name: Build & Publish Images

on:
  push:
    branches: [ main, dev ]
    tags:
      - '*'
  workflow_dispatch:

env:
  REGISTRY: ghcr.io
  IMAGE_BACKEND: papercrate-dms/papercrate-backend
  IMAGE_FRONTEND: papercrate-dms/papercrate-frontend

jobs:
  build:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        component: [backend, frontend]
        platform: [linux/amd64, linux/arm64]

    permissions:
      contents: read
      packages: write
      id-token: write

    steps:
      - name: Check out repository
        uses: actions/checkout@v4

      - name: Set component metadata
        run: |
          if [ "${{ matrix.component }}" = "backend" ]; then
            echo "COMPONENT_CONTEXT=./backend" >> "$GITHUB_ENV"
            echo "COMPONENT_IMAGE=${{ env.IMAGE_BACKEND }}" >> "$GITHUB_ENV"
          else
            echo "COMPONENT_CONTEXT=./frontend" >> "$GITHUB_ENV"
            echo "COMPONENT_IMAGE=${{ env.IMAGE_FRONTEND }}" >> "$GITHUB_ENV"
          fi
          echo "COMPONENT_NAME=${{ matrix.component }}" >> "$GITHUB_ENV"

      - name: Compute tags
        env:
          GITHUB_SHA: ${{ github.sha }}
          GITHUB_REF: ${{ github.ref }}
          REGISTRY: ${{ env.REGISTRY }}
          PLATFORM: ${{ matrix.platform }}
        run: |
          ARCH=${PLATFORM#*/}
          TAGS=("${GITHUB_SHA::7}")

          BRANCH=${GITHUB_REF##*/}
          if [ "$BRANCH" = "dev" ]; then
            TAGS+=("${GITHUB_SHA::7}-dev")
          fi

          if [[ "$GITHUB_REF" == refs/tags/* ]]; then
            TAGS+=("${GITHUB_REF#refs/tags/}")
          fi

          UNIQUE=()
          for tag in "${TAGS[@]}"; do
            [[ -z "$tag" ]] && continue
            skip=false
            for seen in "${UNIQUE[@]}"; do
              if [ "$tag" = "$seen" ]; then
                skip=true
                break
              fi
            done
            if [ "$skip" = false ]; then
              UNIQUE+=("$tag")
            fi
          done

          {
            echo "BASE_TAGS<<EOF"
            for tag in "${UNIQUE[@]}"; do
              printf '%s\n' "$tag"
            done
            echo "EOF"
            echo "IMAGE_TAGS<<EOF"
            for tag in "${UNIQUE[@]}"; do
              printf '%s\n' "$REGISTRY/$COMPONENT_IMAGE:${tag}-${ARCH}"
            done
            echo "EOF"
            echo "ARCH=$ARCH"
          } >> "$GITHUB_ENV"

      - name: Set up QEMU
        uses: docker/setup-qemu-action@v3

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Log in to GHCR
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Build & push ${{ env.COMPONENT_NAME }} (${{ matrix.platform }})
        uses: docker/build-push-action@v5
        with:
          context: ${{ env.COMPONENT_CONTEXT }}
          push: true
          platforms: ${{ matrix.platform }}
          tags: ${{ env.IMAGE_TAGS }}

  manifest:
    runs-on: ubuntu-latest
    needs: build
    strategy:
      matrix:
        component: [backend, frontend]

    permissions:
      contents: read
      packages: write

    env:
      REGISTRY: ghcr.io
      ARCHES: amd64 arm64

    steps:
      - name: Set component metadata
        run: |
          if [ "${{ matrix.component }}" = "backend" ]; then
            echo "COMPONENT_IMAGE=${{ env.IMAGE_BACKEND }}" >> "$GITHUB_ENV"
          else
            echo "COMPONENT_IMAGE=${{ env.IMAGE_FRONTEND }}" >> "$GITHUB_ENV"
          fi
          echo "COMPONENT_NAME=${{ matrix.component }}" >> "$GITHUB_ENV"

      - name: Compute base tags
        env:
          GITHUB_SHA: ${{ github.sha }}
          GITHUB_REF: ${{ github.ref }}
        run: |
          TAGS=("${GITHUB_SHA::7}")

          BRANCH=${GITHUB_REF##*/}
          if [ "$BRANCH" = "dev" ]; then
            TAGS+=("${GITHUB_SHA::7}-dev")
          fi

          if [[ "$GITHUB_REF" == refs/tags/* ]]; then
            TAGS+=("${GITHUB_REF#refs/tags/}")
          fi

          UNIQUE=()
          for tag in "${TAGS[@]}"; do
            [[ -z "$tag" ]] && continue
            skip=false
            for seen in "${UNIQUE[@]}"; do
              if [ "$tag" = "$seen" ]; then
                skip=true
                break
              fi
            done
            if [ "$skip" = false ]; then
              UNIQUE+=("$tag")
            fi
          done

          {
            echo "BASE_TAGS<<EOF"
            for tag in "${UNIQUE[@]}"; do
              printf '%s\n' "$tag"
            done
            echo "EOF"
          } >> "$GITHUB_ENV"

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Log in to GHCR
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Create manifests for ${{ env.COMPONENT_NAME }}
        run: |
          while IFS= read -r tag; do
            [ -n "$tag" ] || continue
            args=()
            for arch in $ARCHES; do
              args+=("$REGISTRY/$COMPONENT_IMAGE:${tag}-${arch}")
            done
            docker buildx imagetools create \
              --tag "$REGISTRY/$COMPONENT_IMAGE:$tag" \
              "${args[@]}"
          done <<< "$BASE_TAGS"