name: Deploy on push

on:
  push:
    branches: ["master"]

jobs:
  detect:
    runs-on: docker2
    outputs:
      swarm_files: ${{ steps.changes.outputs.swarm_files }}
      compose_matrix: ${{ steps.changes.outputs.compose_matrix }}
    steps:
      - name: Checkout repository (no node)
        shell: bash
        run: |
          set -euo pipefail
          git config --global --add safe.directory "$PWD"
          git fetch origin
          git checkout "$GITHUB_REF_NAME"

      - name: Detect changed YAML files
        id: changes
        shell: bash
        run: |
          set -euo pipefail

          BASE="${{ github.event.before }}"
          HEAD="${{ github.sha }}"

          # Handle edge cases (new branch / forced push etc.)
          if [ -z "${BASE}" ] || [ "${BASE}" = "0000000000000000000000000000000000000000" ]; then
            BASE="$(git rev-parse "${HEAD}~1" || true)"
          fi

          if [ -z "${BASE}" ]; then
            echo "No base commit found; deploying nothing."
            echo "swarm_files=" >> "$GITHUB_OUTPUT"
            echo 'compose_matrix={"include":[]}' >> "$GITHUB_OUTPUT"
            exit 0
          fi

          CHANGED="$(git diff --name-only "$BASE" "$HEAD" || true)"
          echo "Changed files:"
          echo "$CHANGED"

          # --------------------
          # Swarm stack YAMLs
          # --------------------
          SWARM_FILES="$(echo "$CHANGED" | grep -E '^services/swarm/stacks/.*\.ya?ml$' || true)"
          echo "Swarm stack files:"
          echo "$SWARM_FILES"
          echo "swarm_files=$(echo "$SWARM_FILES" | xargs)" >> "$GITHUB_OUTPUT"

          # --------------------
          # Compose YAMLs
          # services/compose/<host>/<service>/<file>.yml
          # --------------------
          COMPOSE_FILES="$(echo "$CHANGED" | grep -E '^services/compose/[^/]+/[^/]+/.*\.ya?ml$' || true)"
          echo "Compose files:"
          echo "$COMPOSE_FILES"

          # Build matrix items: {"host":"nas","file":"services/compose/nas/foo/comixed.yaml"}
          JSON='{"include":['
          FIRST=1
          while read -r FILE; do
            [ -z "$FILE" ] && continue
            HOST="$(echo "$FILE" | awk -F/ '{print $3}')"
            if [ $FIRST -eq 0 ]; then JSON+=','; fi
            FIRST=0
            JSON+="{\"host\":\"$HOST\",\"file\":\"$FILE\"}"
          done <<< "$COMPOSE_FILES"
          JSON+=']}'

          echo "compose_matrix=$JSON" >> "$GITHUB_OUTPUT"
          echo "Compose matrix:"
          echo "$JSON"

  deploy_swarm:
    needs: detect
    if: ${{ needs.detect.outputs.swarm_files != '' }}
    runs-on: docker2
    steps:
      - name: Checkout repository (no node)
        shell: bash
        run: |
          set -euo pipefail
          git config --global --add safe.directory "$PWD"
          git fetch origin
          git checkout "$GITHUB_REF_NAME"

      - name: Validate swarm stacks
        shell: bash
        run: |
          set -euo pipefail
          for f in ${{ needs.detect.outputs.swarm_files }}; do
            echo "Validating swarm stack file: $f"
            docker stack config -c "$f" >/dev/null
          done

      - name: Deploy swarm stacks
        shell: bash
        run: |
          set -euo pipefail
          for f in ${{ needs.detect.outputs.swarm_files }}; do
            STACK="$(basename "$f" | sed 's/\.ya\?ml$//')"
            echo "Deploying swarm stack: $STACK from $f"
            docker stack deploy -c "$f" "$STACK"
          done

  deploy_compose:
    needs: detect
    if: ${{ needs.detect.outputs.compose_matrix != '' }}
    strategy:
      fail-fast: false
      matrix: ${{ fromJSON(needs.detect.outputs.compose_matrix) }}
    runs-on: ${{ matrix.host }}
    steps:
      - name: Checkout repository (no node)
        shell: bash
        run: |
          set -euo pipefail
          git config --global --add safe.directory "$PWD"
          git fetch origin
          git checkout "$GITHUB_REF_NAME"

      - name: Validate compose file
        shell: bash
        run: |
          set -euo pipefail
          F="${{ matrix.file }}"
          echo "Validating compose file: $F"
          docker compose -f "$F" config -q

      - name: Deploy compose file
        shell: bash
        run: |
          set -euo pipefail
          F="${{ matrix.file }}"
          echo "Deploying compose file: $F"
          docker compose -f "$F" pull
          docker compose -f "$F" up -d --remove-orphans