all-contributors-auto-credit.yml

name: '🔧 Infra · 🤖 All Contributors Auto-credit on Merge'

# =============================================================================
# 🤖 Auto-credit Contributors on PR Merge
# =============================================================================
#
# When a PR is merged to dev, this workflow detects the contributor's project
# and contribution type, then applies the credit directly. This avoids relying
# on a bot-created issue comment to trigger a second workflow.
#
# Flow:
#   1. SKIP_CHECK     — bots, maintainer allowlist, already-credited PRs
#   2. DETECT_PROJECT — top-level dir of changed files → projects.json key
#                       (deterministic — no LLM)
#   3. CLASSIFY_TYPE  — LLM reads PR title + body + file list, returns types
#                       (LLM because title prefixes alone aren't reliable)
#   4. APPLY_CREDIT   — update the project .all-contributorsrc and README
#                       tables, or ask for clarification if detection fails
#
# Triggers:
#   - pull_request_target: closed (and merged == true)
#
# Why pull_request_target (not pull_request):
#   For PRs from forks, the GITHUB_TOKEN on `pull_request` is read-only — the
#   declared `pull-requests: write` in this workflow is silently ignored, and
#   the comment POST returns 403. `pull_request_target` runs in the base-repo
#   context with the full token, which is exactly what we need.
#
#   This is safe here: we never check out fork code (sparse checkout pulls
#   from dev only) and the LLM prompt only ingests title/body/file-paths as
#   data — there is no shell eval of fork-controlled input.
#
# Related:
#   - all-contributors-add.yml   — manual comment entry point using the same
#                                  contributor helper
#   - update-contributors.yml    — regenerates root config from per-project
#   - .github/workflows/contributors/auto_credit.py — project detection
#
# =============================================================================

on:
  pull_request_target:
    types: [closed]

env:
  TARGET_BRANCH: 'dev'
  # GitHub logins to skip — maintainers don't auto-credit themselves.
  # Comma-separated. Bots (login ending in '[bot]') are always skipped.
  MAINTAINERS: 'profvjreddi'
  # LLM model. Kept in sync with all-contributors-add.yml — see also that
  # workflow's LLM_MODEL env. Both should run the same model.
  LLM_MODEL: 'gemma3:12b'

jobs:
  auto-credit:
    name: Auto-credit
    if: |
      github.event.pull_request.merged == true &&
      github.event.pull_request.base.ref == 'dev'
    runs-on: ubuntu-latest

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

    steps:
      # =====================================================================
      # STEP 0: Sparse-checkout the contributors helpers
      # =====================================================================
      - name: Checkout helpers (sparse)
        uses: actions/checkout@v6
        with:
          ref: ${{ env.TARGET_BRANCH }}
          sparse-checkout: |
            .github/workflows/contributors/projects.json
            .github/workflows/contributors/projects.py
            .github/workflows/contributors/auto_credit.py
          sparse-checkout-cone-mode: false

      - name: Setup Python
        uses: actions/setup-python@v6
        with:
          python-version: '3.11'

      # =====================================================================
      # STEP 1: Skip checks (maintainer, bot, already-credited)
      # =====================================================================
      - name: Skip checks
        id: skip
        uses: actions/github-script@v9
        env:
          MAINTAINERS: ${{ env.MAINTAINERS }}
        with:
          script: |
            const author = context.payload.pull_request.user.login;
            const userType = context.payload.pull_request.user.type || '';
            const maintainers = (process.env.MAINTAINERS || '')
              .split(',').map(s => s.trim()).filter(Boolean);

            if (userType === 'Bot' || author.endsWith('[bot]')) {
              console.log(`Skipping bot: ${author}`);
              core.setOutput('skip', 'true');
              core.setOutput('reason', 'bot');
              return;
            }

            if (maintainers.includes(author)) {
              console.log(`Skipping maintainer: ${author}`);
              core.setOutput('skip', 'true');
              core.setOutput('reason', 'maintainer');
              return;
            }

            // Already credited? Look for any prior @all-contributors comment
            // mentioning this author. The add workflow is idempotent (set-union)
            // but we don't want to spam duplicate trigger comments.
            const { data: comments } = await github.rest.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number,
              per_page: 100
            });

            const triggerRe = new RegExp(
              '@all-contributors\\s+(please add\\s+)?@' + author + '\\b',
              'i'
            );
            const alreadyCredited = comments.some(c => triggerRe.test(c.body || ''));

            if (alreadyCredited) {
              console.log(`Already credited: @${author}`);
              core.setOutput('skip', 'true');
              core.setOutput('reason', 'already_credited');
              return;
            }

            core.setOutput('skip', 'false');
            core.setOutput('author', author);

      # =====================================================================
      # STEP 2: Detect project(s) from PR file paths (deterministic)
      # =====================================================================
      - name: Detect project(s)
        if: steps.skip.outputs.skip != 'true'
        id: project
        uses: actions/github-script@v9
        with:
          script: |
            const { execFileSync } = require('child_process');
            const fs = require('fs');

            const prNum = context.payload.pull_request.number;

            // Fetch all changed files (paginate)
            let files = [];
            let page = 1;
            while (true) {
              const { data } = await github.rest.pulls.listFiles({
                owner: context.repo.owner,
                repo: context.repo.repo,
                pull_number: prNum,
                per_page: 100,
                page
              });
              files = files.concat(data.map(f => f.filename));
              if (data.length < 100) break;
              page += 1;
            }

            // Cap files passed to the LLM step (large PRs would blow the prompt).
            // Project detection uses ALL files; the LLM gets a representative sample.
            const inputPath = '/tmp/auto_credit_input.json';
            fs.writeFileSync(inputPath, JSON.stringify({ files }));

            const stdout = execFileSync('python3', [
              '.github/workflows/contributors/auto_credit.py',
              inputPath
            ], { encoding: 'utf-8' });

            const detected = JSON.parse(stdout);
            console.log('Project detection:', JSON.stringify(detected));

            // Sample up to 30 files for the LLM prompt — enough to convey the
            // file mix without bloating the context. Prefer files in detected
            // project dirs so the LLM sees the substantive ones first.
            const sampledFiles = files.slice(0, 30);

            core.setOutput('projects', detected.projects.join(', '));
            core.setOutput('confidence', detected.confidence);
            core.setOutput('files_sample', sampledFiles.join('\n'));

      # =====================================================================
      # STEP 3: LLM classifies contribution type(s) from PR context
      # =====================================================================
      # The LLM looks at the PR title, body, and a sample of changed file
      # paths. Title prefixes alone (fix:/feat:/docs:) aren't reliable — a
      # "fix:" PR can be code, doc, or design depending on what was touched.
      - name: Classify contribution types with LLM
        if: |
          steps.skip.outputs.skip != 'true' &&
          steps.project.outputs.confidence == 'high'
        uses: ai-action/ollama-action@v2
        id: llm
        with:
          model: ${{ env.LLM_MODEL }}
          prompt: |
            Classify the contribution type(s) for this merged pull request.

            PR TITLE: ${{ github.event.pull_request.title }}

            PR DESCRIPTION:
            ${{ github.event.pull_request.body }}

            CHANGED FILES (sample):
            ${{ steps.project.outputs.files_sample }}

            CONTRIBUTION TYPES (pick one or more):
            - bug: Found, reported, or root-caused a bug
            - code: Wrote code, implemented features or fixes (.py/.ts/.js/.sh/etc.)
            - doc: Wrote or improved documentation, lab content, prose (.md/.qmd/.rst)
            - design: UI/UX/visual design, CSS/SCSS styling, color/layout (.css/.scss/.svg)
            - ideas: Suggested ideas, proposed features
            - review: Reviewed code or PRs
            - test: Wrote or improved tests, QA verification (test files / tests/ dirs)
            - tool: Built tools, scripts, automation, CLI utilities

            RULES:
            - Return MULTIPLE types when both apply. A bug fix that changes
              code is ["bug", "code"]. A bug fix that changes only .qmd/.md
              prose is ["bug", "doc"]. A CSS-only fix is ["bug", "design"].
            - Use the file paths as the primary evidence for what was changed.
              The PR title prefix is a hint, not a rule.
            - If the PR adds a new test file, include "test" in addition to
              whatever the test covers ("code, test" or "doc, test").

            EXAMPLES:
            Title: "fix(kits): typo in raspi lab"
            Files: kits/contents/raspi/foo.qmd
            Output: {"types": ["bug", "doc"]}

            Title: "feat(tinytorch): add tensor reshape op"
            Files: tinytorch/src/01_tensor/reshape.py, tinytorch/tests/test_reshape.py
            Output: {"types": ["code", "test"]}

            Title: "fix(scss): scope dark-mode overrides"
            Files: tinytorch/quarto/assets/styles/style.scss
            Output: {"types": ["bug", "design"]}

            Title: "docs: update install instructions"
            Files: README.md, kits/README.md
            Output: {"types": ["doc"]}

            Return ONLY a JSON object: {"types": ["<type>", ...]}.
            No explanation, no other text.

      # =====================================================================
      # STEP 4: Parse LLM output and decide whether credit can be applied
      # =====================================================================
      - name: Parse contribution credit
        id: parse
        if: steps.skip.outputs.skip != 'true'
        uses: actions/github-script@v9
        env:
          AUTHOR: ${{ steps.skip.outputs.author }}
          PROJECTS: ${{ steps.project.outputs.projects }}
          PROJECT_CONFIDENCE: ${{ steps.project.outputs.confidence }}
          LLM_RESPONSE: ${{ steps.llm.outputs.response || '' }}
        with:
          script: |
            const author = process.env.AUTHOR;
            const projects = process.env.PROJECTS;
            const projectConf = process.env.PROJECT_CONFIDENCE;
            const llmResponse = process.env.LLM_RESPONSE || '';

            const VALID_TYPES = ['bug','code','doc','design','ideas','review','test','tool'];

            // --- Parse LLM types ---
            let types = [];
            try {
              const m = llmResponse.match(/\{[\s\S]*?\}/);
              if (m) {
                const parsed = JSON.parse(m[0]);
                if (Array.isArray(parsed.types)) {
                  types = parsed.types
                    .map(t => String(t).toLowerCase().trim())
                    .filter(t => VALID_TYPES.includes(t));
                }
              }
            } catch (e) {
              console.log('LLM response parse failed:', e.message);
            }
            const typesStr = types.join(', ');
            console.log(`LLM classified types: [${typesStr}]`);

            const haveProject = projectConf === 'high' && projects;
            const haveTypes = types.length > 0;

            // --- Both detected: continue to the apply steps ---
            if (haveProject && haveTypes) {
              const projectList = projects.split(',').map(s => s.trim()).filter(Boolean);
              core.setOutput('success', 'true');
              core.setOutput('username', author);
              core.setOutput('types', JSON.stringify(types));
              core.setOutput('types_csv', typesStr);
              core.setOutput('projects', JSON.stringify(projectList));
              core.setOutput('projects_csv', projectList.join(', '));
              return;
            }

            // --- Otherwise: ask the maintainer to specify the missing piece ---
            core.setOutput('success', 'false');
            const projectPart = haveProject ? projects : '<project>';
            const typePart = haveTypes ? typesStr : '<type>';
            const missing = [];
            if (!haveProject) missing.push('project');
            if (!haveTypes) missing.push('contribution type');

            const body = [
              `Thanks @${author} for the contribution! 🎉`,
              ``,
              `I couldn't auto-detect the ${missing.join(' and ')} for this PR. To credit @${author}, reply with:`,
              ``,
              '```',
              `@all-contributors please add @${author} for ${typePart} in ${projectPart}`,
              '```',
              ``,
              `**Types:** bug, code, doc, design, ideas, review, test, tool _(multi: \`bug, code\`)_`,
              `**Projects:** book, tinytorch, kits, labs, mlsysim, staffml, slides, instructors, periodictable _(multi: \`kits, book\`)_`,
            ].join('\n');

            await github.rest.issues.createComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number,
              body
            });
            console.log(`Posted clarification (missing: ${missing.join(', ')})`);

      # =====================================================================
      # STEP 5: Checkout full repo, apply credit, and push generated files
      # =====================================================================
      - name: Disable lingering sparse-checkout state
        if: steps.parse.outputs.success == 'true'
        shell: bash
        run: |
          git sparse-checkout disable 2>/dev/null || true
          rm -f .git/info/sparse-checkout

      - name: Checkout repository (full)
        if: steps.parse.outputs.success == 'true'
        uses: actions/checkout@v6
        with:
          ref: ${{ env.TARGET_BRANCH }}
          fetch-depth: 0

      - name: Apply contributor credit
        id: apply
        if: steps.parse.outputs.success == 'true'
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          python3 .github/workflows/contributors/add_contributor.py \
            --username '${{ steps.parse.outputs.username }}' \
            --types '${{ steps.parse.outputs.types }}' \
            --projects '${{ steps.parse.outputs.projects }}'

      - name: Configure Git
        if: steps.parse.outputs.success == 'true'
        run: |
          git config --global user.name "github-actions[bot]"
          git config --global user.email "github-actions[bot]@users.noreply.github.com"

      - name: Commit and push changes
        id: commit
        if: steps.parse.outputs.success == 'true'
        run: |
          set -euo pipefail
          UPDATED_DIRS='${{ steps.apply.outputs.updated_dirs }}'
          USERNAME="${{ steps.parse.outputs.username }}"
          TYPES="${{ steps.parse.outputs.types_csv }}"
          PROJECTS_LIST="${{ steps.parse.outputs.projects_csv }}"

          for dir in $(echo "$UPDATED_DIRS" | python3 -c "import sys,json; print(' '.join(json.load(sys.stdin)))"); do
            git add "${dir}/.all-contributorsrc" "${dir}/README.md" 2>/dev/null || true
          done
          git add README.md 2>/dev/null || true

          if git diff --staged --quiet; then
            echo "No contributor changes to commit"
            echo "committed=false" >> "$GITHUB_OUTPUT"
          else
            git commit -m "docs: add @${USERNAME} as contributor for ${TYPES} (${PROJECTS_LIST})"
            git pull --rebase origin ${{ env.TARGET_BRANCH }}
            git push origin ${{ env.TARGET_BRANCH }}
            echo "committed=true" >> "$GITHUB_OUTPUT"
          fi

      # =====================================================================
      # STEP 6: Post confirmation without using a workflow-trigger command
      # =====================================================================
      - name: Post auto-credit confirmation
        if: steps.parse.outputs.success == 'true'
        uses: actions/github-script@v9
        with:
          script: |
            const username = '${{ steps.parse.outputs.username }}';
            const types = '${{ steps.parse.outputs.types_csv }}';
            const projects = '${{ steps.parse.outputs.projects_csv }}';
            const committed = '${{ steps.commit.outputs.committed }}' === 'true';

            const body = [
              `Thanks @${username}! 🎉`,
              ``,
              committed
                ? `I added @${username} to **${projects}** for: ${types}.`
                : `@${username} was already credited in **${projects}** for: ${types}.`,
              ``,
              `The contributor tables are now handled directly by this workflow; no follow-up command is needed.`
            ].join('\n');

            await github.rest.issues.createComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number,
              body
            });