name: Signals DSSE Sign & Evidence Locker

on:
  workflow_dispatch:
    inputs:
      out_dir:
        description: "Output directory for signed artifacts"
        required: false
        default: "evidence-locker/signals/2025-12-01"
      allow_dev_key:
        description: "Allow dev key for testing (1=yes, 0=no)"
        required: false
        default: "0"
  push:
    branches: [main]
    paths:
      - 'docs/modules/signals/decay/**'
      - 'docs/modules/signals/unknowns/**'
      - 'docs/modules/signals/heuristics/**'
      - 'docs/modules/signals/SHA256SUMS'
      - 'tools/cosign/sign-signals.sh'

jobs:
  sign-signals-artifacts:
    runs-on: ubuntu-22.04
    env:
      COSIGN_PRIVATE_KEY_B64: ${{ secrets.COSIGN_PRIVATE_KEY_B64 }}
      COSIGN_PASSWORD: ${{ secrets.COSIGN_PASSWORD }}
      OUT_DIR: ${{ github.event.inputs.out_dir || 'evidence-locker/signals/2025-12-01' }}
      COSIGN_ALLOW_DEV_KEY: ${{ github.event.inputs.allow_dev_key || '0' }}
    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Install cosign
        uses: sigstore/cosign-installer@v3
        with:
          cosign-release: 'v2.2.4'

      - name: Verify artifacts exist
        run: |
          cd docs/modules/signals
          sha256sum -c SHA256SUMS
          echo "All artifacts verified against SHA256SUMS"

      - name: Check signing key availability
        id: check-key
        run: |
          if [[ -n "$COSIGN_PRIVATE_KEY_B64" ]]; then
            echo "key_source=ci_secret" >> "$GITHUB_OUTPUT"
            echo "Signing key available via CI secret"
          elif [[ "$COSIGN_ALLOW_DEV_KEY" == "1" ]]; then
            echo "key_source=dev_key" >> "$GITHUB_OUTPUT"
            echo "[warn] Using development key - NOT for production Evidence Locker"
          else
            echo "key_source=none" >> "$GITHUB_OUTPUT"
            echo "::error::No signing key available. Set COSIGN_PRIVATE_KEY_B64 secret or enable dev key."
            exit 1
          fi

      - name: Sign signals artifacts
        run: |
          chmod +x tools/cosign/sign-signals.sh
          OUT_DIR="${OUT_DIR}" tools/cosign/sign-signals.sh

      - name: Verify signatures
        run: |
          cd "$OUT_DIR"
          # List generated artifacts
          echo "=== Generated Artifacts ==="
          ls -la
          echo ""
          echo "=== SHA256SUMS ==="
          cat SHA256SUMS

      - name: Upload signed artifacts
        uses: actions/upload-artifact@v4
        with:
          name: signals-dsse-signed-${{ github.run_number }}
          path: |
            ${{ env.OUT_DIR }}/*.sigstore.json
            ${{ env.OUT_DIR }}/*.dsse
            ${{ env.OUT_DIR }}/SHA256SUMS
          if-no-files-found: error
          retention-days: 90

      - name: Push to Evidence Locker
        if: ${{ secrets.CI_EVIDENCE_LOCKER_TOKEN != '' && env.EVIDENCE_LOCKER_URL != '' }}
        env:
          TOKEN: ${{ secrets.CI_EVIDENCE_LOCKER_TOKEN }}
          URL: ${{ env.EVIDENCE_LOCKER_URL }}
        run: |
          tar -cf /tmp/signals-dsse.tar -C "$OUT_DIR" .
          curl -f -X PUT "$URL/signals/dsse/$(date -u +%Y-%m-%d)/signals-dsse.tar" \
            -H "Authorization: Bearer $TOKEN" \
            --data-binary @/tmp/signals-dsse.tar
          echo "Pushed to Evidence Locker"

      - name: Evidence Locker skip notice
        if: ${{ secrets.CI_EVIDENCE_LOCKER_TOKEN == '' || env.EVIDENCE_LOCKER_URL == '' }}
        run: |
          echo "::notice::Evidence Locker push skipped (CI_EVIDENCE_LOCKER_TOKEN or EVIDENCE_LOCKER_URL not set)"
          echo "Artifacts available as workflow artifact for manual ingestion"

  verify-signatures:
    runs-on: ubuntu-22.04
    needs: sign-signals-artifacts
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Download signed artifacts
        uses: actions/download-artifact@v4
        with:
          name: signals-dsse-signed-${{ github.run_number }}
          path: signed-artifacts/

      - name: Install cosign
        uses: sigstore/cosign-installer@v3
        with:
          cosign-release: 'v2.2.4'

      - name: Verify decay config signature
        run: |
          if [[ -f signed-artifacts/confidence_decay_config.sigstore.json ]]; then
            cosign verify-blob \
              --key tools/cosign/cosign.dev.pub \
              --bundle signed-artifacts/confidence_decay_config.sigstore.json \
              docs/modules/signals/decay/confidence_decay_config.yaml \
              && echo "✓ decay config signature verified" \
              || echo "::warning::Signature verification failed (may need production public key)"
          fi

      - name: Verify unknowns manifest signature
        run: |
          if [[ -f signed-artifacts/unknowns_scoring_manifest.sigstore.json ]]; then
            cosign verify-blob \
              --key tools/cosign/cosign.dev.pub \
              --bundle signed-artifacts/unknowns_scoring_manifest.sigstore.json \
              docs/modules/signals/unknowns/unknowns_scoring_manifest.json \
              && echo "✓ unknowns manifest signature verified" \
              || echo "::warning::Signature verification failed (may need production public key)"
          fi

      - name: Verify heuristics catalog signature
        run: |
          if [[ -f signed-artifacts/heuristics_catalog.sigstore.json ]]; then
            cosign verify-blob \
              --key tools/cosign/cosign.dev.pub \
              --bundle signed-artifacts/heuristics_catalog.sigstore.json \
              docs/modules/signals/heuristics/heuristics.catalog.json \
              && echo "✓ heuristics catalog signature verified" \
              || echo "::warning::Signature verification failed (may need production public key)"
          fi

      - name: Summary
        run: |
          echo "## Signals DSSE Signing Summary" >> "$GITHUB_STEP_SUMMARY"
          echo "" >> "$GITHUB_STEP_SUMMARY"
          echo "| Artifact | Status |" >> "$GITHUB_STEP_SUMMARY"
          echo "|----------|--------|" >> "$GITHUB_STEP_SUMMARY"
          for f in signed-artifacts/*.sigstore.json signed-artifacts/*.dsse; do
            [[ -f "$f" ]] && echo "| $(basename $f) | ✓ Signed |" >> "$GITHUB_STEP_SUMMARY"
          done
          echo "" >> "$GITHUB_STEP_SUMMARY"
          echo "Run ID: ${{ github.run_number }}" >> "$GITHUB_STEP_SUMMARY"