name: Build and Push Docker Images

on:
  push:
    branches: [main]
    paths:
      - 'images/**'
  workflow_dispatch:
    # Manual trigger builds all images

env:
  REGISTRY: gitea.arnodo.fr

jobs:
  # ============================================================================
  # Job 1 : Detect modified images
  # ============================================================================
  detect-changes:
    runs-on: docker
    container:
      image: alpine:3.20
    outputs:
      image_list: ${{ steps.changes.outputs.image_list }}
      has_changes: ${{ steps.changes.outputs.has_changes }}
    steps:
      - name: Install dependencies
        run: apk add --no-cache git python3

      - name: Checkout repository
        run: |
          git clone --depth 2 https://gitea.arnodo.fr/${{ gitea.repository }}.git .
          git checkout ${{ gitea.sha }}

      - name: Detect changed images
        id: changes
        run: |
          > valid_images.txt

          if [ "${{ github.event_name }}" == "workflow_dispatch" ]; then
             echo "DEBUG: Manual trigger detected. Scanning all images..."
             
             if [ -d "images" ]; then
               # Use find for reliable directory listing
               find images -mindepth 1 -maxdepth 1 -type d | while read DIR; do
                 if [ -f "$DIR/Dockerfile" ]; then
                   BASENAME=$(basename "$DIR")
                   echo "DEBUG: Found image: $BASENAME"
                   echo "$BASENAME" >> valid_images.txt
                 fi
               done
             else
               echo "DEBUG: images/ directory not found."
             fi
             
          else
             echo "DEBUG: Push event detected. Analyzing git diff..."
             
             CHANGED_FILES=$(git diff --name-only HEAD~1 HEAD -- images/ 2>/dev/null || true)
             # Extract unique directories
             CANDIDATES=$(echo "$CHANGED_FILES" | cut -d'/' -f2 | sort -u | grep -v '^$')
             
             for CANDIDATE in $CANDIDATES; do
               if [ -d "images/$CANDIDATE" ] && [ -f "images/$CANDIDATE/Dockerfile" ]; then
                 echo "DEBUG: Change detected in image: $CANDIDATE"
                 echo "$CANDIDATE" >> valid_images.txt
               fi
             done
             
             # Fallback: If push event but no valid images found (e.g. change in root file but paths filter matched?),
             # we generally skip. But if the user wants "Simple: No diff -> Build All", we could enable it.
             # However, typically for push, we only want changes.
             # The user's comment "If no modification is detected ... build all" likely referred to the manual trigger context.
             # So we keep push strictly to changes.
          fi
          
          if [ ! -s valid_images.txt ]; then
             echo "No valid images detected."
             echo "has_changes=false" >> $GITHUB_OUTPUT
             echo "image_list=[]" >> $GITHUB_OUTPUT
          else
             # Use Python for reliable JSON generation
             JSON=$(cat valid_images.txt | python3 -c 'import json, sys; lines = [l.strip() for l in sys.stdin if l.strip()]; print(json.dumps(lines))')
             
             echo "DEBUG: Generated JSON: >$JSON<"
             echo "image_list=$JSON" >> $GITHUB_OUTPUT
             echo "has_changes=true" >> $GITHUB_OUTPUT
          fi

      - name: Show detected changes
        run: |
          echo "Image List: ${{ steps.changes.outputs.image_list }}"
          echo "Has changes: ${{ steps.changes.outputs.has_changes }}"

  # ============================================================================
  # Job 2 : Build and Push (Standard Docker)
  # ============================================================================
  build:
    needs: detect-changes
    if: needs.detect-changes.outputs.has_changes == 'true'
    runs-on: docker
    container:
      image: docker:cli
    strategy:
      matrix:
        image: ${{ fromJson(needs.detect-changes.outputs.image_list) }}
      fail-fast: false
    steps:
      - name: Install dependencies
        run: apk add --no-cache git

      - name: Checkout repository
        run: |
          git clone --depth 2 https://gitea.arnodo.fr/${{ gitea.repository }}.git .
          git checkout ${{ gitea.sha }}

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

      - name: Build and Push
        env:
          IMAGE_NAME: ${{ env.REGISTRY }}/damien/${{ matrix.image }}
          IMAGE_PATH: images/${{ matrix.image }}
        run: |
          echo "Debug: Matrix Image is '${{ matrix.image }}'"
          
          if [ -z "${{ matrix.image }}" ]; then
            echo "Skipping empty image name"
            exit 0
          fi

          echo "Building $IMAGE_NAME:latest from $IMAGE_PATH ..."
          
          if [ ! -d "$IMAGE_PATH" ]; then
            echo "Error: Directory $IMAGE_PATH does not exist."
            exit 1
          fi
          
          if [ ! -f "$IMAGE_PATH/Dockerfile" ]; then
            echo "Error: Dockerfile not found in $IMAGE_PATH."
            exit 1
          fi

          # Use standard docker build
          docker build -t "$IMAGE_NAME:latest" "$IMAGE_PATH"
          docker push "$IMAGE_NAME:latest"
          
          echo "✅ Pushed $IMAGE_NAME:latest"