action.yml

# Copyright (c) Gabriel Santerre
# SPDX-License-Identifier: MIT

name: Setup
description: The only action you'll need before running the main step of a CI job.

inputs:
  output-changed-files:
    required: false
    description: Wether or not to output the changed files list.
    default: "false"

  changed-files-filters:
    required: false
    description: Using glob patterns to filter changed files.

outputs:
  changed-files:
    description: Changed Files
    value: ${{ steps.metadata-changed-files.outputs.changed-files }}

runs:
  using: composite
  steps:
    - name: Checkout Metadata
      id: metadata-checkout
      if: ${{ inputs.output-changed-files == 'true' }}
      shell: bash
      run: |
        FETCH_DEPTH=$(( ${{ github.event.pull_request.commits || 1 }} + 1 ))
        echo "fetch-depth=$FETCH_DEPTH" >> "$GITHUB_OUTPUT"
        CURRENT_COMMIT_SHA="${{ github.event.pull_request.head.sha || github.sha }}"
        echo "current-commit-sha=$CURRENT_COMMIT_SHA" >> "$GITHUB_OUTPUT"

    - name: Checkout Repository
      uses: actions/checkout@v4.1.1
      with:
        fetch-depth: ${{ steps.metadata-checkout.outputs.fetch-depth || 1 }}
        ref: ${{ steps.metadata-checkout.outputs.current-commit-sha }}

    - name: Output Changed Files
      id: metadata-changed-files
      if: ${{ inputs.output-changed-files == 'true' }}
      shell: bash
      run: |
        PARENT_COMMIT_COUNT=$(( ${{ steps.metadata-checkout.outputs.fetch-depth }} - 1 ))
        BASE_COMMIT_SHA=$(git rev-list -n 1 ${{ steps.metadata-checkout.outputs.current-commit-sha }}~$PARENT_COMMIT_COUNT)
        CHANGED_FILES=$(git diff --name-status $BASE_COMMIT_SHA..${{ steps.metadata-checkout.outputs.current-commit-sha }} | grep -E '^[ACMR]' | sed -e 's/^[ACMR]\s*//' -e 's/\s*$//' -e 's/ /\\ /g')

        # Globstar pattern for filtering file paths
        CHANGED_FILES_FILTERS="${{ inputs.changed-files-filters }}"

        # Return all changed files if no filter provided
        if [[ -z "$CHANGED_FILES_FILTERS" ]]; then
          CHANGED_FILES=$(echo $CHANGED_FILES | tr '\n' ' ')
          echo "changed-files=$CHANGED_FILES" >> "$GITHUB_OUTPUT"
          exit 0
        fi

        # Enable glob
        shopt -s globstar
        shopt -s extglob
        shopt -s dotglob

        # Convert CHANGED_FILES_FILTERS to an array
        CHANGED_FILES_FILTER_ARRAY=()
        while IFS= read -r line; do
          TRIMMED_LINE="${line#"${line%%[![:space:]]*}"}"
          TRIMMED_LINE="${TRIMMED_LINE%"${TRIMMED_LINE##*[![:space:]]}"}"

          if [[ -n "$TRIMMED_LINE" ]]; then
            CHANGED_FILES_FILTER_ARRAY+=("$TRIMMED_LINE")
          fi
        done <<< "$CHANGED_FILES_FILTERS"

        echo "::group::CHANGED_FILES_FILTER_ARRAY"
        for  CHANGED_FILES_FILTERS in "${CHANGED_FILES_FILTER_ARRAY[@]}"; do
          echo "$CHANGED_FILES_FILTERS"
        done
        echo "::endgroup::"

        # Convert CHANGED_FILES to an array
        CHANGED_FILE_ARRAY=()
          while IFS= read -r line; do
          TRIMMED_LINE="${line#"${line%%[![:space:]]*}"}"
          TRIMMED_LINE="${TRIMMED_LINE%"${TRIMMED_LINE##*[![:space:]]}"}"

          if [[ -n "$TRIMMED_LINE" ]]; then
            CHANGED_FILE_ARRAY+=("$TRIMMED_LINE")
          fi
        done <<< "$CHANGED_FILES"

        echo "::group::CHANGED_FILE_ARRAY"
        for CHANGED_FILE in "${CHANGED_FILE_ARRAY[@]}"; do
          echo "$CHANGED_FILE"
        done
        echo "::endgroup::"

        # Use filters to gather a list of files on the system
        MATCHED_FILE_ARRAY=()
        for CHANGED_FILE_FILTER in "${CHANGED_FILES_FILTER_ARRAY[@]}"; do
          MATCHING_OUTPUT=$(ls --almost-all --escape -1 --color=never $CHANGED_FILE_FILTER)

          # Read each line of the output into the array
          while IFS= read -r line; do
            MATCHED_FILE_ARRAY+=("$line")
          done <<< "$MATCHING_OUTPUT"
        done

        echo "::group::MATCHED_FILE_ARRAY"
        for MATCHED_FILE in "${MATCHED_FILE_ARRAY[@]}"; do
          echo "$MATCHED_FILE"
        done
        echo "::endgroup::"

        # Create an associative array to track unique elements
        declare -A FILTERED_CHANGED_FILE_ASSOCIATIVE_ARRAY

        # Intersect matched files with changed files
        for MATCHED_FILE in "${MATCHED_FILE_ARRAY[@]}"; do
          for CHANGED_FILE in "${CHANGED_FILE_ARRAY[@]}"; do
            if [[ "$MATCHED_FILE" == "$CHANGED_FILE" ]]; then
              FILTERED_CHANGED_FILE_ASSOCIATIVE_ARRAY["$MATCHED_FILE"]=1
            fi
          done
        done

        # Convert associative array to array
        FILTERED_CHANGED_FILE_ARRAY=("${!FILTERED_CHANGED_FILE_ASSOCIATIVE_ARRAY[@]}")

        echo "::group::FILTERED_CHANGED_FILE_ARRAY"
        for CHANGED_FILE in "${FILTERED_CHANGED_FILE_ARRAY[@]}"; do
          echo "$CHANGED_FILE"
        done
        echo "::endgroup::"

        FILTERED_CHANGED_FILES="${FILTERED_CHANGED_FILE_ARRAY[@]}"
        echo "changed-files=$FILTERED_CHANGED_FILES" >> "$GITHUB_OUTPUT"