name: Modified Target Validation

on:
  pull_request_target:
    branches:
      - master
    paths:
      - "sherlock_project/resources/data.json"

jobs:
  validate-modified-targets:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      pull-requests: write
    steps:
      - name: Checkout repository
        uses: actions/checkout@v5
        with:
          # Checkout the base branch but fetch all history to avoid a second fetch call
          ref: ${{ github.base_ref }}
          fetch-depth: 0

      - name: Set up Python
        uses: actions/setup-python@v6
        with:
          python-version: "3.13"

      - name: Install Poetry
        uses: abatilo/actions-poetry@v4
        with:
          poetry-version: "latest"

      - name: Install dependencies
        run: |
          poetry install --no-interaction --with dev

      - name: Prepare JSON versions for comparison
        run: |
          # Fetch only the PR's branch head (single network call in this step)
          git fetch origin pull/${{ github.event.pull_request.number }}/head:pr

          # Find the merge-base commit between the target branch and the PR branch
          MERGE_BASE=$(git merge-base origin/${{ github.base_ref }} pr)
          echo "Comparing PR head against merge-base commit: $MERGE_BASE"

          # Safely extract the file from the PR's head and the merge-base commit
          git show pr:sherlock_project/resources/data.json > data.json.head
          git show $MERGE_BASE:sherlock_project/resources/data.json > data.json.base

          # CRITICAL FIX: Overwrite the checked-out data.json with the one from the PR
          # This ensures that pytest runs against the new, updated file.
          cp data.json.head sherlock_project/resources/data.json

      - name: Discover modified targets
        id: discover-modified
        run: |
          CHANGED=$(
            python - <<'EOF'
          import json
          import sys
          try:
              with open("data.json.base") as f: base = json.load(f)
              with open("data.json.head") as f: head = json.load(f)
          except FileNotFoundError as e:
              print(f"Error: Could not find {e.filename}", file=sys.stderr)
              sys.exit(1)
          except json.JSONDecodeError as e:
              print(f"Error: Could not decode JSON from a file - {e}", file=sys.stderr)
              sys.exit(1)

          changed = []
          for k, v in head.items():
              if k not in base or base[k] != v:
                  changed.append(k)

          print(",".join(sorted(changed)))
          EOF
          )

          # Preserve changelist
          echo -e ">>> Changed targets: \n$(echo $CHANGED | tr ',' '\n')"
          echo "changed_targets=$CHANGED" >> "$GITHUB_OUTPUT"

      - name: Validate remote manifest against local schema
        if: steps.discover-modified.outputs.changed_targets != ''
        run: |
          poetry run pytest tests/test_manifest.py::test_validate_manifest_against_local_schema

      # --- The rest of the steps below are unchanged ---

      - name: Validate modified targets
        if: steps.discover-modified.outputs.changed_targets != ''
        continue-on-error: true
        run: |
          poetry run pytest -q --tb no -rA -m validate_targets -n 20 \
            --chunked-sites "${{ steps.discover-modified.outputs.changed_targets }}" \
            --junitxml=validation_results.xml

      - name: Prepare validation summary
        if: steps.discover-modified.outputs.changed_targets != ''
        id: prepare-summary
        run: |
          summary=$(
            poetry run python devel/summarize_site_validation.py validation_results.xml || echo "Failed to generate summary of test results"
          )
          echo "$summary" > validation_summary.md

      - name: Announce validation results
        if: steps.discover-modified.outputs.changed_targets != ''
        uses: actions/github-script@v8
        with:
          script: |
            const fs = require('fs');
            const body = fs.readFileSync('validation_summary.md', 'utf8');
            await github.rest.issues.createComment({
              issue_number: context.payload.pull_request.number,
              owner: context.repo.owner,
              repo: context.repo.repo,
              body: body,
            });

      - name: This step shows as ran when no modifications are found
        if: steps.discover-modified.outputs.changed_targets == ''
        run: |
          echo "No modified targets found"