#!/bin/bash
set -euo pipefail

# ─── Kordant Scheduler — Pan Server Setup ─────────────────────
# Usage:
#   bash scripts/setup-pan.sh                          # interactively
#   bash scripts/setup-pan.sh user@pan                  # interactively, remote
#   bash scripts/setup-pan.sh -u <url> -d <url> ...
#
# Flags:
#   -u, --gitea-url URL     Gitea clone URL (skip prompt)
#   -d, --db-url URL        Turso database URL (skip prompt)
#   -t, --db-token TOKEN    Turso auth token (skip prompt)
#   -k, --hooks-dir DIR     Gitea hooks directory (skip prompt; empty=skip hook)
#       --host HOST         SSH host (default: pan)
#   -y, --non-interactive   Skip all prompts (requires -u, -d, -t)
#   -h, --help              Show this message

# ─── Defaults ───────────────────────────────────────────────────

PAN_HOST=""
GITEA_URL=""
DB_URL=""
DB_TOKEN=""
HOOKS_DIR=""
NON_INTERACTIVE=false
REPO_DIR="/opt/kordant"

# ─── Help ───────────────────────────────────────────────────────

usage() {
  sed -n 's/^# //p; s/^#$//p' "$0"
  exit 0
}

# ─── Parse flags ────────────────────────────────────────────────

while [ $# -gt 0 ]; do
  case "$1" in
    -u|--gitea-url)   GITEA_URL="$2";    shift 2 ;;
    -d|--db-url)      DB_URL="$2";       shift 2 ;;
    -t|--db-token)    DB_TOKEN="$2";     shift 2 ;;
    -k|--hooks-dir)   HOOKS_DIR="$2";    shift 2 ;;
    --host)           PAN_HOST="$2";     shift 2 ;;
    -y|--non-interactive) NON_INTERACTIVE=true; shift ;;
    -h|--help)        usage ;;
    -*)
      echo "Unknown option: $1"
      usage
      ;;
    *)  PAN_HOST="${PAN_HOST:-$1}"; shift ;;
  esac
done

PAN_HOST="${PAN_HOST:-pan}"

# ─── Remote detection ───────────────────────────────────────────

if [ "$(hostname)" != "pan" ] && [ "$(hostname -s 2>/dev/null)" != "pan" ]; then
  if [ -n "${SSH_CONNECTION:-}" ]; then
    echo "Already connected to pan via SSH."
  else
    echo "Not on pan. Connecting to $PAN_HOST via SSH..."
    # Rebuild the flag string to pass through
    FLAGS=""
    [ -n "$GITEA_URL" ] && FLAGS="$FLAGS -u '$GITEA_URL'"
    [ -n "$DB_URL" ]    && FLAGS="$FLAGS -d '$DB_URL'"
    [ -n "$DB_TOKEN" ]  && FLAGS="$FLAGS -t '$DB_TOKEN'"
    [ -n "$HOOKS_DIR" ] && FLAGS="$FLAGS -k '$HOOKS_DIR'"
    $NON_INTERACTIVE    && FLAGS="$FLAGS -y"
    scp "$0" "${PAN_HOST}:/tmp/kordant-setup.sh"
    ssh -t "$PAN_HOST" "sudo bash /tmp/kordant-setup.sh $FLAGS && rm /tmp/kordant-setup.sh"
    exit $?
  fi
fi

echo "=== Kordant Scheduler Setup (running on pan) ==="

# ─── Step 1: Install prerequisites ─────────────────────────────

echo "--- Step 1: Checking prerequisites ---"

if ! command -v docker &>/dev/null; then
  echo "Installing Docker..."
  curl -fsSL https://get.docker.com | bash
  systemctl enable --now docker
else
  echo "Docker already installed."
fi

if ! docker compose version &>/dev/null; then
  echo "Installing Docker Compose plugin..."
  apt-get update && apt-get install -y docker-compose-plugin
else
  echo "Docker Compose plugin already installed."
fi

if ! command -v git &>/dev/null; then
  echo "Installing git..."
  apt-get update && apt-get install -y git
else
  echo "Git already installed."
fi

# ─── Step 2: Clone or pull the repo ────────────────────────────

echo "--- Step 2: Setting up repo at $REPO_DIR ---"

if [ ! -d "$REPO_DIR/.git" ]; then
  if [ -z "$GITEA_URL" ]; then
    if $NON_INTERACTIVE; then
      echo "❌ --gitea-url is required in non-interactive mode"
      exit 1
    fi
    while [ -z "$GITEA_URL" ]; do
      read -rp "Gitea clone URL (e.g. http://localhost:3000/kordant/kordant.git): " GITEA_URL
    done
  fi
  echo "Cloning $GITEA_URL ..."
  git clone "$GITEA_URL" "$REPO_DIR"
  cd "$REPO_DIR"
else
  echo "Repo exists. Pulling latest..."
  cd "$REPO_DIR"
  git pull
fi

# ─── Step 3: Create .env with credentials ──────────────────────

echo "--- Step 3: Environment file ---"

if [ ! -f "$REPO_DIR/.env" ]; then
  if [ -z "$DB_URL" ]; then
    if $NON_INTERACTIVE; then
      echo "❌ --db-url is required in non-interactive mode"
      exit 1
    fi
    read -rp "  DATABASE_URL (e.g. libsql://kordant.turso.io): " DB_URL
  fi
  if [ -z "$DB_TOKEN" ]; then
    if $NON_INTERACTIVE; then
      echo "❌ --db-token is required in non-interactive mode"
      exit 1
    fi
    read -rsp "  DATABASE_AUTH_TOKEN: " DB_TOKEN
    echo ""
  fi

  cat > "$REPO_DIR/.env" << ENVEOF
# ─── Kordant Scheduler Environment ─────────────────────────────
# Turso database
DATABASE_URL="${DB_URL}"
DATABASE_AUTH_TOKEN="${DB_TOKEN}"

# Job queue (local Redis container)
REDIS_URL="redis://redis:6379"

# Node environment
NODE_ENV=production
JOB_WORKER=true
JOB_PRIMARY=true
ENVEOF
  chmod 600 "$REPO_DIR/.env"
  echo "✅ Created $REPO_DIR/.env"
else
  echo "$REPO_DIR/.env already exists, keeping it."
fi

# ─── Step 4: Gitea post-receive hook ────────────────────────────

echo "--- Step 4: Gitea post-receive hook ---"

if [ -z "$HOOKS_DIR" ] && ! $NON_INTERACTIVE; then
  read -rp "Gitea repo hooks directory (or leave blank to skip): " HOOKS_DIR
fi

if [ -n "$HOOKS_DIR" ]; then
  if [ ! -d "$HOOKS_DIR" ]; then
    echo "  Directory not found: $HOOKS_DIR"
    if $NON_INTERACTIVE; then
      echo "❌ hooks-dir does not exist"
      exit 1
    fi
  else
    HOOK_FILE="$HOOKS_DIR/post-receive"
    cat > "$HOOK_FILE" << 'HOOKEOF'
#!/bin/bash
cd /opt/kordant
git pull origin main
docker compose -f scheduler/docker-compose.yml up -d --build
HOOKEOF
    chmod +x "$HOOK_FILE"
    echo "✅ Post-receive hook installed at $HOOK_FILE"
  fi
else
  echo "Skipping post-receive hook."
fi

# ─── Step 5: Create systemd service ────────────────────────────

echo "--- Step 5: Systemd service ---"

SERVICE_NAME="kordant-scheduler"
SERVICE_FILE="/etc/systemd/system/${SERVICE_NAME}.service"

if [ ! -f "$SERVICE_FILE" ]; then
  echo "Creating $SERVICE_FILE..."
  cat > "$SERVICE_FILE" << SERVICEEOF
[Unit]
Description=Kordant Background Job Scheduler
After=docker.service network-online.target
Wants=docker.service network-online.target

[Service]
Type=oneshot
RemainAfterExit=yes
WorkingDirectory=$REPO_DIR
ExecStart=docker compose -f scheduler/docker-compose.yml up -d --build
ExecStop=docker compose -f scheduler/docker-compose.yml down
ExecReload=docker compose -f scheduler/docker-compose.yml pull && docker compose -f scheduler/docker-compose.yml up -d --build
StandardOutput=journal
StandardError=journal

[Install]
WantedBy=multi-user.target
SERVICEEOF
  systemctl daemon-reload
else
  echo "$SERVICE_FILE already exists."
fi

# ─── Step 6: Start / restart the scheduler ─────────────────────

echo "--- Step 6: Starting scheduler ---"

systemctl enable "$SERVICE_NAME" 2>/dev/null || true

cd "$REPO_DIR"
docker compose -f scheduler/docker-compose.yml pull 2>/dev/null || true
docker compose -f scheduler/docker-compose.yml up -d --build

echo ""
echo "=== Scheduler status ==="
sleep 3
docker compose -f scheduler/docker-compose.yml ps

echo ""
echo "=== Kordant scheduler setup complete ==="
echo "  Repo:  $REPO_DIR"
echo "  Logs:  journalctl -u kordant-scheduler -f"
echo "  Shell: cd $REPO_DIR && docker compose -f scheduler/docker-compose.yml logs -f"
echo "  .env:  $REPO_DIR/.env"