name: "PR Tasks Completed Check"
on:
  pull_request:
    types: opened

jobs:
  task-check:
    runs-on: ubuntu-latest
    permissions:
      issues: write
      pull-requests: write
    steps:
      # github.event.repository.name only contains 'GildedRose-Refactoring-Kata' (no owner)!
      # we could check owner and name if: github.repository == 'emilybache/GildedRose-Refactoring-Kata'
      # but checking owner is enough/better/more stable
      # Only run from the base repository
      - name: Skip if not main repo or fork testing
        if: ${{ github.repository_owner != 'emilybache' && env.PR_TESTING != 'true' }}
        run: |
          echo "Skipping workflow on fork without PR_TESTING"
          exit 0
      - uses: actions/checkout@v3

      - name: Check PR template via diff
        id: check
        uses: actions/github-script@v7
        with:
          script: |
            const fs = require('fs');
            const path = require('path');
            const diff = require('diff');

            const prBody = context.payload.pull_request.body || "";

            // Read the PR template
            const templatePath = path.join(process.env.GITHUB_WORKSPACE, ".github/pull_request_template.md");
            const template = fs.readFileSync(templatePath, "utf8");

            // Transform unchecked boxes to checked boxes
            const transformedTemplate = template.replace(/- \[ \]/g, '- [x]');

            const normalize = text => text.replace(/\r\n/g, '\n').trim();
            const bodyNormalized = normalize(prBody);
            const templateNormalized = normalize(transformedTemplate);

            // Compute line diff
            const changes = diff.diffLines(templateNormalized, bodyNormalized);

            // Filter out lines that are identical
            const diffLines = changes.filter(c => c.added || c.removed).map(c => c.value.trim()).filter(Boolean);

            // Check if diff is empty or only contains the last line of the template
            const lastLine = normalize(transformedTemplate.split('\n').slice(-1)[0]);
            const isSuspect = diffLines.length === 0 || (diffLines.length === 1 && diffLines[0] === lastLine);

            return { is_suspect: isSuspect };

      - name: Add solution label
        if: steps.check.outputs.is_suspect == 'true'
        uses: actions-ecosystem/action-add-labels@v1
        with:
          labels: solution