# =============================================================================
# vex-mapping-check.yml
# Sprint: SPRINT_20260219_011 (CIAP-03)
# Description: Validates VEX documents and verifies target artifact matching
# =============================================================================
#
# This workflow validates OpenVEX or CycloneDX VEX documents against their
# schemas, asserts required fields are present and valid, and optionally
# verifies target artifact matches a known canonical_id.
#
# =============================================================================

name: VEX Mapping Check

on:
  workflow_call:
    inputs:
      vex_path:
        description: 'Path to VEX document (JSON)'
        required: true
        type: string
      vex_format:
        description: 'VEX format: openvex or cyclonedx'
        required: false
        type: string
        default: 'openvex'
      canonical_id:
        description: 'Expected canonical_id of the target artifact (optional)'
        required: false
        type: string
      schema_path:
        description: 'Path to VEX JSON schema (optional, uses bundled schemas by default)'
        required: false
        type: string

jobs:
  validate-vex:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Validate VEX schema
        id: validate
        run: |
          VEX_FILE="${{ inputs.vex_path }}"
          FORMAT="${{ inputs.vex_format }}"

          # Select schema
          if [ -n "${{ inputs.schema_path }}" ]; then
            SCHEMA="${{ inputs.schema_path }}"
          elif [ "${FORMAT}" = "openvex" ]; then
            SCHEMA="docs/schemas/openvex-0.2.0.schema.json"
          else
            SCHEMA="docs/schemas/cyclonedx-bom-1.7.schema.json"
          fi

          # Validate
          if [ -f "${SCHEMA}" ]; then
            npx ajv-cli validate -s "${SCHEMA}" -d "${VEX_FILE}" && {
              echo "Schema validation: PASS" >> $GITHUB_STEP_SUMMARY
            } || {
              echo "Schema validation: FAIL" >> $GITHUB_STEP_SUMMARY
              exit 1
            }
          else
            echo "Schema file not found: ${SCHEMA}, skipping schema validation" >> $GITHUB_STEP_SUMMARY
          fi

      - name: Assert required VEX fields
        run: |
          FORMAT="${{ inputs.vex_format }}"
          VEX_FILE="${{ inputs.vex_path }}"

          python3 -c "
          import json, sys

          with open('${VEX_FILE}') as f:
              vex = json.load(f)

          errors = []
          format_name = '${FORMAT}'

          if format_name == 'openvex':
              # OpenVEX validation
              if 'statements' not in vex:
                  errors.append('Missing required field: statements')
              else:
                  for i, stmt in enumerate(vex['statements']):
                      if 'status' not in stmt:
                          errors.append(f'Statement [{i}]: missing status')
                      elif stmt['status'] not in ('affected', 'not_affected', 'fixed', 'under_investigation'):
                          errors.append(f'Statement [{i}]: invalid status: {stmt[\"status\"]}')
                      if 'vulnerability' not in stmt:
                          errors.append(f'Statement [{i}]: missing vulnerability')
                      if 'product' not in stmt and 'products' not in stmt:
                          errors.append(f'Statement [{i}]: missing product or products')
          else:
              # CycloneDX VEX (embedded in SBOM vulnerabilities)
              vulns = vex.get('vulnerabilities', [])
              if not vulns:
                  errors.append('No vulnerabilities found in CycloneDX VEX')
              for i, vuln in enumerate(vulns):
                  analysis = vuln.get('analysis', {})
                  state = analysis.get('state')
                  if not state:
                      errors.append(f'Vulnerability [{i}] ({vuln.get(\"id\",\"?\")}): missing analysis.state')
                  elif state not in ('resolved', 'resolved_with_pedigree', 'exploitable', 'in_triage', 'false_positive', 'not_affected'):
                      errors.append(f'Vulnerability [{i}]: invalid analysis.state: {state}')

          if errors:
              print('VEX field validation FAILED:', file=sys.stderr)
              for e in errors:
                  print(f'  - {e}', file=sys.stderr)
              sys.exit(1)
          else:
              print(f'VEX field validation: PASS ({format_name})')
          "

          echo "VEX field assertions: PASS" >> $GITHUB_STEP_SUMMARY

      - name: Verify target canonical_id match
        if: inputs.canonical_id != ''
        run: |
          FORMAT="${{ inputs.vex_format }}"
          VEX_FILE="${{ inputs.vex_path }}"
          EXPECTED_ID="${{ inputs.canonical_id }}"

          python3 -c "
          import json, sys

          with open('${VEX_FILE}') as f:
              vex = json.load(f)

          expected = '${EXPECTED_ID}'
          format_name = '${FORMAT}'
          found_match = False

          if format_name == 'openvex':
              for stmt in vex.get('statements', []):
                  product = stmt.get('product', '')
                  products = stmt.get('products', [])
                  targets = [product] if product else products
                  for t in targets:
                      pid = t if isinstance(t, str) else t.get('@id', '')
                      if expected.replace('sha256:', '') in pid or pid == expected:
                          found_match = True
                          break
          else:
              # CycloneDX: check affects refs
              for vuln in vex.get('vulnerabilities', []):
                  for affects in vuln.get('affects', []):
                      ref = affects.get('ref', '')
                      if expected.replace('sha256:', '') in ref:
                          found_match = True
                          break

          if not found_match:
              print(f'WARNING: canonical_id {expected} not found in VEX targets', file=sys.stderr)
              print('This may indicate the VEX document does not apply to the expected artifact')
              # Warning only, not a hard failure
          else:
              print(f'Target canonical_id match: PASS')
          "

          echo "Target artifact check: completed" >> $GITHUB_STEP_SUMMARY