Improve API generation workflow PR handling

Adds explicit permissions for contents and pull-requests, restricts job to main branch, and enhances branch/PR logic to comment on existing PRs or create new ones as needed. This streamlines automated API documentation updates and prevents duplicate pull requests.

Author: IsakNaslundBh

.github/workflows/generation.yml

@@ -4,6 +4,10 @@ on:
   workflow_dispatch:
   schedule:
     - cron: '0 1 * * 0' # Every Sunday at 1 AM UTC
+    
+permissions:
+  contents: write
+  pull-requests: write
 
 env:
   TARGET_BRANCH: automatic-api-updates
@@ -12,6 +16,7 @@ env:
 
 jobs:
   run:
+    if: github.ref == 'refs/heads/main'
     runs-on: windows-latest
 
     steps:
@@ -283,28 +288,35 @@ jobs:
         # Configure git
         git config --global user.name "github-actions[bot]"
         git config --global user.email "github-actions[bot]@users.noreply.github.com"
-        
-        # Create and checkout new branch
+
+        # Create and checkout new branch (or switch if exists)
         $branch_name = "${{ env.TARGET_BRANCH }}"
-        git checkout -b $branch_name
-        
+        git checkout $branch_name 2>$null || git checkout -b $branch_name
+
         # Add all changes (including new files and directories)
         git add -A
-        
+
         # Check if there are any changes to commit
         $changes = git status --porcelain
         if ($changes) {
           Write-Host "Changes detected, committing..."
           git commit -m "APIGenerator workflow results - $(Get-Date -Format 'yyyy-MM-dd HH:mm:ss')"
-          
+
           # Push the branch
           git push origin $branch_name
           Write-Host "Successfully pushed changes to branch: $branch_name"
-          
-          # Create pull request using GitHub CLI
+
+          # Check if a PR already exists for this branch
+          $existingPr = gh pr list --head $branch_name --base main --json number --jq '.[0].number'
+          if ($existingPr) {
+          Write-Host "PR already exists (#$existingPr), adding a comment..."
+          gh pr comment $existingPr --body "Automated API documentation updates pushed to branch '$branch_name' on $(Get-Date -Format 'yyyy-MM-dd HH:mm:ss')."
+          Write-Host "✓ Comment added to existing PR"
+          } else {
           Write-Host "Creating pull request..."
           gh pr create --title "API Updates" --body "Automated API documentation updates generated by APIGenerator workflow on $(Get-Date -Format 'yyyy-MM-dd HH:mm:ss')" --head $branch_name --base main
           Write-Host "✓ Pull request created successfully"
+          }
         } else {
           Write-Host "No changes to commit"
         }