# The only IDs uses here are MusicBrainz IDs

# Helper methods to retrieve from cache, if it exists, and otherwise populate
# cache and retrieve
__mb_artist_cache_or_fetch() {
  if ! cache_get_artist_mb "$1"; then
    __api_mb_get_artist "$1" | cache_put_artist_mb "$1"
    cache_get_artist_mb "$1"
  fi
}

__mb_artist_cache_or_fetch_releasegroups() {
  if ! cache_get_artist_mb_releasegroups "$1"; then
    __api_mb_browse_release_groups "$1" | cache_put_artist_mb_releasegroups "$1"
    rg="$(cache_get_artist_mb_releasegroups "$1")"
    total=$(printf "%s" "$rg" | $JQ -r '."release-group-count"')
    seen=$MB_BROWSE_STEPS
    while [ "$total" -gt "$seen" ]; do
      # Fetch remaning release groups, and append to cache
      sleep 1 # Make sure we don't get blocked (we prefer not to handle failed requests...)
      __api_mb_browse_release_groups "$1" "$seen" | cache_append_artist_mb_releasegroups "$1"
      seen=$((seen + MB_BROWSE_STEPS))
    done
    cache_get_artist_mb_releasegroups "$1"
  fi
}

# Get MusicBrainz json for artist
# @argument $1: MusicBrainz Artist ID
mb_artist() {
  __mb_artist_cache_or_fetch "$1"
}

# Get Wikidata json for artist
# @argument $1: MusicBrainz Artist ID
mb_artist_wikidata() {
  if ! cache_get_artist_wikidata "$1"; then
    wikidataid=$(mb_artist "$1" |
      $JQ -r '.relations |
      map(select(.type=="wikidata")) |
      .[0].url.resource' |
      awk -F "/" '{print $NF}')
    [ ! "$wikidataid" ] || [ "$wikidataid" != "null" ] || return
    __api_wikidata_get_sitelinks "$wikidataid" | cache_put_artist_wikidata "$1"
    cache_get_artist_wikidata "$1"
  fi
}

# Get Wikipedia (English) summary json for artist
# @argument $1: MusicBrainz Artist ID
mb_artist_enwikipedia() {
  if ! cache_get_artist_enwikipedia "$1"; then
    # To fetch the wikipedia data, we need the wikipedia URL
    # There are two possibly ways to get the wikipedia URL
    # 1. From the website relations in MB (MB artists donw have wiki rels)
    # 2. MB website relations -> Wikidata -> Wikipedia
    # Lately, Wikipedia pages are not stored in the MB artist url relations.
    # For obvious reasons it is recommended to link to wikidata only. So, we
    # take the second route.
    wikidata=$(mb_artist_wikidata "$1" || true)
    wikiid=$(printf "%s" "$wikidata" |
      $JQ -r '.enwiki.url' |
      awk -F "/" '{print $NF}')
    [ ! "$wikiid" ] && return || [ "$wikiid" = "null" ] && return
    __api_wikipedia_en_get_summary "$wikiid" | cache_put_artist_enwikipedia "$1"
    cache_get_artist_enwikipedia "$1"
  fi
}

# Get Discogs json for artist
# @argument $1: MusicBrainz Artist ID
mb_artist_discogs() {
  if ! cache_get_artist_discogs "$1"; then
    discogsid=$(mb_artist "$1" |
      $JQ -r '.relations |
      map(select(.type=="discogs")) |
      .[0].url.resource' |
      awk -F "/" '{print $NF}')
    [ ! "$discogsid" ] && return || [ "$discogsid" = "null" ] && return
    __api_discogs_get_artist "$discogsid" | cache_put_artist_discogs "$1"
    cache_get_artist_discogs "$1"
  fi
}

# Get release-groups json for artist
# @argument $1: MusicBrainz Artist ID
mb_artist_releasegroups() {
  __mb_artist_cache_or_fetch_releasegroups "$1"
}