name: Preview

on:
  pull_request:
    branches:
      - main

permissions:
  contents: read
  pull-requests: write

env:
  PULUMI_VERSION: "3.197.0"

jobs:
  preview:
    name: Preview Changes
    runs-on: ubuntu-latest
    # Skip preview for fork PRs and Dependabot - they don't have access to Actions secrets
    if: github.event.pull_request.head.repo.full_name == github.repository && github.actor != 'dependabot[bot]'
    environment: production
    steps:
      - name: Checkout code
        uses: actions/checkout@v4

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '22'
          cache: 'npm'

      - name: Setup Pulumi
        uses: pulumi/actions@v6
        with:
          pulumi-version: ${{ env.PULUMI_VERSION }}

      - name: Cache Pulumi plugins
        uses: actions/cache@v4
        with:
          path: ~/.pulumi/plugins
          key: pulumi-plugins-${{ hashFiles('Pulumi.yaml') }}
          restore-keys: |
            pulumi-plugins-

      - name: Install Pulumi packages
        env:
          GITHUB_TOKEN: ${{ github.token }}
        run: pulumi install

      - name: Install dependencies
        run: npm ci

      - name: Run validation
        run: npm run check

      - name: Authenticate to Google Cloud
        uses: google-github-actions/auth@v2
        with:
          credentials_json: ${{ secrets.GCP_PROD_SERVICE_ACCOUNT_KEY }}

      - name: Preview changes
        id: preview
        env:
          PULUMI_PASSPHRASE: ${{ secrets.PULUMI_PROD_PASSPHRASE }}
          GITHUB_TOKEN: ${{ secrets.PULUMI_GITHUB_TOKEN }}
          ORG_BILLING_EMAIL: ${{ secrets.ORG_BILLING_EMAIL }}
          DISCORD_BOT_TOKEN: ${{ secrets.DISCORD_BOT_TOKEN }}
          DISCORD_GUILD_ID: ${{ secrets.DISCORD_GUILD_ID }}
        run: |
          echo "$PULUMI_PASSPHRASE" > passphrase.prod.txt
          pulumi login gs://mcp-access-prod-pulumi-state

          # Build config flags for Discord if secrets are available
          CONFIG_FLAGS=""
          if [ -n "$DISCORD_GUILD_ID" ]; then
            CONFIG_FLAGS="$CONFIG_FLAGS --config discord:guildId=$DISCORD_GUILD_ID"
          fi
          if [ -n "$DISCORD_BOT_TOKEN" ]; then
            CONFIG_FLAGS="$CONFIG_FLAGS --config discord:botToken=$DISCORD_BOT_TOKEN"
          fi
          if [ -n "$ORG_BILLING_EMAIL" ]; then
            CONFIG_FLAGS="$CONFIG_FLAGS --config githubBillingEmail=$ORG_BILLING_EMAIL"
          fi

          # Run preview and capture output
          set +e
          PREVIEW_OUTPUT=$(PULUMI_CONFIG_PASSPHRASE_FILE=passphrase.prod.txt pulumi preview --stack prod --diff $CONFIG_FLAGS 2>&1)
          PREVIEW_EXIT_CODE=$?
          set -e

          # Save output for comment
          echo "exit_code=$PREVIEW_EXIT_CODE" >> $GITHUB_OUTPUT

          # Write preview to file (handles multiline)
          echo "$PREVIEW_OUTPUT" > preview_output.txt

          # Also print to logs
          echo "$PREVIEW_OUTPUT"

          # Exit with preview exit code
          exit $PREVIEW_EXIT_CODE

      - name: Comment on PR
        if: always() && steps.preview.conclusion != 'skipped'
        uses: actions/github-script@v7
        with:
          script: |
            const fs = require('fs');
            let output = '';
            try {
              output = fs.readFileSync('preview_output.txt', 'utf8');
            } catch (e) {
              output = 'Failed to read preview output';
            }

            // Truncate if too long for GitHub comment
            const maxLength = 60000;
            if (output.length > maxLength) {
              output = output.substring(0, maxLength) + '\n\n... (truncated)';
            }

            const body = `## Pulumi Preview

            <details>
            <summary>Click to expand preview output</summary>

            \`\`\`
            ${output}
            \`\`\`

            </details>
            `;

            // Find existing comment
            const { data: comments } = await github.rest.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number,
            });

            const botComment = comments.find(c =>
              c.user.type === 'Bot' && c.body.includes('## Pulumi Preview')
            );

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