name: Deploy backend

on:
  push:
    branches: [develop]
    paths:
      - 'Club12-Backend/**'
      - 'docker-compose.yml'
      - '.github/workflows/deploy-backend.yml'
  workflow_dispatch:

concurrency:
  group: deploy-backend-${{ github.ref }}
  cancel-in-progress: false

env:
  IMAGE: ghcr.io/francoru/club12-backend
  SERVICE: backend
  DEPLOY_DIR: /home/docker-compose/Club12

jobs:
  build:
    runs-on: ubuntu-latest
    timeout-minutes: 30
    permissions:
      contents: read
      packages: write
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Set up Buildx
        uses: docker/setup-buildx-action@v3

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

      - name: Build and push
        uses: docker/build-push-action@v6
        with:
          context: ./Club12-Backend
          push: true
          provenance: false
          tags: ${{ env.IMAGE }}:latest
          cache-from: type=gha
          cache-to: type=gha,mode=max

  deploy:
    needs: build
    runs-on: [self-hosted, Club-12-back-runner]
    timeout-minutes: 15
    permissions:
      contents: read
      packages: read
    concurrency:
      group: club12-deploy-${{ github.ref }}
      cancel-in-progress: false
    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          persist-credentials: false

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

      - name: Sync compose file to the server project directory
        run: |
          set -euo pipefail
          if [ ! -d "$DEPLOY_DIR" ]; then
            echo "::error::$DEPLOY_DIR does not exist on this runner host. Create it before deploying."
            exit 1
          fi
          if [ ! -f "$DEPLOY_DIR/.env" ]; then
            echo "::error::$DEPLOY_DIR/.env is missing. Create it once by hand from .env.example (see DEPLOYMENT.md)."
            exit 1
          fi
          install -m 0644 docker-compose.yml "$DEPLOY_DIR/docker-compose.yml"
          echo "Synced docker-compose.yml -> $DEPLOY_DIR/docker-compose.yml"

      - name: Archive the currently running image as :previous
        working-directory: /home/docker-compose/Club12
        run: |
          set -euo pipefail
          if docker image inspect "$IMAGE:latest" >/dev/null 2>&1; then
            docker tag "$IMAGE:latest" "$IMAGE:previous"
            echo "Archived $IMAGE:latest -> $IMAGE:previous"
          else
            echo "No local $IMAGE:latest yet (first deploy) - nothing to archive."
          fi

      - name: Pull the new image
        working-directory: /home/docker-compose/Club12
        run: |
          set -euo pipefail
          docker compose pull "$SERVICE"

      - name: Restart the service
        working-directory: /home/docker-compose/Club12
        run: |
          set -euo pipefail
          docker compose up -d --no-deps --no-build "$SERVICE"
          docker compose ps "$SERVICE"

      - name: Re-point the frontend proxy at the new backend
        working-directory: /home/docker-compose/Club12
        run: |
          set -euo pipefail
          # The frontend's nginx resolves `backend` once at start-up. Recreating
          # the backend gives it a new container IP, so without this restart
          # every /api/* request 502s until the frontend is bounced.
          if docker compose ps --status running --services | grep -qx frontend; then
            docker compose restart frontend
            docker compose ps frontend
          else
            echo "frontend not running on this host - skipping proxy refresh"
          fi

      - name: Prune dangling images
        run: |
          set -euo pipefail
          docker image prune -f