# Production deploy: build the image in CI, publish to GHCR, then SSH into the
# Hetzner VPS to pull + restart. The VPS never builds — it only pulls the image
# that passed CI. Rollback = re-run this workflow from an older commit, or
# `docker compose pull` a previous sha-tag on the VPS.
#
# Secrets: VPS_SSH_KEY (dedicated deploy key), VPS_HOST, VPS_USER.

name: VPS Deploy

on:
  push:
    branches: [main]
  workflow_dispatch:

concurrency:
  group: vps-deploy
  cancel-in-progress: false

env:
  IMAGE: ghcr.io/${{ github.repository }}

jobs:
  build-push:
    name: Build & push to GHCR
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
    steps:
      - uses: actions/checkout@v4

      - uses: docker/setup-buildx-action@v3

      - uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - uses: docker/metadata-action@v5
        id: meta
        with:
          images: ${{ env.IMAGE }}
          tags: |
            type=raw,value=latest
            type=sha,format=long

      - uses: docker/build-push-action@v6
        with:
          context: .
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

  deploy:
    name: Deploy to VPS
    needs: build-push
    runs-on: ubuntu-latest
    steps:
      - name: Install SSH key
        uses: webfactory/ssh-agent@v0.9.1
        with:
          ssh-private-key: ${{ secrets.VPS_SSH_KEY }}

      - name: Trust VPS host key
        run: |
          mkdir -p ~/.ssh
          ssh-keyscan -H "${{ secrets.VPS_HOST }}" >> ~/.ssh/known_hosts

      - name: Pull image and restart app
        run: |
          ssh "${{ secrets.VPS_USER }}@${{ secrets.VPS_HOST }}" bash -s <<'EOF'
          set -euo pipefail
          cd /root/projects/arbpulse
          git fetch origin main
          git checkout main
          git reset --hard origin/main
          cd deploy
          docker compose pull app
          docker compose up -d app
          echo "waiting for health..."
          for i in $(seq 1 12); do
            if curl -fsS http://127.0.0.1:8080/api/health >/dev/null 2>&1; then
              echo "app healthy"
              docker image prune -f >/dev/null
              exit 0
            fi
            sleep 5
          done
          echo "app did not become healthy in time" >&2
          docker compose logs --tail 50 app >&2
          exit 1
          EOF