blurt

#!/bin/sh
set -e

VERSION="2.0.0"

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
DIST="$SCRIPT_DIR/dist"

# Get current time in milliseconds (portable across GNU, BusyBox, macOS)
now_ms() {
  if ts=$(date +%s%N 2>/dev/null) && [ ${#ts} -gt 10 ]; then
    echo $((ts / 1000000))
  elif [ -f /proc/uptime ]; then
    awk '{printf "%.0f", $1 * 1000}' /proc/uptime
  else
    echo $(($(date +%s) * 1000))
  fi
}

slugify() {
  echo "$1" | tr '[:upper:]' '[:lower:]' | sed 's/[^a-z0-9]/-/g' | sed 's/--*/-/g' | sed 's/^-//' | sed 's/-$//'
}

xml_escape() {
  sed 's/&/\&amp;/g; s/</\&lt;/g; s/>/\&gt;/g; s/"/\&quot;/g; s/'"'"'/\&apos;/g'
}

generate_favicon() {
  title="$1"
  highlight="$2"
  output="$3"

  # Extract initials from title (first letter of each word, max 2)
  initials=$(echo "$title" | awk '{
    for (i=1; i<=NF && i<=2; i++) {
      printf toupper(substr($i, 1, 1))
    }
  }')

  cat >"$output" <<EOF
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100">
  <rect width="100" height="100" rx="12" fill="$highlight"/>
  <text x="51" y="51" font-family="'Open Sans', sans-serif" font-size="42" font-weight="bold" fill="rgba(0,0,0,0.2)" text-anchor="middle" dominant-baseline="central">$initials</text>
  <text x="50" y="50" font-family="'Open Sans', sans-serif" font-size="42" font-weight="bold" fill="#fff" text-anchor="middle" dominant-baseline="central">$initials</text>
</svg>
EOF
}

generate_og_image() {
  title="$1"
  site_url="$2"
  date="$3"
  highlight="$4"
  output="$5"

  command -v magick >/dev/null 2>&1 || return

  # Strip protocol from URL for display
  display_url=$(echo "$site_url" | sed 's|https://||; s|http://||')

  # Calculate a very slightly darker shade for almost invisible gradient
  darker=$(magick xc:"$highlight" -modulate 92 -format '%[hex:p{0,0}]' info: 2>/dev/null || echo "${highlight#\#}")

  if [ -n "$date" ]; then
    # Format date as "15 January, 2026"
    formatted_date=$(date -j -f "%Y-%m-%d" "$date" "+%-d %B, %Y" 2>/dev/null || echo "$date")

    # Post page: URL top-left, date top-right, title bottom-left
    # Use 32-bit depth with subtle noise to prevent gradient banding
    magick -size 1200x630 -depth 32 -define gradient:direction=SouthWest gradient:"$highlight-#$darker" \
      -attenuate 0.15 +noise Gaussian \
      -font "Open-Sans-SemiBold" -pointsize 24 -fill 'rgba(0,0,0,0.15)' \
      -gravity NorthWest -annotate +61+51 "$display_url" \
      -font "Open-Sans-SemiBold" -pointsize 24 -fill 'rgba(255,255,255,0.9)' \
      -gravity NorthWest -annotate +60+50 "$display_url" \
      -font "Open-Sans-Regular" -pointsize 24 -fill 'rgba(0,0,0,0.15)' \
      -gravity NorthEast -annotate +59+51 "$formatted_date" \
      -font "Open-Sans-Regular" -pointsize 24 -fill 'rgba(255,255,255,0.9)' \
      -gravity NorthEast -annotate +60+50 "$formatted_date" \
      -font "Open-Sans-Bold" -pointsize 56 -fill 'rgba(0,0,0,0.2)' \
      -gravity SouthWest -annotate +62+58 "$title" \
      -font "Open-Sans-Bold" -pointsize 56 -fill '#ffffff' \
      -gravity SouthWest -annotate +60+60 "$title" \
      -quality 90 "$output" || true
  else
    # Front page: URL top-left, title bottom-left (no date)
    # Use 32-bit depth with subtle noise to prevent gradient banding
    magick -size 1200x630 -depth 32 -define gradient:direction=SouthWest gradient:"$highlight-#$darker" \
      -attenuate 0.15 +noise Gaussian \
      -font "Open-Sans-SemiBold" -pointsize 24 -fill 'rgba(0,0,0,0.15)' \
      -gravity NorthWest -annotate +61+51 "$display_url" \
      -font "Open-Sans-SemiBold" -pointsize 24 -fill 'rgba(255,255,255,0.9)' \
      -gravity NorthWest -annotate +60+50 "$display_url" \
      -font "Open-Sans-Bold" -pointsize 56 -fill 'rgba(0,0,0,0.2)' \
      -gravity SouthWest -annotate +62+58 "$title" \
      -font "Open-Sans-Bold" -pointsize 56 -fill '#ffffff' \
      -gravity SouthWest -annotate +60+60 "$title" \
      -quality 90 "$output" || true
  fi
}

cmd_new() {
  open_editor=false
  [ "$1" = "-e" ] && open_editor=true && shift

  title="$1"
  if [ -z "$title" ]; then
    echo "Usage: blurt new [-e] \"Post Title\""
    exit 1
  fi

  slug=$(slugify "$title")
  file="$SCRIPT_DIR/posts/$slug.md"

  if [ -f "$file" ]; then
    echo "File already exists: $file"
    exit 1
  fi

  cat >"$file" <<EOF
---
title: $title
date: $(date -u +%Y-%m-%d)
---

EOF

  echo "Created $file"
  if $open_editor; then ${EDITOR:-vi} "$file"; fi
}

cmd_build() {
  if ! command -v pandoc >/dev/null 2>&1; then
    echo "pandoc is required but not installed"
    exit 1
  fi

  build_start=$(now_ms)
  commit_sha="${GITHUB_SHA:-$(git rev-parse --short HEAD 2>/dev/null || echo "unknown")}"

  post_template="$SCRIPT_DIR/templates/post.html"
  index_template="$SCRIPT_DIR/templates/index.html"
  data_dir="--data-dir=$SCRIPT_DIR"
  config_flag=""
  [ -f "$SCRIPT_DIR/config.yaml" ] && config_flag="--metadata-file=$SCRIPT_DIR/config.yaml"

  # Read config values for OG image generation
  site_url=$(sed -n 's/^site_url: *"\{0,1\}\([^"]*\)"\{0,1\} *$/\1/p' "$SCRIPT_DIR/config.yaml" 2>/dev/null | head -1)
  social_highlight=$(sed -n 's/^social_highlight: *"\{0,1\}\([^"]*\)"\{0,1\} *$/\1/p' "$SCRIPT_DIR/config.yaml" 2>/dev/null | head -1)
  [ -z "$social_highlight" ] && social_highlight="#6246ea"

  rm -rf "$DIST"
  mkdir -p "$DIST"

  if [ -d "$SCRIPT_DIR/static" ] && [ "$(ls -A "$SCRIPT_DIR/static" 2>/dev/null)" ]; then
    cp -r "$SCRIPT_DIR/static"/* "$DIST/"
  fi

  posts_data=""

  for post in "$SCRIPT_DIR/posts"/*.md; do
    [ -f "$post" ] || continue

    slug=$(basename "$post" .md)
    title=$(sed -n 's/^title: *//p' "$post" | head -1)
    date=$(sed -n 's/^date: *//p' "$post" | head -1)
    description=$(sed -n 's/^description: *//p' "$post" | head -1)

    mkdir -p "$DIST/$slug"
    page_start=$(now_ms)
    pandoc "$post" --template="$post_template" $data_dir $config_flag -M slug="$slug" -M pagetitle="$title" -M pagedescription="$description" -M is_post=true -o "$DIST/$slug/index.html"
    page_time="$(($(now_ms) - page_start))ms"
    sed -i.bak "s/__BUILD_TIME__/$page_time/g" "$DIST/$slug/index.html"
    rm -f "$DIST/$slug/index.html.bak"

    generate_og_image "$title" "$site_url" "$date" "$social_highlight" "$DIST/$slug/og.jpg"

    posts_data="$posts_data$date	$slug	$title
"
  done

  sorted=$(printf '%s' "$posts_data" | sort -r)

  index_list=$(echo "$sorted" | while IFS='	' read -r date slug title; do
    [ -z "$date" ] && continue
    printf '<li><a href="%s/">%s</a> <time datetime="%s">%s</time></li>' "$slug" "$title" "$date" "$date"
  done)

  page_start=$(now_ms)
  site_title=$(sed -n 's/^site_title: *"\{0,1\}\([^"]*\)"\{0,1\} *$/\1/p' "$SCRIPT_DIR/config.yaml" 2>/dev/null | head -1)
  site_description=$(sed -n 's/^site_description: *"\{0,1\}\([^"]*\)"\{0,1\} *$/\1/p' "$SCRIPT_DIR/config.yaml" 2>/dev/null | head -1)
  echo "$index_list" | pandoc --template="$index_template" $data_dir $config_flag -M pagetitle="$site_title" -M pagedescription="$site_description" -o "$DIST/index.html"
  page_time="$(($(now_ms) - page_start))ms"
  sed -i.bak "s/__BUILD_TIME__/$page_time/g" "$DIST/index.html"
  rm -f "$DIST/index.html.bak"

  # Generate OG image for homepage (no date)
  generate_og_image "$site_title" "$site_url" "" "$social_highlight" "$DIST/og.jpg"
  generate_favicon "$site_title" "$social_highlight" "$DIST/favicon.svg"

  # Generate Atom feed
  site_url=$(sed -n 's/^site_url: *"\{0,1\}\([^"]*\)"\{0,1\} *$/\1/p' "$SCRIPT_DIR/config.yaml" 2>/dev/null | head -1)
  site_title=$(sed -n 's/^site_title: *"\{0,1\}\([^"]*\)"\{0,1\} *$/\1/p' "$SCRIPT_DIR/config.yaml" 2>/dev/null | head -1)
  site_author=$(sed -n 's/^site_author: *"\{0,1\}\([^"]*\)"\{0,1\} *$/\1/p' "$SCRIPT_DIR/config.yaml" 2>/dev/null | head -1)

  if [ -n "$site_url" ]; then
    feed_updated=$(echo "$sorted" | head -1 | cut -f1)
    [ -z "$feed_updated" ] && feed_updated=$(date -u +%Y-%m-%d)
    site_url_escaped=$(echo "$site_url" | xml_escape)

    cat >"$DIST/feed.xml" <<'FEED_HEADER'
<?xml version="1.0" encoding="utf-8"?>
<feed xmlns="http://www.w3.org/2005/Atom">
FEED_HEADER
    printf '  <title>%s</title>\n' "$(echo "$site_title" | xml_escape)" >>"$DIST/feed.xml"
    printf '  <link href="%s/feed.xml" rel="self"/>\n' "$site_url_escaped" >>"$DIST/feed.xml"
    printf '  <link href="%s/"/>\n' "$site_url_escaped" >>"$DIST/feed.xml"
    printf '  <id>%s/</id>\n' "$site_url_escaped" >>"$DIST/feed.xml"
    printf '  <updated>%sT00:00:00Z</updated>\n' "$feed_updated" >>"$DIST/feed.xml"
    [ -n "$site_author" ] && printf '  <author><name>%s</name></author>\n' "$(echo "$site_author" | xml_escape)" >>"$DIST/feed.xml"

    echo "$sorted" | while IFS='	' read -r date slug title; do
      [ -z "$date" ] && continue
      article=$(sed -n '/<article>/,/<\/article>/p' "$DIST/$slug/index.html")
      title_escaped=$(echo "$title" | xml_escape)
      content_escaped=$(printf '%s' "$article" | xml_escape)
      printf '  <entry>\n' >>"$DIST/feed.xml"
      printf '    <title>%s</title>\n' "$title_escaped" >>"$DIST/feed.xml"
      printf '    <link href="%s/%s/"/>\n' "$site_url_escaped" "$slug" >>"$DIST/feed.xml"
      printf '    <id>%s/%s/</id>\n' "$site_url_escaped" "$slug" >>"$DIST/feed.xml"
      printf '    <updated>%sT00:00:00Z</updated>\n' "$date" >>"$DIST/feed.xml"
      printf '    <content type="html">%s</content>\n' "$content_escaped" >>"$DIST/feed.xml"
      printf '  </entry>\n' >>"$DIST/feed.xml"
    done

    echo "</feed>" >>"$DIST/feed.xml"
  fi

  # Replace variables in all pages
  find "$DIST" -name '*.html' -exec sed -i.bak "s/__COMMIT_SHA__/$commit_sha/g; s/__BLURT_VERSION__/$VERSION/g" {} \;
  find "$DIST" -name '*.bak' -delete

  echo "Built site in $DIST ($(($(now_ms) - build_start))ms)"
}

cmd_update() {
  remote_url="https://raw.githubusercontent.com/shkm/blurt/refs/heads/main/blurt"
  tmp_file=$(mktemp)
  trap "rm -f '$tmp_file'" EXIT

  echo "Fetching latest version..."
  if command -v curl >/dev/null 2>&1; then
    curl -fsSL "$remote_url" -o "$tmp_file"
  elif command -v wget >/dev/null 2>&1; then
    wget -qO "$tmp_file" "$remote_url"
  else
    echo "curl or wget is required for update"
    exit 1
  fi

  if [ ! -s "$tmp_file" ] || ! head -1 "$tmp_file" | grep -q '^#!/bin/sh'; then
    echo "Failed to download valid script"
    exit 1
  fi

  remote_version=$(grep '^VERSION=' "$tmp_file" | head -1 | cut -d'"' -f2)
  [ -z "$remote_version" ] && remote_version="unknown"

  if [ "$VERSION" = "$remote_version" ]; then
    echo "Already at latest version ($VERSION)"
    exit 0
  fi

  cp "$tmp_file" "$0"
  chmod +x "$0"
  echo "Updated blurt from $VERSION to $remote_version"
}

cmd_start() {
  if ! command -v python3 >/dev/null 2>&1; then
    echo "python3 is required for the dev server"
    exit 1
  fi

  port="${1:-8000}"

  cmd_build

  python3 -m http.server "$port" -d "$DIST" &
  server_pid=$!
  trap "kill $server_pid 2>/dev/null" EXIT

  echo "Serving at http://localhost:$port"

  if command -v fswatch >/dev/null 2>&1; then
    fswatch -o "$SCRIPT_DIR/posts" "$SCRIPT_DIR/templates" "$SCRIPT_DIR/static" "$SCRIPT_DIR/config.yaml" | while read; do
      echo "Rebuilding..."
      cmd_build
    done
  else
    echo "Note: install fswatch for instant rebuilds (currently polling)"
    while true; do
      sleep 1
      changed=$(find "$SCRIPT_DIR/posts" "$SCRIPT_DIR/templates" "$SCRIPT_DIR/static" "$SCRIPT_DIR/config.yaml" -newer "$DIST/index.html" 2>/dev/null | head -1)
      [ -n "$changed" ] && echo "Rebuilding..." && cmd_build
    done
  fi
}

case "$1" in
new)
  shift
  cmd_new "$@"
  ;;
build)
  cmd_build
  ;;
start)
  cmd_start "$2"
  ;;
update)
  cmd_update
  ;;
version | -v | --version)
  echo "blurt $VERSION"
  ;;
*)
  echo "Usage: blurt <new|build|start|update|version>"
  echo "  new [-e] \"Title\"  - Create a new post"
  echo "  build             - Build the site"
  echo "  start [port]      - Watch, rebuild, and serve (default: 8000)"
  echo "  update            - Update blurt to latest version"
  echo "  version           - Show version number"
  exit 1
  ;;
esac