#!/bin/sh
# Sync image-baked plugins into the /config (datadir) plugins directory on
# start. /config is an RWX volume shared across replicas, so plugins baked
# into the image are invisible until copied in here -- and this must be safe
# when several replicas start (or restart) at the same instant:
#   - skip entirely once the correct version is already in place, so the
#     steady state (almost every start) never touches the shared volume;
#   - install a new/changed version via copy-to-staging + atomic rename, so
#     no reader (another replica, or this container's own jellyfin process)
#     ever observes a partially-written plugin directory. A replica that
#     loses the rename race just discards its own copy -- that's success,
#     not an error;
#   - drop stale, differently-versioned copies of the same plugin afterwards
#     so they don't shadow the current one. Best-effort: another replica may
#     already be doing, or have finished, the same cleanup.
# Deliberately no locking: a lock held by a replica that dies mid-sync would
# wedge every future start on this volume, which is worse than the race it
# would prevent.
set -eu

BAKED_DIR=/usr/share/jellyfin/plugins-baked
PLUGIN_DIR=/config/plugins
STAGING_DIR="$PLUGIN_DIR/.sync-tmp"
REPLICA=$(hostname)

if [ -d "$BAKED_DIR" ]; then
  mkdir -p "$PLUGIN_DIR" "$STAGING_DIR"
  for src in "$BAKED_DIR"/*; do
    [ -d "$src" ] || continue
    name=$(basename "$src")   # e.g. "LDAP Authentication_24.0.0.0"
    base=${name%_*}           # plugin name without the trailing _<version>
    target="$PLUGIN_DIR/$name"

    if [ ! -d "$target" ]; then
      # Build the new version privately (keyed by this replica's own
      # hostname, so concurrent replicas never share a staging path), then
      # move it into place in one atomic rename. mv -T fails with
      # "Directory not empty" if another replica's rename already won --
      # that's fine, our copy just becomes garbage we discard.
      staging="$STAGING_DIR/$REPLICA.$name"
      rm -rf "$staging"
      cp -a "$src" "$staging"
      if mv_err=$(mv -T "$staging" "$target" 2>&1); then
        :
      elif [ -d "$target" ]; then
        rm -rf "$staging"
      else
        echo "docker-entrypoint: failed to install plugin $name: $mv_err" >&2
        exit 1
      fi
    fi

    # Remove any other version of this plugin so it can't shadow the one
    # above. Another replica may be racing the same cleanup, or have already
    # finished it -- an entry that's already gone is success, not an error.
    for existing in "$PLUGIN_DIR/$base"_*; do
      [ -e "$existing" ] || continue
      [ "$existing" = "$target" ] && continue
      rm -rf "$existing" 2>/dev/null || true
    done
  done
fi

exec ./jellyfin \
  --datadir /config \
  --cachedir /cache \
  --webdir /jellyfin/jellyfin-web \
  "$@"