name: Deploy (on merge)

on:
  push:
    branches:
      - main
    paths-ignore:
      - "terraform/**"

# Requires these repository secrets:
#   TAILSCALE_CLIENT_ID  — Tailscale OAuth client ID (federated identity)
#   TAILSCALE_AUDIENCE   — Tailscale federated identity audience
#   SSH_PRIVATE_KEY      — SSH key authorized on target hosts
#   AGE_SECRET_KEY       — age private key for SOPS decryption

jobs:
  discover:
    name: Discover hosts
    runs-on: ubuntu-latest
    outputs:
      hosts: ${{ steps.discover.outputs.hosts }}
    steps:
      - uses: actions/checkout@v4

      - name: Read hosts from inventory
        id: discover
        run: |
          HOSTS=$(grep 'ansible_host=' ansible/inventory/hosts.ini | awk '{print $1}' | jq -R . | jq -cs .)
          echo "hosts=$HOSTS" >> "$GITHUB_OUTPUT"

  deploy:
    needs: discover
    name: Deploy → ${{ matrix.host }}
    runs-on: ubuntu-latest
    environment: production
    permissions:
      id-token: write
    strategy:
      matrix:
        host: ${{ fromJson(needs.discover.outputs.hosts) }}
      fail-fast: false
    steps:
      - uses: actions/checkout@v6

      - name: Set up Tailscale
        uses: tailscale/github-action@v4
        with:
          oauth-client-id: ${{ secrets.TAILSCALE_CLIENT_ID }}
          audience: ${{ secrets.TAILSCALE_AUDIENCE }}
          tags: tag:ci

      - name: Set up SSH key
        run: |
          mkdir -p ~/.ssh
          echo "${{ secrets.SSH_PRIVATE_KEY }}" > ~/.ssh/id_ed25519
          chmod 600 ~/.ssh/id_ed25519
          IPS=$(grep 'ansible_host=' ansible/inventory/hosts.ini | awk -F'ansible_host=' '{print $2}' | awk '{print $1}' | tr '\n' ' ')
          ssh-keyscan -H $IPS >> ~/.ssh/known_hosts 2>/dev/null || true

      - name: Install tools
        run: |
          pip install ansible
          wget -qO /tmp/sops.deb https://github.com/getsops/sops/releases/download/v3.9.4/sops_3.9.4_amd64.deb
          sudo dpkg -i /tmp/sops.deb

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

      - name: Decrypt secrets
        env:
          SOPS_AGE_KEY: ${{ secrets.AGE_SECRET_KEY }}
        run: |
          find . -name '*.enc.yml' -o -name '*.enc.yaml' -o -name '*.enc.env' | while read f; do
            out="${f/.enc/}"
            sops -d "$f" > "$out"
          done

      - name: Run playbook
        working-directory: ansible/
        env:
          ANSIBLE_HOST_KEY_CHECKING: "false"
        run: ansible-playbook deploy.yml --limit "${{ matrix.host }}"