name: Build Kernel

on:
  pull_request:
    paths:
      - '.github/workflows/check-kernel-patches.yml'
      - '.github/workflows/build.yml'
      - '.github/workflows/kernel.yml'
      - 'include/kernel*'
      - 'package/kernel/**'
      - 'target/linux/**'
  push:
    paths:
      - '.github/workflows/check-kernel-patches.yml'
      - '.github/workflows/build.yml'
      - '.github/workflows/kernel.yml'
      - 'include/kernel*'
      - 'package/kernel/**'
      - 'target/linux/**'

permissions:
  contents: read

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

jobs:
  determine_targets:
    name: Set targets
    runs-on: ubuntu-latest
    outputs:
      targets_subtargets: ${{ steps.find_targets.outputs.targets_subtargets }}
      targets: ${{ steps.find_targets.outputs.targets }}

    steps:
      - name: Checkout
        uses: actions/checkout@v3
        with:
          fetch-depth: 2

      - name: Get changed files
        id: changed-files
        uses: tj-actions/changed-files@v35

      - name: Set targets
        id: find_targets
        run: |
          ALL_TARGETS="$(perl ./scripts/dump-target-info.pl targets 2>/dev/null)"
          CHANGED_FILES="$(echo ${{ steps.changed-files.outputs.all_changed_files }} | tr ' ' '\n')"

          TARGETS_SUBTARGETS="$(echo "$ALL_TARGETS" | sort -u -t '/' -k1 | awk '{ print $1 }')"
          TARGETS="$(echo "$ALL_TARGETS" | sort -u -t '/' -k1,1 | awk '{ print $1 }')"

          # On testing non-specific target, skip testing each subtarget
          if echo "$CHANGED_FILES" | grep -v -q target/linux ||
            echo "$CHANGED_FILES" | grep -q target/linux/generic; then
            TARGETS_SUBTARGETS=$TARGETS
          fi

          JSON_TARGETS_SUBTARGETS='['
          FIRST=1
          for TARGET in $TARGETS_SUBTARGETS; do
            if echo "$CHANGED_FILES" | grep -v -q target/linux ||
              echo "$CHANGED_FILES" | grep -q target/linux/generic ||
              echo "$CHANGED_FILES" | grep -q $(echo $TARGET | cut -d "/" -f 1); then
              [[ $FIRST -ne 1 ]] && JSON_TARGETS_SUBTARGETS="$JSON_TARGETS_SUBTARGETS"','
              JSON_TARGETS_SUBTARGETS="$JSON_TARGETS_SUBTARGETS"'"'"${TARGET}"'"'
              FIRST=0
            fi
          done
          JSON_TARGETS_SUBTARGETS="$JSON_TARGETS_SUBTARGETS"']'

          JSON_TARGETS='['
          FIRST=1
          for TARGET in $TARGETS; do
            if echo "$CHANGED_FILES" | grep -v -q target/linux ||
              echo "$CHANGED_FILES" | grep -q target/linux/generic ||
              echo "$CHANGED_FILES" | grep -q $(echo $TARGET | cut -d "/" -f 1); then
              [[ $FIRST -ne 1 ]] && JSON_TARGETS="$JSON_TARGETS"','
              JSON_TARGETS="$JSON_TARGETS"'"'"${TARGET}"'"'
              FIRST=0
            fi
          done
          JSON_TARGETS="$JSON_TARGETS"']'

          echo -e "\n---- targets to build ----\n"
          echo "$JSON_TARGETS_SUBTARGETS"
          echo -e "\n---- targets to build ----\n"

          echo -e "\n---- targets to check patch ----\n"
          echo "$JSON_TARGETS"
          echo -e "\n---- targets to check patch ----\n"

          echo "targets_subtargets=$JSON_TARGETS_SUBTARGETS" >> $GITHUB_OUTPUT
          echo "targets=$JSON_TARGETS" >> $GITHUB_OUTPUT

  build:
    name: Build Kernel with external toolchain
    needs: determine_targets
    permissions:
      contents: read
      packages: read
    strategy:
       fail-fast: False
       matrix:
         target: ${{fromJson(needs.determine_targets.outputs.targets_subtargets)}}
    uses: ./.github/workflows/build.yml
    with:
      target: ${{ matrix.target }}
      build_kernel: true
      build_all_kmods: true

  check-kernel-patches:
    name: Check Kernel patches
    needs: determine_targets
    permissions:
      contents: read
      packages: read
    strategy:
       fail-fast: False
       matrix:
         target: ${{fromJson(needs.determine_targets.outputs.targets)}}
    uses: ./.github/workflows/check-kernel-patches.yml
    with:
      target: ${{ matrix.target }}