name: Update `flake.lock`
on:
  workflow_dispatch:
  schedule:
    - cron: '0 0 * * 0' # runs weekly on Sunday at 00:00

jobs:
  update_lockfile:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
      - name: Install nix
        uses: https://github.com/DeterminateSystems/nix-installer-action@main
      - name: Setup Action cache for nix
        uses: https://github.com/DeterminateSystems/magic-nix-cache-action@main

      - name: Update flake.lock
        id: update
        run: |
          nix flake update 2>&1 | awk '
            /^• Updated input/ {in_update = 1; print; next}
            in_update && !/^warning:/ {print}
            /^$/ {in_update = 0}
          ' | tee update.log

          LOG=$(cat update.log)

          LOG="${LOG//'%'/'%25'}"
          LOG="${LOG//$'\n'/'%0A'}"
          LOG="${LOG//$'\r'/'%0D'}"

          echo "update_log=${LOG}" >> $GITHUB_OUTPUT

          cat << EOF >> ../body.md
          - The following Nix Flake inputs were updated

          \`\`\`
          EOF

          cat update.log >> ../body.md

          cat << EOF >> ../body.md
          \`\`\`

          Auto-generated by [update.yml][1] with the help of
          [create-pull-request][2]

          [1]: https://forgejo.stefka.eu/jiriks74/action-update_flake_lock
          [2]: https://forgejo.stefka.eu/jiriks74/create-pull-request
          EOF

          rm update.log

      - name: Create Pull Request
        id: create-pull-request
        uses: https://forgejo.stefka.eu/jiriks74/create-pull-request@9791a4f146d5369620ea3b934822e717d3d90034
        body-path: ../body.md
        with:
            token: ${{ secrets.FORGEJO_TOKEN_FOR_UPDATES  }}
            commit-message: Update `flake.lock`
            title: Update `flake.lock`
            
            branch: update-flake-lock
      - name: Print PR number
        run: |
          echo "Pull request number is ${{ steps.create-pull-request.outputs.pull-request-number }}."
          echo ${{ steps.update.output.update_log }}