name: FLASH usage analysis

permissions:
  contents: read
  pull-requests: write
  issues: write

on:
  push:
    branches:
      - 'main'
    paths-ignore:
      - 'docs/**'
  pull_request:
    branches:
      - '**'
    paths-ignore:
      - 'docs/**'

env:
  MIN_FLASH_POS_DIFF_FOR_COMMENT: 50
  MIN_FLASH_NEG_DIFF_FOR_COMMENT: -50

jobs:
  analyze_flash:
    name: Analyzing ${{ matrix.target }}
    runs-on: [runs-on,runner=4cpu-linux-x64,image=ubuntu24-full-x64,"run-id=${{ github.run_id }}",spot=false,extras=s3-cache]
    container:
      image: ghcr.io/px4/px4-dev:v1.17.0-rc2
    strategy:
      matrix:
        target: [px4_fmu-v5x, px4_fmu-v6x]
    outputs:
      px4_fmu-v5x-bloaty-output: ${{ steps.gen-output.outputs.px4_fmu-v5x-bloaty-output }}
      px4_fmu-v5x-bloaty-summary-map: ${{ steps.gen-output.outputs.px4_fmu-v5x-bloaty-summary-map }}
      px4_fmu-v6x-bloaty-output: ${{ steps.gen-output.outputs.px4_fmu-v6x-bloaty-output }}
      px4_fmu-v6x-bloaty-summary-map: ${{ steps.gen-output.outputs.px4_fmu-v6x-bloaty-summary-map }}
    steps:
      - uses: runs-on/action@v2
      - uses: actions/checkout@v6
        with:
          fetch-depth: 0
          submodules: recursive
      - name: Configure Git Safe Directory
        run: git config --system --add safe.directory '*'

      - name: Cache - Restore ccache (current)
        id: cache_current
        uses: actions/cache/restore@v5
        with:
          path: ~/.ccache
          key: ccache-flash-${{ matrix.target }}-current-${{ github.ref_name }}-${{ github.sha }}
          restore-keys: |
            ccache-flash-${{ matrix.target }}-current-${{ github.ref_name }}-
            ccache-flash-${{ matrix.target }}-current-

      - name: Cache - Configure ccache
        run: |
          mkdir -p ~/.ccache
          echo "base_dir = ${GITHUB_WORKSPACE}" > ~/.ccache/ccache.conf
          echo "compression = true" >> ~/.ccache/ccache.conf
          echo "compression_level = 6" >> ~/.ccache/ccache.conf
          echo "max_size = 200M" >> ~/.ccache/ccache.conf
          echo "hash_dir = false" >> ~/.ccache/ccache.conf
          echo "compiler_check = content" >> ~/.ccache/ccache.conf
          ccache -s
          ccache -z

      - name: Build Target
        run: make ${{ matrix.target }}_flash-analysis

      - name: Store the ELF with the change
        run: cp ./build/**/*.elf ./with-change.elf

      - name: Cache - Stats after Current Build
        run: ccache -s

      - name: Cache - Save ccache (current)
        if: always()
        uses: actions/cache/save@v5
        with:
          path: ~/.ccache
          key: ${{ steps.cache_current.outputs.cache-primary-key }}

      - name: Clean previous build
        run: |
          make clean
          make distclean
          make submodulesclean
          ccache -C

      - name: If it's a PR checkout the base branch
        if: ${{ github.event.pull_request }}
        # As checkout creates a merge commit (merging the base branch into the PR branch), the base branch is the base for a diff of the PR changes.
        run: git checkout ${{ github.event.pull_request.base.ref }}

      - name: If it's a push checkout the previous commit
        if: github.event_name == 'push'
        run: git checkout ${{ github.event.before }}

      - name: Update submodules
        run: make submodulesupdate

      - name: Cache - Restore ccache (baseline)
        id: cache_baseline
        uses: actions/cache/restore@v5
        with:
          path: ~/.ccache
          key: ccache-flash-${{ matrix.target }}-baseline-${{ github.sha }}
          restore-keys: |
            ccache-flash-${{ matrix.target }}-baseline-

      - name: Cache - Reset ccache stats
        run: ccache -z

      - name: Build
        run: make ${{ matrix.target }}_flash-analysis

      - name: Store the ELF before the change
        run: cp ./build/**/*.elf ./before-change.elf

      - name: Cache - Stats after Baseline Build
        run: ccache -s

      - name: Cache - Save ccache (baseline)
        if: always()
        uses: actions/cache/save@v5
        with:
          path: ~/.ccache
          key: ${{ steps.cache_baseline.outputs.cache-primary-key }}

      - name: bloaty-action
        uses: PX4/bloaty-action@v1.0.0
        id: bloaty-step
        with:
          bloaty-file-args: ./with-change.elf -- ./before-change.elf
          bloaty-additional-args: -d sections,symbols -s vm -n 20
          output-to-summary: true

      - name: Generate output
        id: gen-output
        run: |
          EOF=$(dd if=/dev/urandom bs=15 count=1 status=none | base64)
          echo "${{ matrix.target }}-bloaty-output<<$EOF" >> $GITHUB_OUTPUT
          echo "${{ steps.bloaty-step.outputs.bloaty-output-encoded }}" >> $GITHUB_OUTPUT
          echo "$EOF" >> $GITHUB_OUTPUT
          echo "${{ matrix.target }}-bloaty-summary-map<<$EOF" >> $GITHUB_OUTPUT
          echo '${{ steps.bloaty-step.outputs.bloaty-summary-map }}' >> $GITHUB_OUTPUT
          echo "$EOF" >> $GITHUB_OUTPUT

  post_pr_comment:
    name: Publish Results
    runs-on: [runs-on,runner=1cpu-linux-x64,image=ubuntu24-full-x64,"run-id=${{ github.run_id }}"]
    needs: [analyze_flash]
    env:
      V5X-SUMMARY-MAP-ABS: ${{ fromJSON(fromJSON(needs.analyze_flash.outputs.px4_fmu-v5x-bloaty-summary-map).vm-absolute) }}
      V5X-SUMMARY-MAP-PERC: ${{ fromJSON(fromJSON(needs.analyze_flash.outputs.px4_fmu-v5x-bloaty-summary-map).vm-percentage) }}
      V6X-SUMMARY-MAP-ABS: ${{ fromJSON(fromJSON(needs.analyze_flash.outputs.px4_fmu-v6x-bloaty-summary-map).vm-absolute) }}
      V6X-SUMMARY-MAP-PERC: ${{ fromJSON(fromJSON(needs.analyze_flash.outputs.px4_fmu-v6x-bloaty-summary-map).vm-percentage) }}
    if: github.event.pull_request
    steps:
      - name: Find Comment
        uses: peter-evans/find-comment@v4
        id: fc
        with:
          issue-number: ${{ github.event.pull_request.number }}
          comment-author: 'github-actions[bot]'
          body-includes: '<!-- pr-comment-poster:flash-analysis -->'

      - name: Set Build Time
        id: bt
        run: |
          echo "timestamp=$(date +'%Y-%m-%dT%H:%M:%S')" >> $GITHUB_OUTPUT

      - name: Write pr-comment artifact
        # This can't be moved to the job-level conditions, as GH actions don't allow a job-level if condition to access the env.
        if: |
          steps.fc.outputs.comment-id != '' ||
          env.V5X-SUMMARY-MAP-ABS >= fromJSON(env.MIN_FLASH_POS_DIFF_FOR_COMMENT) ||
          env.V5X-SUMMARY-MAP-ABS <= fromJSON(env.MIN_FLASH_NEG_DIFF_FOR_COMMENT) ||
          env.V6X-SUMMARY-MAP-ABS >= fromJSON(env.MIN_FLASH_POS_DIFF_FOR_COMMENT) ||
          env.V6X-SUMMARY-MAP-ABS <= fromJSON(env.MIN_FLASH_NEG_DIFF_FOR_COMMENT)
        run: |
          mkdir -p pr-comment
          cat > pr-comment/manifest.json <<EOF
          {
            "pr_number": ${{ github.event.pull_request.number }},
            "marker": "<!-- pr-comment-poster:flash-analysis -->",
            "mode": "upsert"
          }
          EOF
          cat > pr-comment/body.md <<'PR_COMMENT_BODY_EOF'
          <!-- pr-comment-poster:flash-analysis -->
          ## 🔎 FLASH Analysis
          <details>
          <summary>px4_fmu-v5x [Total VM Diff: ${{ env.V5X-SUMMARY-MAP-ABS }} byte (${{ env.V5X-SUMMARY-MAP-PERC}} %)]</summary>

          ```
          ${{ needs.analyze_flash.outputs.px4_fmu-v5x-bloaty-output }}
          ```
          </details>

          <details>
          <summary>px4_fmu-v6x [Total VM Diff: ${{ env.V6X-SUMMARY-MAP-ABS }} byte (${{ env.V6X-SUMMARY-MAP-PERC }} %)]</summary>

          ```
          ${{ needs.analyze_flash.outputs.px4_fmu-v6x-bloaty-output }}
          ```
          </details>

          **Updated: _${{ steps.bt.outputs.timestamp }}_**
          PR_COMMENT_BODY_EOF

      - name: Upload pr-comment artifact
        if: |
          steps.fc.outputs.comment-id != '' ||
          env.V5X-SUMMARY-MAP-ABS >= fromJSON(env.MIN_FLASH_POS_DIFF_FOR_COMMENT) ||
          env.V5X-SUMMARY-MAP-ABS <= fromJSON(env.MIN_FLASH_NEG_DIFF_FOR_COMMENT) ||
          env.V6X-SUMMARY-MAP-ABS >= fromJSON(env.MIN_FLASH_POS_DIFF_FOR_COMMENT) ||
          env.V6X-SUMMARY-MAP-ABS <= fromJSON(env.MIN_FLASH_NEG_DIFF_FOR_COMMENT)
        uses: actions/upload-artifact@v7
        with:
          name: pr-comment
          path: pr-comment/
          retention-days: 1