name: Harbor Build Once → Deploy Many (Compose)

on:
  workflow_call:
    inputs:
      harbor_registry:
        type: string
        default: harbor.hcmc.online
      harbor_project:
        type: string
        default: ci
      image_repo:
        type: string
        required: true

      context:
        type: string
        default: .
      dockerfile:
        type: string
        default: Dockerfile
      platforms:
        type: string
        default: linux/amd64,linux/arm64

      # IMPORTANT CHANGE
      deploy_runners_json:
        description: 'JSON array of runner labels'
        type: string
        required: true

      compose_workdir:
        type: string
        default: .
      compose_args:
        type: string
        default: up -d --pull always --remove-orphans

    secrets:
      HARBOR_PUSH_USERNAME: { required: true }
      HARBOR_PUSH_PASSWORD: { required: true }
      HARBOR_PULL_USERNAME: { required: true }
      HARBOR_PULL_PASSWORD: { required: true }

jobs:

# ==========================================================
# BUILD ONCE (single powerful runner)
# ==========================================================
  build_and_push:
    name:  Build & Push Image
    runs-on: devsg-atlantic

    outputs:
      image_repo: ${{ steps.meta.outputs.image_repo }}
      image_digest: ${{ steps.build.outputs.digest }}
      image_ref: ${{ steps.meta.outputs.image_repo }}@${{ steps.build.outputs.digest }}

    steps:
      - uses: actions/checkout@v4
      - uses: docker/setup-buildx-action@v3

      - name: Compute image metadata
        id: meta
        shell: bash
        run: |
          set -euo pipefail
          IMAGE="${{ inputs.harbor_registry }}/${{ inputs.harbor_project }}/${{ inputs.image_repo }}"
          SHORT_SHA=$(echo "${{ github.sha }}" | cut -c1-12)
          BRANCH="${{ github.ref_name }}"

          echo "image_repo=$IMAGE" >> $GITHUB_OUTPUT
          echo "sha_tag=sha-$SHORT_SHA" >> $GITHUB_OUTPUT
          echo "branch_tag=$BRANCH" >> $GITHUB_OUTPUT

      - name: Login Harbor (push)
        uses: docker/login-action@v3
        with:
          registry: ${{ inputs.harbor_registry }}
          username: ${{ secrets.HARBOR_PUSH_USERNAME }}
          password: ${{ secrets.HARBOR_PUSH_PASSWORD }}

      # Cached multi-platform build
      - name: Build & Push Image
        id: build
        uses: docker/build-push-action@v6
        with:
          context: ${{ inputs.context }}
          file: ${{ inputs.dockerfile }}
          platforms: ${{ inputs.platforms }}
          push: true

          tags: |
            ${{ steps.meta.outputs.image_repo }}:${{ steps.meta.outputs.sha_tag }}
            ${{ steps.meta.outputs.image_repo }}:${{ steps.meta.outputs.branch_tag }}
            ${{ steps.meta.outputs.image_repo }}:latest

          cache-from: type=registry,ref=${{ steps.meta.outputs.image_repo }}:buildcache
          cache-to: type=registry,ref=${{ steps.meta.outputs.image_repo }}:buildcache,mode=max


# ==========================================================
# DEPLOY MANY (fan-out runners)
# ==========================================================
  deploy:
    name:  Deploy to Fleet
    needs: build_and_push

    strategy:
      fail-fast: false
      matrix:
        runner: ${{ fromJSON(inputs.deploy_runners_json) }}

    runs-on: ${{ matrix.runner }}

    steps:
      - uses: actions/checkout@v4

      - name: Login Harbor (pull)
        uses: docker/login-action@v3
        with:
          registry: ${{ inputs.harbor_registry }}
          username: ${{ secrets.HARBOR_PULL_USERNAME }}
          password: ${{ secrets.HARBOR_PULL_PASSWORD }}

      - name: Show image
        run: echo "Deploying ${{ needs.build_and_push.outputs.image_ref }}"

      # Linux/macOS
      - name: Compose Up (Unix)
        if: runner.os != 'Windows'
        shell: bash
        working-directory: ${{ inputs.compose_workdir }}
        env:
          DOCKER_IMAGE: ${{ needs.build_and_push.outputs.image_ref }}
        run: |
          set -euo pipefail
          docker compose ${{ inputs.compose_args }}

      # Windows runners support
      - name: Compose Up (Windows)
        if: runner.os == 'Windows'
        shell: pwsh
        working-directory: ${{ inputs.compose_workdir }}
        env:
          DOCKER_IMAGE: ${{ needs.build_and_push.outputs.image_ref }}
        run: |
          docker compose ${{ inputs.compose_args }}