update flake lock action

.github/workflows/flake-update.yml

@@ -47,26 +47,101 @@ jobs:
       #     } >> $GITHUB_ENV
 
 
-      - name: Restore flake.lock for next step
-        run: git restore flake.lock
+      # - name: Restore flake.lock for next step
+      #   run: git restore flake.lock
+      # - name: Update flake.lock
+      #   id: update
+      #   uses: DeterminateSystems/update-flake-lock@main
+      #   with:
+      #     token: ${{ secrets.GH_TOKEN_FOR_UPDATES }}
+      #     pr-body: |
+      #       Automated changes by the [update-flake-lock](https://github.com/DeterminateSystems/update-flake-lock) GitHub Action.
+
+      #       ```
+      #       {{ env.GIT_COMMIT_MESSAGE }}
+      #       ```
+
+      #       ```
+      #       {{ env.POSTDIFF }}
+      #       ```
+      #     pr-labels: |                  # Labels to be set on the PR
+      #       dependencies
+      #       automated
+  update_lockfile:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      - name: Install nix
+        uses: https://github.com/DeterminateSystems/nix-installer-action@main
+
       - name: Update flake.lock
         id: update
-        uses: DeterminateSystems/update-flake-lock@main
+        run: |
+          nix flake update 2> >(tee /dev/stderr) | awk '
+            /^• Updated input/ {in_update = 1; print; next}
+            in_update && !/^warning:/ {print}
+            /^$/ {in_update = 0}
+          ' > update.log
+
+          echo "UPDATE_LOG<<EOF" >> $GITHUB_ENV
+          cat update.log >> $GITHUB_ENV
+          echo "EOF" >> $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: Save PR body
+        id: pr_body
+        uses: juliangruber/read-file-action@v1
+        with:
+          path: "pr_body.md"
+
+      - name: Remove temporary files
+        run: |
+          rm pr_body.template
+          rm pr_body.md
+
+      - name: Create Pull Request
+        id: create-pull-request
+        uses: https://forgejo.stefka.eu/jiriks74/create-pull-request@7174d368c2e4450dea17b297819eb28ae93ee645
         with:
           token: ${{ secrets.GH_TOKEN_FOR_UPDATES  }}
-          pr-body: |
-            Automated changes by the [update-flake-lock](https://github.com/DeterminateSystems/update-flake-lock) GitHub Action.
+          body: ${{ steps.pr_body.outputs.content }}
+          author: '"github-actions[bot]" <github-actions[bot]@users.noreply.github.com>'
+          title: 'automated: Update `flake.lock`'
+          commit-message: |
+            automated: Update `flake.lock`
 
-            ```
-            {{ env.GIT_COMMIT_MESSAGE }}
-            ```
+            ${{ steps.pr_body.outputs.content }}
 
-            ```
-            {{ env.POSTDIFF }}
-            ```
-          pr-labels: |                  # Labels to be set on the PR
-            dependencies
-            automated
+          branch: update-flake-lock
+          delete-branch: true
+      - name: Print PR number
+        run: |
+          echo "Pull request number is ${{ steps.create-pull-request.outputs.pull-request-number }}."
+          echo "Pull Request URL - ${{ steps.cpr.outputs.pull-request-url }}"
 permissions:
   pull-requests: write
   contents: write