name: CI

on:
  push:
    branches:
      - master
  pull_request:

env:
  IMAGE_NAME: ${{ vars.IMAGE_NAME }}
  REGISTRY_LOCATION: ${{ vars.REGISTRY_LOCATION }}
  REGISTRY_ORGANIZATION: ${{ vars.REGISTRY_ORGANIZATION }}
  PORT: ${{ vars.PORT }}
  TEST_PORT: ${{ vars.TEST_PORT }}
  REGISTRY_USER: ${{ secrets.REGISTRY_USER }}
  REGISTRY_TOKEN: ${{ secrets.REGISTRY_TOKEN }}
  DEPLOY_SSH_KEY: ${{ secrets.DEPLOY_SSH_KEY }}
  PROD_SERVER_HOST: ${{ secrets.PROD_SERVER_HOST }}
  DEPLOY_USER: ${{ secrets.DEPLOY_USER }}
  BUILD_NUMBER: build-${{ gitea.run_number }}

jobs:
  lint:
    name: ✅ Lint & Validate
    runs-on: ubuntu-latest

    steps:
      - name: 📥 Checkout repository
        uses: actions/checkout@v4

      - name: 🔧 Validate HTML
        run: |
          echo "Basic HTML validation"
          test -f index.html

  build:
    name: Build & Push Docker Image
    runs-on: ubuntu-latest
    needs: lint

    steps:
      - name: 📥 Checkout repository
        uses: actions/checkout@v4

      - name: 🐋 Build Docker image
        run: |
          docker build \
            -t $IMAGE_NAME:$BUILD_NUMBER \
            -t $IMAGE_NAME:latest \
            .

      - name: ℹ️ Image info
        run: docker images | grep $IMAGE_NAME

      - name: 🔑 Login to registry
        run: |
          echo "$REGISTRY_TOKEN" | docker login $REGISTRY_LOCATION \
            -u "$REGISTRY_USER" --password-stdin

      - name: 🏷️ Build images
        run: |
          docker tag $IMAGE_NAME:latest $REGISTRY_LOCATION/$REGISTRY_ORGANIZATION/$IMAGE_NAME:latest
          docker tag $IMAGE_NAME:$BUILD_NUMBER $REGISTRY_LOCATION/$REGISTRY_ORGANIZATION/$IMAGE_NAME:$BUILD_NUMBER

      - name: 🚀 Push images
        run: |
          docker push $REGISTRY_LOCATION/$REGISTRY_ORGANIZATION/$IMAGE_NAME:latest
          docker push $REGISTRY_LOCATION/$REGISTRY_ORGANIZATION/$IMAGE_NAME:$BUILD_NUMBER

  deploy:
    name: 🚀 Deploy image to prod
    runs-on: ubuntu-latest
    needs: build

    steps:
      - name: 🔑 Setup SSH
        run: |
          mkdir -p ~/.ssh
          echo "$DEPLOY_SSH_KEY" > ~/.ssh/id_rsa
          chmod 600 ~/.ssh/id_rsa
          ssh-keyscan -H $PROD_SERVER_HOST >> ~/.ssh/known_hosts

      - name: 🗝️ Login to registry
        run: |
          echo "$REGISTRY_TOKEN" | docker login $REGISTRY_LOCATION \
            -u "$REGISTRY_USER" --password-stdin

      - name: 🔌 SSH into the prod server
        run: |
          ssh $DEPLOY_USER@$PROD_SERVER_HOST << 'EOF'
          sleep 5

      - name: 🚀 Deploy container to prod
        run: |
          set -e
          NEW_IMAGE_NAME="$REGISTRY_LOCATION/$REGISTRY_ORGANIZATION/$IMAGE_NAME:$BUILD_NUMBER"
          TEST_CONTAINER_NAME=test-$IMAGE_NAME
          OLD_IMAGE_NAME=$(docker inspect $IMAGE_NAME --format='{{.Config.Image}}')
          NEW_CONTAINER_IMAGE="$IMAGE_NAME:$BUILD_NUMBER"

          echo "🏗️ Building functions"

          # checks the health of the given container name $1
          # returns "healthy" or "unhealthy"
          is_container_healthy() {
            for i in {1..15}; do
              RETURN=$(docker inspect --format='{{.State.Health.Status}}' $1)
              [ "$RETURN" = "healthy" ] && break
              [ "$RETURN" = "unhealthy" ] && break
              sleep 2
            done
            echo "$RETURN"
          }


          echo "🎣 Pulling image $NEW_IMAGE_NAME"
          docker pull "$NEW_IMAGE_NAME"


          echo "🧪 Test the new container health"
                    
          # if old test container is running then stop and remove it 
          if docker ps -a --format '{{.Names}}' | grep "^$TEST_CONTAINER_NAME$"; then
            echo "Container ${TEST_CONTAINER_NAME} is running. Stopping and removing..."
            docker stop $TEST_CONTAINER_NAME
            docker rm $TEST_CONTAINER_NAME
          fi

          echo "Starting new test container"
          docker run -d \
            --name $TEST_CONTAINER_NAME \
            --health-cmd="curl -f http://$PROD_SERVER_HOST:$TEST_PORT/health || exit 1" \
            --health-interval=5s \
            --health-retries=5 \
            --health-timeout=2s \
            --health-start-period=5s \
            -p $TEST_PORT:80 \
            "$NEW_CONTAINER_IMAGE"

          TEST_CONTAINER_HEALTHCHECK=$(is_container_healthy $TEST_CONTAINER_NAME)

          docker stop $TEST_CONTAINER_NAME
          docker rm $TEST_CONTAINER_NAME

          echo "🚚 Deploy the new image if healthy, otherwise rollback"
          if [ "$TEST_CONTAINER_HEALTHCHECK" = "healthy" ]; then
            echo "✅ Test Container is healthy - starting deployment"
            
            # Stop previous prod running container if found 
            if [ -n "$OLD_IMAGE_NAME" ]; then
              echo "Stopping previous prod running container"
              docker stop $IMAGE_NAME
              docker rm $IMAGE_NAME
            fi
            
            docker run -d \
              --name $IMAGE_NAME \
              --health-cmd="curl -f http://$PROD_SERVER_HOST:$PORT/health || exit 1" \
              --health-interval=5s \
              --health-retries=5 \
              --health-timeout=2s \
              --health-start-period=5s \
              -p $PORT:80 \
              "$NEW_CONTAINER_IMAGE"

            PROD_CONTAINER_HEALTHCHECK=$(is_container_healthy $IMAGE_NAME)
            
            if [ "$PROD_CONTAINER_HEALTHCHECK" != "healthy" ]; then
              echo "❌ Deployment failed — rolling back"
              docker logs $IMAGE_NAME
              docker stop $IMAGE_NAME
              docker rm -f $IMAGE_NAME
              docker image rm $NEW_CONTAINER_IMAGE

              if [ -n "$OLD_IMAGE_NAME" ]; then
                docker run -d \
                  --name $IMAGE_NAME \
                  --health-cmd="curl -f http://$PROD_SERVER_HOST:$PORT/health || exit 1" \
                  --health-interval=5s \
                  --health-retries=5 \
                  --health-timeout=2s \
                  --health-start-period=5s \
                  -p $PORT:80 \
                  "$OLD_IMAGE_NAME"
                
                if [["$(is_container_healthy $IMAGE_NAME)" == "healthy" ]]; then
                  echo "❌ Deployment failed — ✅ rollback successfull"
                else
                  echo "❌ Deployment failed — ❌ rollback failed"
                fi
                exit 1
              fi
              echo "❌ Deployment failed — ❌ rollback not possible (no previous version was running)"
              exit 1            
            fi
            
            if [ -n "$OLD_IMAGE_NAME" ]; then
              docker image rm $OLD_IMAGE_NAME
            fi

            echo "✅ Deployment successfull ($IMAGE_NAME)"
            exit 0
          else
            
            docker image rm $NEW_CONTAINER_IMAGE
            echo "❌ Deployment failed — ❤️ healthcheck failed on the test container"
            exit 1
          fi