name: pkg.pr.new
on:
  pull_request_target:
    types: [opened, synchronize]
  push:
    branches: [main]

permissions: {}

jobs:
  # This job determines the environment to use for the build job. It ensures that:
  # - For pushes to main, we use the "Publish pkg.pr.new (maintainers)" environment.
  # - For PRs from the same repository, we also use the "Publish pkg.pr.new (maintainers)" environment, since these are trusted.
  # - For PRs from forks, we use the "Publish pkg.pr.new (external contributors)" environment, which requires manual approval by a maintainer before the build job can run.
  #   This protects us from running untrusted code while still allowing external contributors to use pkg.pr.new.
  resolve-env:
    runs-on: ubuntu-latest
    outputs:
      environment: ${{ steps.resolve.outputs.environment }}
    steps:
      - name: Determine environment
        id: resolve
        run: |
          if [[ "${{ github.event_name }}" == "push" ]]; then
            echo "environment=Publish pkg.pr.new (maintainers)" >> "$GITHUB_OUTPUT"
          elif [[ "${{ github.event.pull_request.head.repo.full_name }}" == "${{ github.repository }}" ]]; then
            echo "environment=Publish pkg.pr.new (maintainers)" >> "$GITHUB_OUTPUT"
          else
            echo "environment=Publish pkg.pr.new (external contributors)" >> "$GITHUB_OUTPUT"
          fi

  build:
    needs: resolve-env
    runs-on: ubuntu-latest
    # This is the line that ensures forks require manual approval before running the build job
    environment: ${{ needs.resolve-env.outputs.environment }}

    # No permissions — this job runs user-controlled code
    permissions: {}

    steps:
      - uses: actions/checkout@v6
        with:
          # For pull_request_target, we must explicitly check out the PR head.
          # This is safe because the environment gate above has already fired —
          # an org member has approved this specific commit for external PRs.
          ref: ${{ github.event.pull_request.head.sha || github.sha }}

      - uses: pnpm/action-setup@v4
      - uses: actions/setup-node@v6
        with:
          node-version: 22.x
          cache: pnpm

      - name: Install dependencies
        run: pnpm install --frozen-lockfile

      - name: Build
        run: pnpm build

      - run: pnpx pkg-pr-new publish --comment=off --json output.json --compact --no-template './packages/svelte'

      - name: Upload output
        uses: actions/upload-artifact@v4
        with:
          name: output
          path: ./output.json

  # Sanitizes the untrusted output from the build job before it's consumed by
  # jobs with elevated permissions. This ensures that only known package names
  # and valid SHA prefixes make it through.
  sanitize:
    needs: build
    runs-on: ubuntu-latest

    permissions: {}

    steps:
      - name: Download artifact
        uses: actions/download-artifact@v7
        with:
          name: output

      - name: Sanitize output
        uses: actions/github-script@v8
        with:
          script: |
            const fs = require('fs');
            const raw = JSON.parse(fs.readFileSync('output.json', 'utf8'));

            const ALLOWED_PACKAGES = new Set(['svelte']);
            const SHA_PATTERN = /^[0-9a-f]{7}$/;

            const packages = (raw.packages || [])
              .filter(p => {
                if (!ALLOWED_PACKAGES.has(p.name)) {
                  console.log(`Skipping unexpected package: ${JSON.stringify(p.name)}`);
                  return false;
                }
                const sha = p.url?.replace(/^.+@([^@]+)$/, '$1');
                if (!sha || !SHA_PATTERN.test(sha)) {
                  console.log(`Skipping package with invalid SHA: ${JSON.stringify(p.url)}`);
                  return false;
                }
                return true;
              })
              .map(p => ({
                name: p.name,
                sha: p.url.replace(/^.+@([^@]+)$/, '$1'),
              }));

            fs.writeFileSync('sanitized-output.json', JSON.stringify({ packages }), 'utf8');

      - name: Upload sanitized output
        uses: actions/upload-artifact@v4
        with:
          name: sanitized-output
          path: ./sanitized-output.json

  comment:
    needs: sanitize
    if: github.event_name == 'pull_request_target'
    runs-on: ubuntu-latest

    permissions:
      pull-requests: write

    steps:
      - name: Download sanitized artifact
        uses: actions/download-artifact@v7
        with:
          name: sanitized-output

      - name: Post or update comment
        uses: actions/github-script@v8
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const fs = require('fs');
            const { packages } = JSON.parse(fs.readFileSync('sanitized-output.json', 'utf8'));

            if (packages.length === 0) {
              console.log('No valid packages found. Skipping comment.');
              return;
            }

            // Issue number from trusted event context, never from the artifact
            const issue_number = context.issue.number;

            const bot_comment_identifier = `<!-- pkg.pr.new comment -->`;

            const body = `${bot_comment_identifier}

            [Playground](https://svelte.dev/playground?version=pr-${issue_number})

            \`\`\`
            ${packages.map(p => `pnpm add https://pkg.pr.new/${p.name}@${issue_number}`).join('\n')}
            \`\`\`
            `;

            const comments = await github.rest.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number,
            });
            const existing = comments.data.find(c => c.body.includes(bot_comment_identifier));

            if (existing) {
              await github.rest.issues.updateComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                comment_id: existing.id,
                body,
              });
            } else {
              await github.rest.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number,
                body,
              });
            }

  log:
    needs: sanitize
    if: github.event_name == 'push'
    runs-on: ubuntu-latest

    permissions: {}

    steps:
      - name: Download sanitized artifact
        uses: actions/download-artifact@v7
        with:
          name: sanitized-output

      - name: Log publish info
        uses: actions/github-script@v8
        with:
          script: |
            const fs = require('fs');
            const { packages } = JSON.parse(fs.readFileSync('sanitized-output.json', 'utf8'));

            if (packages.length === 0) {
              console.log('No valid packages found.');
              return;
            }

            console.log('\n' + '='.repeat(50));
            console.log('Publish Information');
            console.log('='.repeat(50));
            for (const p of packages) {
              console.log(`${p.name} - pnpm add https://pkg.pr.new/${p.name}@${p.sha}`);
            }
            const svelte = packages.find(p => p.name === 'svelte');
            if (svelte) {
              console.log(`\nPlayground: https://svelte.dev/playground?version=commit-${svelte.sha}`);
            }
            console.log('='.repeat(50));