#!/usr/bin/env bash
set -euo pipefail
shopt -u patsub_replacement
umask 022
# Exit with an error message
die() { echo "Error: $1" >&2 && exit 1; }
# Check required external commands
command -v ffprobe >/dev/null || die "ffprobe required"
command -v sed >/dev/null || die "sed required"
command -v stat >/dev/null || die "stat required"
# Project files
readonly html_file="index.html"
readonly rss_file="rss.xml"
readonly site_conf="site.conf"
readonly item_template="item.html"
# Temp files
html_tmp=$(mktemp)
rss_tmp=$(mktemp)
# Verify required files and directories exist
[[ -f "$site_conf" ]] || die "missing $site_conf"
[[ -d media ]] || die "missing media/"
# Load item template, or use built-in default
if [[ -f "$item_template" ]]; then
item_template_content=$(<"$item_template")
else
item_template_content='
{{title}}
{{synopsis}}
'
fi
# Deletes temp files
trap 'rm -f "$html_tmp" "$rss_tmp"' EXIT
# Default configuration values
podcast_title=""
podcast_description=""
podcast_author=""
podcast_language="en-GB"
podcast_category="Society & Culture"
podcast_explicit="false"
date_format="%d %b %Y"
recursive=false
order=reverse
url_base=""
# Load site configuration
while IFS=':' read -r k v; do
k=$(xargs <<< "$k")
v=$(xargs <<< "$v")
case "$k" in
title) podcast_title="$v" ;;
description) podcast_description="$v" ;;
author) podcast_author="$v" ;;
language) podcast_language="$v" ;;
category) podcast_category="$v" ;;
explicit) podcast_explicit="$v" ;;
date_format) date_format="$v" ;;
recursive) recursive="${v,,}" ;;
order) order="${v,,}" ;;
url) url_base="$v" ;;
esac
done < "$site_conf"
# Check the site.conf
[[ -n $podcast_title ]] || die "title missing from site.conf"
[[ -n $podcast_author ]] || die "author missing from site.conf"
[[ -n $url_base ]] || die "url missing from site.conf"
# Remove trailing slash from site URL
url_base="${url_base%/}"
# Timestamp inserted into generated pages
generated=$(date -Ru)
# Build sort options
sort_args=()
[[ "$order" != "forward" ]] && sort_args+=("-r")
# Read an MP3 metadata tag
meta() {
ffprobe \
-v error \
-show_entries format_tags="$1" \
-of default=noprint_wrappers=1:nokey=1 \
"$2" 2>/dev/null || true
}
# Escape HTML special characters
escape_html() { sed -e 's/&/\&/g' -e 's//\>/g'; }
# Convert URLs in text into HTML links
linkify() { sed -E 's@(https?://[^[:space:]<]+)@\1@g'; }
# Build find command arguments
find_args=(-type f -iname "*.mp3")
[[ "$recursive" != "true" ]] && find_args=(-maxdepth 1 "${find_args[@]}")
# Find MP3 files and sort them by filename
mapfile -t files < <(
find -L media/ "${find_args[@]}" |
awk -F/ '{print $NF "\t" $0}' |
sort "${sort_args[@]}" |
cut -f2
)
# Abort if no MP3 files were found
[[ ${#files[@]} -gt 0 ]] || die "no mp3 files found"
# HTML render top
cat > "$html_tmp" <
$(printf '%s' "$podcast_title" | escape_html)
$( [[ -f style.css ]] && echo '' )
EOF
# Add head.html if it exists
[[ -f head.html ]] && cat head.html >> "$html_tmp"
# RSS render top
cat > "$rss_tmp" <
$(printf '%s' "$podcast_title" | escape_html)
$url_base/avatar.png
$podcast_explicit
$(printf '%s' "$podcast_author" | escape_html)
$podcast_language
$url_base/$rss_file
$generated
EOF
# Render HTML and RSS entries
for url in "${files[@]}"; do
base=$(basename "$url")
echo "Processing: $base"
# Require filenames to begin with YYYYMMDD
[[ "$base" =~ ^[0-9]{8} ]] || die "bad filename: $base"
y=${base:0:4}
m=${base:4:2}
d=${base:6:2}
display_date=$(date -d "$y-$m-$d" +"$date_format")
rss_date=$(date -R -d "$y-$m-$d")
title=$(meta TITLE "$url")
synopsis=$(meta DESCRIPTION "$url")
[[ -n "$title" ]] || title="Untitled"
# Escape HTML, convert URLs to links and preserve line breaks
synopsis_html=$(
printf '%s\n' "$synopsis" |
escape_html |
linkify |
sed ':a;N;$!ba;s/\n/
/g'
)
rss_url="${url_base}/${url}"
rss_length=$(stat -c%s "$url")
# Render HTML item
item="$item_template_content"
item=${item//'{{title}}'/$title}
item=${item//'{{date}}'/$display_date}
item=${item//'{{url}}'/$url}
item=${item//'{{siteurl}}'/$url_base}
item=${item//'{{synopsis}}'/$synopsis_html}
printf '%s\n' "$item" >> "$html_tmp"
cat >> "$rss_tmp" <
$(printf '%s' "$title" | escape_html)
$rss_date
$rss_url
$rss_url
EOF
done
# Add foot.html if it exists
[[ -f foot.html ]] && cat foot.html >> "$html_tmp"
# Finishing HTML
cat >> "$html_tmp" <
EOF
# Finishing RSS
cat >> "$rss_tmp" <
EOF
chmod 644 "$rss_tmp" "$html_tmp"
mv "$rss_tmp" "$rss_file"
mv "$html_tmp" "$html_file"
# Done
echo "Done"