name: Update NPM dependencies

on:
  schedule:
    - cron: "0 5 1,15 * *"
  workflow_dispatch:
    inputs:
      config:
        description: 'Config'
        required: false
        default: ''

jobs:
  update:
    runs-on: ubuntu-latest

    strategy:
      matrix:
        deps: [production, dev-only]

    steps:
      - name: Setup node
        # https://github.com/marketplace/actions/setup-node-js-environment
        uses: actions/setup-node@v1
        with:
          node-version: '12'

      - name: Checkout default branch
        # https://github.com/marketplace/actions/checkout
        uses: actions/checkout@v2

      - name: Read config
        run: |
          CONFIG='{}'
          if [[ ! -z '${{ github.event.inputs.config }}' ]]; then
            CONFIG='${{ github.event.inputs.config }}'
          elif [[ -f "./.github/workflows-config.json" ]]; then
            CONFIG=$( jq -c .updateDeps './.github/workflows-config.json' )
          fi
          echo "CONFIG=$CONFIG" >> $GITHUB_ENV
          echo "Workflow config: $CONFIG"

      - name: Check env variables
        run: |
          if [[ -z "${{ secrets.GH_BOT_USERNAME }}" ]]; then
            echo "Expected 'GH_BOT_USERNAME' secret variable to be set."
            exit 1
          fi
          if [[ -z "${{ secrets.GH_BOT_EMAIL }}" ]]; then
            echo "Expected 'GH_BOT_EMAIL' secret variable to be set."
            exit 1
          fi
          BRANCH_TARGET=$(echo '${{ env.CONFIG }}' | jq -r ".targetBranch")
          if [[ -z "$BRANCH_TARGET" || "$BRANCH_TARGET" == "null" ]]; then
            # Since 'Fetch changes' step fetches default branch, we just get branch name (which will be default one).
            BRANCH_TARGET=$(git rev-parse --abbrev-ref HEAD)
          fi
          echo "BRANCH_TARGET=$BRANCH_TARGET" >> $GITHUB_ENV

      - name: Check if update branch already exists
        run: |
          echo "BRANCH_UPDATE=deps-update_${{ env.BRANCH_TARGET }}_${{ matrix.deps }}" >> $GITHUB_ENV
          if [[ $(git ls-remote --heads | grep deps-update_${{ env.BRANCH_TARGET }}_${{ matrix.deps }} | wc -c) -ne 0 ]]; then
            echo "BRANCH_UPDATE=0" >> $GITHUB_ENV
          fi

      - name: Update NPM dependencies
        if: env.BRANCH_UPDATE != 0
        run: |
          npm i
          npm install -g npm-check
          git checkout -b ${{ env.BRANCH_UPDATE }}
          npm-check -y --${{ matrix.deps }}

      - name: Add changes
        if: env.BRANCH_UPDATE != 0
        run: |
          if [[ $(git diff origin/${{ env.BRANCH_TARGET }} | wc -c) -ne 0 ]]; then
            git config --local user.email "${{ secrets.GH_BOT_EMAIL }}"
            git config --local user.name "${{ secrets.GH_BOT_USERNAME }}"
            git add package*.json
            git commit -m "Update NPM ${{ matrix.deps }} dependencies."
            echo "HAS_CHANGES=1" >> $GITHUB_ENV
          fi

      - name: Push changes
        if: env.HAS_CHANGES == 1
        # https://github.com/marketplace/actions/github-push
        uses: ad-m/github-push-action@master
        with:
          github_token: ${{ secrets.GITHUB_TOKEN }}
          branch: ${{ env.BRANCH_UPDATE }}

      - name: Create PR
        if: env.HAS_CHANGES == 1
        # https://github.com/marketplace/actions/github-pull-request-action
        uses: repo-sync/pull-request@v2
        with:
          source_branch: "${{ env.BRANCH_UPDATE }}"
          destination_branch: "${{ env.BRANCH_TARGET }}"
          pr_title: "Update NPM ${{ matrix.deps }} dependencies"
          pr_body: "Updated NPM ${{ matrix.deps }} dependencies."
          github_token: ${{ secrets.GITHUB_TOKEN }}