Split config module concerns for task 9m0

6 files changed, 624 insertions, 629 deletions

diff --git a/src/lib/config.cli.source.sh b/src/lib/config.cli.source.sh
new file mode 100644
index 0000000..1df4b84
--- /dev/null
+++ b/src/lib/config.cli.source.sh
@@ -0,0 +1,109 @@
+option_value() {
+    local -r option="$1"; shift
+    local -r argument="${CLI_OPTION_ARGUMENT[$option]:-value}"
+
+    if (( $# == 0 )) || [ -z "$1" ]; then
+        printf 'Error: %s requires a %s\n' "$option" "$argument" >&2
+        usage
+        exit 1
+    fi
+
+    printf '%s\n' "$1"
+}
+
+apply_cli_override() {
+    local -r config_target="$1"; shift
+
+    if [[ -v "cli_overrides[$config_target]" ]]; then
+        printf -v "$config_target" '%s' "${cli_overrides[$config_target]}"
+    fi
+}
+
+apply_cli_overrides() {
+    local config_target
+
+    for config_target in "${CLI_CONFIG_OVERRIDE_TARGETS[@]}"; do
+        apply_cli_override "$config_target"
+    done
+
+    if (( ${#cli_sync_destinations[@]} > 0 )); then
+        SYNC_DESTINATIONS=("${cli_sync_destinations[@]}")
+    fi
+}
+
+set_cli_option_value() {
+    local -r option="$1"; shift
+    local -r value="$1"; shift
+    local config_target
+
+    if [ "$option" = --sync-destination ]; then
+        cli_sync_destinations+=("$value")
+        has_config_overrides='yes'
+        return
+    fi
+
+    config_target="${CLI_OPTION_CONFIG_TARGET[$option]:-}"
+    if [ -n "$config_target" ]; then
+        cli_overrides["$config_target"]="$value"
+        has_config_overrides='yes'
+        return
+    fi
+
+    printf -v "${CLI_OPTION_TARGET[$option]}" '%s' "$value"
+}
+
+set_cli_constant_option() {
+    local -r option="$1"; shift
+    local -r value="${CLI_OPTION_VALUE[$option]}"
+    local config_target
+
+    config_target="${CLI_OPTION_CONFIG_TARGET[$option]:-}"
+    if [ -n "$config_target" ]; then
+        cli_overrides["$config_target"]="$value"
+        has_config_overrides='yes'
+        return
+    fi
+
+    printf -v "${CLI_OPTION_TARGET[$option]}" '%s' "$value"
+}
+
+set_cli_action() {
+    local -r selected_action="$1"; shift
+
+    if [ -n "$action" ]; then
+        usage
+        exit 1
+    fi
+
+    action="$selected_action"
+}
+
+parse_cli_arguments() {
+    local option_arg
+    local option
+    local option_kind
+
+    while (( $# > 0 )); do
+        option="$1"
+        shift
+
+        option_kind="${CLI_OPTION_KIND[$option]:-}"
+        case "$option_kind" in
+            value)
+                option_arg=$(option_value "$option" "$@")
+                set_cli_option_value "$option" "$option_arg"
+                shift
+                ;;
+            flag|output)
+                set_cli_constant_option "$option"
+                ;;
+            action)
+                set_cli_action "$option"
+                ;;
+            *)
+                usage
+                exit 1
+                ;;
+        esac
+    done
+}
diff --git a/src/lib/config.print.source.sh b/src/lib/config.print.source.sh
new file mode 100644
index 0000000..1950a26
--- /dev/null
+++ b/src/lib/config.print.source.sh
@@ -0,0 +1,46 @@
+print_shell_assignment() {
+    local -r name="$1"; shift
+    local -r value="$1"; shift
+
+    printf '%s=%q\n' "$name" "$value"
+}
+
+print_shell_array_assignment() {
+    local -r name="$1"; shift
+    local value
+
+    printf '%s=(' "$name"
+    for value in "$@"; do
+        printf ' %q' "$value"
+    done
+    printf ' )\n'
+}
+
+print_config() {
+    local -a tar_opts=()
+    local -a sync_destinations=()
+
+    resolve_tar_opts tar_opts
+    resolve_sync_destinations sync_destinations
+
+    print_shell_assignment CONFIG_SOURCE "${SHURIKEN_CONFIG_SOURCE:-}"
+    print_shell_assignment INCOMING_DIR "$INCOMING_DIR"
+    print_shell_assignment DIST_DIR "$DIST_DIR"
+    print_shell_assignment TEMPLATE_DIR "$TEMPLATE_DIR"
+    print_shell_assignment TITLE "$TITLE"
+    print_shell_assignment HEIGHT "${HEIGHT:-}"
+    print_shell_assignment THUMBHEIGHT "$THUMBHEIGHT"
+    print_shell_assignment MAXPREVIEWS "$MAXPREVIEWS"
+    print_shell_assignment IMAGE_JOBS "$IMAGE_JOBS"
+    print_shell_assignment IMAGEMAGICK_TIMEOUT "$IMAGEMAGICK_TIMEOUT"
+    print_shell_assignment RANDOM_SEED "${RANDOM_SEED:-}"
+    print_shell_assignment SHUFFLE "${SHUFFLE:-no}"
+    print_shell_assignment SPLASH_PAGE "${SPLASH_PAGE:-yes}"
+    print_shell_assignment TARBALL_INCLUDE "${TARBALL_INCLUDE:-no}"
+    print_shell_assignment TARBALL_SUFFIX "${TARBALL_SUFFIX:-.tar}"
+    print_shell_assignment TAR_TIMEOUT "$TAR_TIMEOUT"
+    print_shell_array_assignment TAR_OPTS "${tar_opts[@]}"
+    print_shell_assignment SYNC_DELETE "${SYNC_DELETE:-yes}"
+    print_shell_array_assignment SYNC_DESTINATIONS "${sync_destinations[@]}"
+    print_shell_assignment ORIGINAL_BASEPATH "${ORIGINAL_BASEPATH:-}"
+}
diff --git a/src/lib/config.source.sh b/src/lib/config.source.sh
index 35624b7..348f167 100644
--- a/src/lib/config.source.sh
+++ b/src/lib/config.source.sh
@@ -1,67 +1,3 @@
-print_shell_assignment() {
-    local -r name="$1"; shift
-    local -r value="$1"; shift
-
-    printf '%s=%q\n' "$name" "$value"
-}
-
-print_shell_array_assignment() {
-    local -r name="$1"; shift
-    local value
-
-    printf '%s=(' "$name"
-    for value in "$@"; do
-        printf ' %q' "$value"
-    done
-    printf ' )\n'
-}
-
-print_config() {
-    local -a tar_opts=()
-    local -a sync_destinations=()
-
-    resolve_tar_opts tar_opts
-    resolve_sync_destinations sync_destinations
-
-    print_shell_assignment CONFIG_SOURCE "${SHURIKEN_CONFIG_SOURCE:-}"
-    print_shell_assignment INCOMING_DIR "$INCOMING_DIR"
-    print_shell_assignment DIST_DIR "$DIST_DIR"
-    print_shell_assignment TEMPLATE_DIR "$TEMPLATE_DIR"
-    print_shell_assignment TITLE "$TITLE"
-    print_shell_assignment HEIGHT "${HEIGHT:-}"
-    print_shell_assignment THUMBHEIGHT "$THUMBHEIGHT"
-    print_shell_assignment MAXPREVIEWS "$MAXPREVIEWS"
-    print_shell_assignment IMAGE_JOBS "$IMAGE_JOBS"
-    print_shell_assignment IMAGEMAGICK_TIMEOUT "$IMAGEMAGICK_TIMEOUT"
-    print_shell_assignment RANDOM_SEED "${RANDOM_SEED:-}"
-    print_shell_assignment SHUFFLE "${SHUFFLE:-no}"
-    print_shell_assignment SPLASH_PAGE "${SPLASH_PAGE:-yes}"
-    print_shell_assignment TARBALL_INCLUDE "${TARBALL_INCLUDE:-no}"
-    print_shell_assignment TARBALL_SUFFIX "${TARBALL_SUFFIX:-.tar}"
-    print_shell_assignment TAR_TIMEOUT "$TAR_TIMEOUT"
-    print_shell_array_assignment TAR_OPTS "${tar_opts[@]}"
-    print_shell_assignment SYNC_DELETE "${SYNC_DELETE:-yes}"
-    print_shell_array_assignment SYNC_DESTINATIONS "${sync_destinations[@]}"
-    print_shell_assignment ORIGINAL_BASEPATH "${ORIGINAL_BASEPATH:-}"
-}
-
-sync_dist() {
-    local destination
-    local -a rsync_args=(-av)
-    local -a sync_destinations=()
-
-    resolve_sync_destinations sync_destinations
-
-    if [ "${SYNC_DELETE:-yes}" = yes ]; then
-        rsync_args+=(--delete)
-    fi
-
-    for destination in "${sync_destinations[@]}"; do
-        log_info "Syncing $DIST_DIR/ to $destination"
-        rsync "${rsync_args[@]}" "$DIST_DIR/" "$destination"
-    done
-}
-
 existing_parent_dir() {
     local -r path="$1"; shift
     local existing_parent
@@ -75,223 +11,6 @@ existing_parent_dir() {
     printf '%s\n' "$existing_parent"
 }
 
-generation_staging_dir() {
-    local -r final_dist="$1"; shift
-    local final_base
-    local staging_parent
-
-    final_base=$(basename "$final_dist")
-    staging_parent=$(existing_parent_dir "$final_dist")
-
-    mktemp -d "$staging_parent/.shuriken.$final_base.staging.XXXXXX"
-}
-
-prepare_generation_staging_dir() {
-    local -r final_dist="$1"; shift
-    local -r staging_dir="$1"; shift
-    local cache_dir
-
-    if [ "$SHURIKEN_FORCE_GENERATE" = yes ]; then
-        log_verbose 'Force generation enabled; not reusing existing output cache'
-        return
-    fi
-
-    for cache_dir in photos thumbs blurs .shuriken-cache; do
-        if [ -d "$final_dist/$cache_dir" ]; then
-            if ! mkdir -p "$staging_dir/$cache_dir"; then
-                return 1
-            fi
-            if ! cp -a "$final_dist/$cache_dir/." "$staging_dir/$cache_dir/"; then
-                return 1
-            fi
-        fi
-    done
-}
-
-cleanup_generation_staging_dir() {
-    if [ -n "${SHURIKEN_ACTIVE_STAGING_DIR:-}" ]; then
-        rm -rf "$SHURIKEN_ACTIVE_STAGING_DIR"
-        SHURIKEN_ACTIVE_STAGING_DIR=''
-    fi
-}
-
-terminate_process_tree() {
-    local -r signal="$1"; shift
-    local -r pid="$1"; shift
-    local child
-
-    if [ -z "$pid" ]; then
-        return
-    fi
-
-    while IFS= read -r child; do
-        if [ -n "$child" ]; then
-            terminate_process_tree "$signal" "$child"
-        fi
-    done < <(pgrep -P "$pid" 2>/dev/null || true)
-
-    kill "-$signal" "$pid" 2>/dev/null || true
-}
-
-wait_for_process_exit() {
-    local -r pid="$1"; shift
-    local -i attempts=0
-
-    while kill -0 "$pid" 2>/dev/null; do
-        if (( attempts >= 20 )); then
-            return 1
-        fi
-        (( ++attempts ))
-        sleep 0.05
-    done
-}
-
-terminate_active_generation() {
-    local -r pid="${SHURIKEN_ACTIVE_GENERATION_PID:-}"
-
-    if [ -z "$pid" ]; then
-        return
-    fi
-
-    terminate_process_tree TERM "$pid"
-    if ! wait_for_process_exit "$pid"; then
-        terminate_process_tree KILL "$pid"
-    fi
-    wait "$pid" 2>/dev/null || true
-    SHURIKEN_ACTIVE_GENERATION_PID=''
-}
-
-handle_generation_staging_signal() {
-    local -r status="$1"; shift
-
-    clear_generation_staging_traps
-    terminate_active_generation
-    cleanup_generation_staging_dir
-    exit "$status"
-}
-
-clear_generation_staging_traps() {
-    trap - EXIT INT TERM HUP PIPE
-}
-
-ignore_generation_staging_interrupts() {
-    trap '' INT TERM HUP PIPE
-}
-
-replace_dist_with_staging() {
-    local -r staging_dir="$1"; shift
-    local -r final_dist="$1"; shift
-    local backup_dist=''
-    local backup_parent=''
-    local final_base
-    local final_parent
-    local staging_parent
-    local -i status=0
-
-    final_base=$(basename "$final_dist")
-    final_parent=$(dirname "$final_dist")
-    staging_parent=$(existing_parent_dir "$final_dist")
-
-    if ! mkdir -p "$final_parent"; then
-        return 1
-    fi
-
-    if [ -e "$final_dist" ]; then
-        if ! backup_parent=$(
-            mktemp -d "$staging_parent/.shuriken.$final_base.backup.XXXXXX"
-        ); then
-            return 1
-        fi
-        backup_dist="$backup_parent/dist"
-
-        if ! mv "$final_dist" "$backup_dist"; then
-            rm -rf "$backup_parent"
-            return 1
-        fi
-    fi
-
-    if mv "$staging_dir" "$final_dist"; then
-        if [ -n "$backup_parent" ]; then
-            rm -rf "$backup_parent"
-        fi
-        return 0
-    else
-        status=$?
-    fi
-
-    if [ -n "$backup_dist" ] && [ -e "$backup_dist" ]; then
-        if [ -e "$final_dist" ] && ! rm -rf "$final_dist"; then
-            printf 'ERROR: Failed to restore %s from %s\n' \
-                "$final_dist" "$backup_dist" >&2
-            return "$status"
-        fi
-        if ! mv "$backup_dist" "$final_dist"; then
-            printf 'ERROR: Failed to restore %s from %s\n' \
-                "$final_dist" "$backup_dist" >&2
-            return "$status"
-        fi
-        rm -rf "$backup_parent"
-    fi
-
-    return "$status"
-}
-
-generate_staged() {
-    local -r final_dist="$DIST_DIR"
-    local staging_dir
-    local -i status=0
-
-    staging_dir=$(generation_staging_dir "$final_dist")
-    log_verbose "Effective output directory: $final_dist"
-    log_verbose "Generation staging directory: $staging_dir"
-    SHURIKEN_ACTIVE_STAGING_DIR="$staging_dir"
-    trap cleanup_generation_staging_dir EXIT
-    trap 'handle_generation_staging_signal 130' INT
-    trap 'handle_generation_staging_signal 143' TERM
-    trap 'handle_generation_staging_signal 129' HUP
-    trap 'handle_generation_staging_signal 141' PIPE
-
-    if ! prepare_generation_staging_dir "$final_dist" "$staging_dir"; then
-        cleanup_generation_staging_dir
-        clear_generation_staging_traps
-        return 1
-    fi
-
-    set +e
-    (
-        set -e
-        SHURIKEN_FINAL_DIST_DIR="$final_dist"
-        export SHURIKEN_FINAL_DIST_DIR
-        DIST_DIR="$staging_dir" generate
-    ) &
-    SHURIKEN_ACTIVE_GENERATION_PID=$!
-    wait "$SHURIKEN_ACTIVE_GENERATION_PID"
-    status=$?
-    SHURIKEN_ACTIVE_GENERATION_PID=''
-    set -e
-
-    if (( status != 0 )); then
-        cleanup_generation_staging_dir
-        clear_generation_staging_traps
-        return "$status"
-    fi
-
-    ignore_generation_staging_interrupts
-    set +e
-    replace_dist_with_staging "$staging_dir" "$final_dist"
-    status=$?
-    set -e
-
-    if (( status != 0 )); then
-        cleanup_generation_staging_dir
-        clear_generation_staging_traps
-        return "$status"
-    fi
-
-    SHURIKEN_ACTIVE_STAGING_DIR=''
-    clear_generation_staging_traps
-}
-
 resolve_config_file() {
     local -r config_file="${1:-}"
 
@@ -329,351 +48,3 @@ apply_config_defaults() {
         SYNC_DESTINATIONS=()
     fi
 }
-
-option_value() {
-    local -r option="$1"; shift
-    local -r argument="${CLI_OPTION_ARGUMENT[$option]:-value}"
-
-    if (( $# == 0 )) || [ -z "$1" ]; then
-        printf 'Error: %s requires a %s\n' "$option" "$argument" >&2
-        usage
-        exit 1
-    fi
-
-    printf '%s\n' "$1"
-}
-
-apply_cli_override() {
-    local -r config_target="$1"; shift
-
-    if [[ -v "cli_overrides[$config_target]" ]]; then
-        printf -v "$config_target" '%s' "${cli_overrides[$config_target]}"
-    fi
-}
-
-apply_cli_overrides() {
-    local config_target
-
-    for config_target in "${CLI_CONFIG_OVERRIDE_TARGETS[@]}"; do
-        apply_cli_override "$config_target"
-    done
-
-    if (( ${#cli_sync_destinations[@]} > 0 )); then
-        SYNC_DESTINATIONS=("${cli_sync_destinations[@]}")
-    fi
-}
-
-config_error() {
-    local -r message="$1"; shift
-
-    printf 'ERROR: %s\n' "$message" >&2
-    return 1
-}
-
-require_config_var() {
-    local -r name="$1"; shift
-
-    if [ -z "${!name+x}" ] || [ -z "${!name}" ]; then
-        config_error "$name must be set in shuriken configuration"
-    fi
-}
-
-validate_positive_integer_config_var() {
-    local -r name="$1"; shift
-    local -r value="${!name}"
-
-    if [[ ! "$value" =~ ^[0-9]+$ ]] || (( value < 1 )); then
-        config_error "$name must be a positive integer"
-    fi
-}
-
-validate_optional_positive_integer_config_var() {
-    local -r name="$1"; shift
-
-    if [ -n "${!name}" ]; then
-        validate_positive_integer_config_var "$name"
-    fi
-}
-
-validate_yes_no_config_var() {
-    local -r name="$1"; shift
-    local -r value="${!name}"
-
-    case "$value" in
-        yes|no)
-            ;;
-        *)
-            config_error "$name must be yes or no"
-            ;;
-    esac
-}
-
-validate_dist_dir() {
-    local existing_parent
-
-    if [ -e "$DIST_DIR" ]; then
-        if [ ! -d "$DIST_DIR" ]; then
-            config_error "DIST_DIR $DIST_DIR must be a directory"
-        fi
-        if [[ ! -w "$DIST_DIR" || ! -x "$DIST_DIR" ]]; then
-            config_error "DIST_DIR $DIST_DIR must be writable"
-        fi
-
-        return
-    fi
-
-    existing_parent=$(existing_parent_dir "$DIST_DIR")
-
-    if [ ! -d "$existing_parent" ]; then
-        config_error "DIST_DIR parent $existing_parent must be a directory"
-    fi
-    if [[ ! -w "$existing_parent" || ! -x "$existing_parent" ]]; then
-        config_error "DIST_DIR parent $existing_parent must be writable"
-    fi
-}
-
-validate_template_dir_access() {
-    if [[ ! -d "$TEMPLATE_DIR" || ! -r "$TEMPLATE_DIR" \
-        || ! -x "$TEMPLATE_DIR" ]]; then
-        config_error "TEMPLATE_DIR $TEMPLATE_DIR must be a readable directory"
-    fi
-}
-
-validate_template_file() {
-    local -r template_name="$1"; shift
-
-    if [ ! -r "$TEMPLATE_DIR/$template_name.tmpl" ]; then
-        config_error \
-            "template file $TEMPLATE_DIR/$template_name.tmpl must be readable"
-    fi
-}
-
-validate_template_dir() {
-    local template_name
-    local -a required_templates=(
-        details
-        footer
-        header
-        next
-        prev
-        preview
-        redirect
-        view
-    )
-
-    validate_template_dir_access
-
-    if [ "${SPLASH_PAGE:-yes}" = yes ]; then
-        required_templates+=(splash)
-    fi
-
-    for template_name in "${required_templates[@]}"; do
-        validate_template_file "$template_name"
-    done
-}
-
-validate_refresh_splash_config() {
-    local required_var
-    local -a required_vars=(
-        TITLE
-        DIST_DIR
-        TEMPLATE_DIR
-    )
-
-    for required_var in "${required_vars[@]}"; do
-        require_config_var "$required_var"
-    done
-
-    validate_yes_no_config_var SPLASH_PAGE
-
-    if [ "${SPLASH_PAGE:-yes}" != yes ]; then
-        config_error 'SPLASH_PAGE must be yes to refresh the splash page'
-    fi
-
-    validate_dist_dir
-
-    validate_template_dir_access
-    validate_template_file splash
-
-    if [ ! -d "$DIST_DIR/photos" ]; then
-        config_error "DIST_DIR photos directory $DIST_DIR/photos must exist"
-    fi
-
-    if [ ! -d "$DIST_DIR/blurs" ]; then
-        config_error "DIST_DIR blurs directory $DIST_DIR/blurs must exist"
-    fi
-}
-
-validate_imagemagick() {
-    if command -v magick >/dev/null 2>&1; then
-        return
-    fi
-    if command -v convert >/dev/null 2>&1; then
-        return
-    fi
-
-    config_error 'ImageMagick is required; install magick or convert'
-}
-
-validate_common_config() {
-    local required_var
-    local -a required_vars=(
-        TITLE
-        THUMBHEIGHT
-        MAXPREVIEWS
-        IMAGE_JOBS
-        INCOMING_DIR
-        DIST_DIR
-        TEMPLATE_DIR
-    )
-
-    for required_var in "${required_vars[@]}"; do
-        require_config_var "$required_var"
-    done
-
-    validate_optional_positive_integer_config_var HEIGHT
-    validate_positive_integer_config_var THUMBHEIGHT
-    validate_positive_integer_config_var MAXPREVIEWS
-    validate_positive_integer_config_var IMAGE_JOBS
-    validate_positive_integer_config_var IMAGEMAGICK_TIMEOUT
-    validate_positive_integer_config_var TAR_TIMEOUT
-    validate_yes_no_config_var SHUFFLE
-    validate_yes_no_config_var SPLASH_PAGE
-    validate_yes_no_config_var TARBALL_INCLUDE
-}
-
-validate_generation_config() {
-    local -r require_imagemagick="${1:-yes}"
-
-    validate_common_config
-
-    if [ ! -d "$INCOMING_DIR" ]; then
-        config_error "You have to create $INCOMING_DIR first"
-    fi
-    if [[ ! -r "$INCOMING_DIR" || ! -x "$INCOMING_DIR" ]]; then
-        config_error "INCOMING_DIR $INCOMING_DIR must be readable"
-    fi
-
-    validate_dist_dir
-    validate_template_dir
-    if [ "$require_imagemagick" = yes ]; then
-        validate_imagemagick
-    fi
-}
-
-validate_print_config() {
-    local -a tar_opts=()
-    local -a sync_destinations=()
-
-    validate_common_config
-    resolve_tar_opts tar_opts
-    resolve_sync_destinations sync_destinations
-    validate_yes_no_config_var SYNC_DELETE
-}
-
-validate_sync_destinations() {
-    local -a sync_destinations=()
-
-    resolve_sync_destinations sync_destinations
-
-    if (( ${#sync_destinations[@]} == 0 )); then
-        config_error 'SYNC_DESTINATIONS must contain at least one destination'
-    fi
-}
-
-validate_rsync() {
-    if command -v rsync >/dev/null 2>&1; then
-        return
-    fi
-
-    config_error 'rsync is required to sync generated output'
-}
-
-validate_sync_config() {
-    require_config_var DIST_DIR
-    validate_yes_no_config_var SYNC_DELETE
-    validate_sync_destinations
-
-    if [[ ! -d "$DIST_DIR" || ! -r "$DIST_DIR" || ! -x "$DIST_DIR" ]]; then
-        config_error "DIST_DIR $DIST_DIR must be a readable directory"
-    fi
-
-    validate_rsync
-}
-
-set_cli_option_value() {
-    local -r option="$1"; shift
-    local -r value="$1"; shift
-    local config_target
-
-    if [ "$option" = --sync-destination ]; then
-        cli_sync_destinations+=("$value")
-        has_config_overrides='yes'
-        return
-    fi
-
-    config_target="${CLI_OPTION_CONFIG_TARGET[$option]:-}"
-    if [ -n "$config_target" ]; then
-        cli_overrides["$config_target"]="$value"
-        has_config_overrides='yes'
-        return
-    fi
-
-    printf -v "${CLI_OPTION_TARGET[$option]}" '%s' "$value"
-}
-
-set_cli_constant_option() {
-    local -r option="$1"; shift
-    local -r value="${CLI_OPTION_VALUE[$option]}"
-    local config_target
-
-    config_target="${CLI_OPTION_CONFIG_TARGET[$option]:-}"
-    if [ -n "$config_target" ]; then
-        cli_overrides["$config_target"]="$value"
-        has_config_overrides='yes'
-        return
-    fi
-
-    printf -v "${CLI_OPTION_TARGET[$option]}" '%s' "$value"
-}
-
-set_cli_action() {
-    local -r selected_action="$1"; shift
-
-    if [ -n "$action" ]; then
-        usage
-        exit 1
-    fi
-
-    action="$selected_action"
-}
-
-parse_cli_arguments() {
-    local option_arg
-    local option
-    local option_kind
-
-    while (( $# > 0 )); do
-        option="$1"
-        shift
-
-        option_kind="${CLI_OPTION_KIND[$option]:-}"
-        case "$option_kind" in
-            value)
-                option_arg=$(option_value "$option" "$@")
-                set_cli_option_value "$option" "$option_arg"
-                shift
-                ;;
-            flag|output)
-                set_cli_constant_option "$option"
-                ;;
-            action)
-                set_cli_action "$option"
-                ;;
-            *)
-                usage
-                exit 1
-                ;;
-        esac
-    done
-}
diff --git a/src/lib/config.staging.source.sh b/src/lib/config.staging.source.sh
new file mode 100644
index 0000000..8a5f8f1
--- /dev/null
+++ b/src/lib/config.staging.source.sh
@@ -0,0 +1,216 @@
+generation_staging_dir() {
+    local -r final_dist="$1"; shift
+    local final_base
+    local staging_parent
+
+    final_base=$(basename "$final_dist")
+    staging_parent=$(existing_parent_dir "$final_dist")
+
+    mktemp -d "$staging_parent/.shuriken.$final_base.staging.XXXXXX"
+}
+
+prepare_generation_staging_dir() {
+    local -r final_dist="$1"; shift
+    local -r staging_dir="$1"; shift
+    local cache_dir
+
+    if [ "$SHURIKEN_FORCE_GENERATE" = yes ]; then
+        log_verbose 'Force generation enabled; not reusing existing output cache'
+        return
+    fi
+
+    for cache_dir in photos thumbs blurs .shuriken-cache; do
+        if [ -d "$final_dist/$cache_dir" ]; then
+            if ! mkdir -p "$staging_dir/$cache_dir"; then
+                return 1
+            fi
+            if ! cp -a "$final_dist/$cache_dir/." "$staging_dir/$cache_dir/"; then
+                return 1
+            fi
+        fi
+    done
+}
+
+cleanup_generation_staging_dir() {
+    if [ -n "${SHURIKEN_ACTIVE_STAGING_DIR:-}" ]; then
+        rm -rf "$SHURIKEN_ACTIVE_STAGING_DIR"
+        SHURIKEN_ACTIVE_STAGING_DIR=''
+    fi
+}
+
+terminate_process_tree() {
+    local -r signal="$1"; shift
+    local -r pid="$1"; shift
+    local child
+
+    if [ -z "$pid" ]; then
+        return
+    fi
+
+    while IFS= read -r child; do
+        if [ -n "$child" ]; then
+            terminate_process_tree "$signal" "$child"
+        fi
+    done < <(pgrep -P "$pid" 2>/dev/null || true)
+
+    kill "-$signal" "$pid" 2>/dev/null || true
+}
+
+wait_for_process_exit() {
+    local -r pid="$1"; shift
+    local -i attempts=0
+
+    while kill -0 "$pid" 2>/dev/null; do
+        if (( attempts >= 20 )); then
+            return 1
+        fi
+        (( ++attempts ))
+        sleep 0.05
+    done
+}
+
+terminate_active_generation() {
+    local -r pid="${SHURIKEN_ACTIVE_GENERATION_PID:-}"
+
+    if [ -z "$pid" ]; then
+        return
+    fi
+
+    terminate_process_tree TERM "$pid"
+    if ! wait_for_process_exit "$pid"; then
+        terminate_process_tree KILL "$pid"
+    fi
+    wait "$pid" 2>/dev/null || true
+    SHURIKEN_ACTIVE_GENERATION_PID=''
+}
+
+handle_generation_staging_signal() {
+    local -r status="$1"; shift
+
+    clear_generation_staging_traps
+    terminate_active_generation
+    cleanup_generation_staging_dir
+    exit "$status"
+}
+
+clear_generation_staging_traps() {
+    trap - EXIT INT TERM HUP PIPE
+}
+
+ignore_generation_staging_interrupts() {
+    trap '' INT TERM HUP PIPE
+}
+
+replace_dist_with_staging() {
+    local -r staging_dir="$1"; shift
+    local -r final_dist="$1"; shift
+    local backup_dist=''
+    local backup_parent=''
+    local final_base
+    local final_parent
+    local staging_parent
+    local -i status=0
+
+    final_base=$(basename "$final_dist")
+    final_parent=$(dirname "$final_dist")
+    staging_parent=$(existing_parent_dir "$final_dist")
+
+    if ! mkdir -p "$final_parent"; then
+        return 1
+    fi
+
+    if [ -e "$final_dist" ]; then
+        if ! backup_parent=$(
+            mktemp -d "$staging_parent/.shuriken.$final_base.backup.XXXXXX"
+        ); then
+            return 1
+        fi
+        backup_dist="$backup_parent/dist"
+
+        if ! mv "$final_dist" "$backup_dist"; then
+            rm -rf "$backup_parent"
+            return 1
+        fi
+    fi
+
+    if mv "$staging_dir" "$final_dist"; then
+        if [ -n "$backup_parent" ]; then
+            rm -rf "$backup_parent"
+        fi
+        return 0
+    else
+        status=$?
+    fi
+
+    if [ -n "$backup_dist" ] && [ -e "$backup_dist" ]; then
+        if [ -e "$final_dist" ] && ! rm -rf "$final_dist"; then
+            printf 'ERROR: Failed to restore %s from %s\n' \
+                "$final_dist" "$backup_dist" >&2
+            return "$status"
+        fi
+        if ! mv "$backup_dist" "$final_dist"; then
+            printf 'ERROR: Failed to restore %s from %s\n' \
+                "$final_dist" "$backup_dist" >&2
+            return "$status"
+        fi
+        rm -rf "$backup_parent"
+    fi
+
+    return "$status"
+}
+
+generate_staged() {
+    local -r final_dist="$DIST_DIR"
+    local staging_dir
+    local -i status=0
+
+    staging_dir=$(generation_staging_dir "$final_dist")
+    log_verbose "Effective output directory: $final_dist"
+    log_verbose "Generation staging directory: $staging_dir"
+    SHURIKEN_ACTIVE_STAGING_DIR="$staging_dir"
+    trap cleanup_generation_staging_dir EXIT
+    trap 'handle_generation_staging_signal 130' INT
+    trap 'handle_generation_staging_signal 143' TERM
+    trap 'handle_generation_staging_signal 129' HUP
+    trap 'handle_generation_staging_signal 141' PIPE
+
+    if ! prepare_generation_staging_dir "$final_dist" "$staging_dir"; then
+        cleanup_generation_staging_dir
+        clear_generation_staging_traps
+        return 1
+    fi
+
+    set +e
+    (
+        set -e
+        SHURIKEN_FINAL_DIST_DIR="$final_dist"
+        export SHURIKEN_FINAL_DIST_DIR
+        DIST_DIR="$staging_dir" generate
+    ) &
+    SHURIKEN_ACTIVE_GENERATION_PID=$!
+    wait "$SHURIKEN_ACTIVE_GENERATION_PID"
+    status=$?
+    SHURIKEN_ACTIVE_GENERATION_PID=''
+    set -e
+
+    if (( status != 0 )); then
+        cleanup_generation_staging_dir
+        clear_generation_staging_traps
+        return "$status"
+    fi
+
+    ignore_generation_staging_interrupts
+    set +e
+    replace_dist_with_staging "$staging_dir" "$final_dist"
+    status=$?
+    set -e
+
+    if (( status != 0 )); then
+        cleanup_generation_staging_dir
+        clear_generation_staging_traps
+        return "$status"
+    fi
+
+    SHURIKEN_ACTIVE_STAGING_DIR=''
+    clear_generation_staging_traps
+}
diff --git a/src/lib/config.sync.source.sh b/src/lib/config.sync.source.sh
new file mode 100644
index 0000000..d2256d3
--- /dev/null
+++ b/src/lib/config.sync.source.sh
@@ -0,0 +1,16 @@
+sync_dist() {
+    local destination
+    local -a rsync_args=(-av)
+    local -a sync_destinations=()
+
+    resolve_sync_destinations sync_destinations
+
+    if [ "${SYNC_DELETE:-yes}" = yes ]; then
+        rsync_args+=(--delete)
+    fi
+
+    for destination in "${sync_destinations[@]}"; do
+        log_info "Syncing $DIST_DIR/ to $destination"
+        rsync "${rsync_args[@]}" "$DIST_DIR/" "$destination"
+    done
+}
diff --git a/src/lib/config.validate.source.sh b/src/lib/config.validate.source.sh
new file mode 100644
index 0000000..373f05d
--- /dev/null
+++ b/src/lib/config.validate.source.sh
@@ -0,0 +1,237 @@
+config_error() {
+    local -r message="$1"; shift
+
+    printf 'ERROR: %s\n' "$message" >&2
+    return 1
+}
+
+require_config_var() {
+    local -r name="$1"; shift
+
+    if [ -z "${!name+x}" ] || [ -z "${!name}" ]; then
+        config_error "$name must be set in shuriken configuration"
+    fi
+}
+
+validate_positive_integer_config_var() {
+    local -r name="$1"; shift
+    local -r value="${!name}"
+
+    if [[ ! "$value" =~ ^[0-9]+$ ]] || (( value < 1 )); then
+        config_error "$name must be a positive integer"
+    fi
+}
+
+validate_optional_positive_integer_config_var() {
+    local -r name="$1"; shift
+
+    if [ -n "${!name}" ]; then
+        validate_positive_integer_config_var "$name"
+    fi
+}
+
+validate_yes_no_config_var() {
+    local -r name="$1"; shift
+    local -r value="${!name}"
+
+    case "$value" in
+        yes|no)
+            ;;
+        *)
+            config_error "$name must be yes or no"
+            ;;
+    esac
+}
+
+validate_dist_dir() {
+    local existing_parent
+
+    if [ -e "$DIST_DIR" ]; then
+        if [ ! -d "$DIST_DIR" ]; then
+            config_error "DIST_DIR $DIST_DIR must be a directory"
+        fi
+        if [[ ! -w "$DIST_DIR" || ! -x "$DIST_DIR" ]]; then
+            config_error "DIST_DIR $DIST_DIR must be writable"
+        fi
+
+        return
+    fi
+
+    existing_parent=$(existing_parent_dir "$DIST_DIR")
+
+    if [ ! -d "$existing_parent" ]; then
+        config_error "DIST_DIR parent $existing_parent must be a directory"
+    fi
+    if [[ ! -w "$existing_parent" || ! -x "$existing_parent" ]]; then
+        config_error "DIST_DIR parent $existing_parent must be writable"
+    fi
+}
+
+validate_template_dir_access() {
+    if [[ ! -d "$TEMPLATE_DIR" || ! -r "$TEMPLATE_DIR" \
+        || ! -x "$TEMPLATE_DIR" ]]; then
+        config_error "TEMPLATE_DIR $TEMPLATE_DIR must be a readable directory"
+    fi
+}
+
+validate_template_file() {
+    local -r template_name="$1"; shift
+
+    if [ ! -r "$TEMPLATE_DIR/$template_name.tmpl" ]; then
+        config_error \
+            "template file $TEMPLATE_DIR/$template_name.tmpl must be readable"
+    fi
+}
+
+validate_template_dir() {
+    local template_name
+    local -a required_templates=(
+        details
+        footer
+        header
+        next
+        prev
+        preview
+        redirect
+        view
+    )
+
+    validate_template_dir_access
+
+    if [ "${SPLASH_PAGE:-yes}" = yes ]; then
+        required_templates+=(splash)
+    fi
+
+    for template_name in "${required_templates[@]}"; do
+        valida