name: Verify API Backward Compatibility

on: [pull_request]

permissions:
  contents: read
  pull-requests: write

jobs:
  api-compatibility-check:
    runs-on: ubuntu-24.04
    timeout-minutes: 15

    env:
      TZ: Asia/Kolkata

    steps:
      - name: Checkout base branch
        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v5
        with:
          repository: ${{ github.event.pull_request.base.repo.full_name }}
          ref: ${{ github.event.pull_request.base.ref }}
          fetch-depth: 0
          path: baseline

      - name: Set up JDK 21
        uses: actions/setup-java@v5
        with:
          distribution: 'zulu'
          java-version: '21'

      - name: Generate baseline spec
        working-directory: baseline
        run: ./gradlew :fineract-provider:resolve --no-daemon

      - name: Checkout PR branch
        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v5
        with:
          repository: ${{ github.event.pull_request.head.repo.full_name }}
          ref: ${{ github.event.pull_request.head.sha }}
          fetch-depth: 0
          path: current

      - name: Generate PR spec
        working-directory: current
        run: ./gradlew :fineract-provider:resolve --no-daemon

      - name: Sanitize specs
        run: |
          python3 -c "
          import json, sys

          def sanitize(path):
              with open(path) as f:
                  spec = json.load(f)
              fixed = 0
              for path_item in spec.get('paths', {}).values():
                  for op in path_item.values():
                      if not isinstance(op, dict) or 'requestBody' not in op:
                          continue
                      for media in op['requestBody'].get('content', {}).values():
                          if 'schema' not in media:
                              media['schema'] = {'type': 'object'}
                              fixed += 1
              if fixed:
                  with open(path, 'w') as f:
                      json.dump(spec, f)
              print(f'{path}: fixed {fixed} entries')

          sanitize('${GITHUB_WORKSPACE}/baseline/fineract-provider/build/resources/main/static/fineract.json')
          sanitize('${GITHUB_WORKSPACE}/current/fineract-provider/build/resources/main/static/fineract.json')
          "

      - name: Check breaking changes
        id: breaking-check
        continue-on-error: true
        working-directory: current
        run: |
          set -o pipefail
          ./gradlew :fineract-provider:checkBreakingChanges \
            -PapiBaseline="${GITHUB_WORKSPACE}/baseline/fineract-provider/build/resources/main/static/fineract.json" \
            --no-daemon --quiet 2>&1 | tail -50

      - name: Build report
        if: steps.breaking-check.outcome == 'failure'
        id: report
        run: |
          REPORT_DIR="current/fineract-provider/build/swagger-brake"

          python3 -c "
          import json, glob, os
          from collections import defaultdict

          RULE_DESC = {
              'R001': 'Standard API changed to beta',
              'R002': 'Path deleted',
              'R003': 'Request media type deleted',
              'R004': 'Request parameter deleted',
              'R005': 'Request parameter enum value deleted',
              'R006': 'Request parameter location changed',
              'R007': 'Request parameter made required',
              'R008': 'Request parameter type changed',
              'R009': 'Request attribute removed',
              'R010': 'Request type changed',
              'R011': 'Request enum value deleted',
              'R012': 'Response code deleted',
              'R013': 'Response media type deleted',
              'R014': 'Response attribute removed',
              'R015': 'Response type changed',
              'R016': 'Response enum value deleted',
              'R017': 'Request parameter constraint changed',
          }

          report_dir = '${REPORT_DIR}'
          files = sorted(glob.glob(os.path.join(report_dir, '*.json')))
          if not files:
              body = 'Breaking change detected but no report file found.'
          else:
              with open(files[0]) as f:
                  data = json.load(f)

              all_changes = []
              for items in data.get('breakingChanges', {}).values():
                  all_changes.extend(items)

              if not all_changes:
                  body = 'Breaking change detected but no details available in report.'
              else:
                  def detail(c):
                      for key in ('attributeName', 'attribute', 'name', 'mediaType', 'enumValue', 'code'):
                          v = c.get(key)
                          if v:
                              val = v.rsplit('.', 1)[-1]
                              if key in ('attributeName', 'attribute', 'name'):
                                  return val
                              return f'{key}={val}'
                      return '-'

                  groups = defaultdict(list)
                  for c in all_changes:
                      groups[(c.get('ruleCode', '?'), detail(c))].append(c)

                  lines = []
                  lines.append('| Rule | Description | Detail | Affected endpoints | Count |')
                  lines.append('|------|-------------|--------|--------------------|-------|')
                  for (rule, det), items in sorted(groups.items()):
                      desc = RULE_DESC.get(rule, '')
                      eps = sorted(set(
                          f'{c.get(\"method\",\"\")} {c.get(\"path\",\"\")}'
                          for c in items if c.get('path')
                      ))
                      ep_str = ', '.join(f'\`{e}\`' for e in eps[:5])
                      if len(eps) > 5:
                          ep_str += f' +{len(eps)-5} more'
                      lines.append(f'| {rule} | {desc} | \`{det}\` | {ep_str} | {len(items)} |')

                  lines.append('')
                  lines.append(f'**Total: {len(all_changes)} violations across {len(groups)} unique changes**')
                  body = '\n'.join(lines)

          with open(os.environ['GITHUB_OUTPUT'], 'a') as f:
              f.write('has_report=true\n')

          report_file = '${GITHUB_WORKSPACE}/breaking-changes-report.md'
          with open(report_file, 'w') as f:
              f.write('## Breaking API Changes Detected\n\n')
              f.write(body)
              f.write('\n\n> **Note:** This check is informational only and does not block the PR.\n')

          # Also write to step summary
          with open(os.environ['GITHUB_STEP_SUMMARY'], 'a') as f:
              f.write('## Breaking API Changes Detected\n\n')
              f.write(body)
              f.write('\n\n> **Note:** This check is informational only and does not block the PR.\n')
          "

      - name: Comment on PR
        if: always()
        continue-on-error: true
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          PR_NUMBER: ${{ github.event.pull_request.number }}
        run: |
          MARKER="<!-- swagger-brake-report -->"

          # Find existing comment by marker
          COMMENT_ID=$(gh api "repos/${{ github.repository }}/issues/${PR_NUMBER}/comments" \
            --jq ".[] | select(.body | contains(\"${MARKER}\")) | .id" | head -1)

          if [ "${{ steps.breaking-check.outcome }}" == "failure" ] && [ -f "${GITHUB_WORKSPACE}/breaking-changes-report.md" ]; then
            # Prepend marker to the report
            BODY="${MARKER}
          $(cat ${GITHUB_WORKSPACE}/breaking-changes-report.md)"

            if [ -n "$COMMENT_ID" ]; then
              gh api "repos/${{ github.repository }}/issues/comments/${COMMENT_ID}" \
                -X PATCH -f body="${BODY}"
            else
              gh pr comment "${PR_NUMBER}" --repo ${{ github.repository }} --body "${BODY}"
            fi
          elif [ -n "$COMMENT_ID" ]; then
            # No breaking changes anymore, delete the old comment
            gh api "repos/${{ github.repository }}/issues/comments/${COMMENT_ID}" -X DELETE
          fi

      - name: Report no breaking changes
        if: steps.breaking-check.outcome == 'success'
        run: |
          echo "## No Breaking API Changes Detected" >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY
          echo "The API contract is backward compatible." >> $GITHUB_STEP_SUMMARY

      - name: Archive breaking change report
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: api-compatibility-report
          path: current/fineract-provider/build/swagger-brake/
          retention-days: 30

      - name: Fail if breaking changes detected
        if: steps.breaking-check.outcome == 'failure'
        run: |
          echo "::error::Breaking API changes detected. See the report above for details."
          exit 1