Refactor photoalbum bash script

2 files changed, 282 insertions, 144 deletions

diff --git a/README.md b/README.md
index e1631fb..709682b 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,8 @@ make
 sudo make install
 ```
 
-Also, as a requirement, `convert` from ImageMagick needs to be installed.  
+Also, as a requirement, ImageMagick needs to be installed. The script prefers the
+modern `magick` command and falls back to `convert` when needed.
 
 ## Usage
 
diff --git a/src/photoalbum.sh b/src/photoalbum.sh
index 7eb3e3b..bc721ee 100755
--- a/src/photoalbum.sh
+++ b/src/photoalbum.sh
@@ -1,21 +1,20 @@
-#!/bin/env bash
+#!/usr/bin/env bash
+set -euo pipefail
 
 # photoalbum (c) 2011 - 2014, 2022 by Paul Buetow
 # https://codeberg.org/snonux/photoalbum
 
-readonly VERSION='PHOTOALBUMVERSION'
-readonly DEFAULTRC='/etc/default/photoalbum'
-declare  ARG1="$1"    ; shift
-declare  RC_FILE="$1" ; shift
+declare -r VERSION='PHOTOALBUMVERSION'
+declare -r DEFAULTRC='/etc/default/photoalbum'
 
-usage () {
+usage() {
     cat - <<USAGE >&2
-    Usage: 
+    Usage:
     $0 clean|generate|version|makemake [rcfile]
 USAGE
 }
 
-makemake () {
+makemake() {
     [ ! -f ./photoalbumrc ] && cp "$DEFAULTRC" ./photoalbumrc
     cat <<MAKEFILE > ./Makefile
 all:
@@ -26,50 +25,76 @@ MAKEFILE
     echo 'You may now customize ./photoalbumrc and run make'
 }
 
-tarball () {
+imagemagick() {
+    if command -v magick >/dev/null 2>&1; then
+        magick "$@"
+    elif command -v convert >/dev/null 2>&1; then
+        convert "$@"
+    else
+        echo 'ERROR: ImageMagick is required; install magick or convert' >&2
+        return 127
+    fi
+}
+
+tarball() {
+    local -r tarball_name="$1"; shift
+    local -r tar_opts="${TAR_OPTS:--c}"
+    local base
+
     # Cleanup tarball from prev run if any
-    find "$DIST_DIR" -maxdepth 1 -type f -name \*.tar -delete
-    declare base="$(basename "$INCOMING_DIR")"
+    find "$DIST_DIR" -maxdepth 1 -type f -name '*.tar' -delete
+    base=$(basename "$INCOMING_DIR")
 
     echo "Creating tarball $DIST_DIR/$tarball_name from $INCOMING_DIR"
-    cd "$(dirname "$INCOMING_DIR")"
-    tar "$TAR_OPTS" -f "$DIST_DIR/$tarball_name" "$base"
-    cd - &>/dev/null
+    (
+        cd "$(dirname "$INCOMING_DIR")"
+        tar "$tar_opts" -f "$DIST_DIR/$tarball_name" "$base"
+    )
 }
 
-template () {
-    declare template="$1" ; shift
-    declare html="$1"     ; shift
-    declare dist_html="$DIST_DIR/$html_dir"
+template() {
+    local -r template_name="$1"; shift
+    local -r html="$1"; shift
+    local -r dist_html="$DIST_DIR/$html_dir"
+
     echo "Generating $dist_html/$html"
 
-    [ ! -d "$dist_html" ] && mkdir -p "$dist_html"
-    source "$TEMPLATE_DIR/$template.tmpl" >> "$dist_html/$html"
+    mkdir -p "$dist_html"
+    source "$TEMPLATE_DIR/$template_name.tmpl" >> "$dist_html/$html"
 }
 
-cleanphotos () {
-    find "$DIST_DIR/photos" -maxdepth 1 -type f | while read photo; do
-        local basename=$(basename $photo)
+cleanphotos() {
+    local basename
+    local photo
+    local sub
+
+    while IFS= read -r photo; do
+        basename=$(basename "$photo")
+
         if [ -f "$INCOMING_DIR/$basename" ]; then
             continue
         fi
+
         echo "Cleaning up $photo"
         for sub in thumbs blurs photos; do
             if [ -f "$DIST_DIR/$sub/$basename" ]; then
                 rm -v "$DIST_DIR/$sub/$basename"
             fi
         done
-    done
+    done < <(find "$DIST_DIR/photos" -maxdepth 1 -type f)
 }
 
-scalephotos () {
-    cd "$INCOMING_DIR" && find ./ -maxdepth 1 -type f | sort |
-    while read -r photo; do
-        declare photo="$(sed 's#^\./##' <<< "$photo")"
-        declare destphoto="$DIST_DIR/photos/$photo"
-        declare destphoto_nospace="${destphoto// /_}"
-        declare dirname="$(dirname "$destphoto")"
-        [ ! -d "$dirname" ] && mkdir -p "$dirname"
+scalephotos() {
+    local destphoto
+    local destphoto_nospace
+    local dirname
+    local photo
+
+    while IFS= read -r photo; do
+        destphoto="$DIST_DIR/photos/$photo"
+        destphoto_nospace="${destphoto// /_}"
+        dirname=$(dirname "$destphoto")
+        mkdir -p "$dirname"
 
         if [ -f "$destphoto_nospace" ]; then
             echo "Already exists: $destphoto_nospace"
@@ -77,198 +102,310 @@ scalephotos () {
         fi
 
         echo "Processing $photo to $destphoto_nospace"
-        if [ -n "$HEIGHT" ]; then
+        if [ -n "${HEIGHT:-}" ]; then
             # Scale down size.
-            convert -auto-orient -geometry "$HEIGHT" "$photo" "$destphoto_nospace"
+            imagemagick \
+                -auto-orient \
+                -geometry "$HEIGHT" \
+                "$INCOMING_DIR/$photo" \
+                "$destphoto_nospace"
         else
-            # Keep original size
-            convert -auto-orient "$photo" "$destphoto_nospace"
+            # Keep original size.
+            imagemagick \
+                -auto-orient \
+                "$INCOMING_DIR/$photo" \
+                "$destphoto_nospace"
         fi
-    done
-}
-
-randomphoto () {
-    declare photos_dir="$1" ; shift
-    basename $(find "$photos_dir" -type f -maxpdeth 1 -mindepth 1 | sort -R | head -n 1)
+    done < <(
+        find "$INCOMING_DIR" -maxdepth 1 -type f -printf '%f\n' \
+            | sort
+    )
 }
 
-random_animation_css_class () {
+random_animation_css_class() {
     local -r speed="$1"; shift
-    cat <<END | grep -v fading | sort -R | head -n 1
-animate-fading-$speed
-animate-opacity-$speed
-animate-top-$speed
-animate-left-$speed
-animate-right-$speed
-animate-bottom-$speed
-animate-zoom-$speed
-END
+    local -a classes=(
+        "animate-opacity-$speed"
+        "animate-top-$speed"
+        "animate-left-$speed"
+        "animate-right-$speed"
+        "animate-bottom-$speed"
+        "animate-zoom-$speed"
+    )
+
+    printf '%s\n' "${classes[@]}" | sort -R | sed -n '1p'
 }
 
-maybe_shuffle () {
-    if [ "$SHUFFLE" = yes ]; then
+maybe_shuffle() {
+    if [ "${SHUFFLE:-no}" = yes ]; then
         sort -R
     else
         sort
     fi
 }
 
-albumhtml () {
-    declare photos_dir="$1" ; shift
-    declare html_dir="$1"   ; shift
-    declare thumbs_dir="$1" ; shift
-    declare blurs_dir="$1"  ; shift
-    export backhref="$1"    ; shift
+newest_html() {
+    local -r pattern="$1"; shift
 
-    declare -i num=1
-    declare -i i=0
-    declare name="page-$num"
+    find "$DIST_DIR/$html_dir" \
+        -maxdepth 1 \
+        -name "$pattern" \
+        -printf '%T@ %f\n' \
+        | sort -nr \
+        | sed -n '1{s/^[^ ]* //;p}'
+}
+
+albumhtml() {
+    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="$1"; shift
+
+    local animation_class
+    local background_image
+    local dirname
+    local height
+    local lastview
+    local name
+    local next
+    local nextredirect
+    local page
+    local photo
+    local prev
+    local prefix
+    local prevredirect
+    local redirect_page
+    local show_header_bar
+    local -i i=0
+    local -i num=1
+
+    export backhref
+    name="page-$num"
 
     # Random background image for preview page.
-    export background_image="$(randomphoto $photos_dir)"
-    export show_header_bar='yes'
+    background_image=$(randomphoto "$photos_dir")
+    show_header_bar='yes'
+    export background_image show_header_bar
     template 'header' "$name.html"
 
-    cd "$DIST_DIR/$photos_dir" && find ./ -type f | maybe_shuffle | sed 's;^\./;;' |
-    while read -r photo; do 
-        let i++
+    while IFS= read -r photo; do
+        (( ++i ))
 
-        if [ "$i" -gt "$MAXPREVIEWS" ]; then
+        if (( i > MAXPREVIEWS )); then
             i=1
-            let num++
-            declare next="page-$num"
+            (( ++num ))
+            next="page-$num"
+            prev="${prev:-}"
+            export next prev
             template next "$name.html"
             template footer "$name.html"
 
-            export prev="$name"
-            declare name="$next"
+            prev="$name"
+            name="$next"
 
-            export background_image="$(randomphoto $photos_dir)"
-            export show_header_bar='no'
+            background_image=$(randomphoto "$photos_dir")
+            show_header_bar='no'
+            export background_image prev show_header_bar
             template header "$name.html"
             template prev "$name.html"
         fi
 
-        # Preview page
-        export animation_class=$(random_animation_css_class slow)
+        # Preview page.
+        animation_class=$(random_animation_css_class slow)
+        export animation_class
         template preview "$name.html"
 
-        # View page
-        export background_image="$photo"
-        export show_header_bar='no'
+        # View page.
+        background_image="$photo"
+        show_header_bar='no'
+        export background_image show_header_bar
         template header "$num-$i.html"
 
-        export animation_class=$(random_animation_css_class fast)
+        animation_class=$(random_animation_css_class fast)
+        export animation_class
         template view "$num-$i.html"
         template footer "$num-$i.html"
 
-        if [[ -f "$DIST_DIR/$thumbs_dir/$photo" && -f "$DIST_DIR/$blurs_dir/$photo" ]]; then 
-            echo "Already exists: $DIST_DIR/$thumbs_dir/$photo and $DIST_DIR/$blurs_dir/$photo"
+        if [[ -f "$DIST_DIR/$thumbs_dir/$photo" \
+            && -f "$DIST_DIR/$blurs_dir/$photo" ]]; then
+            echo "Already exists: $DIST_DIR/$thumbs_dir/$photo and" \
+                "$DIST_DIR/$blurs_dir/$photo"
         else
-            declare dirname="$DIST_DIR/$thumbs_dir"
-            test ! -d "$dirname" && mkdir -p "$dirname"
+            dirname="$DIST_DIR/$thumbs_dir"
+            mkdir -p "$dirname"
             echo "Creating thumb $DIST_DIR/$thumbs_dir/$photo"
-            # Double the height, as CSS will scale up/down images based on boxing too.
-            declare height=$((THUMBHEIGHT * 2))
-            convert -geometry "x$height" "$photo" "$DIST_DIR/$thumbs_dir/$photo"
+            # Double the height, as CSS scales images based on boxing too.
+            height=$(( THUMBHEIGHT * 2 ))
+            imagemagick \
+                -geometry "x$height" \
+                "$DIST_DIR/$photos_dir/$photo" \
+                "$DIST_DIR/$thumbs_dir/$photo"
 
             dirname="$DIST_DIR/$blurs_dir"
-            test ! -d "$dirname" && mkdir -p "$dirname"
+            mkdir -p "$dirname"
             echo "Creating blur $DIST_DIR/$blurs_dir/$photo"
-            convert -flip -blur 0x8 "$DIST_DIR/$thumbs_dir/$photo" "$DIST_DIR/$blurs_dir/$photo"
+            imagemagick \
+                -flip \
+                -blur 0x8 \
+                "$DIST_DIR/$thumbs_dir/$photo" \
+                "$DIST_DIR/$blurs_dir/$photo"
         fi
-    done
-
-    template footer "$(cd "$DIST_DIR/$html_dir";ls -t page-*.html | head -n 1)"
+    done < <(
+        find "$DIST_DIR/$photos_dir" -maxdepth 1 -type f -printf '%f\n' \
+            | maybe_shuffle
+    )
 
-    cd "$DIST_DIR/$html_dir" && ls | grep '.*\.html$' |
-        grep -v page- | cut -d'-' -f1 | uniq |
+    template footer "$(newest_html 'page-*.html')"
 
-    while read -r prefix; do 
-        declare page="$(ls -t "$prefix"-*.html | head -n 1 | sed 's#\(.*\)-.*.html#\1#')"
-        declare lastview="$(ls -t "$prefix"-*.html | head -n 1 | sed 's/.*-\(.*\).html/\1/')"
+    while IFS= read -r prefix; do
+        page=$(newest_html "$prefix-*.html" | sed 's#\(.*\)-.*.html#\1#')
+        lastview=$(newest_html "$prefix-*.html" | sed 's/.*-\(.*\).html/\1/')
 
-        declare prevredirect="${page}-0"
-        declare nextredirect="${page}-$((lastview+1))"
+        prevredirect="${page}-0"
+        nextredirect="${page}-$(( lastview + 1 ))"
 
-        declare redirect_page="$(( page-1 ))-${MAXPREVIEWS}"
+        redirect_page="$(( page - 1 ))-${MAXPREVIEWS}"
+        export redirect_page
         template redirect "$prevredirect.html"
 
-        if [ "$lastview" -eq "$MAXPREVIEWS" ]; then
-            declare redirect_page="$(( page+1 ))-1"
+        if (( lastview == MAXPREVIEWS )); then
+            redirect_page="$(( page + 1 ))-1"
         else
-            declare redirect_page="${page}-$lastview"
+            redirect_page="${page}-$lastview"
+            export redirect_page
             template redirect "0-$MAXPREVIEWS.html"
             redirect_page='1-1'
         fi
 
         export redirect_page
         template redirect "$nextredirect.html"
-    done
-
-    # Create per album index/redirect page
-    declare redirect_page='page-1'
+    done < <(
+        find "$DIST_DIR/$html_dir" \
+            -maxdepth 1 \
+            -name '*.html' \
+            ! -name 'page-*' \
+            -printf '%f\n' \
+            | cut -d'-' -f1 \
+            | sort -u
+    )
+
+    # Create per album index/redirect page.
+    redirect_page='page-1'
+    export redirect_page
     template 'redirect' 'index.html'
 }
 
-randomphoto () {
-    ls -f "$DIST_DIR/photos/" | sort -R | head -n 1
+randomphoto() {
+    local -r photos_dir="$1"; shift
+    local photo
+    local -a photos=()
+
+    while IFS= read -r photo; do
+        photos+=("$photo")
+    done < <(
+        find "$DIST_DIR/$photos_dir" -maxdepth 1 -type f -printf '%f\n' \
+            | sort
+    )
+
+    if (( ${#photos[@]} == 0 )); then
+        echo "ERROR: No photos found in $DIST_DIR/$photos_dir" >&2
+        return 1
+    fi
+
+    printf '%s\n' "${photos[RANDOM % ${#photos[@]}]}"
 }
 
-generate () {
+generate() {
+    local base
+    local html_dir
+    local now
+    local redirect_page
+    local tarball_name=''
+
     if [ ! -d "$INCOMING_DIR" ]; then
         echo "ERROR: You have to create $INCOMING_DIR first" >&2
         exit 1
     fi
 
-    if [ "$TARBALL_INCLUDE" = yes ]; then
-        declare base="$(basename "$INCOMING_DIR")"
-        declare now="$(date +'%Y-%m-%d-%H%M%S')"
-        declare tarball_name="${base}-${now}$TARBALL_SUFFIX"
+    if [ "${TARBALL_INCLUDE:-no}" = yes ]; then
+        base=$(basename "$INCOMING_DIR")
+        now=$(date +'%Y-%m-%d-%H%M%S')
+        tarball_name="${base}-${now}${TARBALL_SUFFIX:-.tar}"
     fi
 
-    test ! -d "$DIST_DIR/photos" && mkdir -p "$DIST_DIR/photos"
+    mkdir -p "$DIST_DIR/photos"
     cleanphotos
     scalephotos
 
-    find "$DIST_DIR" -type f -name \*.html -delete
-    declare -a dirs=( $(find "$DIST_DIR/photos" -mindepth 1 -maxdepth 1 -type d | sort) )
-
+    find "$DIST_DIR" -type f -name '*.html' -delete
     albumhtml 'photos' 'html' 'thumbs' 'blurs' '..'
 
-    # Create top level index/redirect page
-    declare html_dir='./'
-    declare redirect_page='./html/index'
+    # Create top level index/redirect page.
+    html_dir='./'
+    redirect_page='./html/index'
+    export redirect_page
     template 'redirect' 'index.html'
 
-    if [ "$TARBALL_INCLUDE" = 'yes' ]; then
-        tarball
+    if [ "${TARBALL_INCLUDE:-no}" = yes ]; then
+        tarball "$tarball_name"
     fi
 }
 
-if [ -z "$RC_FILE" ]; then
-    if [ -f photoalbumrc ]; then
-        RC_FILE=photoalbumrc
+resolve_rc_file() {
+    local rc_file="${1:-}"
+
+    if [ -n "$rc_file" ]; then
+        printf '%s\n' "$rc_file"
+    elif [ -f photoalbumrc ]; then
+        printf '%s\n' photoalbumrc
     elif [ -f ~/.photoalbumrc ]; then
-        RC_FILE=~/.photoalbumrc
+        printf '%s\n' ~/.photoalbumrc
     else
-        RC_FILE="$DEFAULTRC"
+        printf '%s\n' "$DEFAULTRC"
     fi
-fi
+}
 
-if [ ! -f "$RC_FILE" ]; then
-    echo "Error: Can not find config file $RC_FILE" >&2
-    exit 1
-fi
+apply_config_defaults() {
+    HEIGHT="${HEIGHT:-}"
+    ORIGINAL_BASEPATH="${ORIGINAL_BASEPATH:-}"
+    SHUFFLE="${SHUFFLE:-no}"
+    TARBALL_INCLUDE="${TARBALL_INCLUDE:-no}"
+    TARBALL_SUFFIX="${TARBALL_SUFFIX:-.tar}"
+    TAR_OPTS="${TAR_OPTS:--c}"
+}
+
+main() {
+    local -r arg1="${1:-}"
+    local -r rc_file="$(resolve_rc_file "${2:-}")"
 
-source "$RC_FILE"
+    if [ ! -f "$rc_file" ]; then
+        echo "Error: Can not find config file $rc_file" >&2
+        exit 1
+    fi
 
-case "$ARG1" in
-    clean)      [ -d "$DIST_DIR" ] && rm -Rf "$DIST_DIR";;
-    generate)   generate;;
-    version)    echo "This is Photoalbum Version $VERSION";;
-    makemake)   makemake;;
-    *)          usage;;
-esac
+    source "$rc_file"
+    apply_config_defaults
+
+    case "$arg1" in
+        clean)
+            if [ -d "$DIST_DIR" ]; then
+                rm -rf "$DIST_DIR"
+            fi
+            ;;
+        generate)
+            generate
+            ;;
+        version)
+            echo "This is Photoalbum Version $VERSION"
+            ;;
+        makemake)
+            makemake
+            ;;
+        *)
+            usage
+            ;;
+    esac
+}
 
-exit 0
+main "$@"