workflow: use PR fork and branch (#2078)

* Align with API

* Improve logging

* Fix CHECK_BRANCH_URL

.github/workflows/maven.yml

@@ -27,23 +27,27 @@ jobs:
       - name: Determine PR source branch and fork repository
         id: vars
         run: |
-          # Get branch name from either pull_request or push context
-          if [[ "${GITHUB_EVENT_NAME}" == "pull_request" ]]; then
-            # Get branch and fork repo for PR events
-            echo "BRANCH_NAME=${GITHUB_HEAD_REF}" >> $GITHUB_ENV
-            echo "FORK_REPO=${GITHUB_HEAD_REPOSITORY:-informatici/openhospital-core}" >> $GITHUB_ENV
-          elif [[ "${GITHUB_EVENT_NAME}" == "push" ]]; then
-            # Get branch name for push events
-            echo "BRANCH_NAME=${GITHUB_REF##*/}" >> $GITHUB_ENV
-
-            # Default FORK_REPO to main repository, with option to fallback if the fork exists
-            OWNER=${GITHUB_ACTOR}
-            if curl -s -o /dev/null -w "%{http_code}" "https://api.github.com/repos/${OWNER}/openhospital-core/branches/${GITHUB_REF##*/}" | grep -q "200"; then
-              echo "FORK_REPO=${OWNER}/openhospital-core" >> $GITHUB_ENV
-            else
-              echo "FORK_REPO=informatici/openhospital-core" >> $GITHUB_ENV
-            fi
+          # Set default FORK_REPO and BRANCH_NAME values.
+          BRANCH_NAME="${GITHUB_HEAD_REF:-${GITHUB_REF##*/}}"
+          FORK_REPO="${GITHUB_HEAD_REPOSITORY:-${GITHUB_ACTOR}/openhospital-core}"
+          CHECK_BRANCH_URL="https://github.com/${GITHUB_ACTOR}/openhospital-core/tree/$BRANCH_NAME"
+          echo "Checking branch existence with: curl -s -o /dev/null -w \"%{http_code}\" $CHECK_BRANCH_URL"
+          
+          # Determine FORK_REPO with fallback logic
+          if [[ -n "${GITHUB_HEAD_REPOSITORY}" ]]; then
+            echo "Using ${GITHUB_HEAD_REPOSITORY}."
+            FORK_REPO=${GITHUB_HEAD_REPOSITORY}
+          elif curl -s -o /dev/null -w "%{http_code}" $CHECK_BRANCH_URL | grep -q "200"; then
+            echo "Using ${GITHUB_ACTOR}/openhospital-core"
+            FORK_REPO=${GITHUB_ACTOR}/openhospital-core
+          else
+            echo "Using informatici/openhospital-core."
+            FORK_REPO="informatici/openhospital-core"
           fi
+          
+          # Export FORK_REPO and BRANCH_NAME to GITHUB_ENV for the next step
+          echo "BRANCH_NAME=$BRANCH_NAME" >> $GITHUB_ENV
+          echo "FORK_REPO=$FORK_REPO" >> $GITHUB_ENV
 
       - name: Log variables
         run: |