#! /bin/bash


main() {
   set -e
   set -o pipefail
   #set -x

   local output="$(mktemp -d)"
   log "$output"

   #list_chapters_in_book https://www.dndbeyond.com/sources/sdw

   #scrape_book_chapter https://www.dndbeyond.com/sources/phb/races | less
   #scrape_book_chapter https://www.dndbeyond.com/sources/phb/appendix-a-conditions | less

   #scrape_book "$output" https://www.dndbeyond.com/sources/phb

   for book in $(scrape_books); do
      book="${book%/}"
      log book=$book
      scrape_book "$output/${book##*/}" "$book"
      break
   done


   log "$output"
}

log() {
   echo "$(date) > $*" >&2
}

scrape_books() {
   scrape_dndbeyond "https://www.dndbeyond.com/sources#Sourcebooks" \
      | grep class..sources-listing--item \
      | grep href=.*sources \
      | grep -o 'href="[^"]*' \
      | sed 's/^href="//' \
      | sed 's/^\///' \
      | sed 's/^/\//' \
      | sed 's/^/https:\/\/www.dndbeyond.com/'
}

scrape_book() {
   local output="$1"
   local book_url="$2"

   mkdir -p "$output"
   local f="$(mktemp)"

   for chapter in $(list_chapters_in_book "$book_url"); do
      log scraping book chapter $chapter of $book_url
      scrape_book_chapter "$chapter" > "$f"
      log scraping book title from $f
      local title="$(grep '^\#' "$f" | head -n 1 | sed 's/^\#*//' | sed 's/^[ ]*//' | sed 's/[ ]*$//')"
      if [ -z "$title" ]; then
         log "WARNING: NO TITLE FOUND IN $f ($chapter): $(head -n 3 $f)"
         return 1
      fi
      mv "$f" "$output"/"$title"
   done

   rm "$f"
}

scrape_book_chapter() {
   local url="$1"
   scrape_dndbeyond $url \
      | html_to_markdown
}

list_chapters_in_book() {
   local book_url="${1%/}"
   local raw="$(scrape_dndbeyond "$book_url")"

   if echo "$raw" | grep -q 'https:..www.dndbeyond.com.compendium[^"]*'; then
      echo "$raw" | grep -o 'https:..www.dndbeyond.com.compendium[^"]*'
   elif echo "$raw" | grep -q "$book_url/"; then
      echo "$raw" | grep -o "${book_url//\//.}\/[^\"]*"
   else
      echo "ERROR: FOUND NO CHAPTERS IN $book_url" >&2
      return 1
   fi \
      | sed 's/#.*//' \
      | sort -u
}

scrape_dndbeyond() {
   rate_limit_1s scrape_dndbeyond
   curl -L -sS \
      "$1" \
      --compressed \
      -H 'Cookie: Preferences=undefined; Preferences=undefined; _pxhd=NHdkEjOXnAEHojER86i0Egmnm85GLvifiQxURPISwVtzWLNwuqQbIk1Y/2MjheQqNP4CsBXhuc4UG5-qcmLjYw==:hGx3TOEjeVaJPMfrXXnmyG7-btpQhZutwvpVBKwEbNXTAkEQvgmIs/faKB6s8537Nivj6epH9HpOWYURQeazeMwSMReW6EMazW09Rci-PJI=; ResponsiveSwitch.DesktopMode=1; ddbSiteBanner:00523ca3-81a4-4d2a-8f86-9e40273af2e2=true; LoginState=2c011278-8a3d-4cf7-a141-221f42694333; G_ENABLED_IDPS=google; CobaltSession=eyJhbGciOiJkaXIiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0..vh9-_2G_aEjMvJ2PFAAE4w.eheZuOJLp-3NyiAJZzKqaSc91lH0ganCRsDZPYMGIG3265AppaHh0uMQLu_-P6WX.bHRi_gX8PKtQGZwVmNeb1Q; Preferences.Language=1; Preferences.TimeZoneID=1; ddbSiteBanner:d8879cae-c68e-4411-9ea0-a49d77fe5454=true; Ratings=null; _pxvid=f6abe72c-49a6-11ec-b844-57447254714c; ddbSiteBanner:fd981371-c501-4638-a64b-0d9a5c8da68b=true; Geo={%22region%22:%22ON%22%2C%22country%22:%22CA%22%2C%22continent%22:%22NA%22}; RequestVerificationToken=983cd9ce-c03c-4b8b-b6c1-a0561b39cb47; sublevel=ANON; Preferences=undefined; User.ID=109926924; User.Username=squeaky2x3; UserInfo={"UserId":109926924,"UserJoinDate":"2021-03-25","UserSessionId":"77896779-c672-42d1-903b-f6caba6ec599"}; pxcts=5eb1b230-525e-11ec-aa22-793bf1473016; WarningNotification.Lock=1' \
      -H 'User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:91.0) Gecko/20100101 Firefox/91.0' \
      -H 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8' \
      -H 'Accept-Language: en-US,en;q=0.5' \
      -H 'Referer: https://www.dndbeyond.com/' \
      -H 'DNT: 1' \
      -H 'Connection: keep-alive' \
      -H 'Upgrade-Insecure-Requests: 1' \
      -H 'Sec-Fetch-Dest: document' \
      -H 'Sec-Fetch-Mode: navigate' \
      -H 'Sec-Fetch-Site: same-origin' \
      -H 'Sec-Fetch-User: ?1' \
      -H 'Pragma: no-cache' \
      -H 'Cache-Control: no-cache' \
      -H 'TE: trailers';
}

html_to_markdown() {
   local out="$(
      pandoc -f html -t markdown --ascii --toc --wrap=none --strip-comments -o - \
      | sed '/^:::.*/d' \
      | sed -e '/^Share$/,$d' \
      | sed 's/^\(\#\#*\) \[](#\([^)]*\))/\1 /' \
      | sed 's/{#\([^ ]*\)[^}]*}/\n\n<a name="\1"><\/a>/' \
      | sed 's/\[\([^]]*\)]\(([^)]*)\)*\({[^}]*}\)*/\1/g' \
      | sed "s/\\\\\([\"']\)/\1/g"
   )"
   local target="$(
      (echo "$out" | grep -q '^##* Appendix' && echo Appendix) \
      || (echo "$out" | grep -q '^##* Chapter' && echo Chapter) \
      || (echo "$out" | grep -q '^##* Introduction' && echo Introduction) \
      || echo Chapter
   )"
   echo "$out" \
      | sed -e '/^# '"$target"'/p' -e '0,/^# '"$target"'/d'
}

rate_limit_1s() {
   local name="$1"
   local d="${TMPDIR:-/tmp}"/rate_limited
   mkdir -p "$d"
   local last_run="$(date -r "$d/$name" +%s)"
   local now="$(date +%s)"
   local interval=6
   log "should sleep while $(($(date +%s)-last_run)) < $interval"
   if [ -f "$d/$name" ]; then
      while [ "$(($(date +%s)-last_run))" -lt $interval ]; do
         sleep 1
      done
   fi
   touch "$d/$name"
}

if [ "$0" == "$BASH_SOURCE" ]; then
   main "$@"
fi