#!/bin/bash
# =============================================================================
# FORGEJO RUNNER - FULL SYSTEM DEPLOYMENT WITH SYSTEMD
# Supports both DIRECT and DOCKER modes
# =============================================================================

# --- CONFIGURATION VARIABLES ---
FORGEJO_URL="https://your-forgejo-domain.com"    # CHANGE THIS
REGISTRATION_TOKEN="your-registration-token"      # CHANGE THIS
RUNNER_NAME="selfhosted-runner-01"
RUNNER_VERSION="latest"                           # Can be "latest" or specific like "v4.0.0"
RUNNER_MODE="direct"                              # "direct" or "docker"

# Direct mode variables
RUNNER_USER="forgejo-runner"
RUNNER_HOME="/opt/forgejo-runner"

# Docker mode variables
COMPOSE_DIR="$HOME/forgejo-runner"
DIND_IMAGE="docker:dind"
RUNNER_IMAGE="data.forgejo.org/forgejo/runner"
# =============================================================================

set -e

echo "============================================================"
echo "FORGEJO RUNNER DEPLOYMENT"
echo "============================================================"
echo "Mode: $RUNNER_MODE"
echo "Version: $RUNNER_VERSION"
echo "Instance: $FORGEJO_URL"
echo ""

# --- STEP 1: Detect system architecture ---
ARCH=$(uname -m)
case $ARCH in
    x86_64)
        ARCH="amd64"
        ;;
    aarch64|arm64)
        ARCH="arm64"
        ;;
    armv7l|armhf)
        ARCH="armv7"
        ;;
    *)
        echo "Unsupported architecture: $ARCH"
        exit 1
        ;;
esac
echo "Detected architecture: $ARCH"

# --- STEP 2: Get actual version if "latest" ---
if [ "$RUNNER_VERSION" = "latest" ]; then
    echo "Fetching latest version..."
    RUNNER_VERSION=$(curl -s https://code.forgejo.org/forgejo/runner/releases/latest | \
        grep -o 'v[0-9]\+\.[0-9]\+\.[0-9]\+' | head -1)
    if [ -z "$RUNNER_VERSION" ]; then
        echo "Failed to fetch latest version, using fallback v4.0.0"
        RUNNER_VERSION="v4.0.0"
    fi
    echo "Latest version: $RUNNER_VERSION"
fi

# --- STEP 3: Check Docker ---
echo "Checking Docker..."
if ! command -v docker &> /dev/null; then
    echo "ERROR: Docker is not installed. Please install Docker first."
    exit 1
fi

if ! systemctl is-active --quiet docker; then
    echo "ERROR: Docker service is not running."
    echo "Start it with: sudo systemctl start docker"
    exit 1
fi
echo "Docker is running as systemd service"
echo ""

# =============================================================================
# DIRECT MODE INSTALLATION
# =============================================================================
if [ "$RUNNER_MODE" = "direct" ]; then
    echo "=== DIRECT MODE INSTALLATION ==="
    echo ""

    # --- Create runner user ---
    echo "Creating runner user..."
    if ! id "$RUNNER_USER" &>/dev/null; then
        sudo useradd -r -m -d "$RUNNER_HOME" -s /bin/bash "$RUNNER_USER"
        sudo usermod -aG docker "$RUNNER_USER"
    else
        echo "User $RUNNER_USER already exists"
        sudo usermod -aG docker "$RUNNER_USER"
    fi

    # --- Download runner binary ---
    echo "Downloading Forgejo runner binary..."
    sudo -u "$RUNNER_USER" mkdir -p "$RUNNER_HOME/bin"

    VERSION_NUM=${RUNNER_VERSION#v}
    DOWNLOAD_URL="https://code.forgejo.org/forgejo/runner/releases/download/$RUNNER_VERSION/forgejo-runner-${VERSION_NUM}-linux-$ARCH"

    echo "Downloading from: $DOWNLOAD_URL"
    sudo -u "$RUNNER_USER" curl -L "$DOWNLOAD_URL" -o "$RUNNER_HOME/bin/forgejo-runner"
    sudo chmod +x "$RUNNER_HOME/bin/forgejo-runner"
    sudo chown -R "$RUNNER_USER":"$RUNNER_USER" "$RUNNER_HOME"

    # --- Register runner ---
    echo "Registering runner with Forgejo..."
    sudo -u "$RUNNER_USER" "$RUNNER_HOME/bin/forgejo-runner" register \
        --token "$REGISTRATION_TOKEN" \
        --name "$RUNNER_NAME" \
        --instance "$FORGEJO_URL" \
        --labels docker:docker://node:20-bookworm \
        --no-interactive

    # --- Create config.yaml ---
    echo "Creating configuration..."
    sudo -u "$RUNNER_USER" tee "$RUNNER_HOME/config.yaml" > /dev/null << 'EOF'
log:
  level: info

runner:
  file: .runner
  envs:
    DOCKER_HOST: unix:///var/run/docker.sock
  cache:
    enabled: false
    dir: /opt/forgejo-runner/cache
  fetch_interval: 30
  fetch_timeout: 30s

docker:
  host: unix:///var/run/docker.sock
  privileged: false
  options: >-
    -v /var/run/docker.sock:/var/run/docker.sock
    --add-host=host.docker.internal:host-gateway

container:
  network: host
  options: >-
    --add-host=host.docker.internal:host-gateway
  volumes:
    - /opt/forgejo-runner/cache:/cache
    - /var/run/docker.sock:/var/run/docker.sock
EOF

    # --- Create systemd service ---
    echo "Creating systemd service..."
    sudo tee /etc/systemd/system/forgejo-runner.service > /dev/null << EOF
[Unit]
Description=Forgejo Actions Runner
After=docker.service
Requires=docker.service

[Service]
Type=simple
User=$RUNNER_USER
Group=$RUNNER_USER
WorkingDirectory=$RUNNER_HOME
ExecStart=$RUNNER_HOME/bin/forgejo-runner daemon --config $RUNNER_HOME/config.yaml
Restart=always
RestartSec=10
StartLimitBurst=3
StartLimitInterval=60s
LimitNOFILE=65536
LimitNPROC=65536

[Install]
WantedBy=multi-user.target
EOF

    # --- Enable and start service ---
    echo "Starting service..."
    sudo systemctl daemon-reload
    sudo systemctl enable forgejo-runner.service
    sudo systemctl start forgejo-runner.service

    echo ""
    echo "=== DIRECT MODE DEPLOYMENT COMPLETE ==="
    echo ""
    echo "Service status:"
    sudo systemctl status forgejo-runner.service --no-pager
    echo ""
    echo "To view logs:"
    echo "  sudo journalctl -u forgejo-runner -f"
    echo ""
    echo "Runner location: $RUNNER_HOME"

# =============================================================================
# DOCKER MODE INSTALLATION
# =============================================================================
elif [ "$RUNNER_MODE" = "docker" ]; then
    echo "=== DOCKER MODE INSTALLATION ==="
    echo ""

    # --- Create working directory ---
    echo "Creating working directory..."
    mkdir -p "$COMPOSE_DIR"/{data,cache}
    cd "$COMPOSE_DIR"

    # --- Register runner using Docker ---
    echo "Registering runner with Forgejo..."
    docker run -it --rm \
        -v "$(pwd)/data:/data" \
        -w /data \
        --user root \
        "${RUNNER_IMAGE}:${RUNNER_VERSION#v}" \
        forgejo-runner register \
        --no-interactive \
        --token "$REGISTRATION_TOKEN" \
        --name "$RUNNER_NAME" \
        --instance "$FORGEJO_URL" \
        --labels "$RUNNER_NAME:host"

    # --- Generate config.yaml ---
    echo "Generating configuration..."
    docker run --rm \
        -v "$(pwd)/data:/data" \
        -w /data \
        "${RUNNER_IMAGE}:${RUNNER_VERSION#v}" \
        forgejo-runner generate-config > data/config.yaml

    # --- Customize config.yaml ---
    echo "Customizing configuration..."
    cat > data/config.yaml << EOF
instance: $FORGEJO_URL
token: "$REGISTRATION_TOKEN"

log:
  level: info

runner:
  file: .runner
  capacity: 1
  timeout: 30m
  shutdown_timeout: 30m
  insecure: true
  fetch_timeout: 30s
  fetch_interval: 60s
  report_interval: 10s
  labels:
    - "$RUNNER_NAME:host"

cache:
  enabled: true
  dir: ""

container:
  privileged: false
  valid_volumes:
    - '**'
  docker_host: ""
  force_pull: false

host:
  workdir_parent: ""
EOF

    # --- Create docker-compose.yml ---
    echo "Creating docker-compose.yml..."
    cat > docker-compose.yml << EOF
version: '3.8'

services:
  docker-in-docker:
    image: $DIND_IMAGE
    container_name: ${RUNNER_NAME}_dind
    privileged: true
    command: ['dockerd', '-H', 'tcp://0.0.0.0:2375', '--tls=false']
    restart: unless-stopped
    volumes:
      - dind-storage:/var/lib/docker

  runner:
    image: ${RUNNER_IMAGE}:${RUNNER_VERSION#v}
    container_name: ${RUNNER_NAME}
    depends_on:
      docker-in-docker:
        condition: service_started
    environment:
      DOCKER_HOST: tcp://docker-in-docker:2375
    user: 0:0
    volumes:
      - ./data:/data
      - ./cache:/cache
    restart: unless-stopped
    command: /bin/sh -c "
      apk update && apk add --no-cache nodejs npm &&
      sleep 5 &&
      forgejo-runner daemon --config /data/config.yaml
      "

volumes:
  dind-storage:
EOF

    # --- Create systemd service for docker-compose ---
    echo "Creating systemd service..."
    sudo tee /etc/systemd/system/forgejo-runner-docker.service > /dev/null << EOF
[Unit]
Description=Forgejo Runner (Docker Compose)
After=docker.service
Requires=docker.service

[Service]
Type=oneshot
RemainAfterExit=yes
WorkingDirectory=$COMPOSE_DIR
ExecStart=/usr/bin/docker compose up -d
ExecStop=/usr/bin/docker compose down
ExecReload=/usr/bin/docker compose restart
StandardOutput=journal
User=$USER
Group=$USER

[Install]
WantedBy=multi-user.target
EOF

    # --- Enable and start service ---
    echo "Starting service..."
    sudo systemctl daemon-reload
    sudo systemctl enable forgejo-runner-docker.service
    sudo systemctl start forgejo-runner-docker.service

    echo ""
    echo "=== DOCKER MODE DEPLOYMENT COMPLETE ==="
    echo ""
    echo "Service status:"
    sudo systemctl status forgejo-runner-docker.service --no-pager
    echo ""
    echo "To view logs:"
    echo "  docker compose -f $COMPOSE_DIR/docker-compose.yml logs -f runner"
    echo ""
    echo "To manage:"
    echo "  cd $COMPOSE_DIR"
    echo "  docker compose up -d    # start"
    echo "  docker compose down     # stop"
    echo "  docker compose restart  # restart"
    echo ""
    echo "Runner location: $COMPOSE_DIR"

# =============================================================================
# INVALID MODE
# =============================================================================
else
    echo "ERROR: Invalid RUNNER_MODE. Use 'direct' or 'docker'"
    exit 1
fi

echo ""
echo "============================================================"
echo "DEPLOYMENT COMPLETE"
echo "============================================================"
echo ""
echo "Runner should now appear online in Forgejo Admin -> Actions -> Runners"
echo "URL: $FORGEJO_URL/admin/actions/runners"
echo ""
echo "If runner shows offline, check:"
echo "  - Registration token is valid"
echo "  - Forgejo URL is accessible"
echo "  - Docker is running: sudo systemctl status docker"
echo "============================================================"