name: pre-commit

on:
  push:
    branches:
      - develop
      - release/therock-*
  pull_request:
    branches: [develop]

permissions:
  contents: read

concurrency:
  # For PRs, group by PR number so a new commit cancels any in-progress run
  # for the same PR. For postsubmits, group by commit SHA (unique per commit)
  # so runs never cancel each other. The workflow name is prepended to avoid
  # conflicts between different workflows.
  group: ${{ github.workflow }}-${{ github.event.number || github.sha }}
  cancel-in-progress: true

jobs:
  pre-commit:
    runs-on: ubuntu-24.04
    env:
      # For PRs, diff against the base branch. For pushes, diff against the
      # commit that existed before the push (github.event.before).
      FROM_REF: ${{ github.event.pull_request.base.ref && format('origin/{0}', github.event.pull_request.base.ref) || github.event.before }}
      DEFAULT_REF: ${{ format('origin/{0}', github.event.repository.default_branch) }}
      # A branch-creation push has no source ref in its event payload. It falls
      # back to the default branch's merge base and can include inherited changes
      # when the branch originates elsewhere. PRs use their actual base ref.
      NULL_REF: 0000000000000000000000000000000000
    steps:
      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
        with:
          # Blobless partial clone; the sparse-checkout below materializes only
          # the projects touched by the diff instead of the full ~9 GB tree.
          filter: blob:none
          sparse-checkout: .github

      - name: Select diff base for new branch
        if: env.FROM_REF == env.NULL_REF
        run: echo "FROM_REF=${DEFAULT_REF}" >> "$GITHUB_ENV"

      - name: Fetch diff base
        env:
          CURRENT_BRANCH: ${{ github.ref_name }}
        run: |
          # FROM_REF is origin/<base branch> for PRs and the prior commit SHA
          # for pushes. Fetch the PR base branch or the complete pushed-branch
          # history so the three-dot merge base is available in this shallow clone.
          UNSHALLOW=""
          if [ -f "$(git rev-parse --git-dir)/shallow" ]; then UNSHALLOW="--unshallow"; fi
          if [[ "$FROM_REF" == origin/* ]]; then
            BASE_BRANCH="${FROM_REF#origin/}"
            TARGET_REF="refs/remotes/${FROM_REF}"
          else
            BASE_BRANCH="$CURRENT_BRANCH"
            TARGET_REF="refs/remotes/origin/${CURRENT_BRANCH}"
          fi
          git fetch --no-tags --prune --no-recurse-submodules --filter=blob:none $UNSHALLOW origin \
            "+refs/heads/${BASE_BRANCH}:${TARGET_REF}"

      - name: Sparse-checkout changed projects
        run: |
          # Reduce each changed path to its project prefix and materialize only
          # those subtrees.
          mapfile -t DIRS < <(git diff --name-only "${FROM_REF}...HEAD" \
            | awk -F/ 'NF==2{print $1} NF>=3{print $1"/"$2}' | sort -u)
          git sparse-checkout set --cone "${DIRS[@]}"

      - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0

      - name: Detect project changes
        id: changes
        env:
          # Add project names here (one per line) to enable conditional dependency installation
          PROJECTS_WITH_OPTIONAL_DEPS: >-
            hipdnn
        run: |
          CHANGED_FILES=$(git diff --name-only ${FROM_REF}...HEAD)

          # Check each project for changes
          for project in $PROJECTS_WITH_OPTIONAL_DEPS; do
            if echo "$CHANGED_FILES" | grep -qE "^(projects|shared)/$project/"; then
              echo "${project}_changed=true" >> $GITHUB_OUTPUT
            else
              echo "${project}_changed=false" >> $GITHUB_OUTPUT
            fi
          done

      # To install optional deps for a project:
      # 1. Add project name to PROJECTS_WITH_OPTIONAL_DEPS above
      # 2. Like the example below, add an install step conditional on:
      #    - steps.changes.outputs.<project-name>_changed == 'true'

      - name: Install hipDNN dependencies
        if: steps.changes.outputs.hipdnn_changed == 'true'
        run: |
          wget -q https://github.com/google/flatbuffers/releases/download/v25.9.23/Linux.flatc.binary.g++-13.zip
          unzip -q Linux.flatc.binary.g++-13.zip
          sudo mv flatc /usr/local/bin/
          sudo chmod +x /usr/local/bin/flatc
          rm Linux.flatc.binary.g++-13.zip

      - uses: pre-commit/action@2c7b3805fd2a0fd8c1884dcaebf91fc102a13ecd # v3.0.1
        with:
          # Only check changed files in the PR/push.
          extra_args: --from-ref ${{ env.FROM_REF }} --to-ref HEAD