name: Nightly build & deploy

# Rebuilds the site (refreshing the Discord embed's "today" snapshot), uploads
# the built dist/ to the CMU AFS space over SFTP, then triggers CMU's publish
# CGI so the files go live.
on:
  # Midnight run. NOTE: cron here is UTC. 00:00 UTC is 8pm/7pm Eastern.
  # For midnight *Eastern*, use "0 5 * * *" (EST) or "0 4 * * *" (EDT).
  schedule:
    - cron: "0 5 * * *"
  # Allow manual runs from the Gitea Actions UI.
  workflow_dispatch: {}
  # Also deploy on pushes to the main branch.
  push:
    branches:
      - main

jobs:
  build-and-deploy:
    runs-on: ubuntu-latest

    env:
      # Absolute base URL where the site is served. Used to build the absolute
      # icon URL embedded for Discord. Set SITE_BASE_URL as a secret/variable,
      # e.g. https://www.andrew.cmu.edu/user/<username>
      SITE_BASE_URL: ${{ secrets.SITE_BASE_URL }}

    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Set up Node
        uses: actions/setup-node@v4
        with:
          node-version: "20"
          cache: "npm"

      - name: Install dependencies
        run: npm ci

      - name: Build (injects today's Red-plan embed)
        env:
          # Discord fetches this absolute URL for the embed thumbnail.
          SITE_ICON_URL: "${{ secrets.SITE_BASE_URL }}/apple-touch-icon.png"
        run: npm run build

      - name: Install lftp
        run: |
          sudo apt-get update
          sudo apt-get install -y lftp

      - name: Upload dist/ via SFTP
        env:
          SFTP_HOST: ${{ secrets.SFTP_HOST }}
          SFTP_PORT: ${{ secrets.SFTP_PORT }}
          SFTP_USERNAME: ${{ secrets.SFTP_USERNAME }}
          SFTP_PASSWORD: ${{ secrets.SFTP_PASSWORD }}
          SFTP_REMOTE_PATH: ${{ secrets.SFTP_REMOTE_PATH }}
        run: |
          set -euo pipefail
          PORT="${SFTP_PORT:-22}"

          # Mirror the local dist/ into the remote path.
          #   -R              : reverse mirror (local -> remote)
          #   --delete        : remove remote files no longer present locally
          #   --verbose       : log transferred files
          # Host key checking is disabled because CMU's key is not pre-seeded on
          # the runner; the connection is still encrypted.
          lftp -c "
            set sftp:auto-confirm yes;
            set net:max-retries 3;
            set net:timeout 20;
            open -u '${SFTP_USERNAME}','${SFTP_PASSWORD}' sftp://${SFTP_HOST}:${PORT};
            mirror -R --delete --verbose ./dist/ '${SFTP_REMOTE_PATH}';
            bye
          "

      - name: Trigger CMU publish
        env:
          SFTP_USERNAME: ${{ secrets.SFTP_USERNAME }}
        run: |
          set -euo pipefail
          # FLAG=0 publishes; NAME is the AFS username (same as the SFTP user).
          # --fail makes curl exit non-zero on HTTP errors so the job fails
          # loudly if publishing is rejected.
          curl --fail --show-error --silent \
            "https://www.andrew.cmu.edu/cgi-bin/publish?FLAG=0&NAME=${SFTP_USERNAME}"
          echo "Publish request sent for ${SFTP_USERNAME}."