir" "$blurs_dir" \
+            "$photo" &
+        image_job_pids+=("$!")
+    done < <(
+        find "$DIST_DIR/$photos_dir" -maxdepth 1 -type f -printf '%f\n' \
+            | sort
+    )
+
+    wait_for_image_jobs image_job_pids failed
+    if (( failed != 0 )); then
+        return 1
+    fi
+}
+
+render_album_page_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="$1"; shift
+
+    render_preview_thumbnail \
+        "$page_name" \
+        "$html_dir" \
+        "$thumbs_dir" \
+        "$backhref" \
+        "$page_num" \
+        "$preview_num" \
+        "$photo"
+}
+
+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_view_redirects() {
+    local -r html_dir="$1"; shift
+    # shellcheck disable=SC2178
+    local -n view_pages_ref="$1"; shift
+    # shellcheck disable=SC2178
+    local -n last_views_ref="$1"; shift
+    local lastview
+    local max_page
+    local nextredirect
+    local page
+    local prevredirect
+
+    if (( ${#view_pages_ref[@]} == 0 )); then
+        return
+    fi
+
+    max_page=${view_pages_ref[$(( ${#view_pages_ref[@]} - 1 ))]}
+
+    for page in "${view_pages_ref[@]}"; do
+        lastview=${last_views_ref[$page]}
+        prevredirect="${page}-0"
+        nextredirect="${page}-$(( lastview + 1 ))"
+
+        template redirect "$prevredirect.html" \
+            html_dir "$html_dir" \
+            redirect_page "$(( page - 1 ))-${MAXPREVIEWS}"
+
+        if (( page == max_page )); then
+            template redirect "0-$MAXPREVIEWS.html" \
+                html_dir "$html_dir" \
+                redirect_page "${page}-$lastview"
+            template redirect "$nextredirect.html" \
+                html_dir "$html_dir" \
+                redirect_page '1-1'
+        else
+            template redirect "$nextredirect.html" \
+                html_dir "$html_dir" \
+                redirect_page "$(( page + 1 ))-1"
+        fi
+    done
+}
+
+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}" = 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"
+}
+
+advance_album_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 tarball_name="$1"; shift
+    # shellcheck disable=SC2178
+    local -n page_name_ref="$1"; shift
+    # shellcheck disable=SC2178
+    local -n prev_page_ref="$1"; shift
+    # shellcheck disable=SC2178
+    local -n page_num_ref="$1"; shift
+    # shellcheck disable=SC2178
+    local -n preview_num_ref="$1"; shift
+    local next_page_name
+
+    next_page_name=$(album_page_name "$(( page_num_ref + 1 ))")
+    finish_preview_page_with_next \
+        "$page_name_ref" \
+        "$html_dir" \
+        "$backhref" \
+        "$tarball_name" \
+        "$next_page_name" \
+        "${prev_page_ref:-}"
+
+    prev_page_ref="$page_name_ref"
+    (( ++page_num_ref ))
+    # shellcheck disable=SC2034
+    preview_num_ref=1
+    page_name_ref=$(album_page_name "$page_num_ref")
+
+    start_preview_page \
+        "$photos_dir" \
+        "$html_dir" \
+        "$blurs_dir" \
+        "$backhref" \
+        "$page_name_ref" \
+        'no'
+    render_previous_page_link "$page_name_ref" "$html_dir" "$prev_page_ref"
+}
+
+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
+    # shellcheck disable=SC2178
+    local -n render_failed_ref="$1"; shift
+
+    wait_for_image_job_slot render_job_pids_ref render_failed_ref
+    render_photo_view_and_details \
+        "$photos_dir" \
+        "$blurs_dir" \
+        "$html_dir" \
+        "$backhref" \
+        "$tarball_name" \
+        "$page_num" \
+        "$preview_num" \
+        "$photo" &
+    render_job_pids_ref+=("$!")
+}
+
+wait_for_album_view_render_jobs() {
+    # shellcheck disable=SC2178
+    local -n render_job_pids_ref="$1"; shift
+    # shellcheck disable=SC2178
+    local -n render_failed_ref="$1"; shift
+
+    wait_for_image_jobs render_job_pids_ref render_failed_ref
+    if (( render_failed_ref != 0 )); then
+        return 1
+    fi
+}
+
+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="$1"; shift
+
+    local name
+    local photo
+    # Passed by name to advance_album_preview_page.
+    # shellcheck disable=SC2034
+    local prev
+    local -i i=0
+    local -i num=1
+    # Passed by name to queue_album_view_render_job.
+    # shellcheck disable=SC2034
+    local -i render_failed=0
+    # Passed by name to queue_album_view_render_job.
+    # shellcheck disable=SC2034
+    local -a render_job_pids=()
+    # Passed by name to record_rendered_view_page and render_view_redirects.
+    # shellcheck disable=SC2034
+    local -A rendered_last_views=()
+    # Passed by name to record_rendered_view_page and render_view_redirects.
+    # shellcheck disable=SC2034
+    local -a rendered_view_pages=()
+
+    name=$(album_page_name "$num")
+
+    start_preview_page \
+        "$photos_dir" "$html_dir" "$blurs_dir" "$backhref" "$name" 'yes'
+
+    while IFS= read -r photo; do
+        (( ++i ))
+
+        if (( i > MAXPREVIEWS )); then
+            advance_album_preview_page \
+                "$photos_dir" \
+                "$html_dir" \
+                "$blurs_dir" \
+                "$backhref" \
+                "$tarball_name" \
+                name \
+                prev \
+                num \
+                i
+        fi
+
+        render_album_page_thumbnail \
+            "$name" \
+            "$html_dir" \
+            "$thumbs_dir" \
+            "$backhref" \
+            "$num" \
+            "$i" \
+            "$photo"
+        queue_album_view_render_job \
+            "$photos_dir" \
+            "$blurs_dir" \
+            "$html_dir" \
+            "$backhref" \
+            "$tarball_name" \
+            "$num" \
+            "$i" \
+            "$photo" \
+            render_job_pids \
+            render_failed
+        record_rendered_view_page rendered_view_pages rendered_last_views \
+            "$num" "$i"
+    done < <(album_photo_files "$photos_dir")
+
+    finish_preview_page "$name" "$html_dir" "$backhref" "$tarball_name"
+    if ! wait_for_album_view_render_jobs render_job_pids render_failed; then
+        return 1
+    fi
+    render_view_redirects "$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]}"
+}
+
+count_files() {
+    local -r dir="$1"; shift
+    local -r name="${1:-}"; shift || true
+
+    if [ ! -d "$dir" ]; then
+        printf '0\n'
+        return
+    fi
+
+    if [ -n "$name" ]; then
+        find "$dir" -maxdepth 1 -type f -name "$name" | wc -l
+    else
+        find "$dir" -maxdepth 1 -type f | wc -l
+    fi
+}
+
+count_incoming_images() {
+    incoming_image_files | wc -l
+}
+
+tarball_name_plan() {
+    local base
+
+    base=$(basename "$INCOMING_DIR")
+    printf '%s-<timestamp>%s\n' "$base" "${TARBALL_SUFFIX:-.tar}"
+}
+
+generated_tarball_name() {
+    local base
+    local timestamp
+
+    base=$(basename "$INCOMING_DIR")
+    timestamp=$(current_timestamp_slug)
+    printf '%s-%s%s\n' "$base" "$timestamp" "${TARBALL_SUFFIX:-.tar}"
+}
+
+count_tree_files() {
+    local -r dir="$1"; shift
+    local -r name="$1"; shift
+
+    if [ ! -d "$dir" ]; then
+        printf '0\n'
+        return
+    fi
+
+    find "$dir" -type f -name "$name" | wc -l
+}
+
+write_generation_metadata() {
+    local -r tarball_file="$1"; shift
+    local -r generated_at=$(current_timestamp_iso)
+    local -r config_source="${PHOTOALBUM_CONFIG_SOURCE:-}"
+    local -r template_name=$(basename "$TEMPLATE_DIR")
+    local -r source_image_count=$(count_incoming_images)
+    local -r generated_photo_count=$(count_files "$DIST_DIR/photos")
+    local -r generated_thumb_count=$(count_files "$DIST_DIR/thumbs")
+    local -r generated_html_count=$(count_tree_files "$DIST_DIR" '*.html')
+
+    {
+        printf '{\n'
+        printf '  "generator": {\n'
+        printf '    "name": "photoalbum",\n'
+        printf '    "version": %s\n' "$(_json_string "$VERSION")"
+        printf '  },\n'
+        printf '  "generated_at": %s,\n' "$(_json_string "$generated_at")"
+        printf '  "config_source": %s,\n' "$(_json_string "$config_source")"
+        printf '  "template": {\n'
+        printf '    "name": %s,\n' "$(_json_string "$template_name")"
+        printf '    "directory": %s\n' "$(_json_string "$TEMPLATE_DIR")"
+        printf '  },\n'
+        printf '  "source": {\n'