deploy-backend.yml

name: Deploy Backend to Heroku

on:
  push:
    branches: [main]
    paths:
      - "backend/**"
      - ".github/workflows/deploy-backend.yml"

jobs:
  deploy-backend:
    runs-on: ubuntu-latest
    permissions:
      contents: read
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Detect backend changes
        id: changes
        uses: dorny/paths-filter@v3
        with:
          token: ${{ github.token }}
          filters: |
            backend:
              - 'backend/Dockerfile'
              - 'backend/Cargo.toml'
              - 'backend/Cargo.lock'
              - 'backend/src/**'
              - 'backend/migrations/**'
              - 'backend/rustfmt.toml'

      - name: Install Heroku CLI
        run: |
          curl https://cli-assets.heroku.com/install.sh | sh
        if: steps.changes.outputs.backend == 'true'

      - name: Heroku Container Registry login
        env:
          HEROKU_EMAIL: ${{ secrets.HEROKU_EMAIL }}
          HEROKU_API_KEY: ${{ secrets.HEROKU_API_KEY }}
        run: |
          echo "$HEROKU_API_KEY" | docker login -u "$HEROKU_EMAIL" --password-stdin registry.heroku.com
        if: steps.changes.outputs.backend == 'true'

      - name: Build and push (linux/amd64)
        env:
          HEROKU_BACKEND_APP: ${{ secrets.HEROKU_BACKEND_APP }}
        run: |
          DOCKER_BUILDKIT=0 docker build \
            --platform linux/amd64 \
            --target production \
            -t registry.heroku.com/${HEROKU_BACKEND_APP}/web \
            -f backend/Dockerfile backend

          docker push registry.heroku.com/${HEROKU_BACKEND_APP}/web
        if: steps.changes.outputs.backend == 'true'

      - name: Release on Heroku
        env:
          HEROKU_API_KEY: ${{ secrets.HEROKU_API_KEY }}
          HEROKU_BACKEND_APP: ${{ secrets.HEROKU_BACKEND_APP }}
        run: |
          heroku container:release web -a "${HEROKU_BACKEND_APP}"
        if: steps.changes.outputs.backend == 'true'