#!/bin/bash
# Configuration from environment
SERVICE_NAME="navidrome"
SERVICE_ID="${SERVICE_NAME}-${NOMAD_ALLOC_ID:-$(hostname)}"
PORT=4533
CONSUL_HTTP_ADDR="${CONSUL_URL:-http://localhost:8500}"
NODE_IP="${ADVERTISE_IP}"
NAVIDROME_PID=0

# Tags for the Primary service (Traefik enabled)
PRIMARY_TAGS='["navidrome","web","traefik.enable=true","urlprefix-/navidrome","tools","traefik.http.routers.navidromelan.rule=Host(`navidrome.service.dc1.consul`)","traefik.http.routers.navidromewan.rule=Host(`m.fbleagh.duckdns.org`)","traefik.http.routers.navidromewan.middlewares=dex@consulcatalog","traefik.http.routers.navidromewan.tls=true"]'

# --- Helper Functions ---

# Check if this node is the LiteFS Primary
check_primary() {
  local status=$(curl -s http://localhost:20202/info || echo "{}")
  local is_primary=$(echo "$status" | jq -r 'if type == "object" then (.isPrimary // false) else false end' 2>/dev/null || echo "false")
  
  if [ "$is_primary" = "true" ]; then
    return 0 # We are the primary
  fi
  return 1 # We are a replica
}

# Wait for LiteFS to settle and determine its role
wait_for_litefs() {
  echo "Waiting for LiteFS to settle..."
  local timeout=60
  local count=0
  while [ $count -lt $timeout ]; do
    local status=$(curl -s http://localhost:20202/info || echo "null")
    local is_primary_val=$(echo "$status" | jq -r 'if type == "object" then (.isPrimary // "null") else "null" end' 2>/dev/null || echo "null")
    
    if [ "$is_primary_val" != "null" ]; then
      local role="replica"
      if [ "$is_primary_val" = "true" ]; then role="primary"; fi
      echo "LiteFS initialized. Role: $role"
      return 0
    fi
    sleep 2
    count=$((count + 2))
    echo -n "."
  done
  echo "ERROR: LiteFS failed to settle after ${timeout}s"
  return 1
}

# Register Service with TTL Check
register_service() {
  echo "Registering service ${SERVICE_ID} with Consul..."
  curl -s -X PUT "${CONSUL_HTTP_ADDR}/v1/agent/service/register" -d "{
    \"ID\": \"${SERVICE_ID}\",
    \"Name\": \"${SERVICE_NAME}\",
    \"Tags\": ${PRIMARY_TAGS},
    \"Address\": \"${NODE_IP}\",
    \"Port\": ${PORT},
    \"Check\": {
      \"DeregisterCriticalServiceAfter\": \"1m\",
      \"TTL\": \"15s\"
    }
  }"
}

# Send Heartbeat to Consul
pass_ttl() {
  curl -s -X PUT "${CONSUL_HTTP_ADDR}/v1/agent/check/pass/service:${SERVICE_ID}" > /dev/null
}

# Deregister Service
deregister_service() {
  echo "Deregistering service ${SERVICE_ID} from Consul..."
  curl -s -X PUT "${CONSUL_HTTP_ADDR}/v1/agent/service/deregister/${SERVICE_ID}"
}

# Start Navidrome in Background
start_app() {
  echo "Node is Primary. Starting Navidrome..."
  
  # Ensure shared directories exist
  mkdir -p /shared_data/plugins /shared_data/cache /shared_data/backup /shared_data/artist_images

  # SEEDING LOGIC: If DB doesn't exist, restore from backup
  if [ ! -f /data/navidrome.db ]; then
    echo "Database /data/navidrome.db not found. Looking for backups to seed..."
    local latest_backup=$(ls -t /shared_data/backup/navidrome.db_*.bak 2>/dev/null | head -n 1)
    if [ -n "$latest_backup" ]; then
       echo "Seeding from $latest_backup..."
       # We use litefs import to properly initialize the distributed state
       litefs import -name navidrome.db "$latest_backup"
    else
       echo "No backups found. Navidrome will start with a fresh database."
    fi
  fi

  # Wait for LiteFS to expose the DB file in the FUSE mount
  echo "Waiting for /data/navidrome.db..."
  local db_timeout=30
  local db_count=0
  while [ ! -f /data/navidrome.db ] && [ $db_count -lt $db_timeout ]; do
    sleep 1
    db_count=$((db_count + 1))
  done

  if [ ! -f /data/navidrome.db ]; then
    echo "ERROR: /data/navidrome.db did not appear after ${db_timeout}s"
    return 1
  fi

  # Bind mount the DB so Navidrome finds it in its DataFolder
  touch /shared_data/navidrome.db
  mount --bind /data/navidrome.db /shared_data/navidrome.db

  # Configuration
  export ND_DATAFOLDER="/shared_data"
  export ND_CACHEFOLDER="/shared_data/cache"
  export ND_BACKUP_PATH="/shared_data/backup"
  export ND_PLUGINS_FOLDER="/shared_data/plugins"
  export ND_ARTISTIMAGEFOLDER="artist_images"

  /app/navidrome &
  NAVIDROME_PID=$!
  echo "Navidrome running (PID: $NAVIDROME_PID) with data folder at /shared_data (DB bind-mounted to /data)"
}

# Stop Navidrome
stop_app() {
  if [ "${NAVIDROME_PID}" -gt 0 ]; then
    echo "Stopping Navidrome (PID ${NAVIDROME_PID})..."
    kill -SIGTERM "${NAVIDROME_PID}"
    wait "${NAVIDROME_PID}" 2>/dev/null || true
    NAVIDROME_PID=0
    umount /shared_data/navidrome.db 2>/dev/null || true
  fi
}

# --- Cleanup ---
cleanup() {
  echo "Shutting down..."
  stop_app
  deregister_service
  exit 0
}

trap cleanup TERM INT

# --- Main Loop ---

echo "Starting Supervisor. Waiting for leadership settle..."
wait_for_litefs || exit 1

while true; do
  if check_primary; then
    # === WE ARE PRIMARY ===
    if [ "${NAVIDROME_PID}" -eq 0 ] || ! kill -0 "${NAVIDROME_PID}" 2>/dev/null; then
      start_app
      register_service
    fi
    pass_ttl
  else
    # === WE ARE REPLICA ===
    if [ "${NAVIDROME_PID}" -gt 0 ]; then
      echo "Lost leadership. Demoting..."
      stop_app
      deregister_service
    fi
  fi
  sleep 10
done