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_ENV

          rm update.log

      - name: Write PR body template
        uses: https://github.com/DamianReeves/write-file-action@v1.3
        with:
          path: ../pr_body.template
          contents: |
            - The following Nix Flake inputs were updated:

            ```
            ${{ env.UPDATE_LOG }}
            ```

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

            [1]: https://forgejo.stefka.eu/jiriks74/nix.nvim/src/branch/main/.github/workflows/update.yml
            [2]: https://forgejo.stefka.eu/jiriks74/create-pull-request

      - name: Generate PR body
        uses: pedrolamas/handlebars-action@v2.4.0 # v2.4.0
        with:
          files: "../pr_body.template"
          output-filename: "../pr_body.md"

      - name: Create Pull Request
        id: create-pull-request
        uses: https://forgejo.stefka.eu/jiriks74/create-pull-request@9791a4f146d5369620ea3b934822e717d3d90034
        with:
          token: ${{ secrets.FORGEJO_TOKEN_FOR_UPDATES  }}
          body-path: ${{ steps.pr_body.outputs.content }}
          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 }}."