name: "Build & Upload NixOS Proxmox Image"

on:
  push:
    tags:
      - "v*" # triggers on v1.0.0, v1.2.3, etc.
  workflow_dispatch:

jobs:
  build-upload:
    runs-on: nixos-latest
    env:
      PROXMOX_HOST: 192.168.1.205
      PROXMOX_USER: forgejo-runner
      NIXOS_BUILER_HOST: nixos-builder.lab
      NIXOS_BUILER_USER: runner
      TEMPLATE_VMID: 9001
      LATEST_TEMPLATE_VMID: 9000

    steps:
      - name: Install nodejs
        run: nix-env -iA nixpkgs.nodejs

      - name: Checkout repo
        uses: actions/checkout@v4

      - name: Set VERSION from tag or fallback
        id: version
        run: |
          if [ -n "${CI_COMMIT_TAG}" ]; then
            echo "tag=${CI_COMMIT_TAG}" >> $GITHUB_OUTPUT
          else
            echo "tag=dev-$(date +%s)" >> $GITHUB_OUTPUT
          fi

      - name: Enable experimental features
        run: |
          mkdir -p ~/.config/nix
          echo "experimental-features = nix-command flakes" >> ~/.config/nix/nix.conf

      - name: Prepare SSH
        run: |
          mkdir -p ~/.ssh
          echo "${{ secrets.RUNNER_SSH_KEY }}" > ~/.ssh/id_rsa
          chmod 600 ~/.ssh/id_rsa
          ssh-keyscan -H $PROXMOX_HOST >> ~/.ssh/known_hosts
          ssh-keyscan -H $NIXOS_BUILER_HOST >> ~/.ssh/known_hosts

      - name: Test SSH connection
        run: |
          echo "Testing SSH connection to $PROXMOX_HOST..."
          ssh -o StrictHostKeyChecking=yes $PROXMOX_USER@$PROXMOX_HOST "echo 'SSH success. Hostname:' && hostname"
          echo "Testing SSH connection to $NIXOS_BUILER_HOST..."
          ssh -o StrictHostKeyChecking=yes $NIXOS_BUILER_USER@$NIXOS_BUILER_HOST "echo 'SSH success. Hostname:' && hostname"

      - name: Setup Cachix
        run: |
          nix-env -iA cachix -f https://cachix.org/api/v1/install
          cachix use plasmagoat
          cachix authtoken ${{ secrets.CACHIX_AUTH_TOKEN }}

      - name: Build NixOS image
        id: build
        run: |
          nix build .#base \
          --no-link --print-out-paths \
          --builders "ssh://$NIXOS_BUILER_USER@$NIXOS_BUILER_HOST x86_64-linux ~/.ssh/id_rsa 1 1 kvm" \
          --max-jobs 0 \
          --no-link --print-out-paths \
           | cachix push plasmagoat

          ls
          echo "image=$(ls ./result/*.vma.zst | head -n 1)" >> $GITHUB_OUTPUT

      - name: Upload image to Proxmox and manage templates
        run: |
          set -e
          ls
          IMAGE="${{ steps.build.outputs.image }}"
          REMOTE_NAME="nixos-base-image-${{ steps.version.outputs.tag}}.vma.zst"
          REMOTE_PATH="/var/lib/vz/template/images/$REMOTE_NAME"

          echo "Uploading $IMAGE to Proxmox as $REMOTE_NAME"
          scp $IMAGE $PROXMOX_USER@$PROXMOX_HOST:$REMOTE_PATH

          echo "Restoring as VMID $TEMPLATE_VMID"
          ssh $PROXMOX_USER@$PROXMOX_HOST "
            qm destroy $TEMPLATE_VMID --purge || true
            qmrestore $REMOTE_PATH $TEMPLATE_VMID --unique
            qm template $TEMPLATE_VMID

            echo 'Cloning to $LATEST_TEMPLATE_VMID as latest'
            qm destroy $LATEST_TEMPLATE_VMID --purge || true
            qm clone $TEMPLATE_VMID $LATEST_TEMPLATE_VMID --name nixos-base-latest
            qm template $TEMPLATE_VMID
          "