name: Fuzz
on:
  schedule:
    - cron: '0 21 * * *' # run at 9 PM UTC
  # Allow manual runs
  workflow_dispatch:
env:
  CC: clang
jobs:
  fuzz:
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        ipv6: [0, 1] # fuzz code always feeds IPv6, so this fuzzes ignoring while going parallel in sync
    name: fuzz IPV6=${{ matrix.ipv6 }}
    env:
      TFLAGS: -DMG_ENABLE_IPV6=${{ matrix.ipv6 }}
    steps:
    - uses: actions/checkout@v5
      with: { fetch-depth: 2 }
    - name: Restore Combined Fuzzing Corpus
      uses: dawidd6/action-download-artifact@v21
      with:
        name: combined-fuzz-corpus
        path: test/corpus_dir
        branch: ${{ github.base_ref || github.ref_name }}
        search_artifacts: true
        if_no_artifact_found: warn
    - name: Run Matrix Fuzzers
      run: mkdir -p test/corpus_dir && make -C test fuzz ARGS="corpus_dir -seed=${{ github.run_id }} -max_total_time=14400"
    # Keep failures split by matrix leg so the offending input is easy to find.
    - name: Upload Fuzz Failure Artifacts
      if: failure()
      uses: actions/upload-artifact@v7
      with:
        name: fuzz-failure-ipv6-${{ matrix.ipv6 }}
        path: |
          test/corpus_dir
          test/crash-*
          test/leak-*
          test/oom-*
          test/timeout-*
        if-no-files-found: ignore
        retention-days: 14
    # v4 artifacts are immutable, so each parallel leg uploads its own corpus.
    - name: Upload Corpus Shard
      uses: actions/upload-artifact@v7
      with:
        name: fuzz-corpus-ipv6-${{ matrix.ipv6 }}
        path: test/corpus_dir
        retention-days: 14

  merge_fuzz_corpus:
    runs-on: ubuntu-latest
    needs: fuzz
    name: merge fuzz corpus
    steps:
    # Merge both parallel fuzzing corpuses into the shared seed for next run.
    - name: Merge Corpus Shards
      uses: actions/upload-artifact/merge@v7
      with:
        name: combined-fuzz-corpus
        pattern: fuzz-corpus-ipv6-*
        delete-merged: true
        retention-days: 14
  # see NOTE

  fuzz_tls:
    runs-on: ubuntu-latest
    name: fuzz_tls
    env:
      TFLAGS: -DMG_ENABLE_IPV6=0
    steps:
    - uses: actions/checkout@v5
      with: { fetch-depth: 2 }
    - name: Restore Fuzzing Corpus
      uses: actions/cache/restore@v6
      with:
        path: test/corpus_dir
        key: fuzz-corpus-${{ github.head_ref || github.ref_name }}-${{ github.run_id }}
        restore-keys: |
          fuzz-corpus-${{ github.head_ref || github.ref_name }}-
          fuzz-corpus-main-
          fuzz-corpus-
    - name: Run Fuzzer
      run: mkdir -p test/corpus_dir && make -C test fuzz_tls ARGS="corpus_dir -seed=${{ github.run_id }} -max_total_time=14400"
    - name: Upload Fuzz TLS Failure Artifacts
      if: failure()
      uses: actions/upload-artifact@v7
      with:
        name: fuzz-tls-failure-artifacts
        path: |
          test/corpus_dir
          test/crash-*
          test/leak-*
          test/oom-*
          test/timeout-*
        if-no-files-found: ignore
        retention-days: 14
    - name: Save Updated Corpus to Cache
      uses: actions/cache/save@v6
      with:
        path: test/corpus_dir
        key: fuzz-corpus-${{ github.head_ref || github.ref_name }}-${{ github.run_id }}

# NOTE
# In case we can't get access to test units causing a problem, convert from the log:
# base64 -d > dataofdeath
# then paste the base64 data, enter, Ctrl-D; maybe check with hexdump -C dataofdeath