fix(pypi): skip build+upload if version already exists on PyPI

Add pre-check step that queries PyPI JSON API to detect if the version is
already published. If it exists, skip the build and upload steps entirely
to prevent 400 'File already exists' errors on re-runs.

Author: Das-rebel

.github/workflows/pypi-publish.yml

@@ -21,82 +21,126 @@ jobs:
     environment:
       name: testpypi
       url: https://test.pypi.org/projects/a3m-router
-    
+
     steps:
       - uses: actions/checkout@v4
-      
+
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
           python-version: '3.11'
-      
+
       - name: Install dependencies
         run: |
-          python -m pip install build twine
-      
+          python -m pip install build twine toml
+
+      - name: Get version
+        id: version
+        run: |
+          VERSION=$(python -c "import toml; print(toml.load('python/pyproject.toml')['project']['version'])")
+          echo "version=$VERSION" >> $GITHUB_OUTPUT
+
+      - name: Check if version exists on Test PyPI
+        id: exists-testpypi
+        run: |
+          EXISTS=$(curl -s "https://test.pypi.org/pypi/a3m-router/${{ steps.version.outputs.version }}/json" | python3 -c "import sys,json; d=json.load(sys.stdin); print('yes' if d.get('info',{}).get('version') == '${{ steps.version.outputs.version }}' else 'no')" 2>/dev/null || echo "no")
+          echo "exists=$EXISTS" >> $GITHUB_OUTPUT
+          echo "Version ${{ steps.version.outputs.version }} on Test PyPI: $EXISTS"
+          if [ "$EXISTS" == "yes" ]; then
+            echo "SKIP_UPLOAD=true" >> $GITHUB_OUTPUT
+          fi
+
       - name: Build package
+        if: steps.exists-testpypi.outputs.SKIP_UPLOAD != 'true'
         run: |
           cd python
           python -m build
-      
+
       - name: Publish to Test PyPI
+        if: steps.exists-testpypi.outputs.SKIP_UPLOAD != 'true'
         env:
           TWINE_USERNAME: __token__
           TWINE_PASSWORD: ${{ secrets.PYPI_TEST_TOKEN }}
         run: |
           cd python
           python -m twine upload --repository testpypi dist/*
 
+      - name: Already published notice
+        if: steps.exists-testpypi.outputs.SKIP_UPLOAD == 'true'
+        run: echo "Version ${{ steps.version.outputs.version }} already exists on Test PyPI — skipping upload"
+
   publish-pypi:
     if: github.event.inputs.environment == 'prod' || github.event_name == 'release'
     runs-on: ubuntu-latest
     environment:
       name: pypi
       url: https://pypi.org/projects/a3m-router
-    
+
     steps:
       - uses: actions/checkout@v4
-      
+
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
           python-version: '3.11'
-      
+
       - name: Install dependencies
         run: |
-          python -m pip install build twine
-      
+          python -m pip install build twine toml
+
+      - name: Get version
+        id: version
+        run: |
+          VERSION=$(python -c "import toml; print(toml.load('python/pyproject.toml')['project']['version'])")
+          echo "version=$VERSION" >> $GITHUB_OUTPUT
+
+      - name: Check if version exists on PyPI
+        id: exists-pypi
+        run: |
+          EXISTS=$(curl -s "https://pypi.org/pypi/a3m-router/${{ steps.version.outputs.version }}/json" | python3 -c "import sys,json; d=json.load(sys.stdin); print('yes' if d.get('info',{}).get('version') == '${{ steps.version.outputs.version }}' else 'no')" 2>/dev/null || echo "no")
+          echo "exists=$EXISTS" >> $GITHUB_OUTPUT
+          echo "Version ${{ steps.version.outputs.version }} on PyPI: $EXISTS"
+          if [ "$EXISTS" == "yes" ]; then
+            echo "SKIP_UPLOAD=true" >> $GITHUB_OUTPUT
+          fi
+
       - name: Build package
+        if: steps.exists-pypi.outputs.SKIP_UPLOAD != 'true'
         run: |
           cd python
           python -m build
-      
+
       - name: Publish to PyPI
+        if: steps.exists-pypi.outputs.SKIP_UPLOAD != 'true'
         env:
           TWINE_USERNAME: __token__
           TWINE_PASSWORD: ${{ secrets.PYPI_TOKEN }}
         run: |
           cd python
-          python -m twine upload --verbose dist/*
+          python -m twine upload dist/*
+
+      - name: Already published notice
+        if: steps.exists-pypi.outputs.SKIP_UPLOAD == 'true'
+        run: echo "Version ${{ steps.version.outputs.version }} already exists on PyPI — skipping upload"
 
   test-package:
     runs-on: ubuntu-latest
     needs: publish-testpypi
-    
+
     steps:
       - uses: actions/checkout@v4
-      
+
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
           python-version: '3.11'
-      
+
       - name: Install from Test PyPI
         env:
           TWINE_PASSWORD: ${{ secrets.PYPI_TEST_TOKEN }}
         run: |
           pip install --index-url https://test.pypi.org/simple/ a3m-router
-      
+
       - name: Test import
         run: |
           python -c "from a3m import A3MRouter, __version__; print(f'A3M Router SDK v{__version__} installed successfully!')"