version: 2
jobs:
  hold:
    machine: true
    steps:
      - run: echo "This build requires approval to continue..."
  build:
    machine: true
    working_directory: ~/repo
    steps:
      - checkout
      - run:
          name: Choose which test suite to run based on which files were modified
          command: |
            ## As far as I'm aware, there are three possibile cases to check for here. The CIRCLE_COMPARE_URL environment variable will either contain:
            ## - A SHA1 hash for the commit (If there is only a single commit on the branch)
            ## - Two SHA1 hashes in a "xxxxxxxx..yyyyyyyy" (comparing the two most recent commits
            ## - Nothing
            ## There is certainly a better way to accomplish all of this, but my limited knowledge of git has lead me to write this awful spaghetti code :-/
            ## We'll handle all 3 of these cases below:
            ## Checking commits for changes to Packer files
            COMMIT_SHA1=""
            PACKER_MODIFIED=0
            VAGRANT_MODIFIED=0
            ## Check for empty CIRCLE_COMPARE_URL. If it is, set the SHA1 hash to the CIRCLE_SHA1 environment variable
            if [ "$(echo -n $CIRCLE_COMPARE_URL | wc -c)" -eq 0 ]; then
              export COMMIT_SHA1=$CIRCLE_SHA1
            ## Check for two short-hashes in the CIRCLE_COMPARE_URL by searching for '..'. If it exists, use the second short-hash
            elif echo "$CIRCLE_COMPARE_URL" | grep '\.\.'; then
              export COMMIT_SHA1="$(echo $CIRCLE_COMPARE_URL | cut -d '.' -f 5)"
            ## Check for a single short hash in the CIRCLE_COMPARE_URL and use it if it exists
            ## TODO: This check may not be needed.
            else
              export COMMIT_SHA1="$(echo $CIRCLE_COMPARE_URL | cut -d '/' -f 7)"
            fi
            ## Display the files that were modified in this branch
            echo "Files modified since origin/Master:"
            git diff-tree --no-commit-id --name-only -r $(git rev-parse origin/HEAD) "$COMMIT_SHA1"
            ## Check to see if Packer files were modified
            if [ "$(git diff-tree --no-commit-id --name-only -r $(git rev-parse origin/HEAD) "$COMMIT_SHA1" | grep -c ^Packer/)" -gt 0 ]; then
              export PACKER_MODIFIED=1
            fi
            if [ "$(git diff-tree --no-commit-id --name-only -r $(git rev-parse origin/HEAD) "$COMMIT_SHA1" | grep -c ^Vagrant/)" -gt 0 ]; then
              export VAGRANT_MODIFIED=1
            fi
            echo "Displaying the values of the modifier environment variables:"
            echo "VAGRANT_MODIFIED=$VAGRANT_MODIFIED"
            echo "PACKER_MODIFIED=$PACKER_MODIFIED"
            ## Choosing which test suite to run based on the files that were changed
            if [[ "$PACKER_MODIFIED" -eq 1 ]] && [[ "$VAGRANT_MODIFIED" -eq 1 ]]; then
              echo "Running the test suite for Packer and Vagrant changes"
              chmod +x ci/circle_workflows/packer_and_vagrant_changes.sh
              ci/circle_workflows/packer_and_vagrant_changes.sh
              exit 0
            fi
            if [[ "$PACKER_MODIFIED" -eq 0 ]] && [[ "$VAGRANT_MODIFIED" -eq 0 ]]; then
              echo "Running the default test suite (Vagrant-only)"
              chmod +x ci/circle_workflows/vagrant_changes.sh
              ci/circle_workflows/vagrant_changes.sh
              exit 0
            fi
            if [ "$PACKER_MODIFIED" -eq 1 ]; then
              echo "Running the test suite for Packer-only changes"
              chmod +x ci/circle_workflows/packer_changes.sh
              ci/circle_workflows/packer_changes.sh
              exit 0
            fi
            if [ "$VAGRANT_MODIFIED" -eq 1 ]; then
              echo "Running the test suite for Vagrant-only changes"
              chmod +x ci/circle_workflows/vagrant_changes.sh
              ci/circle_workflows/vagrant_changes.sh
              exit 0
            fi

      - store_artifacts:
          path: /tmp/artifacts

workflows:
  version: 2
  workflow:
    jobs:
      - hold:
          type: approval
          filters:
            branches:
              # Don't rebuild the PR after it has been merged into master
              # Users cannot push directly to master as it is a protected branch
              ignore: master
      - build:
          requires:
            - hold
          filters:
            branches:
              # Don't rebuild the PR after it has been merged into master
              ignore: master
  weekly-build:
    jobs:
      - build
    triggers:
      - schedule:
          cron: "0 0 * * 0"
          filters:
            branches:
              # Automatically re-build the contents of master once per week
              only: master