fix: move auto-merge script to action

.github/actions/merge-main/action.yml

@@ -21,4 +21,84 @@ runs:
     - name: Run Script
       shell: bash
       run: |
-        .github/scripts/merge-main.sh ${{ inputs.exempt-branches }}
+        input=${{ inputs.exempt-branches }}
+
+        function fetch_latest_changes() {
+          echo "Fetching the latest remote branches"
+          git fetch --all
+        }
+
+        fetch_latest_changes
+
+        function find_feature_branches() {
+          echo "Searching for feature branches"
+          feature_branches=($(git branch -r --list "*-main" | sed 's|origin/||'))
+
+          if [ ${#feature_branches[@]} -eq 0 ]; then
+            echo "...none found"
+            return
+          fi
+
+          for feature_branch in "${feature_branches[@]}"; do
+            echo "...found feature branch: $feature_branch"
+          done
+        }
+
+        find_feature_branches
+
+        function find_exempt_branches() {
+          echo "Searching for exempt branches"
+          IFS=',' read -r -a exempt_branches <<< "$input"
+
+          if [ ${#exempt_branches[@]} -eq 0 ]; then
+            echo "...none found"
+            return
+          fi
+
+          for exempt_branch in "${exempt_branches[@]}"; do
+            echo "...found exempt branch: $exempt_branch"
+          done
+        }
+
+        find_exempt_branches
+
+        function filter_feature_branches() {
+          echo "Filtering branches"
+          branches=()
+
+          for feature_branch in "${feature_branches[@]}"; do
+            if ! [[ "${exempt_branches[*]}" =~ "$feature_branch" ]]; then
+              echo "...including feature branch: $feature_branch"
+              branches+=("$feature_branch")
+            else
+              echo "...excluding feature branch: $feature_branch"
+            fi
+          done
+        }
+
+        filter_feature_branches
+
+        function merge_main() {
+          echo "Merging main into branches"
+
+          if [ ${#branches[@]} -eq 0 ]; then
+            echo "...no branches to merge into"
+            return
+          fi
+
+          for branch in "${branches[@]}"; do
+            echo "...switching to branch: $branch"
+            git switch "$branch"
+            echo "...merging main"
+            git merge -m "misc: merge from main" origin/main
+            if [ $? -eq 0 ]; then
+              echo "...pushing to origin"
+              git push origin "$branch"
+            else
+              echo "...merge failed"
+              git merge --abort
+            fi
+          done
+        }
+
+        merge_main