name: Build and Push Docker Images

on:
  push:
    branches: [main]
    paths:
      - 'images/**'
  workflow_dispatch:
    inputs:
      image:
        description: 'Image to build (e.g., terraform-ci)'
        required: false

env:
  REGISTRY: gitea.arnodo.fr

jobs:
  detect-changes:
    runs-on: docker
    container:
      image: alpine/git:latest
    outputs:
      matrix: ${{ steps.changes.outputs.matrix }}
      has_changes: ${{ steps.changes.outputs.has_changes }}
    steps:
      - uses: actions/checkout@v3
        with:
          fetch-depth: 2

      - name: Detect changed images
        id: changes
        run: |
          if [ -n "${{ github.event.inputs.image }}" ]; then
            # Manual trigger - build specific image
            echo "matrix=[\"${{ github.event.inputs.image }}\"]" >> $GITHUB_OUTPUT
            echo "has_changes=true" >> $GITHUB_OUTPUT
          else
            # Auto-detect changed images
            CHANGED=$(git diff --name-only HEAD~1 HEAD -- images/ | cut -d'/' -f2 | sort -u | grep -v '^$' || true)
            if [ -z "$CHANGED" ]; then
              echo "has_changes=false" >> $GITHUB_OUTPUT
              echo "matrix=[]" >> $GITHUB_OUTPUT
            else
              # Convert to JSON array
              JSON=$(echo "$CHANGED" | jq -R -s -c 'split("\n") | map(select(length > 0))')
              echo "matrix=$JSON" >> $GITHUB_OUTPUT
              echo "has_changes=true" >> $GITHUB_OUTPUT
            fi
          fi

  build:
    needs: detect-changes
    if: needs.detect-changes.outputs.has_changes == 'true'
    runs-on: docker
    strategy:
      matrix:
        image: ${{ fromJson(needs.detect-changes.outputs.matrix) }}
    steps:
      - uses: actions/checkout@v3

      - name: Set up Docker Buildx
        run: |
          docker buildx create --use --name gitea-builder || docker buildx use gitea-builder

      - name: Login to Gitea Registry
        run: |
          echo "${{ secrets.REGISTRY_TOKEN }}" | docker login ${{ env.REGISTRY }} -u ${{ gitea.actor }} --password-stdin

      - name: Build and push
        run: |
          IMAGE_NAME="${{ env.REGISTRY }}/damien/${{ matrix.image }}"
          
          docker buildx build \
            --platform linux/amd64 \
            --tag "${IMAGE_NAME}:latest" \
            --tag "${IMAGE_NAME}:${{ gitea.sha }}" \
            --push \
            ./images/${{ matrix.image }}

      - name: Summary
        run: |
          echo "### ✅ Image built and pushed" >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY
          echo "- **Image**: ${{ env.REGISTRY }}/damien/${{ matrix.image }}" >> $GITHUB_STEP_SUMMARY
          echo "- **Tags**: latest, ${{ gitea.sha }}" >> $GITHUB_STEP_SUMMARY