name: "Collect changes"
description: "Collects and stores changed files/charts"

outputs:
  changesDetected:
    description: "Whether or not changes to charts have been detected"
    value: ${{ steps.filter.outputs.addedOrModified }}
  addedOrModifiedFiles:
    description: "A list of the files changed"
    value: ${{ steps.filter.outputs.addedOrModified_files }}
  addedOrModifiedCharts:
    description: "A list of the charts changed"
    value: ${{ steps.filter-charts.outputs.addedOrModified }}
  changesDetectedAfterTag:
    description: "Flag if there are any modified and bump Charts after last tag"
    value: ${{ steps.filter-bumped-charts.outputs.changesDetectedAfterTag }}
  modifiedChartsAfterTag:
    description: "A list of the charts changed and bumped after last Tag"
    value: ${{ steps.filter-bumped-charts.outputs.modifiedChartsAfterTag }}

runs:
  using: "composite"
  steps:
    - name: Collect changed files
      uses: dorny/paths-filter@v2
      id: filter
      with:
        list-files: shell
        filters: |
          addedOrModified:
            - added|modified: 'charts/*/**'

    - name: Collect changed charts
      if: |
        steps.filter.outputs.addedOrModified == 'true'
      id: filter-charts
      shell: bash
      run: |
        CHARTS=()
        PATHS=(${{ steps.filter.outputs.addedOrModified_files }})
        # Get only the chart paths
        for CHARTPATH in "${PATHS[@]}"
        do
          IFS='/' read -r -a path_parts <<< "${CHARTPATH}"
          CHARTS+=("${path_parts[0]}/${path_parts[1]}/${path_parts[2]}")
        done

        # Remove duplicates
        CHARTS=( `printf "%s\n" "${CHARTS[@]}" | sort -u` )
        # Set output to changed charts
        echo "Changed charts: ${CHARTS[*]}"
        printf "::set-output name=addedOrModified::%s\n" "${CHARTS[*]}"

    - name: Collect bumped charts after last tag
      id: filter-bumped-charts
      shell: bash
      run: |
        lookup_latest_tag() {
            git fetch --tags > /dev/null 2>&1

            if ! git describe --tags --abbrev=0 2> /dev/null; then
                git rev-list --max-parents=0 --first-parent HEAD
            fi
        }
        export -f lookup_latest_tag

        filter_charts() {
            while read -r chart; do
                [[ ! -d "$chart" ]] && continue
                if [[ $(git diff $latest_tag $chart/Chart.yaml | grep "+version") ]]; then
                    echo "$chart"
                else
                   echo "Version not bumped. Skipping." 1>&2
                fi
            done
        }
        export -f filter_charts

        lookup_changed_charts() {
            local commit="$1"

            local changed_files
            changed_files=$(git diff --find-renames --name-only "$commit" -- 'charts/**' | grep "Chart.yaml")
            local depth=$(( $(tr "/" "\n" <<< 'charts/**' | sed '/^\(\.\)*$/d' | wc -l) + 1 ))
            local fields="1-${depth}"

            cut -d '/' -f "$fields" <<< "$changed_files" | uniq | filter_charts
        }
        export -f lookup_changed_charts

        repo_root=$(git rev-parse --show-toplevel)
        pushd "$repo_root" > /dev/null

        echo 'Looking up latest tag...'
        latest_tag=$(lookup_latest_tag)

        echo "Discovering changed charts since '$latest_tag'..."
        changed_charts=()
        readarray -t changed_charts <<< "$(lookup_changed_charts "$latest_tag")"

        CHARTS=()
        for CHARTPATH in "${changed_charts[@]}"
        do
          IFS='/' read -r -a path_parts <<< "${CHARTPATH}"
          CHARTS+=("${path_parts[1]}/${path_parts[2]}")
        done

        # Remove duplicates
        CHARTS=( `printf "%s\n" "${CHARTS[@]}" | sort -u` )

        echo "Number of detected changed charts: ${#CHARTS[@]}"
        if [ ${#CHARTS[@]} -eq 0 ] || [ "${CHARTS[0]}" == ' ' ] || [ "${CHARTS[0]}" == '/' ]; then
          echo "No Changed Charts detected since latest tag..."
          printf "::set-output name=changesDetectedAfterTag::%s\n" "false"
        else
          echo "Changed Charts detected since latest tag, parsing..."
          printf "::set-output name=changesDetectedAfterTag::%s\n" "true"

          # Get only the chart paths

          # Set output to changed charts
          echo "Changed charts since latest tag: ${CHARTS[*]}"
          printf "::set-output name=modifiedChartsAfterTag::%s\n" "${CHARTS[*]}"
        fi
        popd > /dev/null