name: Website Monitor

on:
  schedule:
    - cron: "*/10 * * * *"
  workflow_dispatch:

permissions:
  contents: write

jobs:
  monitor:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Check website
        id: check
        env:
          WEBSITE_URL: ${{ secrets.WEBSITE_URL }}
        run: |
          set +e

          # Follow redirects and fail on HTTP errors.
          curl \
            --silent \
            --show-error \
            --location \
            --fail \
            --max-time 30 \
            --connect-timeout 10 \
            "$WEBSITE_URL"

          EXIT_CODE=$?

          if [ "$EXIT_CODE" -eq 0 ]; then
            echo "status=up" >> "$GITHUB_OUTPUT"
          else
            echo "status=down" >> "$GITHUB_OUTPUT"
          fi

      - name: Handle website status
        env:
          WEBSITE_STATUS: ${{ steps.check.outputs.status }}
          WEBSITE_URL: ${{ secrets.WEBSITE_URL }}
          NTFY_URL: ${{ secrets.NTFY_URL }}
          NTFY_TOKEN: ${{ secrets.NTFY_TOKEN }}
        run: |
          if [ -f "./websiteIsDown" ]; then
            # Website was previously detected as down.
            if [ "$WEBSITE_STATUS" = "up" ]; then
              echo "Website is back up."

              rm ./websiteIsDown

              git config user.name "github-actions[bot]"
              git config user.email "github-actions[bot]@users.noreply.github.com"

              git add ./websiteIsDown
              git commit -m "chore: website is back up"
              git push

              curl \
                --fail \
                --silent \
                --show-error \
                -X POST \
                -H "Authorization: Bearer $NTFY_TOKEN" \
                -d "Website is back up: $WEBSITE_URL" \
                "$NTFY_URL"
            else
              echo "Website is still down. No notification."
            fi

          else
            # Website was not previously detected as down.
            if [ "$WEBSITE_STATUS" = "down" ]; then
              echo "Website is down."

              touch ./websiteIsDown

              git config user.name "github-actions[bot]"
              git config user.email "github-actions[bot]@users.noreply.github.com"

              git add ./websiteIsDown
              git commit -m "chore: website is down"
              git push

              curl \
                --fail \
                --silent \
                --show-error \
                -X POST \
                -H "Authorization: Bearer $NTFY_TOKEN" \
                -d "Website is down: $WEBSITE_URL" \
                "$NTFY_URL"
            else
              echo "Website is up. Nothing to do."
            fi
          fi