name: CI

on:
  pull_request:
  push:
    branches: [master]

concurrency:
  group: ci-${{ github.ref }}
  cancel-in-progress: ${{ github.event_name == 'pull_request' }}

env:
  PYTHONDONTWRITEBYTECODE: 1

jobs:
  lint:
    name: Lint
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Install system dependencies
        run: sudo apt-get update && sudo apt-get install -y libcairo2-dev

      - uses: astral-sh/setup-uv@v6
        with:
          python-version-file: ".python-version"
          enable-cache: true

      - run: uv sync --locked

      - name: Pre-commit hooks (ruff, formatting, file hygiene)
        run: uv run prek run --all-files --show-diff-on-failure

      - name: Django system checks
        run: uv run python manage.py check

      - name: Check for missing migrations
        run: uv run python manage.py makemigrations --check --dry-run

  test:
    name: Test
    runs-on: ubuntu-latest
    env:
      DATABASE_ENGINE: sqlite3
      DATABASE_NAME: db.sqlite3
    steps:
      - uses: actions/checkout@v4

      - name: Install system dependencies
        run: sudo apt-get update && sudo apt-get install -y libcairo2-dev

      - uses: astral-sh/setup-uv@v6
        with:
          python-version-file: ".python-version"
          enable-cache: true

      - uses: actions/setup-node@v7
        with:
          node-version: 24
          cache: npm

      - run: uv sync --locked

      - name: Build frontend assets
        run: |
          npm ci
          npm run build

      - run: uv run python manage.py collectstatic --noinput

      - name: Run tests
        run: uv run pytest -n auto --cov

      - name: Coveralls
        run: uv run coveralls --service=github
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

  # Each architecture builds on a native runner: emulating arm64 under QEMU (compiling pycairo, npm, uv) was the slow part
  docker-build:
    name: Docker build (${{ matrix.platform }})
    runs-on: ${{ matrix.runner }}
    needs: [lint, test]
    permissions:
      contents: read
      packages: write
    strategy:
      fail-fast: true
      matrix:
        include:
          - platform: linux/amd64
            runner: ubuntu-latest
          - platform: linux/arm64
            runner: ubuntu-24.04-arm
    steps:
      - uses: actions/checkout@v4

      - uses: docker/setup-buildx-action@v4

      # Only authenticate when we are actually going to push (never for PRs, which may come from forks)
      - name: Log in to GHCR
        if: github.event_name == 'push'
        uses: docker/login-action@v4
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # Registry references must be lowercase, but the repository name is not
      - name: Set image name
        run: echo "IMAGE=ghcr.io/${GITHUB_REPOSITORY,,}" >> "$GITHUB_ENV"

      - id: build
        name: Build (and push by digest on master)
        uses: docker/build-push-action@v6
        with:
          context: .
          platforms: ${{ matrix.platform }}
          build-args: GIT_SHA=${{ github.sha }}
          outputs: type=image,name=${{ env.IMAGE }},push-by-digest=true,name-canonical=true,push=${{ github.event_name == 'push' }}
          cache-from: type=gha,scope=${{ matrix.platform }}
          cache-to: type=gha,mode=max,scope=${{ matrix.platform }}

      - name: Export digest
        if: github.event_name == 'push'
        env:
          DIGEST: ${{ steps.build.outputs.digest }}
        run: |
          mkdir -p "$RUNNER_TEMP/digests"
          touch "$RUNNER_TEMP/digests/${DIGEST#sha256:}"

      - name: Upload digest
        if: github.event_name == 'push'
        uses: actions/upload-artifact@v4
        with:
          name: digests-${{ strategy.job-index }}
          path: ${{ runner.temp }}/digests/*
          if-no-files-found: error
          retention-days: 1

  docker:
    name: Docker image
    runs-on: ubuntu-latest
    needs: [docker-build]
    if: github.event_name == 'push'
    outputs:
      tag: ${{ steps.sha-tag.outputs.tag }}
    permissions:
      contents: read
      packages: write
    steps:
      - uses: actions/download-artifact@v4
        with:
          path: ${{ runner.temp }}/digests
          pattern: digests-*
          merge-multiple: true

      - uses: docker/setup-buildx-action@v4

      - name: Log in to GHCR
        uses: docker/login-action@v4
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - id: meta
        uses: docker/metadata-action@v5
        with:
          images: ghcr.io/${{ github.repository }}
          tags: |
            type=raw,value=latest
            type=sha

      - id: sha-tag
        name: Pick the commit tag
        env:
          TAGS: ${{ steps.meta.outputs.tags }}
        run: |
          ref="$(grep -m1 ':sha-' <<< "$TAGS")"
          test -n "$ref"
          echo "tag=${ref##*:}" >> "$GITHUB_OUTPUT"

      - name: Create multi-arch manifest
        working-directory: ${{ runner.temp }}/digests
        run: |
          IMAGE="ghcr.io/${GITHUB_REPOSITORY,,}"
          docker buildx imagetools create \
            $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
            $(printf "$IMAGE@sha256:%s " *)

  deploy:
    name: Deploy
    runs-on: ubuntu-latest
    needs: [docker]
    if: github.event_name == 'push' && github.ref == 'refs/heads/master'
    environment: production
    concurrency: deploy-production
    steps:
      - name: Deploy the image built for this commit
        env:
          DEPLOY_SSH_KEY: ${{ secrets.DEPLOY_SSH_KEY }}
          DEPLOY_KNOWN_HOSTS: ${{ secrets.DEPLOY_KNOWN_HOSTS }}
          TAG: ${{ needs.docker.outputs.tag }}
        run: |
          install -m 700 -d ~/.ssh
          printf '%s\n' "$DEPLOY_SSH_KEY" > ~/.ssh/id_ed25519
          chmod 600 ~/.ssh/id_ed25519
          printf '%s\n' "$DEPLOY_KNOWN_HOSTS" > ~/.ssh/known_hosts
          ssh deploy@rigs.nottinghamtec.co.uk "$TAG"