#!/usr/bin/env bash
set -euo pipefail

########################################
# Configuration
########################################
VM_NAME="forgejo-runner-vm"
IMAGE="images:debian/trixie"
MEMORY="2GiB"
CPUS="4"

########################################
# Helper functions
########################################
log() {
  echo "[+] $*"
}

vm_exists() {
  incus info "$VM_NAME" >/dev/null 2>&1
}

########################################
# Create VM if needed
########################################
if vm_exists; then
  log "VM '$VM_NAME' already exists, skipping creation"
else
  log "Creating VM '$VM_NAME'"
  incus launch "$IMAGE" "$VM_NAME" \
    --vm \
    -c limits.memory="$MEMORY" \
    -c limits.cpu="$CPUS" 
fi

########################################
# Wait for VM to be ready
########################################
log "Waiting for VM to become ready"
incus exec "$VM_NAME" -- cloud-init status --wait >/dev/null 2>&1 || true

log "Waiting for Incus Agent to start"
# This loop tries a simple command until it succeeds or times out
RETRIES=0
MAX_RETRIES=30
until incus exec "$VM_NAME" -- uptime >/dev/null 2>&1; do
    RETRIES=$((RETRIES + 1))
    if [ $RETRIES -ge $MAX_RETRIES ]; then
        echo "Error: Timeout waiting for VM agent to start."
        exit 1
    fi
    echo "$RETRIES retries"
    sleep 1
done

log "Agent is responsive. Proceeding..."
########################################
# Install Docker inside the VM
########################################
log "Installing Docker inside VM"

incus exec "$VM_NAME" -- bash -eux <<'EOF'
export DEBIAN_FRONTEND=noninteractive

# Base packages
apt-get update
apt-get install -y \
  ca-certificates \
  curl \
  gnupg

# Docker GPG key
install -m 0755 -d /etc/apt/keyrings
curl -fsSL https://download.docker.com/linux/debian/gpg \
  -o /etc/apt/keyrings/docker.asc
chmod a+r /etc/apt/keyrings/docker.asc

# Docker repository
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] \
  https://download.docker.com/linux/debian \
  $(. /etc/os-release && echo "$VERSION_CODENAME") stable" \
  > /etc/apt/sources.list.d/docker.list

# Install Docker
apt-get update
apt-get install -y \
  docker-ce \
  docker-ce-cli \
  containerd.io \
  docker-buildx-plugin \
  docker-compose-plugin

# Enable Docker
systemctl enable docker
systemctl start docker
EOF

########################################
# Done
########################################
log "Docker successfully installed in VM '$VM_NAME'"
log "You can access it with:"
echo "    incus exec $VM_NAME -- bash"