image: docker:latest
stages:
  - test
  - build
  - push

test:
  stage: test
  image: python:3.11-alpine
  script:
    - pip install -q -r requirements.txt
    - python -m unittest discover tests
  only:
    - main

before_script:
  - apk add --no-cache docker-cli curl jq
  - |
    until docker info; do
      echo "Waiting for Docker to be ready..."
      sleep 5
    done

build:
  needs:
    - test
  stage: build
  script:
    - docker info
    - docker build -t $CI_REGISTRY/$CI_PROJECT_PATH:$CI_COMMIT_REF_SLUG .
    - docker tag $CI_REGISTRY/$CI_PROJECT_PATH:$CI_COMMIT_REF_SLUG $CI_REGISTRY/$CI_PROJECT_PATH:$CI_COMMIT_SHORT_SHA
    - docker tag $CI_REGISTRY/$CI_PROJECT_PATH:$CI_COMMIT_REF_SLUG $CI_REGISTRY/$CI_PROJECT_PATH:latest

push:
  needs:
    - build
  stage: push
  script:
    - |
      CURRENT_IMAGE_HASH=$(docker inspect --format='{{index .RepoDigests 0}}' $CI_REGISTRY/$CI_PROJECT_PATH:$CI_COMMIT_REF_SLUG)
      EXISTING_IMAGE_HASH=$(curl -s --header "PRIVATE-TOKEN: $CI_JOB_TOKEN" "https://gitlab.com/api/v4/projects/$CI_PROJECT_ID/registry/repositories/1/tags/$CI_COMMIT_REF_SLUG" | jq -r '.digest')
      if [ "$CURRENT_IMAGE_HASH" != "$EXISTING_IMAGE_HASH" ]; then
        echo "Image has changed, pushing to the registry..."
        echo "$CI_REGISTRY_PASSWORD" | docker login -u "$CI_REGISTRY_USER" --password-stdin $CI_REGISTRY
        docker push $CI_REGISTRY/$CI_PROJECT_PATH:$CI_COMMIT_REF_SLUG
        docker push $CI_REGISTRY/$CI_PROJECT_PATH:$CI_COMMIT_SHORT_SHA
        docker push $CI_REGISTRY/$CI_PROJECT_PATH:latest
      else
        echo "Image is unchanged, skipping push."
      fi
  only:
    - main