name: Drift Detection

on:
  schedule:
    # Daily at 06:00 AEST (20:00 UTC previous day)
    - cron: "0 20 * * *"
  workflow_dispatch:
    inputs:
      target:
        description: "Which layer to check: all | terraform | ansible"
        required: false
        default: "all"

env:
  TF_IN_AUTOMATION: "true"

jobs:
  terraform-drift:
    name: Terraform — detect drift
    runs-on: ubuntu-latest
    if: ${{ github.event.inputs.target == 'all' || github.event.inputs.target == 'terraform' || github.event_name == 'schedule' }}
    steps:
      - uses: actions/checkout@v4

      - name: Setup Terraform
        uses: hashicorp/setup-terraform@v3
        with:
          terraform_version: "~1.9"

      - name: Terraform init + plan (proxmox)
        id: tf_proxmox
        env:
          TF_VAR_proxmox_endpoint: ${{ secrets.PROXMOX_ENDPOINT }}
          TF_VAR_proxmox_api_token_id: ${{ secrets.PROXMOX_API_TOKEN_ID }}
          TF_VAR_proxmox_api_token_secret: ${{ secrets.PROXMOX_API_TOKEN_SECRET }}
        run: |
          cd terraform/proxmox
          terraform init -input=false
          set +e
          terraform plan -detailed-exitcode -input=false -no-color -out=plan.out 2>&1 | tee plan.log
          PLAN_EXIT=${PIPESTATUS[0]}
          set -e
          if [ "$PLAN_EXIT" -eq 2 ]; then
            echo "drift=true" >> "$GITHUB_OUTPUT"
            echo "### Proxmox drift detected" >> "$GITHUB_STEP_SUMMARY"
            echo '```' >> "$GITHUB_STEP_SUMMARY"
            cat plan.log >> "$GITHUB_STEP_SUMMARY"
            echo '```' >> "$GITHUB_STEP_SUMMARY"
          elif [ "$PLAN_EXIT" -eq 0 ]; then
            echo "drift=false" >> "$GITHUB_OUTPUT"
            echo "Proxmox: no drift" >> "$GITHUB_STEP_SUMMARY"
          else
            exit $PLAN_EXIT
          fi

      - name: Terraform init + plan (dns)
        id: tf_dns
        env:
          TF_VAR_dynu_api_key: ${{ secrets.DYNU_API_KEY }}
        run: |
          cd terraform/dns
          terraform init -input=false
          set +e
          terraform plan -detailed-exitcode -input=false -no-color 2>&1 | tee plan.log
          PLAN_EXIT=${PIPESTATUS[0]}
          set -e
          if [ "$PLAN_EXIT" -eq 2 ]; then
            echo "drift=true" >> "$GITHUB_OUTPUT"
            echo "### DNS drift detected" >> "$GITHUB_STEP_SUMMARY"
            echo '```' >> "$GITHUB_STEP_SUMMARY"
            cat plan.log >> "$GITHUB_STEP_SUMMARY"
            echo '```' >> "$GITHUB_STEP_SUMMARY"
          fi

      - name: Notify on drift
        if: steps.tf_proxmox.outputs.drift == 'true' || steps.tf_dns.outputs.drift == 'true'
        env:
          GOTIFY_URL: ${{ secrets.GOTIFY_URL }}
          GOTIFY_TOKEN: ${{ secrets.GOTIFY_TOKEN }}
        run: |
          curl -s -X POST "${GOTIFY_URL}/message" \
            -H "X-Gotify-Key: ${GOTIFY_TOKEN}" \
            -F "title=Infrastructure drift detected" \
            -F "message=Terraform plan found changes. Check the CI run for details." \
            -F "priority=7"

  ansible-drift:
    name: Ansible — check mode
    runs-on: ubuntu-latest
    if: ${{ github.event.inputs.target == 'all' || github.event.inputs.target == 'ansible' || github.event_name == 'schedule' }}
    steps:
      - uses: actions/checkout@v4

      - name: Install Ansible
        run: pip install ansible

      - name: Install collections
        run: ansible-galaxy collection install -r ansible/collections/requirements.yml

      - name: Write SSH key
        env:
          ANSIBLE_SSH_KEY: ${{ secrets.ANSIBLE_SSH_KEY }}
        run: |
          install -m 600 /dev/null /tmp/ansible_key
          echo "$ANSIBLE_SSH_KEY" > /tmp/ansible_key

      - name: Ansible check mode (site.yml)
        env:
          ANSIBLE_PRIVATE_KEY_FILE: /tmp/ansible_key
          ANSIBLE_HOST_KEY_CHECKING: "False"
        run: |
          cd ansible
          ansible-playbook playbooks/site.yml --check --diff \
            -e "@inventory/group_vars/all.yml" \
            2>&1 | tee check.log
          # Summarise
          echo "### Ansible check summary" >> "$GITHUB_STEP_SUMMARY"
          grep -E '(changed|failed|ok)=' check.log | tail -20 >> "$GITHUB_STEP_SUMMARY" || true

      - name: Notify on changes detected
        if: failure()
        env:
          GOTIFY_URL: ${{ secrets.GOTIFY_URL }}
          GOTIFY_TOKEN: ${{ secrets.GOTIFY_TOKEN }}
        run: |
          curl -s -X POST "${GOTIFY_URL}/message" \
            -H "X-Gotify-Key: ${GOTIFY_TOKEN}" \
            -F "title=Ansible drift detected" \
            -F "message=ansible --check found pending changes. Check CI for details." \
            -F "priority=7"